Revalidatiewetenschappen en Kinesitherapie
Academiejaar 2014-2015
Functional Movement Screen and Y-balance test:
validity in hamstring injury risk prediction?
A prospective study
Masterproef voorgelegd tot het behalen van de graad van
Master of Science in de Revalidatiewetenschappen en Kinesitherapie
Van pellicom Bert
Vanmaele Ruben
Welvaert Mathieu
Promotor: Prof. Dr. Damien Van Tiggelen
Co-promotor: Mevr. Joke Schuermans
Revalidatiewetenschappen en Kinesitherapie
Academiejaar 2014-2015
Functional Movement Screen and Y-balance test:
validity in hamstring injury risk prediction?
A prospective study
Masterproef voorgelegd tot het behalen van de graad van
Master of Science in de Revalidatiewetenschappen en Kinesitherapie
Van pellicom Bert
Vanmaele Ruben
Welvaert Mathieu
Promotor: Prof. Dr. Damien Van Tiggelen
Co-promotor: Mevr. Schuermans Joke
Foreword
We would like to thank everyone who has guided us in creation of our master scription. Our greatest
gratitude goes out to some individuals in particular.
First of all we would like to thank our promotor Prof. Dr. Damien Van Tiggelen and our co-promotor
Joke Schuermans for their support and accurate feedback in the past 2 years during the testing and
writing of our paper.
We wish to express our sincere appreciation for all the subjects who participated to the testing
voluntarily.
Likewise, we would like to thank the Faculty of Medicine and Health Sciences and the department of
Rehabilitation Sciences and Physiotherapy for putting the research labs, testing equipment and
computers
to
our
disposal.
As a last a special word of gratitude to our family and friends who supported us during these tough
years.
Because
of
them,
we
had
the
opportunity
to
write
this
thesis.
Before the beginning of our study, we were already very fascinated in the sports dimension of
physiotherapy and the sciences of rehabilitation. Especially in soccer we were particularly interested.
We were very delighted when we knew that we could write our study around this topic.
Fully encouraged, we started to browse the great amount of literature regarding this subject. This
has led to our literature study in the first year. In the beginning of the second year we could start
screening soccer players ourselves. This essay is the final outcome of a tremendous amount of
reading,
testing,
processing
of
results
and
writing.
Table of Contents
1
2
ABSTRACT ……………………………………………………………………………………………………………….. 1
1.1
Abstract ( English ) …………………………………………………………………………………………. 1
1.2
Abstract ( Dutch ) …………………………………………………………………………………………… 2
INTRODUCTION ………………………………………………………………………………………………………. 3
2.1
3
4
Functional screening tools ……………………………………………………………………………… 4
2.1.1
Functional Movement Screen ……………………………………………………………. 4
2.1.2
Y-balance test ……………………………………………………………………………………. 5
2.2
General conclusion ………………………………………………………………………………………… 5
2.3
Research question …………………………………………………………………………………………. 5
METHODS ………………………………………………………………………………………………………………. 6
3.1
Recruitment study population ………………………………………………………………………. 6
3.2
Testing protocol ……………………………………………………………………………………………. 6
3.2.1
Functional Movement Screen ………………………………………………………….. 7
3.2.2
Y-balance test ………………………………………………………………………………….. 8
3.3
Follow-up ……………………………………………………………………………………………………… 9
3.4
Statistical analysis …………………………………………………………………………………………. 10
RESULTS ………………………………………………………………………………………………………………… 11
4.1
Subject characteristics ………………………………………………………………………………….. 11
4.2
Retrospective research …………………………………………………………………………………. 12
4.2.1
FMS and YBT performance in association with hamstring injury history 12
4.2.1.1 Functional Movement Screen ………………………………………………. 12
4.2.1.2 Y-balance test ………………………………………………………………………. 14
4.2.2
Questionnaire in association with hamstring injury history ………………. 15
I
4.3
Prospective research ……………………………………………………………………………………. 16
4.3.1
Functional Movement Screen performance in association with future
hamstring injury risk ………………………………………………………………………… 16
4.3.2
5
Y-balance test in association with future hamstring injury risk ………… 20
DISCUSSION ………………………………………………………………………………………………………….. 21
5.1
Functional Movement Screen ………………………………………………………………………. 21
5.1.1
Deep squat ………………………………………………………………………………………. 21
5.1.1.1 Core stability ……………………………………………………………………….. 21
5.1.1.2 Ankle dorsiflexion ………………………………………………………………… 22
5.1.1.3 Eccentric hamstring power …………………………………………………... 23
5.1.1.4 Hamstring and quadriceps co-contraction ……………………………. 23
5.1.2
Active straight leg raise …………………………………………………………………….. 24
5.1.2.1 Hamstring flexibility …………………………………………………………….. 25
5.1.2.2 Rectus femoris flexibility ……………………………………………………… 26
5.1.2.3 Neural extensibility ……………………………………………………………… 27
5.1.3
FMS composite score of deep squat and active straight leg raise test 27
5.1.4
Other FMS component tests …………………………………………………………….. 28
5.2
Y-balance test ……………………………………………………………………………………………….. 28
5.3
New insights in the clinical use of FMS and YB ………………………………………………. 29
5.4
Reoccurence of hamstring injury …………………………………………………………………… 29
5.5
Similar research …………………………………………………………………………………………….. 30
6
LIMITATIONS …………………………………………………………………………………………………………..31
7
CONCLUSION …………………………………………………………………………………………………………. 33
8
ACKNOWLEDGEMENTS ………………………………………………………………………………………….. 33
9
REFERENCES …………………………………………………………………………………………………………. 34
II
10 ABSTRACT ……………………………………………………………………………………………………………… 41
10.1
Abstract ( layman’s terms ) …………………………………………………………………………… 41
11 APPENDICES ………………………………………………………………………………………………………… 42
11.1
Functional Movement Screen …………………………………………………………………….. 42
11.2
Y-balance test …………………………………………………………………………………………….. 56
11.3
Questionnaire pre-testing ………………………………………………………………………….. 58
11.4
Questionnaire after 6 months follow-up ……………………………………………………. 60
11.5
Score sheet FMS ………………………………………………………………………….…………….. 62
11.6
Score sheet YBT ……………………………………………………………………………….….…….. 63
11.7
Informed consent ………………………………………………………………………….…………… 64
III
Table of Tables
Table 1: subjects characteristics ………………………………………………………………………….......................... 11
Figure 1: FMS results ………………………………………………………………………………………………………………….. 12
Figure 2: trunk stability push up results ……………………………………………………………………………………… 12
Table 2: FMS results …………………………………………………………………………………………………………………… 13
Figure 3: distribution of the component test scores ( control – previous injury) ………………………… 13
Table 3: Y-Balance and variables characteristics ………………………………………………………………………… 14
Table 4: Y-balance results ………………………………………………………………………………………………………….. 15
Table 5: Comparison of players with and without injuries during the season …………………………….. 16
Figure 4: Boxplot DS and ASLR score ………………………………………………………………………………………….. 17
Figure 5 and 6: Histogram Deep Squat and Active Straight Leg Raise …………………………………………. 18
Table 6: 2 x 2 contingency table: DS & ASLR score x hamstring injury ………………………………………… 19
Table 7: Influence of the DS & ASLR on first hamstring injury ……………………………………………………. 19
Table 8: Influence of the DS & ASLR on subsequent hamstring injury ……………………………………….. 19
IV
Table of abbreviations
FMS: Functional Movement Screen
YBT: Y-balance test
FMS LL: FMS lower limb
Y Balance C: Y balance control
DS: Deep squat
Y Balance I: Y balance injury
HS: Hurdle step
YB_A_C: Y balance anterior control
ILL: In-line lunge
YB_A_I: Y balance anterior injury
SM: Shoulder mobility
YB_PM_C: Y balance postero-medial control
ASLR: Active straight leg raise
YB_PL_C: Y balance postero-lateral control
TS: Trunk stability push-up
YB_PM_I: Y balance postero-medial injury
RS: Rotary stability
YB_PL_I: Y balance postero-lateral injury
SEBT: star excursion balance test
RTP: Return to play
Cf: confer
Eg.: example given
Etc.: Et cetera
V
1 Abstract
1.1
Abstract ( English )
Background: Among muscle injuries, hamstring injuries present the highest incidence and
reoccurrence rates in explosive field sports like soccer. There are many screening tools which try to
identify an increased risk of hamstring (re)injuries, two of those are the Functional Movement Screen
(FMS) and the Y-balance test (YBT). Both are functional tests which have the capacity to screen the
entire kinetic chain. Besides, they evaluate the most essential motor competences that are majorly
important in soccer athlete’s performance and injury vulnerability.
Purpose: To analyze if the functional screening tools FMS and Y-balance are useful in predicting an
increased risk of sustaining hamstring strain injuries in the population of male soccer players.
Methods: In the pre-season period of July 2014, an injury-group consisting of 28 male soccer players
with a hamstring injury history and a matched control group consisting of 30 male soccer players,
were tested on FMS and Y-balance testing performances. An additional cohort of 10 soccer players (3
with and 7 without hamstring injury history), was screened for FMS performance only. After testing,
the injury incidence of all 68 players was registered during a follow-up period of 6 months (half a
season). Data analysis evaluated the association between functional testing performance and the risk
of sustaining a hamstring injury during follow-up.
Results: Cross sectional data analysis did not reveal an association between the FMS total-score, FMS
LL –score or Y-balance testing performance and the presence/absence of a hamstring injury history.
Nevertheless, the injury-group scored significant lower on the trunk stability push-up test (p=0.047).
For the prospective data analysis, no association between FMS and Y-balance scores and the
incidence of hamstring injuries during follow-up could be demonstrated. Only a poor performance on
the deep squat test (p=0.043) and the active straight leg raise test (p=0.041) was associated with a
significantly higher risk of sustaining a hamstring injury. Unlike FMS- and Y-balance total scores, a
new component score taking deep squat and active straight leg raise performances together ( with a
total score ranging from 0-6), has the ability to predict future hamstring injury. When assessing its
association with getting injured for the first time and re-injuries separately, this combined screening
tool clearly presented the highest validity in terms of a first injury risk detection (p=0.006). In the reinjury group, there are likely more different covariates that could influence the result, giving no
significant correlation.
We were able to demonstrate that the relative risk of sustaining an index hamstring injury was 27%
for players who scored less than 4 out of 6, and was reduced to 0% in players who scored 4 or more
out of 6.
Conclusion: The FMS in total does not have the ability to predict the risk of sustaining a hamstring
injury. The FMS component tests ‘deep squat’ and ‘active straight leg raise’ are able to predict future
hamstring injury, this especially for the group of players who sustained first hamstring injury. Based
on our results, we propose that the combined score of these two tests provides a valid prediction of
the index hamstring injury risk in soccer players. In this study, the Y-balance did not appear to be a
valid test to predict future hamstring injury.
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1.2
Abstract ( Dutch )
Achtergrond: Van alle spierletsels kennen hamstringletsels niet alleen de hoogste incidentiecijfers,
maar hebben ze bovendien ook het meest recidief karakter bij explosieve veldsporten zoals voetbal.
Er zijn verschillende testbatterijen die trachten het risico op hamstring (her)aandoeningen te
identificeren, waarvan de Functional Movement Screen (FMS) en Y-balance test (YBT) er twee zijn.
Beide zijn functionele testen die de capaciteit hebben om de volledige kinetische keten te screenen.
Bovendien evalueren zij de meeste essentiële motorische vaardigheden die voornamelijk belangrijk
zijn voor de prestatie en letselgevoeligheid van de voetbalspeler.
Doel: Analyseren in welke mate de functionele testbatterijen FMS en Y-balance bruikbaar zijn om
een verhoogd risico op hamstringletsels te voorspellen bij mannelijke voetbalspelers.
Methode: In het voorseizoen (juli 2014) werden een patiëntengroep van 28 spelers met een verleden
van een hamstringletsel en een overeenkomstige controlegroep van 30 spelers getest op de FMS en
Y-balance. Bij een bijkomende cohorte van 10 spelers (3 met en 7 zonder hamstringletsel in het
verleden) werd enkel de FMS afgenomen. Na testing werd de letselincidentie van alle 68 spelers
geregistreerd tijdens een follow-up periode van 6 maanden (een half seizoen).
Data-analyse evalueerde het verband tussen de functionele testprestaties en het risico een
hamstringletsel op te lopen tijdens de follow-up periode.
Resultaten: cross-sectioneel onderzoek kon geen verband aantonen tussen de totale FMS-score, de
FMS LL-score of de Y-balance prestatie en de aan– of afwezigheid van een hamstringletsel in het
verleden. Anderzijds scoorde de patiëntengroep wel significant lager op de trunk stability push-up
test (P=0.047). Voor de prospectieve data-analyse kon er geen verband aangetoond worden tussen
de FMS en Y-balance scores en de incidentie van een hamstringletsel gedurende de follow-up
periode. Enkel een zwakke score op de deep squat test (p=0.043) en de active straight leg raise test
(p=0.041) resulteerde in een significant hoger risico op een hamstringletsel. In tegenstelling tot de
totale FMS- en Y-balance scores had een nieuwe componentscore, samengesteld uit de deep squat –
en active straight leg raise resultaten (met een totale score variërend tussen 0-6), wel de
mogelijkheid om een toekomstig hamstringletsel te voorspellen. Wanneer we voor dit verband een
onderscheid maken tussen het oplopen van een eerste of een nieuw hamstringletsel, toonde deze
gecombineerde testbatterij de hoogste validiteit op het vlak van blessurepreventie bij spelers zonder
hamstringletsel in het verleden (p=0.006). Bij spelers met een verleden van een hamstringletsel zijn
er waarschijnlijk meerdere covariaten van invloed. We waren in staat aan te tonen dat het relatief
risico om een index hamstringletsel op te lopen 27% was voor spelers die minder scoorden dan 4 op
6, en dit daalde tot 0% voor deze die 4 of meer scoorden op 6.
Conclusies: De FMS test in totaal heeft niet de predictieve waarde om het risico om
hamstringblessures op te lopen te voorspellen. De FMS componenttesten ‘deep squat’ en ‘active
straight leg raise’ zijn in staat om een hamstringletsel te voorspellen, dit vooral bij spelers die een
eerste hamstringblessure opliepen.
Gebaseerd op onze resultaten, stellen we dat de gecombineerde score van deze twee testen een
valide voorspelling voorziet van het index hamstringletsel risico bij voetbalspelers.
In deze studie bleek de Y-balance geen valide test is om een toekomstig hamstringletsel te
voorspellen.
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2 Introduction
Hamstring injuries are amongst the most common non-contact injuries in explosive field sports27. In
soccer for example, they account for 10% - 23% of all acute non-contact injuries2,21,66-67. Even more
troublesome than their high incidence rates, are their exceptionally high reoccurrence rates in
football players. (16-60%)23, because those recurring injuries often result in more time loss and
subsequent financial consequences than the original insults8,23. In the context of hamstring strain
injuries, intrinsic risk factors related to individual features, seem to be of a higher value in predicting
future hamstring injury risk than the extrinsic ones50. The most common non-modifiable intrinsic risk
factors that are currently acknowledged in literature are age3,65,71, previous injury3,19,65 and black or
aboriginal ethnic origin65,71. The most common modifiable risk factors are bilateral strength
imbalances, strength deficits and low antagonist ratios17,19,72 , muscle fatigue19,72 , hamstring
tightness70 , insufficient warm-up procedures19,72 , morphological and anatomical hamstring muscle
features71 , poor lumbar posture and core stability35, and knee joint angle of concentric hamstring
peak torque7. Given the high injury and re-injury rates, and personal/financial costs associated with
the hamstring injuries, it is clear that better screening tools to identify athletes at risk for hamstring
injuries are needed
Previous research revealed that there are many screening tools to evaluate readiness for Return To
Play (RTP) or performance, which try to identify an increased risk of hamstring (re)injuries in
explosive fields sports (like soccer) in order to (1) decrease their (re)occurence, (2) enhance player’s
performance, and (3) ultimately improve quality of life. However this research is inconsistent and
unclear concerning which of those screening tools have the highest validity to achieve this main goal
[45].
In our systematic review: ‘Which functional screening tools are able to predict hamstring injuries in
explosive field sports’ we aimed at providing a literature to establish the effectiveness of current
functional screening tools for hamstring injury risk detection. In this review, we particularly
investigated the value of the commonly implemented ‘Functional Movement Screen’ and ‘Y-balance
test’, for the purpose of hamstring strain injury prediction and -prevention in explosive field athletes.
We chose to narrow the scope of our literature search down to these two functional screening tools
because of their international popularity and user-friendliness.
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2.1
Functional screening tools
2.1.1
Functional Movement Screen
In our previous systematic research we particularly focused on the Functional Movement Screen
(FMS). The FMS is a relatively new comprehensive evaluation tool, not intended to diagnose
orthopaedic problems, but rather to assess the quality of fundamental movement patterns to
identify functional movement deficits and asymmetries [39, 62]. Functional movement is the ability
to produce and maintain a balance between mobility and stability along the kinetic chain while
performing fundamental patterns with accuracy and efficiency.
This testing tool incorporates the evaluation of all major motor requirements in athletes such as
muscle strength, flexibility, range of motion, coordination, balance, and proprioception. It is known
as a time-efficient, noninvasive, inexpensive and user friendly screening tool14. Plisky et al. (2006)
hypothesized that tests, such as the FMS, which assesses multiple domains of functioning
simultaneously, may improve the accuracy of identifying athletes at risk for hamstring injury through
pre-participation assessment. When the score reached ≤14/21, the subject had a greater risk of
injury. 55
In our systematic review we could state that this test has a good to moderate intrarater
reliability31,58,62 and a good interrater reliability46,58,62. The reliability of the component test for the
‘shoulder mobility’ is high, and for the ‘hurdle step’ is poor. The other tests scored a good
reliability49, indicating moderate to good reliability when making an average for all component tests.
At this moment there is a lack of knowledge about the predictive value of the FMS in terms of the
identification of athletes at risk for future injury. The results of our review showed that the FMS Is
mostly reliable within the group of college students, but further investigation is needed within the
group of explosive field athletes such as soccer players. Certainly in terms of hamstring injury-specific
FMS screening and outcome, no research is available to date.
For our study we were curious to find out to what extent the FMS can be attributed to establish an
increased risk of sustaining hamstring strain injuries in the population of male soccer players.
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2.1.2
Y-balance test
The Y-Balance Test (YBT) assesses the athlete’s balance by challenging his postural control system in
3 (anterior, posteromedial, and posterolateral) of the 8 SEBT (star excursion balance test) directions
and has been advocated as a method for assessing dynamic balance (requires strength, flexibility and
proprioception). As these motor requirements are of capital importance in muscle injury prevention
and rehabilitation, this test could be valuable in hamstring injury risk assessment as well. The Ybalance test (YBT) is one of the few field expedient tests that has shown predictive validity in terms
of the identification of injury risk in an athletic population. Amongst other risk factors, impaired
balance has been associated with an increased risk of lower extremity injuries.
The clinical application of the SEBT led to the development of the Y-Balance Test (YBT). The goal of
the YBT is to maintain single leg stance on one leg while reaching as far as possible with the
contralateral leg. Almost perfect agreement on the interrater test–retest reliability of the maximal
reach for the 3 reach directions (anterior, posteromedial, and posterolateral). Also, almost perfect
agreement on the interrater test–retest reliability of the average reach of 3 trails. Specifically, Plisky
et al. (2006) identified that individuals with anterior left/right asymmetries greater than 4 cm on the
YBT were 2.5 times more likely to sustain a lower extremity injury. Further, they reported that the
sum of three reach directions (anterior, posteromedial, and posterolateral) were predictive of lower
extremity injury.
2.2
General conclusion
The FMS and the Y-balance test are functional tests, unlike isokinetic testing etc., that have the
capacity to screen the entire kinetic chain and are very easy to administer. They evaluate the most
essential motor competences that are majorly important in the soccer athlete’s load bearing
capacity and thus their performance and injury vulnerability.
2.3
Research question
In current literature, evidence about the predictive value of these field tests for the purpose of
(secondary) hamstring injury prevention is non-existing. That is why we have chosen to assess the
validity of both the FMS and the Y-balance screening tools in hamstring injury risk detection in a
population at risk, like male soccer players.
-5-
3 Methods
3.1
Recruitment study population
In order to find suitable patients and control subjects, we principally used social media or contacted
soccer clubs. Finally, we had a group of 28 patients who had a hamstring injury in the past (injurygroup) and 30 control subjects who voluntarily participated in our survey at UZ Gent to perform the
FMS and YBT. We also recruited 10 field players, but only the FMS assessment was conducted within
this smaller sample.
To subcategorize the potential candidates to the injury- or control group, we applied quite a few
inclusion –and exclusion criteria. Included athletes had to meet following requirements:
-
male soccer field players between the age limits of 18 and 35 years
-
active in amateur soccer competition (provincial divisions),
-
never having sustained any (serious) lower limb injuries that required surgical interventions
For the injury-group, the key requirement was that they had at least one hamstring injury in the past
and that this injury or re-injury occurred in the last season.
3.2
Testing protocol
Before examining the subjects, they were asked to fill in a questionnaire (cf. appendix). The first part
contained administrative data, medical history, and current health. The second part contained
questions regarding the most recent soccer related hamstring injury and corresponding rehabilitation
period, so was only filled in by the injury group.
After this questionnaire, the investigators explained the purpose and content of the testing series,
after which the participants were asked to sign informed consent forms. Subsequently, each
participant performed a 5 min warm-up on a stationary bike before the actual testing commenced.
The functional screening of all subjects commenced with the Functional Movement Screen
(recorded by 2 investigators), followed by the Y-balance test (recorded by only 1 investigator), with
an overall duration of approximately 25-30 minutes. When a researcher wasn’t recording a test, they
could give a second opinion if there was some doubt or disagreement. All tests were performed
wearing soccer shoes and comfortable sports clothing.
-6-
3.2.1
Functional Movement Screen
After filling in the questionnaire, all the participants were examined using the Functional Movement
Screen in the first place. This test contains 7 sub-tests: deep squat, hurdle step, in-line lunge,
shoulder mobility, active straight leg raise, trunk stability push-up and rotary stability; which were
always evaluated in the same order to advance standardization. Since the quality of movement
patterns is the most important goal, clear instructions and a short demonstration were given in a
standardized way. Each player was given three trials on each of the seven sub-tests and received a
score from zero to three on each. Scoring criteria were as follows: 0) pain was reported during the
movement; 1) failure to complete the movement or loss of balance during the movement; 2)
completion of the movement with compensation; and 3) performance of the movement without any
compensation. Each test was scored by at least 2 evaluators. One evaluator checked the frontal
plane, the other took account with requirements in the sagittal plane. When there was doubt, we
scored low. For each sub-test, the highest score from the three trials was recorded. For the sub-tests
that were assessed bilaterally, the lowest score was used. Three of the sub-tests (shoulder mobility,
trunk stability push-up and rotary stability) also have associated clearing exams (impingement
clearing test, press-up clearing test, posterior rocking clearing test), performed before each sub-test,
and are scored as either positive or negative with a positive response indicating that pain was
reproduced during the examination. Should there have been a positive result on a clearing sub-test;
the score for that movement would be zero regardless of how well the subject could perform the
movement. An overall composite FMS score with a maximum value of 21 was then calculated and
participants were informed of their score.
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3.2.2
Y-balance test
After the FMS evaluation, each participant was immediately submitted to the Y-balance assessment,
as the investigator’s instruction allowed the participants to rest for a moment, without needing a
second warming up session prior to testing.
The Y Balance Test Kit™ consists of a stance platform to which three pieces of PVC bars are attached
in the anterior, posteromedial, and posterolateral reach directions. The posterior bars are positioned
at 135 degrees from the anterior bar, with 45 degrees between both posterior bars. Each bar is
marked in 5 millimeter increments for performance measurement. The subject was asked to push a
target (reaching- indicator) along the bar with the reaching foot, by simultaneously bending through
the hip-, knee- and ankle-joints of the supporting leg, which was subject of dynamic stability testing.
When the subject reached his limit, he had to return to the starting position without pushing off with
the reaching foot and without losing his balance, so solely by using muscle strength and control in
the supporting leg and core. When the reaching-indicator was moved during the returning phase,
this trial was discarded, making the determination of reach distance more precise.
The Y-balance test was thoroughly explained and demonstrated by the raters. The subjects practiced
3 trials on each leg in each of the three reach directions prior to formal testing, giving the time
management and avoiding a certain learning effect. The subjects were tested directly after
practicing. The subjects took place on the center platform of the Y-balance kit on his right leg (which
was tested first), with his toes just behind the red line, indicating the attempted position of the
supporting leg on the Y-balance platform. While maintaining single leg stance, the subject was asked
to reach with the free limb in the anterior, posteromedial, and posterolateral directions. In order to
improve the reproducibility of the test and establish a consistent testing protocol, a standard testing
order was developed and utilized. The testing order was three trials standing on the right foot
reaching in the above mentioned direction with the left foot. Per direction, 3 trials were registered
and taken along for data-analysis. Afterwards the three tests were repeated standing on the left foot.
The subjects were motivated by the raters to really trying to reach their optimal performance. One
rater noted the reaching distance and one rater took care of trial registration. The raters dependently
determined if a successful trial was completed (i.e. that the foot was positioned correctly behind the
line and that all of the criteria were met for a successful trial). The maximal reaching distance was
measured by reading the tape measure at the edge of the reaching-indicator. The trial was discarded
and repeated if the subject: 1) failed to maintain unilateral stance on the platform (e.g. touched
down to the floor with the reach foot or fell off the stance platform), 2) failed to maintain reach foot
contact with the reach indicator on the target area while it was in motion (e.g. kicked the reach
-8-
indicator), 3) used the reach indicator for stance support (e.g. placed foot on top of reach indicator),
or 4) failed to return the reach foot to the starting position under control. We allowed a one minute
break between the tests for the right and left leg.
To conclude the functional screening, lower limb length was measured for the analysis of the Ybalance scores. This was done with the subject lying down supine on an examination table. The
subject’s limb length was then measured in centimeters by assessing the distance between the
anterior superior iliac spine and the most distal portion of the medial malleolus with a cloth tape
measure.
The data were analyzed for each subject for the right limb in the anterior, posterolateral, and
posteromedial reaching directions. Means and standard deviations were calculated for the reaching
distance in each direction. Since reach distance is related to limb length, reaching distance was
normalized to limb length to allow inter-subject comparison. To express reaching distance as a
percentage of limb length, the normalized value was calculated as reaching distance divided by limb
length, and then multiplied by 100. Composite reaching distance was obtained by taking the sum of
the three reaching distances in the different directions divided by three times limb length, and then
multiplied by 100.
3.3
Follow up
Players were tested pre-season in July, after which they were included in injury follow-up during the
first half of the subsequent season. They were asked to contact the investigators immediately when
they sustained a hamstring injury which would prevent them from participating in training or
competition for at least 1 session of exposure. The investigators also contacted each participant by
mail or Facebook, making sure no injury could have been missed due to lost to follow-up. We started
contacting the players from the beginning of December until the end of February.
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3.4
Statistical analysis
All data were imported in the SPSS Statistics software, version 22.
First, descriptive statistics were performed to assess covariate distribution in our test sample. In this
way, normality-assessment could be performed and basic parameters could be summarized (mean,
SD).
The Kolmogorov-Smirnov and Shapiro-Wilkinson test were performed to prove the level of normal
distribution of these data.
Retrospectively, we investigated if there were significant differences within continuous and
categorical variables. Hypothesis testing for continuous variables was performed by using General
Linear Models. In the case of categorical variables, Fisher’s Exact Test was performed.
Prospectively, to assess a possible relationship between testing results and subsequent injury
incidence, we used Independent Sample T-test and one-way Anova test for starters. Binary Logistic
and Ordinal Regression analyses were attributed to make a prediction model, assessing the validity of
both functional tests for future injury risk detection.
- 10 -
4 Results
4.1
Subject characteristics
The control– and injury group present similar physical characteristics (weight, height, BMI).
Concerning the age of both groups, we can see that the injury-group (mean: 24.31 year; SD [ 2,94 y] )
is significant ( p=0.001) older than the control group ( mean: 21.94 year ; SD [1.92 y]). This difference
is statistically from high significance. The average competition level was also the same for both
groups, with the majority of participants playing in 2nd provincial division.
Variable
Hamstring injury
Without ( n=37)
With ( n=31)
P value
Characteristics
Age (year)
Height (cm)
Weight (kg)
21.94 +- 1.92
182.2 +- 6.64
74.68 +- 7.76
24.31 +- 2.94
181.0 +- 5.15
74.90 +- 5.75
0.001
0.407
0.893
BMI (kg/m2)
22.47 +- 1.80
22.87 +- 1.40
0.327
Table 1.
- 11 -
4.2
Retrospective research
4.2.1
FMS and Y-balance performance in association with hamstring injury history
When looking at the FMS and Y-balance scores in the formerly injured and the control groups, the
average FMS-score for the control group appeared to be a little bit higher (15.35 vs 14.94). This
minor difference was also seen in the average FMS-LL-score (FMS-Lower Limb; 8.81 vs 8.52). At last,
the Y-balance-score was more or less equal in both groups, with very symmetrical results in both
legs. None of the above mentioned discrete differences were of statistical significance. Chi Square
hypothesis testing revealed no association between the FMS total (p=0.169) - or FMS-LL (p=0.596)
scores and the presence or absence of a hamstring injury history, indicating that having a history of a
hamstring injury has no influence on the FMS total - or FMS LL-score.
4.2.1.1
Functional Movement Screen
Even though we could not demonstrate a difference in FMS score based on the presence or absence
of a hamstring injury history, categorical hypothesis testing revealed that the subjects who sustained
a hamstring strain injury in the past, scored significant lower on the trunk stability push-up test.
(p=0.047)
Figure 1.
Figure 2.
- 12 -
Variable
Hamstring injury
Without ( n=37)
With ( n=31)
FMS
FMS total score
FMS lower limb
Deep squat
Hurdle step
In-line lunge
Active straight leg raise
Trunk stability push up
Rotary stability
15.35 +- 1.814
8.81 +- 1.221
2.24 +- 0.495
2.16 +- 0.374
2.68 +- 0.475
2.11 +- 0.774
1.73 +- 0.769
2.14 +- 0.347
P value
14.94 +- 1.931
8.52 +- 1.288
2.16 +- 0.374
2.29 +- 0.461
2.58 +- 0.502
2.23 +- 1.023
1.48 +- 0.724
2.03 +- 0.315
0.364
0.337
0.440
0.219
0.426
0.591
0.182
0.208
Table 2.
FMS Score
100
80
60
40
20
0
DS
HS
ILL
ASLR
TSPU
RS
Figure 3.
- 13 -
4.2.1.2
Y-balance test
Although no association was found between the hamstring injury history and the performance on the
Y-balance test, we found a correlation between player’s age and the score on the Y-balance in the
injured group. Older subjects had a weaker Y-balance performance and this in both the injured leg
(p=0.043) and the control leg (p=0.036). Playing division could also be associated with Y-balance
testing performance. In the injury group, players competing in lower levels tended to have poorer Ybalance results than their colleagues in higher division (p=0.045).
TEST
History of injury
Y BALANCE I
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
Y BALANCE C
YB_PL_I
YB_PM_I
YB_PL_C
YB_PM_C
YB_A_I
YB_A_C
BIRTHYEAR
DIVISION
PLAYING POSITION
MUSCLE
MEAN
± SD
102,581 ± 9,711
101,894 ± 7,0179
102,237 ± 8,1563
101,854 ± 6,7826
118,422 ± 12,5567
116,239 ± 10,793
117,956 ± 12,7411
116,762 ± 9,9575
117,633 ± 10,7939
115,952 ± 10,45051
116,944 ± 9,6101
116,573 ± 9,2017
71,367 ± 7,6345
72,68 ± 5,6618
72,133 ± 9,2586
73,036 ± 6,3559
1992,6 ± 1,958
1990,43 ± 2,937
5,7 ± 1,512
6,36 ± 1,446
3,03 ± 1,629
2,79 ± 1,343
0
2,04 ± 1,347
Table 3.
- 14 -
VARIABLE
TEST
BIRTHYEAR
Y BALANCE I
0,043
Y BALANCE C
0,036
YB_PL_I
0,068
YB_PM_I
0,027
YB_PL_C
0,121
YB_PM_C
0,008
Y BALANCE I
0,045
YB_PL_I
0,025
YB_PM_I
0,025
YB_PM_C
0,035
PLAYING POSITION
YB_A_I
0,061
MUSCLE
YB_A_I
0,092
DIVISION
Significance (p<0,05)
Table 4.
4.2.2
Questionnaire results in association with hamstring injury history
Additionally, hypothesis testing revealed a significant association between division and injury history
(p= 0.011), as players participating in lower divisions seem to report a higher injury history than
athletes active in higher levels of competition.
- 15 -
4.3
Prospective research
4.3.1
Functional Movement Screen performance in association with future hamstring injury risk
In total, 68 players were screened in this study. Of those 68, 31 have had one or more hamstring
injuries in the past. We followed these players during the season. Of these 68 players, 14 players got
a hamstring injury (20.6%) during follow-up. 3 players got a hamstring injury for the first time, so
78.6% got a re-injury of their hamstring. Of those 11 players, 5 got injured at the same side of their
first
injury
and
6
got
a
hamstring
injury
on
the
other
leg.
For the prospective statistical analysis we can conclude that, when performing poorer on the deep
squat (p=0.043) and active straight leg raise (p=0.041) , there is significant higher risk of sustaining
hamstring injury. (cf. table 5)
Variable
Characteristics
Age (year)
Height (cm)
Weight (kg)
BMI (kg/m2)
FMS
FMS total score
FMS lower limb
Deep squat
Hurdle step
In-line lunge
Active straight leg raise
Trunk stability push up
Rotary stability
Hamstring injury
Without ( n=54)
With ( n=14)
P
value
23,04 +-2,840
181,9 +- 6,06
74,96 +- 6,659
23,09 +- 1,950
180,5 +- 5,83
74,07 +- 7,849
0,948
0,432
0,668
22,64 +- 1,55
22,72 +- 1,99
0,873
15.26 +- 1.845
8.80 +- 1.234
2.26 +- 0.442
2.19 +- 0.392
2.65 +- 0.482
1.70 +- 0.786
2.17 +- 0.795
2.07 +- 0.328
14,79 +-1,968
8,21 +-1,251
2,00 +- 0,392
2,36 +- 0,497
2,57 +- 0,514
1,29 +- 0,611
2,14 +- 1,231
2,14 +- 0,363
0,401
0,122
0,043*
0,246
0,602
0,041*
0,946
0,496
* P<0.05
TABLE 5.
- 16 -
Figure 4.
Ordinal regression analysis revealed borderline non-significance when assessing the predictive value
of the Deep Squat (=0.077) and the Straight Leg Raise (p=0.053) testing performances in identifying
future hamstring injury risk. The score on the Deep Squat tended to explain 9.2% of the variance
around the observations for ‘prospective injury [yes/no]’, whereas the SLR could explain about 7.2%
of the observed variance.
- 17 -
Figure 5.
Figure 6.
- 18 -
When performing binary logistic regression on the deep squat – and active straight leg raise score,
without distinguishing between sustaining first or subsequent hamstring injury, the test result on
each test wasn’t able to predict future injury. However, the total score (0-6) from the deep squat and
active straight leg raise test has, in the contrary, the ability to predict a subsequent injury. When the
score of this composite FMS increased by one, the risk of future hamstring injury reduced with 65%.
This model is in the ability to predict 10% of the observed incidence of injury.
Furthermore, separating between sustaining first of subsequent hamstring injury didn’t revealed any
correlation
between
the
individual
scores
of
these
two
test.
Separate cohorts were subjected to chi-square testing. When combining the combination of the deep
squat and straight leg raise test, there could be made a prediction of future hamstring injury. The
validity is clearly more for the group of players who sustained first hamstring injury ( p=0.006 ). Here,
when the score reached ≥4, the risk was decreased to nothing (RR = 0%), opposed to the players who
scored ≤3 ( RR = 27%). No significant result was found when we considered the group of subsequent
injury ( p=0.236 ), probably because of the influence of various covariates.
Variable
Hamstring injury
Without ( n=54)
With ( n=14)
FMS
DS & ASLR score ≤ 3
20
11
DS & ASLR score ≥ 4
34
3
TABLE 6.
DS & ASLR score ≤ 3
DS & ASLR score ≥ 4
OR
27.27%
0,00%
P value
0.006
OR
P value
88.89%
27.27%
0,236
TABLE 7.
DS & ASLR score ≤ 3
DS & ASLR score ≥ 4
TABLE 8.
- 19 -
4.3.2
Y-balance test in association with future hamstring injury risk
Research showed us that the Y-balance test, however, is unfortunately not able to predict hamstring
injury in the future. For each direction of this test.
- 20 -
5. Discussion
In our study we examined if the FMS has a predictive value on sustaining hamstring injuries. We can
conclude that the FMS isn’t a specific test battery on predicting hamstring injuries. The positive tests
are the DS and the ASLR. The last one confirms what is proven in other studies. We think that
strength assessment of the hamstring is absent in the FMS protocol. Butler et al. (2013) found by
ROC curve analysis that a FMS cut score of ≤ 14 was able to discriminate between those at a greater
risk for injury. Further research is still needed because there’s a lack of research of the predictive
value of the FMS in athletes, and especially in our interest in soccer players. After all, we can assume
that the FMS is a general and not a specific test battery.
5.1
Functional Movement Screen
5.1.1
Deep squat
Based on the results of this mixed cross-sectional – prospective cohort study, we can conclude that,
soccer players who scored lower on the deep squat FMS component test, have an increased risk of
sustaining a hamstring injury. The squat is a movement that is essential within most closed kinetic
chain sports and corresponding movement requirements. It is the “ready position” and is required
for the majority of powerful movements involving the lower extremities. The deep squat component
test challenges total body mechanics, when performed properly. It is used to assess bilateral
symmetry and functional mobility of the hip-, knee-, and ankle joints. The bar that needs to be held
overhead assesses bilateral, symmetrical mobility of the shoulders and the thoracic spine, as well as
stability and motor control of the core musculature. Poor performance of this test can be the result
of several factors. Limited mobility in the upper torso can be attributed to poor glenohumeral and
thoracic spine mobility. Limited mobility in the lower extremity including poor closed kinetic chain
dorsiflexion of the ankles or poor flexion of the hips may also cause poor test performance, as well as
limited stability/motor control of the core.
5.1.1.1 Core stability
Surprisingly, the subtests of the FMS that contain core stability evaluation such as the trunk stability
push up and the rotary stability test, did not show significant results in predicting hamstring injuries.
We thought this was rather conflicting because we think core stability and core muscle endurance
- 21 -
are essential in performance as well as in injury prevention. Lumbopelvic/core stability is a major
factor during those 2 tests. Dewitt et al. (2014) concluded that restoration of core stability,
neuromuscular control and lengthening eccentric hamstring interventions are proposed key
components to reduce hamstring re-injury. Rehabilitation programs consisting of lengthened state
eccentric loading and lumbopelvic stability training, have shown to be effective in reducing
recurrence after injury. The implementation of lumbopelvic stability interventions, should (in theory)
enhance the length tension capacity of the hamstring muscle group by stabilizing the proximal
muscle attachments, thus avoiding unnecessary tension in the early phases of rehab which may limit
tissue healing. However, Okada et al. (2011) reported no significant relationships between any of the
core stability and FMS variables. Although dynamic, the FMS requires stabilization of the core to
complete the tasks for each screen. One would believe a strong core would be necessary to achieve
endeavour. Therefore, the lack of significant correlations is rather odd. Until further evidence is
available, current practice and widely published rehabilitation protocols cannot either be supported
or refuted. Bennell et al. (1999) evaluated the relationship between hamstring- and lumbar spine
flexibility on one hand and the incidence of hamstring injuries, on the other. In this cohort, the toetouch test did not appear to be a useful screening tool to identify footballers at risk for hamstring
strains. However, we can conclude that neuromuscular control, adequate eccentric strength and
musculotendinous elasticity are key components to achieve (1) a correct alignment in the three
planes of motion and (2) a balanced interaction between the internal –and external joint moments.
5.1.1.2 Ankle dorsiflexion
A second plausible cause of poorer deep squat performance could be a restricted ankle dorsiflexion.
When the subject was unable to reach the DS position, he was allowed to place the bar underneath
his heels, allowing a slight plantar flexion in the ankle joint. In this way, it was more likely to reach
the terminal deep squatting position without other major compensations, the athlete was assigned a
score 2. Via this slight modification, the actual presence of a dorsiflexion restriction was confirmed.
Gabbe et al. (2006) proved that a dorsiflexion restriction in the ankle is a risk factor for sustaining a
hamstring injury. In his study, a cohort of 222 Australian football players underwent a baseline
measurement in the form of a self-reported questionnaire and a musculoskeletal screening, of which
an ankle dorsiflexion lunge range, during the pre-season period of the 2002 Australian football
season, after which this cohort was submitted to follow up for registration of hamstring injury
incidence. Players with restricted ankle dorsiflexion on the lunge test were at elevated risk of
sustaining a hamstring injury but this was not significant. The nature of this relationship is unclear
and
has
not
been
investigated
previously.
- 22 -
Hamstring injuries are believed to occur during the terminal swing phase of sprinting, or at early
ground contact with the foot in a relatively plantar flexed position61,72. Given this, the relationship
between reduced dorsiflexion and hamstring injury risk is not obvious. Potentially, dorsiflexion
stiffness could be associated with the presence of another possible but yet to be identified risk
factor, like poor proprioception. Poor proprioception or neuromuscular control could impact
hamstring functioning during the terminal swing phase of the sprinting cycle, increasing the
likelihood of hamstring injury at this point. Further studies could assess the relationship between
dorsiflexion stiffness and sprinting mechanics or could target improvement in ankle dorsiflexion
range as a potential prevention strategy for hamstring injuries.
5.1.1.3 Eccentric hamstring power
A deep squat requires negative/eccentric work of the hamstrings. Hamstring injuries tend to occur
during a deceleration or landing task suggesting the negative work may be a key component in the
hamstrings injury risk. Recent research has suggested that the hamstrings musculature has the
highest injury rate of lower extremity musculature54, mostly occurring during negative work
associated with deceleration54,71. The high rate of hamstring injuries may be associated with the
exaggerated load placed on these muscles in response to diminished gluteal function or gluteal
amnesia, or just because of eccentric strength deficits within the hamstring muscle complex, without
involvement of the gluts. Given the high rate of hamstring injuries in sport, a need emerges to
determine the precise role of the hamstrings, the gluts and their synergistic interplay during athletic
movements (especially squat positions) involving shortening and lengthening contractions as well as
the
stretch-shortening
cycle.
5.1.1.4 Hamstring and quadriceps co-contraction
The high incidence of hamstring injuries in athletes can be attributed to a combination of muscular
and mechanical factors including muscle activation and external loading. Most of these injuries occur
during highly dynamic movements with rapid changes in direction. During an unloaded squat,
hamstring and quadriceps co-contraction has been documented and explained via a co-contraction
hypothesis. This hypothesis suggests that the hamstring provide a stabilizing force at the knee during
a posteriorly-directed force on the tibia to counteract the anterior tibial force imparted by the
quadriceps. In contrast with this suggestion, Isear et al. (1997) reported that at no time during the
squat, however, did the hamstrings demonstrate significantly greater EMG activity than the
quadriceps even though both muscles demonstrated their greatest EMG activity during the 90-60°
- 23 -
arc of knee angle. Since the hamstrings appear to be minimally active during closed kinetic chain
activities such as an unloaded squat, perhaps other factors, such as compressive forces ( e.g., axial
loading) and joint geometry ( e.g., 9% posterior tilt of the proximal articulation surface of the tibia),
play more integral roles in knee joint stability than does muscular co-contraction of the hamstrings
and quadriceps. To further question the importance of the hamstrings during an unloaded squat, we
reviewed Wickiewicz et al. (1983) cadaveric study of lower extremity muscle architecture which
demonstrated that the cross-sectional area of the hamstrings was approximately 40% smaller than
that of the quadriceps. Thus, to offset the large forces imparted by the quadriceps, we believe that
the hamstrings would need to demonstrate significantly more relative EMG activity than the
quadriceps regardless of any advantages that might be realized as a result of line of pull or muscle
length relationships. Isear et al. (1997), however, demonstrated hamstring activity of more than five
times less than that of the quadriceps. Therefore, we believe these data provide adequate support
from which to question the notion, as suggested by the co-contraction hypothesis, that hamstring
muscle activity is sufficient to provide the necessary posterior tibial shear forces to counteract
adequately the anterior tibial shear forces imparted by the quadriceps, thus providing a stabilizing
force at the knee during an unloaded squat.
5.1.2
Active straight leg raise
Aside from poorer performance on the Deep Squat test, a weaker score on the Active straight Leg
Raise test (ASLR) , could also be associated with a higher risk of sustaining a hamstring injury. The
ASLR evaluates the ability to disassociate the lower extremity from the trunk, as the testing leg needs
to be lifted maximally with an extended knee and ankle, while maintaining stability in the torso. The
ASLR test assesses active hamstring and gastro‐soleus flexibility while maintaining a stable pelvis and
core, and active extension of the opposite leg. The ability to perform the ASLR test requires
functional hamstring, gluteal, and iliotibial band flexibility, all essential for adequate (soccer)
performance. This is different from passive flexibility, which is more commonly assessed. Next to
(active) muscle flexibility, adequate hip extension ROM in the opposite leg and pelvic and core
stability
are
required.
Poor performance during this test can be the result of several factors. First, the athlete may lack
functional hamstring flexibility. Second, the athlete may have inadequate mobility of the opposite
hip, possible due to iliopsoas tightness, associated with an anteriorly tilted pelvis. If this limitation is
considerable, true active hamstring flexibility cannot be assessed. Consecutively, ASLR performance
is highly dependent on contralateral hip extension mobility and the results should be interpreted as
- 24 -
such. Next to the ASLR, the Hurdle Step component test is also highly dependent on adequate hip
mobility (both in flexion and extension directions); however, this test directly scores the flexibility of
the hamstrings, gluts and iliopsoas and the results are less likely to be biased.
5.1.2.1 Hamstring flexibility
We found that 2 studies measured the hamstring flexibility with a passive knee extension test. They
came to the same conclusion, that there is no association between hamstring flexibility and an
increased
risk
of
sustaining
a
injury3,24.
hamstring
One study, using an active knee extension test, presented that a decrease of active hamstring
flexibility, showed an association with the incidence or former presence of hamstring injuries, with a
correlation that approached significance.28
Two other tests, measuring the flexibility of the hamstring, are the active and passive Straight leg
raise test (SLR). For the active SLR-test, authors demonstrated that for every 1° decrease in the active
hip
flexion
range
of
motion,
the
propensity
for
injury
increased
x
1,29. 34
The passive SLR was used as screening tool in two studies. The first study approached a significant
correlation between a preseason decrease in hamstring flexibility and a higher risk of hamstring
injury during the season31. The second study presented contradictory results, and found no
correlation between hamstring flexibility and hamstring injury, measured with the passive SLR-test38.
The supine straight leg raise test is often recognized as the gold standard for measuring hip ROM and
concordant hamstring flexibility, also because this test allows unilateral measurement 20.
For the SLR test, we need to notice that it is important to make a difference between the passive and
active SLR. The results show us that the active range of hip-flexion is a predictor of hamstring injury38,
in contrast to the passive ROM of hip-flexion, for which we found contradictory results
31,38
.
Furthermore, considering the small number of observed hamstring injuries in the study of Gabbe et
al. (2005), the power of the study was not high which means that their conclusion must be
interpreted carefully.
Lockie et al. (2015) found a positive correlation between the unilateral sit-and-reach test (both
sides), which assess lower body flexibility (hamstring flexibility), and active straight leg raise test
(p=0,027). The left-leg active straight leg raise also best predicted the left-and-right-leg sit-and-reach.
The between-leg sit-and-reach difference had negative correlations with the left-leg active straightleg raise. Limitation of this study is that it had a small sample size (n=9) and that the subjects were
healthy female athletes.
- 25 -
5.1.2.2 Rectus femoris flexibility
Lastly, we found one screening tool, the Modified Thomas test, that could prove that flexibility of the
hip flexors, especially Rectus Femoris flexibility, is an independent risk factor of hamstring injury 31.
However, a second study of the same author refuted former statement and showed that hip flexor
flexibility is not a risk factor for hamstring injury up until the football player reaches the age of 25,
after which it is significantly associated with an increased HSI vulnerability30. However, this is in
contrast with our results that only showed one player, of 11 players older than 25, who became
injured in the season after testing. Hagel et al. (2005) also concluded (after adjustment for exposure)
that younger age was associated with a lower relative risk of injury, as were quadriceps flexibility and
active knee extension range of motion. They conclude that it’s highly probable that there is an
association between a decrease in muscle flexibility, especially hamstring flexibility and possibly
iliopsoas flexibility, and a higher risk of hamstring injury. A plausible mechanism may involve
alteration in the mechanics of running and sprinting. In both studies the RF (hip flexors) flexibility was
tested in the modified Thomas test position. This position mimics the terminal stance and pre-swing
position of the leg during running and sprinting. At this point, the bi-articular Rectus Femoris is
lengthened over both hip and knee, and is acting eccentrically to control extension of the hip and
flexion of the knee. As it stretches, the tendon of the rectus femoris absorbs energy, which is
released during the active flexion of the hip and extension of the knee through mid to late swing
phase, accelerating the forward movement of the leg. Before initial ground contact, the hamstrings
must contract eccentrically to decelerate the forward momentum of the tibia. During this forceful
eccentric action, the hamstrings are susceptible for strain injury. The higher the running speed, the
higher the muscle loading and thus the higher the injury risk. When the Rectus Femoris is very tight,
this might increase the positive elastic recoil of the tendon, increasing the acceleration of hip flexion
and knee extension, which must be counteracted by the eccentrically contracting hamstrings.
Therefore a greater load may be placed on the hamstring muscles, potentially increasing their risk of
future
31
. This study also gives another plausible explanation for this association, namely that the
reduction in hip flexor length could result in a restriction of hip extension in sprinting. Compensation
with increased movement at the lumbar spine, could be required to gain sufficient hip extension.
Over time, reliance on lumbar spine movement to compensate for restricted hip extension could lead
to joint hypermobility, irritation of the neural structures and activation problems within the
hamstring
muscles,
resulting
in
increased
injury
However, in the study of Gabbe et al. (2006), quadriceps (RF) flexibility could not be identified as a
predictor of hamstring injuries across all ages.32
- 26 -
5.1.2.3 Neural extensibility
Lastly, Bennell et al. (1998) suggest that the SLR may be more of an indicator of the magnitude of
neural extensibility, rather than hamstring muscle length, which the reader should acknowledge as
well It has been suggested that neural extensibility may play a role in hamstring injury vulnerability63
In cases where neural pathology produces altered tension in the hamstring muscles, the intensity or
synergy of muscle contraction may be altered and injury to the musculotendinous unit may occur. It
is possible that momentary stretch on irritated neural tissue may cause a protective reflex
contraction in the hamstring muscles, resulting in an uncoordinated agonist-antagonist action.
Regarding the possible influence of contralateral iliopsoas flexibility on the hamstring injury risk, no
literature is available to date. Therefore, further research is needed.
5.1.3
FMS composite score of deep squat and active straight leg raise test
The binary logistic regression analysis revealed that a score of ≤3 on the DS & ASLR, influenced the
incidence of sustaining first hamstring injury after adjusting for subjects’ characteristics ( RR=27%),
unlike those who scored ≥4 ( RR=0%). The relatively strong predictability of running injuries according
to the DS & ASLR score was attributed to the following reasons. First, the DS test by itself had a
strong predictability of injuries, which was in accordance with the result of Butler et al.’s study36. The
DS test assesses bilateral, symmetrical mobility, especially mobility of hips, ankles, and thoracic
spine, and coordination in the close kinetic chain. Renström et al. (1993) reported that poor flexibility
and deficit in neuromuscular coordination can cause running injuries. Additionally, excessive
pronation and knee-in during testing, which was one of the causes that decreased the score on the
DS test14, was also reported to be a risk factor for injury45. Second, the ASLR test was also found to be
related to running injuries; it assesses active hamstring and gastric-soleus flexibility while maintaining
a stable pelvis. This finding agreed with the study by Yagi et al. (2013), who also reported that limited
SLR ability increased the injury risk in high school runners. Additionally, Lysholm et al. (1987)
reported that flexibility of the hamstrings was a risk factor for injury. Consequently, deficits in the DS
and ASLR tests are likely to induce asymmetric or compensatory movement patterns and thus result
in running injuries. Thus, the FMS contains both helpful and less helpful movement tests for
predicting injury risk in competitive male runners.36
- 27 -
5.1.4
Other FMS component tests
The HS test assesses stepping ability, which requires mobility and stability of the legs as well as
coordination. The ILL test requires mobility and stability in the split stance as well as coordination.
Although these 2 tests seem to be relevant for running, they were not significantly associated with
incidence of running injury because most subjects received a score of 2 (91.7% for HS, 86.9% for ILL).
Due to their ceiling effects, these 2 tests were ineffective in screening injury risk. As a result, the FMS
composite score had low predictability. For the SM, TSPU, and RS tests, there is no solid evidence
that shoulder mobility and core-stability influence the incidence of running injuries.36
5.2
Y balance test
Next to the value of the FMS in hamstring injury risk identification, we also evaluated the possible
role of the Y-balance test (YBT). We can conclude that the YBT is not able to differentiate players with
a low or high risk of sustaining future injury, nor has the capacity to identify athletes with a
hamstring injury history.
Overmoyer et al. (2015) examined how deficits in flexibility are related to the Y-Balance testing
performance, because joint flexibility, bilateral asymmetries in flexibility, and bilateral asymmetries
in performance of the Y Balance Test have been associated with injuries. . Based on their results,
when used with recreationally active healthy adults, the Y-Balance Test may help identify lower
extremity flexibility deficits and flexibility asymmetries in the ankle and hip regions, but may need to
be used in conjunction with additional tests to understand the broader picture regarding the
association between functional movement quality and injury risk. Especially for an athletic
population and regarding the predictive value for injuries. Recently, Smith et al. (2015) did some
interesting findings. The YBT has been proposed as a screen for injury risk; however, limited research
is available concerning the actual association between YBT performance and future injury risk. The
purpose of the study of Smith et al. (2015) was to examine the association between YBT (asymmetry
and composite score (CS)) and noncontact injury in a sample of Division I (DI) college athletes from
multiple sports. ROC curves determined that bilateral asymmetry of more than 4 cm would be the
associated with an elevated injury risk. Only asymmetry in the anterior direct was significantly
associated with noncontact injury. CS in this sample of DI athletes was not associated with increased
risk of injury.
- 28 -
Muscle fatigue is related to a decline in force output and proprioception. These can ultimately have
an adverse effect on neuromuscular control and functional performance. Local muscle fatigue has
been shown to have adverse consequences on dynamic standing balance. However, physical
therapists should be aware of the adverse influence distant fatigue may exhibit on neuromuscular
control in muscles not actively involved in the fatiguing exercise. The balance deficits noted may
indicate an increased risk of injury with muscle fatigue in muscles not directly contributing to
standing balance. (Wassinger et al. (2014))68 Therefore, this is obviously an important view in making
an overall screening tool, because when upper limb testing is followed by the Y balance test, or even
the Functional Movement screen, this could affect the results of these last two tests.
5.3
New insights in the clinical use of FMS and YB
Recently, a couple of new papers concerning the FMS and Y-balance tests were published. Chimera
et al. (2015) found that research is limited regarding the effects of injury or surgery history and sex
on the Functional Movement Screen (FMS) and Y Balance Test (YBT). Their findings suggest, lower
overall FMS component scores were found in athletes with a history of hip-, elbow- and hand injuries
as well as subject with a history of shoulder surgery. Worse FMS movement pattern performance
was observed in athletes with a history of knee surgery, hip injury, hip surgery, shoulder injury and
shoulder surgery. Female athletes performed worse in FMS movement patterns for trunk and rotary
stability but better in the lunge, shoulder mobility and straight-leg raise. Anterior asymmetry was
greater for male athletes.
5.4
Reoccurence of hamstring injury
We can confirm the results of previous studies, indicating that previous hamstring injury is a great
risk factor of sustaining a new hamstring injury. Previous injury is often proposed to be a risk factor
for soccer injuries, but most studies rely on players reporting their own medical history and are thus
potentially subject to recall bias. Little is known about the natural variation in injury pattern between
seasons. Hägglund et al. (2006) investigated whether prospectively recorded injuries during one
season are associated with injuries sustained during the following season, and to compare injury risk
and injury pattern between consecutive seasons. Players who were injured in the 2001 season were
at greater risk of any injury in the following season compared with the non-injured players. Players
with a previous hamstring injury, groin injury, and knee joint trauma were 2 to 3 times more likely to
sustain an identical injury in the following season, whereas no such relation was found for ankle
- 29 -
sprain. However age was not associated with an increased injury risk. Engebretsen et al. (2010) found
similar results. Previous acute hamstring injury was found to be a significant risk factor for new
hamstring injuries. Previously injured players have more than twice as high a risk of sustaining a new
hamstring injury.
5.5
Similar research
In 2013, Lehr et al. ( 2013) did a similar prospective study as ours. In athletics, efficient screening
tools are sought to curb the rising number of noncontact injuries and associated health care costs.
The authors hypothesized that an injury prediction algorithm incorporating a functional movement
screen, demographic information, and injury history, can accurately categorize the magnitude of the
risk of noncontact lower extremity (LE) injury. It is unrealistic to individually test for each of the
known risk factors. Therefore, a screening process that uses field-expedient tests that incorporates
multiple potential risk factors, along with proper weighting of these factors, may be useful. The
above mentioned author used the Lower Quarter Y-Balance test and the FMS-test for injury risk
assessment. Athletes were then prospectively followed for noncontact LE injury. 12% of the study
sample sustained a hamstring injury. Subsequent analysis divided the sample into two risk
categories: Low (normal and slight) and High (moderate and substantial) risk of sustaining future
injury. Athletes subcategorized in the ‘high risk’ group, were at a significantly greater risk of
noncontact LE injury during the season. These results suggest that an injury prediction algorithm
composed of performance on efficient, low-cost, field-ready tests can help identify individuals at
elevated risk of noncontact LE injury. It is unknown if an athlete’s risk category can be altered with
injury prevention systems. However, individual components of the injury risk algorithm are
modifiable. A neuromuscular training program has been shown to be able to elevate the YBT-LQ
composite scores above the injury threshold in high school soccer players.47 The study of Lehr et al.
(2013) used bench marks for injury risk that were sports, gender, and age specific. The sports
medicine clinician can immediately apply the results of this study in two ways. First, the YBT-LQ, FMS
and injury prediction algorithm can be implemented in pre- participation screening to identify
athletes with the highest injury risk so that these athletes can be remediated via individual
prevention strategies before the start of a new season. Furthermore, these field-expedient tests and
the Move2Perform algorithm can be used for return to sport decisions.
- 30 -
6 Limitations
First, our study relies on players reporting their own medical history and are thus potentially subject
to recall bias. We can wonder if you may believe the self-report of the players concerning which
hamstring muscle was injured and if the injury was proximal or distal in the muscle. This is why we
could not meet the influence of the exact location of a hamstring injury on functional score as reinjury risk.
During the testing at the UZ of Ghent, the functional screening was consequently conducted by the
same 3 researchers (RV, BVP, MW). In that way scoring could be performed quite objectively, with
mutual agreement. However, the field testing was done by only one assessor, so this evaluation was
more subjective.
A limitation of the FMS is that there is no specific test that the hamstring strength examines. Yeung
et al. (2009) concluded that quadriceps peak torque ratio assessments may be useful to identify
sprinters susceptible to hamstring injury. Van der horst et al. (2014) proved that eccentric hamstring
strength exercises are hypothesized to reduce the incidence of hamstring injury among male
amateur soccer players by 70%. The prevention of such injuries will be beneficial to soccer players,
clubs, football associations, health insurance companies and society.
Another huge limitation of the FMS in our study is that we did not incorporated the shoulder mobility
test in our analysis. We just focused on the FMS lower limb and core stability tests. A lack of shoulder
mobility could be an injury risk factor for hamstring injury, perhaps because of the compensation in
the lower kinetic chain that is the immediate consequence. This need to be investigated by future
research, in combination with the Y-balance upper limb test. In that way, we could get a view if a lack
of upper limb dysfunction could predict injuries in the lower kinetic chain.
A limitation of the Y-balance test is that due to the fact that this test is dynamic, difficulties can occur
in attempting to accurately assess the maximal reach point and what criteria constitutes a successful
reach (e.g. how much movement of the stance foot is allowed or if the reach foot is allowed to touch
down). Touching down with the reach foot introduces error by making it difficult to quantify the
amount of support gained from that touchdown. If touchdown is not allowed, standardizing the
distance from the ground that the person reaches is difficult, as well as instantaneously marking the
maximal reach point. In addition, it is difficult for examiners to determine how much movement of
the stance foot is allowed. Precise determination of the heel or forefoot lift off from the surface is
- 31 -
difficult due to the contours of the foot and the rapid position changes due to co-contraction of the
lower limb muscles during unilateral stance.
In both the FMS and Y-balance test, error could have been introduced by fatigue and practice effect.
The last limitation in our study is that we didn’t do a follow-up through the whole season. That
wasn’t practical attainable. Our follow-up went till the end of February. When we would have a done
a follow-up till now, till the end of the season, we expect we would have more injuries. Injuries occur
more at the end of the season when the players are more fatigue.
- 32 -
7 Conclusion
The functional screening tool FMS itself is not useful to predict an increased risk of sustaining
hamstring strain injuries in the population of male soccer players.
However, The FMS component tests ‘deep squat’ and ‘active straight leg raise’ are able to predict
future hamstring injury, this especially in terms of the risk of sustaining a hamstring injury for the first
time. For this purpose, a combined screening tool of these two tests should be created for a good
prediction of future hamstring injury.
The Y-balance is not a specific valid test to predict hamstring injury. It’s a more useful screening tool
to evaluate the knee –and ankle stability.
8 Acknowledgements
The authors would like to extend their sincere appreciation to our promotor Prof. Dr. Damien Van
Tiggelen and our co-promotor Joke Schuermans who helped us when we had some issues during the
2 years we wrote our thesis. We would also like to thank our fellow students Xavier Verstraeten,
Thomas De Jonghe, Alexander Blondeel, Elien Boulangier and Naomi Fevery for the good teamwork
during the testing in the summer.
- 33 -
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10 Abstract
10.1
Abstract ( Layman’s terms )
Achtergrond: Hamstringletsels (achterste dijbeenspier) horen bij de meest voorkomende letsels in
het voetbal en kennen bovendien een groot risico op herval. De FMS en Y-balance zijn 2 functionele
testen die trachten het risico op een hamstring(her)aandoening op te sporen door de belangrijke
bewegingsvaardigheden te evalueren die bepalend zijn voor de prestatie en letselgevoeligheid van
de voetbalspelers.
Doel: Onderzoeken in welke mate de functionele testen FMS en Y-balance bruikbaar zijn om een
verhoogd risico op hamstringletsels te voorspellen.
Methode: In het voorseizoen (juli 2014) werd een groep van 28 spelers met een verleden van een
hamstringletsel (patiëntengroep) en 30 spelers zonder verleden (controlegroep) getest in het UZ
Gent. Een andere groep van 10 spelers (3 met en 7 zonder verleden) werd op het voetbelveld getest,
maar enkel de FMS werd afgenomen bij deze kleine groep.
Alle 68 spelers werden gedurende de eerste helft van het daaropvolgende seizoen opgevolgd om te
kijken of ze een (nieuw) hamstringletsel opliepen.
Resultaten: Er was geen belangrijk verschil tussen de patiënten en controlegroep wat betreft de
totale scores van de FMS en Y-balance. Maar, de patiëntengroep behaalde wel een duidelijk lagere
score op de Trunk-stability push-up (deeltest van de FMS). Een zwakke score op de deeltesten (1)
deep squat en (2) active straight leg raise vertoonde een verband met de
hamstringblessuregevoeligheid tijdens de opvolgperiode. Een gecombineerde test van deze twee
testen bleek in staat te zijn om een verhoogd risico op een toekomstig hamstringletsel te detecteren,
dit voornamelijk bij spelers die nog nooit een blessure hebben opgelopen aan de hamstring. Een
score van minder dan 4 op 6 ging gepaard met een risico van 27%, terwijl het risico op een
toekomstige hamstringblessure voor de spelers die op deze gecombineerde score 4 of meer
scoorden, tot 0 werd reduceerd.
Conclusie: De totale FMS score heeft geen voorspellende waarde op het voorspellen van
hamstringblessure. De twee deeltesten FMS deep squat en active straight leg raise kunnen een
hamstringletsel voorspellen, voornamelijk bij spelers zonder verleden van een hamstringletsel. Om
een goede voorspelling te maken van het risico moet wel een gecombineerde test worden gemaakt
van deze twee testen. De Y-balance is geen goede test om dit risico te voorspellen.
- 41 -
11 Appendices
11.1
Functional Movement Screen
1.Deep squat
Purpose: The ability to perform the deep squat requires appropriate pelvic rhythm, closedkinetic chain dorsiflexion of the ankles, flexion of the knees and hips. Extension of the
thoracic spine and flexion and abduction of the shoulders as well as stability and motor
control of the core musculature.
-
-
placing his/her feet approximately shoulder width apart and the feet aligned in the
sagittal plane.
adjusts their hands on the dowel to assume a 90‐degree angle of the elbows with the
dowel overhead
instruction: descend as far as they can into a squat position while maintaining an
upright torso, keeping the heels and the dowel in position. Hold the descended
position for a count of one, and then return to the starting position. As many as three
repetitions may be performed.
Not achieved?  the athlete is then asked to perform the test with a 2x6 block under
the heels.
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Score 3:
Upper body // tibia
Femur below the horizontal
Knees above feet
Dowel above feet
Score 2:
Upper body // tibia or vertical
Femur below horizontal
Knees above feet
Dowel above feet
Block under heels
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Score 1:
Upper body and tibia not //
Femur not below the horizontal
Knees not above feet
Dowel not above feet
2. Hurdle step
Purpose: The movement requires proper coordination and stability between the hips and
torso during the stepping motion as well as single leg stance stability. The hurdle step
assesses bilateral functional mobility and stability of the hips, knees and ankles. Performing
the hurdle step test requires stanceleg stability of the ankle, knee and hip as well as maximal
closed-kinetic chain extension of the hip. The hurdle step also requires step-leg open-kinetic
chain dorsifl exion of the ankle and fl exion of the knee and hip. In addition, the subject must
also display adequate balance because the test imposes a need for dynamic stability.
-
-
placing the feet together and aligning the toes touching the base of the hurdle. The
hurdle is then adjusted to the height of the athlete's tibial tuberosity.
The dowel is grasped with both hands and positioned behind the neck and across the
shoulders.
maintain an upright posture and step over the hurdle, raising the foot toward the
shin, and maintaining alignment between the foot, knee, and hip, and touch their
heel to the floor (without accepting weight) while maintaining the stance leg in an
extended position.
The moving leg is then returned to the starting position.
If one repetition is completed bilaterally meeting the criteria provide, a “3”is given.
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Score 3:
Hips, knees and ankles remain aligned in the sagittal plane.
Minimal to no lumbar movement
Dowel // hurdle
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Score 2:
Alignment is lost between the hips, knees, and ankles.
Movement is noted in the lumbar spine
The dowel and hurdle do not remain //
Score1:
Contact with hurdle
Loss of balance
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3. In-line lunge
Purpose: This test assesses torso, shoulder, hip and ankle mobility and stability, quadriceps
flexibility and knee stability. The ability to perform the in-line lunge test requires stance-leg
stability of the ankle, knee and hip as well as apparent closed kinetic chain hip abduction.
The in-line lunge also requires step-leg mobility of the hip, ankle dorsiflexion and rectus
femoris flexibility. The subject must also display adequate stability due to the rotational
stress imposed.
-
-
-
Place the end of their heel on the end of the board or a tape measure taped to the
floor.
The previous tibial measurement is then applied from the end of the toes of the foot
on the board and a mark is made.
The dowel is placed behind the back touching the head, thoracic spine, and middle of
the buttocks. The hand opposite to the front foot should be the hand grasping the
dowel at the cervical spine. The other hand grasps the dowel at the lumbar spine.
Both toes must point forward, and feet must begin flat.
The individual then lowers the back knee enough to touch the surface behind the
heel of the front foot, while maintaining an upright posture, and then returns to the
starting position.
The lunge is performed up to three times bilaterally in a slow controlled fashion.
- 47 -
Score 3:
the dowel remains vertical
Dowel in contact with the head, thorax and sacrum
there is no torso movement noted
the dowel and feet remain in the sagittal plane
Knee touches block
Score 2:
If 1 of upper conditions is not fulfilled
- 48 -
Score 1:
Loss of balance
Athlete fails
4. Shoulder mobility
Purpose: assesses bilateral shoulder range of motion, combining internal rotation with
adduction and external rotation with abduction. It also requires normal scapular mobility
and thoracic spine extension.
-
-
The tester first determines the hand length by measuring the distance from the distal
wrist crease to the tip of the third digit in inches.
The individual is then instructed to make a fist with each hand, placing the thumb
inside of the fist.
They are then asked to assume a maximally adducted, extended, and internally
rotated position with on shoulder and a maximally abducted, flexed, and externally
rotated position with the other.
The tester then measures the distance between the to closest bony prominences.
The flexed shoulder identifies the side being scored.
Score 3:
Fists are within one hand length.
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Score 2:
Fists are within one and one half hand lengths.
Score 1:
Fists are not within one and one half hand lengths.
An impingement clearing exam should be performed at the end of the shoulder mobility
test. This movement is not scored; rather it is performed to observe a pain response. If pain
is produced, a score of zero is given to the entire shoulder mobility test.
- 50 -
5. Active straight Leg Raise
Purpose: assesses active hamstring, gastroc-soleus, gluteal and iliotibial flexibility while
maintaining a stable pelvis and active extension (iliopsoas flexibility) of the opposite leg. The
ability to perform the active straight-leg raise test requires functional hamstring flexibility,
which is the flexibility that is available during training and competition.
-
-
The individual first assumes the starting position by lying supine with the arms in
anatomical position, legs over the 2 × 6 board, and head flat on the floor.
The tester then identifies the mid‐point between the anterior superior iliac spine, and
the midpoint of the patella of the leg on the floor, and a dowel is placed at this
position.
Next the individual is instructed to slowly lift the test leg with a dorsiflexed ankle and
an extended knee. During the test the opposite knee (the down leg) must remain in
contact with the ground and the toes pointed upward, and the head in contact with
the floor.
Score 3:
the vertical line of the malleolus of the tested leg resides between the mid‐thigh and the
SIAS. The non‐moving limb must remain in neutral position.
Score 2:
the vertical line of the malleolus of the tested leg resides between the mid‐thigh and the
knee joint line. The non‐moving limb must remain in the neutral position.
- 51 -
Score 1:
Note the vertical line of the malleolus of the tested leg resides below the knee joint line. The
non‐moving leg must remain in the neutral position.
6. Extension test en trunk stability test
Purpose: The ability to perform the trunk stability push-up requires symmetric trunk stability
in the sagittal plane during a symmetric upper extremity movement.
-
-
-
-
The individual assumes a prone position with the feet together.
The hands are placed shoulder width apart at the appropriate position per the
described criteria.
During this test, men and women have different starting arm positions. Men begin
with their thumbs at the top of the forehead, while women begin with their thumbs
at chin level.
The individual is asked to perform one push‐up in this position. The body should be
lifted as a unit; no “lag” (or arch) should occur in the lumbar spine when performing
the movement.
If the individual cannot perform a push‐up in this position, the thumbs are moved to
the next easiest position, chin level for males, shoulder level for females, and the
push‐up is attempted again.
The trunk stability push‐up can be performed a maximum of three times.
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Score 3:
Men perform a repetition with thumbs aligned with the top of the head
Women perform a repetition with thumbs aligned with the chin
Score 2:
M: thumbs//chin
F: thumbs //clavicle
Score 1:
M: thumbs not // chin
F: thumbs not //clavicle
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A clearing exam is performed at the end of the trunk stability push‐up test. This movement is
not scored; the test is simply performed to observe a pain response. If pain is produced,
positive is recorded on the score sheet and a score of zero is given for the test.
7. Rotary stability test
Purpose: a complex movement requiring proper neuromuscular coordination and energy
transfer from one segment of the body to another through the torso. The rotary stability test
assesses multi-plane trunk stability during a combined upper and lower extremity motion.
The ability to perform the rotary stability test requires asymmetric trunk stability in both
sagittal and transverse planes during asymmetric upper and lower extremity movement.
-
-
The individual assumes the starting position in quadruped, their shoulders and hips at
90‐degree angles, relative to the torso, with the 2 × 6 board between their hands and
knees.
The individual then flexes the shoulder and extends the same side hip and knee.
The same shoulder is then extended and the knee flexed enough for the elbow and
knee to touch.
This is performed bilaterally, for up to three attempts each side.
If the individual cannot complete this maneuver (score a “3”), they are then
instructed perform a diagonal pattern using the opposite shoulder and hip in the
same manner as described for the previous test.
Score 3:
The subject performs a correct unilateral repetition.
- 54 -
Score 2:
The subject performs a correct diagonal repetition.
Score 1:
The subject is unable to perform a diagonal repetition.
A clearing exam is performed at the end of the rotary stability test. This movement is not
scored; it is performed to observe a pain response. If pain is produced, a positive is recorded
on the score sheet and a score of zero is given for the test.
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11.2
Y-balance test
FIGURE 1 and 2. Starting position Y-balance test / Anterior reach Y-balance test.
FIGURE 3 and 4. Posteromedial reach Y-balance test / Posterolateral reach Y-balance test.
- 56 -
Participants.
- 57 -
11.3 Questionnaire pre-testing
IDENTIFICATIE EN SPECIFICATIE VAN HET RISICOPROFIEL OP ‘HAMSTRING STRAIN INJURY’ BIJ DE
VOETBALSPELER
ADMINISTRATIEVE VRAGENLIJST
Naam
Club en divisie
Adres
Telefoonnummer
Email-adres
Geboortedatum
Lengte
Gewicht
Dominant been
Hoelang voetbalt u reeds (in jaren)?
Spelpositie?
Beoefent u naast voetbal nog een andere sport? Zo ja,
welke?
Wordt er tijdens de trainingen systematisch voldoende
aandacht besteed aan een adequate gedoseerde warming
up en cooling down?
Medische voorgeschiedenis?
=> gelieve hiernaast uw voormalige sportblessures zo
volledig mogelijk te noteren, met vermelden van
datum/periode van voorkomen en duur van de
revalidatieperiode (hoelang u ingevolge het letsel niet
voluit hebt kunnen deelnemen aan training en competitie)
Letsel
1.
Datum letsel
Duur revalidatie
2.
3.
4.
5.
6.
7.
8.
9.
Heeft u momenteel ergens last van (bewegingsapparaat)?
Waar precies?
Maakt u gebruik van een supplementaire ‘beschermende’
voetbaluitrusting? (dragen van thermische shorts, braces,
steunkousen, ed. )
Rookt u?
Bent u bewust bezig met het consumeren van evenwichtige
voeding?
- 58 -
Hoeveel liter water drinkt u dagelijks? (bij benadering)
Enkel voor letselgroep:
Hoeveel keer liep u reeds een hamstringletsel op?
Kan u een benaderende datum geven aan elk van deze letsels? Zo niet, geef dan enkel de datum van uw laatste
hamstringblessure:
Hoelang kon u ingevolge uw letsel niet deelnemen aan trainingen en wedstrijden? Wat was met andere woorden de
omvang van uw Time-Loss?
Waar was dit laatste letsel exact gesitueerd?
Duid aan:
Geef aan hoe omvangrijk uw laatste blessure was aan de hand van volgende vragen:

Betrof het een verrekking of een echte scheur?

Hoe groot was de omvang van uw functioneel deficiet? Welke bewegingen en/of activiteiten kon u niet meer
uitvoeren door uw letsel? (sprinten, passen, schieten op doel, lopen, jogging, stappen, trappen doen,..?)
Bent u tevreden over de medische begeleiding en de kwaliteit van uw revalidatie/kinesitherapie na uw laatste
hamstringblessure?
Gelieve deze revalidatie een score tussen 0 en 10 te geven (waarbij 0 = helemaal niet tevreden over het gevolgde
revalidatieprotocol en 10 = geen betere revalidatie denkbaar)
Vat hieronder kort samen waar precies aandacht aan besteed werd bij uw revalidatie / kinesitherapeutische behandelingen
(manuele therapie, frictie, massage, elektrotherapie, oefentherapie onderste lidmaat, oefeningen op core-stability,
sportspecifieke- en veldtrainingen,..):
In hoeverre voelt u zich voldoende uit gerevalideerd? Hoe zelfzeker voelt u zich in het hervatten van intensieve trainingen
en competitie? Geef een score tussen 0 (zeer onzeker en bang om opnieuw gekwetst te raken) en 10 (sterker dan ooit
tevoren en absoluut geen zorgen over letselrecidief):
- 59 -
11.4
Questionnaire after 6 months follow-up
Vragenlijst voetballers winterstop 2014
1/ Algemene vragen
-Naam en voornaam:
-Club + divisie:
-Lengte(cm):
-Gewicht:
-Dominant been(schopbeen li/re):
2/ Sport specifieke vragen
-Hoeveel trainingen gemiddeld per week meegedaan?
-Welke blessures zijn er in de periode van de testing tot nu (december 2014) voorgevallen?
Soort letsel + (li/re)
Datum opgelopen letsel
Duur revalidatie/out
- 60 -
-Specifiek hamstringblessures:
Vragen
Antwoord( zo specifiek mogelijk aub)
Wanneer (datum)
Hoe
is
het
letsel
ontstaan
(lopen/trappen…/tijdens match of training?)
Linker of rechter been
Aan zelfde zijde als vorig hamstring letsel: ja/nee
Locatie letsel:
1) Binnenzijde/buitenzijde been
2) Bovenaan(bil)/midden/onderaan(thv
knieholte)
Heeft
u
een
kinesitherapeut/
1)
2)
arts
geconsulteerd?
Werd er medische beeldvorming uitgevoerd?
ja:
wat
was
de
diagnose?
nee: hoe werd diagnose gesteld?
Duur revalidatie
Indien revalidatie: wat werd er gedaan?
Hoeveel trainingen gemist
Hoeveel matchen gemist
- 61 -
11.5
Score sheet FMS.
- 62 -
11.6
Score sheet YBT.
- 63 -
11.7 Informed consent
Informed Consent
Ik ondergetekende, .........................................................................., verklaar hierbij dat ik, als participant aan
een onderzoek van de masterscriptie ‘ Does the Functional Movement Screen and Y balance test have the
ability to predict hamstring injuries in male soccer players?’ (Universiteit Gent):
(1) de informatiebrief heb gelezen. Die geeft uitleg over de aard van de vragen, taken, opdrachten en stimuli
die tijdens het onderzoek zullen worden aangeboden. Op elk ogenblik wordt me de mogelijkheid geboden om
bijkomende informatie te verkrijgen.
(2) totaal vrijwillig deelneem aan het onderzoek.
(4) de toestemming geef aan de proefleiders om mijn resultaten op anonieme wijze te bewaren, te verwerken
en te rapporteren.
(5) de toestemming geef fotomateriaal, getrokken tijdens mijn onderzoek, te mogen gebruiken / publiceren.
(6) op de hoogte ben van de mogelijkheid om mijn deelname aan het onderzoek op ieder moment stop te
zetten.
(7) ervan op de hoogte ben dat ik een samenvatting van de onderzoeksbevindingen kan krijgen.
Gelezen en goedgekeurd te .............................(plaats) op ............. (datum)
Handtekening van participant:
……………………………………
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