Purpose of this
presentation
Scapulothoracic mechanisms:
Neurophysiology and control
of scapular movement
Prof dr Ann Cools, PT, PhD
Dept Rehab. Sciences & Physiotherapy
Ghent University, Belgium
Normal biomechanics scapular
muscles and muscle recruitment
patterns
Scapular muscle dysfunction in
shoulder pathology
Rehabilitation exercises: activity
patterns
BESS Instructional Course 2009
Gent-Belgium-2009
Shoulder kinematics:
Importance of muscle action
Role of the static stabilizers?
stabilizers?
Limited static articular constraints in
glenohumeral and scapulothoracic joint
BESS Instructional Course 2009
ForceForce-couples
Shoulder kinematics:
Importance of muscle action
Role of the physiotherapist:
physiotherapist:
Muscle function can be changed by
preventive of rehabilitation exercises
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Scapulothoracic force couples
Muscles with
different/opposite
action
Working together
Specific action
Functional
stability and
performance
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UT + SA:
MOVEMENT
LT:
MOVEMENT
REGULATION
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(Johnson Clin Biomech 1994)
(Johnson Clin Biomech 1994)
Upper trapezius
Upward rotation +
elevation
Lower trapezius
Scapular upward
rotation in endendrange elevation of
the shoulder
Serratus Anterior
Upward rotation +
protraction
Lower trapezius
Stability and
movement control
BESS Instructional Course 2009
Scapular muscle dysfunction
in relation to shoulder pain
(impingement)
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Scapular Muscle
Recruitment?
Muscle STRENGTH
Muscle BALANCE
– Isokinetic muscle Peak Force, Power & Fatigue
– Strength ratio agonist/antagonist
– EMG during isokinetic movements
Doctoral Project 2003
Ann Cools - UGent
Dept. Rehabilitation Sciences
& Physiotherapy
Muscle TIMING
– EMG latency times during scapular (protraction(protractionretraction) and glenohumeral (abduction &
external rotation) movements
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Strength Deficit
METHODS:
METHODS:
Strength Deficit
RESULTS (N=19, N=30):
Isokinetic assessment
of scapular muscle strength
protractionprotraction-retraction
movements
in the scapular plane
Decreased muscle strength in
serratus anterior
Compared to nonnon-injured side &
healthy control group
A. Cools, E. Witvrouw, G. Declercq et al. 2004, Br J Sports Med
A. Cools, E. Witvrouw, G. Declercq et al. 2005, J Athl Train
A. Cools, E. Witvrouw, G. Declercq et al. 2002, Iso Exc Sci
BESS Instructional Course 2009
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Muscle Imbalances during
scapular movements
Muscle imbalances
RESULTS ProtractionProtraction-retraction
(N=19):
METHODS:
METHODS:
Agonist/antagonist
Agonist/antagonist ratio
(protraction/
protraction/retraction)
retraction)
Surface EMG scapular muscles
during isokinetic assessment
BESS Instructional Course 2009
BESS Instructional Course 2009
A. Cools, E. Witvrouw, G. Declercq et al. 2004, Br J Sports Med
Muscle Imbalances during
shoulder movements
Muscle Latency Times
METHODS:
METHODS:
RESULTS external rotation –
abduction (N=39):
Increased upper trapezius activity
Decreased lowerlower-middle trapezius
activity
Decreased ratio protraction/
protraction/retraction
Decreased lower trapezius activity
during retraction
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Sudden
perturbation
Surface EMG:
EMG:
muscle onset
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A. Cools, E. Witvrouw, G. Declercq et al. 2006, Scand J Med Sci Sports
A. Cools, E. Witvrouw, G. Declercq et al. 2002, JOSPT
Muscle Latency Times
RESULTS (N=39):
Delayed onset lower trapezius
Bilateral disorders
Abnormal recruitment pattern
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References:
References:
– Cools et al. 2002, JOSPT,
JOSPT, 32(5):22132(5):221-229
– Cools et al. 2002, Iso Exc Sci,
Sci, 10(3): 129129-136
– Cools et al. 2003, Am J Sports Med, 31(4), 542542-549
– Cools et al. 2004, Br J Sports Med, 38:6438:64-68
– Cools et al. 2005, J Athl Training, 40(2): 104104-110
– Cools & Walravens: Oefentherapie bij schouderaandoeningen,
Standaard Uitgeverij, 2007
– Cools et al. 2007, Scand J Med Sci Sports,
Sports, 17(1): 2525-35
– Cools et al. 2007, Am J Sports Med, 35(10):174435(10):1744-1751
– Cools et al. 2007, J Athl Training,42(4):458–463
Training,
– Cools et al. 2008, BJSM, 42(8), 628628-635
– Cools et al. 2008, BJSM, 42(3):16542(3):165-71
– De Mey et al. 2009, JOSTP, in press
– Maenhout et al. 2009, BJSM, submitted June 2009
– Cools et al. 2009, paper in progress, to be submitted to SJMSS
BESS Instructional Course 2009
A. Cools, E. Witvrouw, G. Declercq et al. 2003, Am J Sports Med
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CAUSE - CONSEQUENCE
RELATIONSHIP
-
Cause – consequence?
Relevance of treatment?
Detection in clinical practice?
Which exercises?
Guarantee for pain and symptom relief?
extrapolation of results to functional
overhead activities?
(Scapula Summit, Lexington USA, 2003: B. Kibler, E.
Witvrouw, A. Cools, P. Ludewig, P. Mc Clure, M. Kelley, P.
Donley, M. Schwellnus, T. Uhl)
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BESS Instructional Course 2009
CAUSE - CONSEQUENCE RELATIONSHIP:
RELATIONSHIP:
CAUSE - CONSEQUENCE RELATIONSHIP:
RELATIONSHIP:
“Secondary phenomenon based on
muscle inhibition as result of pain”
pain”
“Primary cause of shoulder pain
and impingement symptoms”
symptoms”
Reflexive muscle inhibition known
phenomenon
Aspecific scapular dyskinesis,
no direct correlation with
shoulder pathology
Scapular dyskinesis tends to narrow
subacromial space (Ludewig 2000, Lukasiewicz
1999)
Bilateral scapulothoracic
dysfunction (Cools 2003)
(scapula summit 2003)
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Preliminary conclusion:
conclusion:
Primary predisposition,
predisposition,
aggravated by pain
inhibition mechanisms
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-
Cause – consequence?
Relevance of treatment?
Detection in clinical practice?
Which exercises?
Guarantee for pain and symptom relief?
extrapolation of results to functional
overhead activities?
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Scapular involvement in
shoulder pain?
Scapular Assistance
Test
Scapular Retraction
Test
-
Cause – consequence?
Relevance of treatment?
Detection in clinical practice?
Which exercises?
Guarantee for pain and symptom relief?
extrapolation of results to functional
overhead activities?
BESSTate
Instructional
Course 2008)
2009
(Kibler AJSM 2006, Rabin JOSPT 2006,
JOSPT
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Classification of scapular
dyskinesis (Kibler JSES 2002)
TYPE I
Type I:
– prominent inferior angle
scapula
– anteriorly tilted scapula
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Type I scapular dyskinesia
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Classification of scapular
dyskinesis (Kibler JSES 2002)
Type II:
–
–
–
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prominent medial border scapula
internally rotated scapula
“winging”
winging”
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TYPE II
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Classification of scapular
dyskinesis (Kibler JSES 2002)
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TYPE III
Type III:
– prominent superior/medial
superior/medial
border scapula
– downward rotated scapula
– “shrug”
shrug” with elevation
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BESS Instructional Course 2009
However: scapular dyskinesia is
difficult to classify!!
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Scapular Rehab Algorithm
Lack of
Soft-tissue flexibility
-
Cause – consequence?
Relevance of treatment?
Detection in clinical practice?
Which exercises?
Guarantee for pain and symptom relief?
extrapolation of results to functional
overhead activities?
Scapular muscles
- Levator scapulae
- pectoralis minor
Conscious muscle control lower
trapezius:
trapezius: Scapular Orientation
Exercise
Angulus inferior
Sternum
Proc coracoideus
- Manual stretching
- home stretching
- soft tissue techniques
- manual mobilisations
(accessory movements)
Muscle Control
- co-contraction
- force couples
Muscle Strength
- lower/middle trap
- serratus anterior
NEUROMUSCULAR
COORDINATION
STRENGTH
TRAINING
Conscious muscle
control
Conscious muscle
control
Advanced control
During basic activities
Balance -ratio
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Advanced control
During sports movements
Endurance/strength
Conscious muscle control lower
trapezius:
trapezius: Scapular Orientation
Exercise
(Mottram 1997,2003,2009
Cools 2008)
GH muscles/capsule
- infraspinatus
- posterior capsule
STRETCHING & MOBILISATION
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Lack of
Muscle performance
Subjects are able to perform consistent
movements of the scapula into posterior tilt
and upward rotation
Significant increase scapular muscle activity
(however also upper trap)
High correlation between
assisted and unassisted
exercise
(Mottram 2009)
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Rehabilitation muscle
balance UT/LT & UT/MT
Exercises with low UT/LT & UT/MT
ratio
(N=45)(Cools et al. AJSM 2007)
Exercises to improve
timing of muscle activity?
activity?
EMG analysis of muscle onset of UT, MT, and LT (in relation to
posterior deltoid)
deltoid) in previously selected selected exercises
(n=30)
MT
LT
UT
Deltoid actvity
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Integration Kinetic Chain into
open chain shoulder
rehabilitation exercises
6 modalities for 4 shoulder rehabilitation
exercises (N=41)
(Cools et al. 2007, unpublished data Master Thesis Sohier et al.)
(De Mey & Cools, in press, JOSPT 2009)
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Results:
Results: muscle balance ratios
UT/LT and UT/MT
Unilateral performance superior to bilateral
Sitting position superior to standing
Stance on one leg = stance on two legs
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(Cools et al. 2007,
unpublished data Master Thesis Sohier et al.)
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Integration Kinetic Chain into
closed chain shoulder
rehabilitation exercises
6 modalities of the pushpush-up plus exercise (N=32)
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Results:
Results: EMGEMG-activity and muscle
balance ratios
Highest SA activity (44%MVC) en best
UT/SA ratio (0.40) when ipsilateral leg is
extended
Results:
Results: EMGEMG-activity and muscle
balance ratios
Lowest UT activity (13%MVC) in pushpush-up
both legs support
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(Maenhout & Cools, submitted BJSM 2009)
(Maenhout & Cools, submitted BJSM 2009)
Results:
Results: EMGEMG-activity and muscle
balance ratios
In general low activity of MT & LT, except
when heterolateral leg is extended
(LT=20%MVC)
Conclusion
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Scapular muscle function: FORCE
COUPLES
Try to identify SPECIFIC movement
disorders and possible underlying
mechanisms
Muscle BALANCE and proper TIMING
are important issues in rehabilitation
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(Maenhout & Cools, submitted BJSM 2009)
Thank you!
BESS Instructional Course 2009
(Gent – Belgium)
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