Florida State University Libraries
Electronic Theses, Treatises and Dissertations
The Graduate School
2007
Effects of Cognitive-Linguistic Load on
Measurements of Gait in Healthy Elderly
Derek Cicchitto
Follow this and additional works at the FSU Digital Library. For more information, please contact [email protected]
THE FLORIDA STATE UNIVERSITY
COLLEGE OF COMMUNICATION
EFFECTS OF COGNITIVE-LINGUISTIC LOAD ON MEASUREMENTS OF
GAIT IN HEALTHY ELDERLY
BY
DEREK CICCHITTO
A Thesis submitted to the
Department of Communication Disorders
in partial fulfillment of the
requirements for the degree of
Master of Science
Degree Awarded:
Summer Semester, 2007
The members of the Committee approve the thesis of Derek N. Cicchitto on January 5,
2007.
__________________________________
Leonard L. LaPointe
Professor Directing Thesis
__________________________________
Gary Heald
Outside Committee Member
_________________________________
Julie Stierwalt
Committee Member
The Office of Graduate Studies has verified and approved the above named
committee members.
ii
TABLE OF CONTENTS
Page
LIST OF TABLES
iv
LIST OF FIGURES
v
ABSTRACT
vi
CHAPTER I
Review of Literature
1
CHAPTER II
Methods and Procedures
Participants
5
Apparatus
5
Procedures
6
Demographic Data
8
Gait Measurement
8
CHAPTER III
Results
Functional Ambulation Profile (FAP)
11
Correlational Measures
13
CHAPTER IV
Discussion
15
Theoretical Implications
16
Future Research
17
A
Intake Information
19
B
Directions for High Load
20
C
Load Counterbalancing Form
21
D
Informed Consent Form
23
APPENDIX
REFERENCES
25
BIOGRAPHICAL SKETCH
27
iii
LIST OF TABLES
Table
1
2
3
4
Page
Demographic Variables for 20 Participants (10 males, 10 females)……………….....8
Descriptive Statistics for 10 Variables Across Three Cognitive Conditions for 20
Participants with Trials 1 & 2 Averaged……………………………..……………….9
Comparison of Functional Ambulation Profile (FAP) Scored for Baseline, Low, and
High Cognitive Loads for 20 Participants…………………………………………...14
Pearson “r” values comparing FAP and Age with Trials 1 and 2
Averaged…………………………………………………………...………………...15
iv
LIST OF FIGURES
Figure
1
2
3
Page
Mean Measures of 6 Temporal Gait Variables Across Cognitive Conditions for 20
Participants with Trials 1 & 2 Averaged……………………………………………..10
Mean Measures of 3 Spatial Gait Variables Across Cognitive Conditions for 20
Participants with Trials 1 & 2 Averaged……………………………………………..11
Functional Ambulation Profile (FAP) for Baseline, Low, and High Cognitive Load
for 20 Participants with Mean of 2 Trials…………………………………………....14
v
ABSTRACT
This study was conducted in an effort to gain insight on falls, an important issue facing
the elderly population. Falls are the leading cause of injury-related visits to emergency
departments in the United States and the primary etiology of accidental deaths in persons
over the age of 65 years (Fuller, 2002.) This investigation analyzed gait measurements
and cognitive-linguistic processing in healthy elderly participants. The participants
involved 20 healthy elderly individuals. They were required to walk across a mat known
as the GAITRite Walkway System. This system was used to record gait measurements
and to generate a Functional Ambulation Profile (FAP). FAP is a composite score
derived from a formula that includes several critical parameters of gait that have been
shown to be a valid indicator of risk for falls. Several conditions were conducted in
which participants simultaneously walked across the mat while performing cognitivelinguistic tasks that varied in complexity such as counting by ones (low cognitive
linguistic task) and reciting an alpha-numeric sequences (high cognitive linguistic task).
Results indicated several changes in spatial/temporal gait parameters, primarily during
high-cognitive linguistic tasks. These changes in gait measures indicated participant
usage of an altered and perhaps more cautious walking style. Scores for FAP were found
to be significantly below normal range during high cognitive-linguistic tasks as well as
significantly changed from a control condition of walking with no talking. Normal FAP
scores range from 95 to 100. These findings suggested that reciting alpha-numeric
sequences simultaneously during walking increased the predictive risk for falls as
measured by the FAP. The information offered insight into the performance of dual tasks
or increased cognitive-linguistic load as possible contributors to falls, and highlighted the
importance of limiting distractions or task competition for elderly individuals during
ambulation.
vi
CHAPTER 1
Review of Literature
Falls are the leading cause of injury-related visits to emergency departments in the
United States and the primary cause of accidental deaths in persons over the age of 65
years. The mortality rate after falls increases dramatically with age in both genders and
in all racial and ethnic groups, with falls accounting for 70 percent of accidental deaths in
persons 75 years of age and older (Fuller, 2000, p. 2173). A recent study reported that
the number of emergency room visits by Americans 75 and older resulting from productrelated injuries have increased by 73 percent from 1991 to 2002 (“Alarming Increase”,
2005). Several factors have been attributed to causing falls among elderly individuals
ranging from age to physical causes. Many studies have analyzed the magnitude of
effects of these factors on the gait of elderly subjects who are suffering from various
diseases (Whelan, Murdoch, Theodoros, Silburn, & Hall, 2005; Stierwalt, LaPointe,
Maitland, Toole, & Wilson, 2006). Research has also been conducted to study the effects
of these factors on gait in the healthy elderly population (Mills and Barret, 2001.)
However, few studies have considered the effects of cognitive-linguistic load on gait in
elderly subjects, and more importantly, no extensive normative data on effects of such
loading have been established using healthy elderly subjects.
It is important to understand the mechanics of gait, and which phases pose the
greatest risk to falls. The gait cycle is composed of the support phase and the swing
phase. During the support phase the net extensor movement generated by the hip, knee,
and ankle joints is required to prevent the collapse of the stance limb (Winter 1983). The
principal swing phase task is the progression of the foot of the swing limb from the
previous to the next support position, providing the basis for the forward progression of
the body (Winter, 1983.) The two critical points in the gait cycle from a falls perspective
are minimum toe clearance and heel contact, which occur during the swing phase
(Winter, 1991). Past research has analyzed different phases in gait and the changes in
these phases associated with age. One research article examined the effect of ageing on
the swing phase mechanics on young and elderly gait (Mills and Barret, 2001). In this
study the sagittal plane marker trajectories and force plate data were collected for 10
1
young adults (M age 24.9) and eight elderly adults (M age 68.9) as the subjects walked at
their preferred walking speed. The elderly subjects were found to have a greater hip
extension moment at the time of minimum metatarsal-phalangeal joint clearance,
significantly higher anterior-posterior velocity, and a significantly higher shank and foot
angular velocity at heel contact. The findings may explain why slips are the primary
cause of falls in elderly people given that Gronquist, Roine, Jarvinen, and Korhonen,
(1989) found the majority of slips to occur in the moments following heel contact and
increased risk of slips occur when high anterior-posterior heel contact velocity is present.
The study analyzed differences of gait characteristics during high risk phases in young
adult and elderly subjects while performing their preferred walking speed. No trials were
conducted to assess changes in gait during dual tasks such as walking and talking.
Past research has studied the influence of age and gender on physical mobility
among elderly people without disabilities (Steffen, Hacker, & Mollinger, 2002). These
researchers’ analyzed age, gender, and physical mobility among 96 healthy elderly
people, 61-89 years of age to establish normative data. The four clinical tests conducted
were: Six-Minute Walk Test (6MW), Berg Balance Scale (BBS), Timed Up and Go Test
(TUG), and Comfortable- and Fast- Gate Speed (CGS and FGS). The 6MW was used to
measure the maximum distance that a person could walk in six minutes. The BBS was a
performance-oriented measure of balance in elderly individuals using simple mobility
tasks (e.g. standing unsupported, sit and stand) and difficult mobility tasks (e.g. turning
360 degrees, single-leg stance). The TUG measured the time it takes a subject to stand
up from an armchair, walk a distance of 3m, turn, walk back to the chair, and sit down.
The CGS and FGS measured the subject’s ability to increase or decrease walking speed.
The findings supplied data describing a range of performance in the 4 tests among elderly
people without disabilities and found a trend toward age-related declines as measured for
both male and female subjects. However, the study used multiple tests to measure
subject performance, which may have resulted in a possible cumulative effect making it
difficult to establish whether these tests are sensitive enough to measure change over time
and useful to the clinician (Steffen et al. 2002.) Also, no trials were conducted to assess
the effects of distraction or dual-tasking on gait.
2
Rosengreen, McAuley, and Mihalko (1998) examined gait adjustments in active
and sedentary healthy adults ages 60-85 when presented with challenging walking
circumstances. The study used a series of physical activity self-efficacy measures
(walking with and without an obstacle placed in their path) and the Berg Balance Scale
(BBS). Results found that sedentary older adults adopted a more cautious walking style
than active ones, exhibiting shorter step length, and slower step velocities. Also, as
walking obstacles became more difficult, subjects acquired a more cautious walking
style. The study did not examine cognitive challenges that may cause gait variability
such as tasks involving working memory.
More specifically related to extrinsic influences of gait was a study by Springer,
Giladi, Peretz, Yogev, Simon, and Hausdorff (2006) that contrasted the effects of
executive functioning on gait in elderly idiopathic fallers, elderly non-fallers, and healthy
young adults. This study defined executive functioning as cognitive processes that
orchestrate goal directed activities and allocate attention among competing tasks and the
complex process by which an individual goes about performing a novel problem-solving
task from its inception to its completion. The ability to divide attention was also stated to
be considered an example of executive functioning. In this study gait speed, swing time,
and swing time variability (measure of dynamic balance), were measured at a selfselected walking speed for 25 m with no tasks and during three different dual-tasking
conditions (simple, complex, and arithmetic). Simple tasks consisted of listening to a
short passage while walking, then answering 10 multiple choice questions about the
passage after completing the walk. The complex task involved the subjects listening to a
different passage while counting how many times two prespecified words were heard.
The arithmetic task required reciting aloud serial subtractions of seven, starting from 500.
Results found that attention demanding dual tasks had a destabilizing effect on the
postural control (swing time and swing time variability) only in elderly fallers, but not in
young adults and elderly non-fallers. Walking with no other tasks and walking during
dual tasking was shown to be similar in comparison of elderly non-fallers and young
adults, revealing no evidence of age-associated increase in the dual task effect on gait
variability. Elderly non-fallers coped with dual tasking trials with decreased gait speed
and swing times. The study offered vital data towards the topic of changes in gait with
3
age and factors associated with increasing the risk of falls; however more research is
needed to contribute to the extent literature on the parameters of gait and the effects of
various dual-tasks.
Statements of Problem and Purposes
Additional investigation of dual-tasking, cognitive-linguistic loading and effects on gait
and balance would further our understanding of cognitive loading and fall risk. A
sensitive measurement tool should be applied such as the Functional Ambulation Profile
(FAP) to provide the predictive data on fall risk from varying levels of cognitivelinguistic loading. FAP is a composite score derived from a formula that includes several
critical parameters of gait that have been shown to be a valid indicator of risk for falls.
The purpose of the present study was to observe changes in objective
measurements of gait when several cognitive-linguistic loads were applied to healthy
elderly adults. The goal was to test the hypothesis that high cognitive-linguistic load
would result in declines of FAP potentially increasing the risk for falls. The data
collected would provide normative data on the effects of cognitive-linguistic load on the
Functional Ambulation Profile (FAP), which in turn might serve a useful purpose in
advising individuals with increased risk for falls. While previous research has been
conducted to establish preliminary data on the changes in gait during dual-tasks in
healthy elderly people (Springer et al. 2006), their investigation has focused on the
following: preferred walking speed to assess phases (Mills et al. 2001), various physically
demanding clinical tests (Steffen et al. 2002), and obstacles as a distraction (Rosengreen
et al. 1998). Little data on the effects of load during gait exist. Because the dual task of
walking while talking is a common one, testing for changes in gait under these
circumstances is essential
In addition the descriptive data provided by the performance
of healthy elderly adults in this study can be used in future studies to compare and
contrast the performances of various clinical populations (Parkinson’s Disease, multiple
sclerosis, stroke, dementia).
4
CHAPTER 2
Method
Participants
The participants involved in the experiment were 25 elderly people with no
reported history of neurological damage, however, because they did not meet enrollment
criteria five participants were excluded. Of the 20 participants that remained, ten were
men and ten were women. They ranged in age from 61-84 (M 71.8; SD of 6.5). The
number of years of post secondary education was relatively high in this sample and
ranged from 0-12 years of post secondary education (M 6; SD 3.5). Participants from a
list of Florida State University alumni and professors ages 60 and older who lived in
Tallahassee were contacted by phone and asked to take part in an experiment that
analyzed walking and talking. Exclusion criteria included history of speech problems,
respiratory problems, special diet, neurologic trauma, neurologic disease, or insult, gait
mechanics trauma, balance problems, and/or participation in previous gait studies.
Information gathered at the time of appointment included date of birth, height, medical
diagnoses, and leg measurements.
Apparatus
The experiment took place at the Florida State University Tallahassee Memorial
Health Care Foundation Neurolinguistic-Neurocognitive Rehabilitation Research Center.
The equipment used to record and analyze gait was the GAITRite Portable Walkway
System. The GAITRite Portable Walkway System was used to collect and record the gait
data. The GAITRite contains six sensor pads encapsulated in a roll up carpet to produce
an active area of 24 inches (61cm) wide and 144 inches (366cm) long. In this
arrangement the active area is a grid, 48 sensors by 288 sensors placed on .5 inch
(1.27cm) canters, totaling 13824 sensors. The walkway is laid over a flat surface,
requires minimal test time, and no placement of any device on the participant. The
GAITRite software program was used to measure the data collected by the Walkway
System. The program automates measuring temporal (timing) and spatial (distance) gait
parameters via the electronic walkway connected to the serial port of a Windows®
95/98/ME personal computer. As the participant ambulates across the walkway, the
system captures the geometry and the relative arrangement of each footfall as a function
5
of time, space, and pressure. The application software processed the raw data into
footfall patterns and computed the temporal (timing) and spatial (distance) parameters.
The software’s relational database stored tests individually under each participant, and
supports a variety of reports and analysis. Microsoft Excel and SPSS software programs
were used to perform statistical analysis on the measurements taken from the GAITRite
software program (CIR Systems Inc., 1996).
Other materials used included a video recorder, audio-link system, and measuring
tape. A Sony Video Recorder was used to document each trial for each participant. A
Radio Shack 9000MHz Multi-Channel Wireless Audio-Link System was used to record
speech during trials. Measurements were taken of both legs on each participant using
standard measuring tape from the greater trochanter (upper leg) to the lateral malleolus
(ankle), as required by the GAITRite program.
Procedures
Prior to the experimental procedure, all participants completed a brief medical
history questionnaire to ensure inclusion criteria then read and signed a consent form
approved by the FSU Institutional Review Board. A research design strategy was used in
which a baseline or control condition was taken first, followed by conditions of low
cognitive-linguistic load (independent variable A) and high cognitive-linguistic load
(independent variable B) which were counter balanced to prevent order effect. Two trials
of each condition were administered to account for learning effect. First, a baseline
control condition of a gait trial without speech was administered. The examiner
instructed the participant to stand behind the line (approx. 2 ft. before the mat) and walk
across the mat to an end point (approx. 2 ft. after the mat.) Next, the participants were
asked to repeat the same walk, but to do so while counting by ones (low cognitivelinguistic load.) After the two low cognitive-linguistic trials were completed, the
participant was asked to repeat the same walk but this time recite an alpha-numeric
sequence while walking (high cognitive-linguistic load.) The participant was given an
example of an alpha-numeric sequence (e.g. B5-C6-D7-E8-F9-G10). The participant was
told to do their best at reciting the correct alpha-numeric sequence while completing the
walk. Participants immediately began the trial after instruction to prevent rehearsal of the
task. The entire procedure took no longer than 10 minutes.
6
The gait temporal parameters recorded included Ambulation Time, Velocity,
Swing Time (Left), Swing Time (Right), Double Support Time (seconds) Left, Double
Support Time (Right), and Step Time Differential. Spatial parameters included Step
Length (Left), Step Length (Right), Step Length Differential, and Functional Ambulation
Profile (FAP). The following section defines these parameters of gait:
•
Ambulation time is the time elapsed between contact of the first and last footfalls.
•
Velocity is obtained by dividing the Distance Traveled by Ambulation Time.
•
Swing Time is the time elapsed between the last contact of the current footfall to
the first contact of the next footfall on the same foot.
•
Double Support Time is the time elapsed between the first contact of the current
footfall and the last contact of the previous footfall, added to the time elapsed
between the last contact of the current footfall and first contact of the next
footfall.
•
Step Time Differential is the degree of difference between time elapsed from the
first contact of one foot and the first contact of the second foot.
•
Step Length is the measurement along the line of progression, from the heel
center of the current footprint to the heel center of the previous footprint on the
opposite foot.
•
Step Length Differential is the degree of difference between measurements of
Step Length (Left) and Step Length (Right).
•
Functional Ambulation Profile (FAP) is the ratio of step length to leg length to
step time. This composite score is derived from a formula that includes several
critical gait parameters that is highly related to fall risk (CIR Systems Inc., 1996).
•
All temporal parameters were measured in seconds and all spatial parameters
were measured in centimeters.
These variables were measured and recorded using the GAITRite System and software to
determine frequencies for each parameter across trials.
The demographic variable of age was also recorded and used for subsequent
analysis. Gait variables and age were transformed to spread sheets that allowed the SPSS
software program to perform descriptive, and correlation analyses.
7
CHAPTER 3
Results
The results of this study will be displayed in a series of tables and graphs.
Demographic Data
The range, mean, and standard deviation of age and number of years of college
education for all participants are summarized in Table 1.
Table 1
Demographic Variables for 20 Participants (10 males, 10 females)
Age
Range
Mean
Standard Deviation
61-84
71.8
6.5
Post Secondary Education
0-12
6.0
3.5
Gait Measurement
Descriptive Statistics across 10 Gait Variables
The mean and standard deviation of 10 gait variables across conditions are
summarized in Table 2. Participants increased ambulation time (sec) during baseline (M
3.2; SD .79), low load (M 3.3; SD 1.2), and high load (M 5.16; SD 5.2). Participants
showed an increase in swing time (sec) left and right from baseline (M .41; SD left .04
right .03), low load (M .43; SD left .54 right .09), to high load (M .56; SD’s .24).
Participants increased in double support time (sec) left and right from baseline (M left
.33; M right .34; SDs .07), to low load (M .35; SD left .08; SD right .09) and high load
(M left .57; M right .58; SD left .42; SD right .39). The mean measures for these
variables are shown in Figure 1.
8
Participants displayed decreased velocity (cm/sec) as load increased from baseline
(M 114.3; SD 21.2), low load (M 112.5; SD 24.6), to high load (M 83.4; SD 31.7).
Participants showed changes in step length (cm) left and right with baseline (M left 65.6;
M right 64.2; SD left 8.79; SD right 9.6), low load (M left 66.0; M right 65.5; SD left 8.5;
SD right 8.3), and high load (M 59.8; SDs 9.1). The mean measures for these variables
are visually displayed in Figure 2.
Table 2
Descriptive Statistics for 10 Variables Across Three Cognitive Conditions for 20
Participants with Trials 1 & 2 Averaged
Baseline
Low Cognitive Load High Cognitive Load
Mean SD
Mean
SD
Mean
SD
Ambulation Time (sec)
3.2
.79
3.3
1.2
5.16
5.2
Velocity (cm/sec)
114.3 21.2 112.5
24.6
83.4
31.7
Step Length L (cm)
65.6
8.79 66.0
8.5
59.8
9.1
Step Length R (cm)
64.2
9.6
65.5
8.3
*59.8
*9.1
Swing Time L (sec)
.41
.04
.43
.54
.56
.24
Swing Time R (sec)
.41
.03
.43
.09
*.56
*.24
Double
.33
.07
.35
.08
.57
.42
Support Time L (sec)
Double Support Time R .34
.07
.35
.09
.58
.39
(sec)
Step Time Differential
.02
.03
.02
.02
.10
.19
Step Length Differential 2.7
2.6
2.0
1.7
2.6
2.2
*Data were suspect or missing for mean and standard deviation from Step Length (R) and
Swing Time (L). These missing cells were extrapolated from the data derived from Step
Length (L) and Swing Time (R).
9
Mean Measures of 6 Temporal Gait Variables Across Cognitive
Conditions for 20 Participants with Trials 1 & 2 Averaged
6
5.16
Baseline
5
Low
High
4
Mean
3
(sec)
3.3
3.2
2
0.56
0.58
0.57
0.43
0.43
0.35
0.56
0.41
0.35
0.1
0.41
0.33
0.34
0.02 0.02
1
0
Amb.
Time
Swing
Time L
Swing
Time R
D. Supp.
Time L
D. Supp.
Time R
S/T Diff.
Figure 1
Mean measure of 6 temporal gait variables across cognitive conditions for 20 participants
with trials 1 & 2 averaged.
10
Mean Measures of 3 Spatial Gait Variables Across Cognitive Conditions for 20
Participants with Trials 1 & 2 Averaged
120
114.3 112.5
Baseline
Low
High
100
83.4
80
65.6 66
Mean
(cm)
59.8
64.2
65.5
59.8
60
40
20
0
Velocity
Step Length L
Step Length R
Figure 2
Mean measured of 3 spatial gait variables across cognitive condition for 20 participants
with trials 1 & 2 averaged.
Functional Ambulation Profile (FAP)
Descriptive statistics to examine the distribution characteristics of the FAP across
conditions were conducted using SPSS-13 software. The effect of low and high cognitive
load on FAP when compared with baseline performance can be seen in Table 3. The
normal range of FAP measurement for the gait variables incorporated into the FAP
formula is from 95-100. This normative range assumes gait measurements that involve
walking only at a normal pace, without any concurrent dual cognitive or linguistic task.
During conditions of cognitive-linguistic loading, participants were outside this normal
range under low cognitive load (M 94.2; SD 9.7) with a greater effect observed under
conditions of high cognitive load (M 80.7; SD 18.7).
11
Table 3
Comparison of Functional Ambulation Profile (FAP) Scored for Baseline, Low, and High
Cognitive Loads for 20 Participants
Subjects
Baseline
FAP (Mean of 2
Trials) Under
Low Load
FAP (Mean of 2
Trials) Under
High Load
100
20
20
85-100
56-100
95.5
94.2
Standard
Deviation
5.2
9.7
20
50-99.5
80.7
18.7
95.5
Range
94.2
Baseline
Low
High
95
90
FAP
85
Mean
80.7
80
75
70
Cognitive Linguistic Load
Figure 3 Functional Ambulation Profile (FAP) for Baseline, Low, and High
Cognitive Load for 20 Participants Mean of 2 trials
12
Correlation Analyses
To determine if age was a predictive factor for performance, Pearson correlation
coefficients were calculated for age and FAP scores across the baseline, low load, and
high load conditions. The results of these analyses can be seen in table 4.
Comparison of Age and Functional Ambulation Profile (FAP) Scores Across Conditions
Age was shown to have no effect on the value of FAP score during the low
cognitive load condition. During the high cognitive load condition, age had only slight
effect on the FAP score. This slight correlation between age and FAP performance
during the high cognitive load condition was expectedly negative, that is, the higher the
age, the lower the FAP score during high cognitive load.
Table 4
Pearson “r” values comparing FAP and Age with Trials 1 and 2 averaged.
Low Load FAP
AGE
-.08*
*Pearson “r” value statistically significant at < .05
13
High Load FAP
-.45*
CHAPTER 4
Discussion
Twenty healthy elderly adults were asked to walk while completing a low
cognitive-linguistic task and a high cognitive-linguistic task. The experiment was
conducted to assess changes that might occur in gait under different cognitive-linguistic
loads. Results indicated that cognitive- linguistic load affects gait in several ways.
Participants showed a slight alteration of gait performance when required to
simultaneously perform low cognitive-linguistic tasks. During high cognitive-linguistic
tasks that were heavily loaded with working memory demands, however, greater
alterations in gait performance were measured.
During simultaneous high cognitive
load performance and walking along the gait pad measurement device, participants
changed several measurable spatial/temporal parameters of gait. The parameters of gait
that were most altered included:
•
Ambulation Time
•
Velocity
•
Step Length
•
Swing Time
•
Double Support Time
•
Step Time Differential
•
Step Length Differential
Also, one of the prime questions of this study was to calculate the Functional
Ambulation Profile (FAP) for each participant. FAP has been shown to be a valid
indicator of risk for injurious falls and in order to determine fall risk (by FAP scores) of
clinical populations in the future, we attempted to determine if the FAP score changed
under cognitive-linguistic load conditions in non-neurologically damaged healthy elderly
adults. FAP was indeed altered by changes in load condition. High cognitive-linguistic
load (reciting alpha-numeric sequences simultaneously during walking) resulted in
marked reductions in FAP and inferentially, increased the risk for falls. This information
will be invaluable as we explore further the impact that dual task inference, competition,
and distraction has on parameters of gait and balance.
14
Theoretical Implications
Contrary to the findings of previous research by Springer et al. (2006) that
suggested dual tasking does not affect gait variability of elderly non-fallers, our results
indicate that low cognitive load may not influence gait, but high cognitive load,
particularly a task that has high working memory demand, places individuals at greater
risk for falls. One explanation to explain our findings lies in cognitive resource
allocation theory (Kahneman, 1973). It is possible that participants vary in their ability to
perform simultaneous tasks and perhaps participants declined in gait performance
because of an increased effort or attention to the cognitive-linguistic tasks with
subsequent relative neglect of the demands of the usually automatically processed act of
walking. An increase in effort in performing one task (gait and speech) may have caused
a decrease performance of another concomitant task (gait). The required demands of this
study perhaps resulted in a change in the automatic versus controlled cognitive
processing ratio that usually occurs during low load or single task walking.
The age of the participants was shown to have only a slight relationship and
relevance as to how gait was executed. Increasing the age of a participant only slightly
predicted a change in gait performance. We may not have had a wide enough range of
age or adequate numbers of participants across various ages to produce and age-gait
correlation under the conditions of the study, but for this sample, age does not appear to
be predictive of gait performance. These finding were consistent with previous research
conducted by Springer et al. (2006) who found no evidence to support the existence of an
age-related increase in dual-task effect on gait variability.
The data collected in this study produced preliminary normative data in healthy
elderly gait functioning under different circumstances. Several changes occurred in gait
performance primarily along the parameters of velocity, step length, and swing time and
Functional Ambulation Profile (FAP) during different cognitive-speech tasks. These
changes suggest decreased gait performance when comparing low-cognitive linguistic
tasks with high cognitive-linguistic tasks. The changes in gait variables under demanding
cognitive-linguistic tasks may be indicative of the acquisition of a more cautious gait
resulting in slower speed and shorter stride length. The result is consistent with previous
research done by Steffen, Hacker, and Mollinger (2002) that concluded a more cautious
15
walking style was characterized by shorter step length and slower step velocities.
However, these data alone are not conclusive enough to provide definitive information
regarding fall risk.
The findings presented highlight the importance of reducing distractions and
competitive tasks for elderly adults during highly coordinated and automatized tasks such
as walking. These results can be applied to other settings where distraction during
physical tasks are apparent and may increase risk of injury, such as in physical therapy.
Previous research (Stierwalt, et al, 2006) has implicated increased gait and balance
alteration and perhaps on increased risk for falls in participants with Parkinson disease.
Now we have normative data on a gait measure (FAP) that has been associated with
increased fall risk using paradigms of research that can be extended in Parkinson disease
and across neurologically-impaired clinical populations. It may be necessary for
individuals who interact with the elderly population or with those who have neurogenic
disorders to reduce or exclude topics and questioning that require in-depth cognitive
processing to respond. Furthermore, it may be speculated that the practice of conducting
speech therapy simultaneously with physical therapy may result in reduction in
ambulatory coordination. More studies are necessary to determine the specific speech
functions and cognitive-linguistic tasks that influence coordinated physical movements.
Future Research
The principles of this study, alteration of performance under conditions of
simultaneous task performance, can be extended to a variety of skilled motor behaviors as
well as to further defining the hierarchy of cognitive-linguistic tasks that may prove
detrimental to balance, gait, and general aspects of safety.
It may be of interest to examine different forms of distraction that encompass a
more descriptive analysis of speech. Further research is warranted to understand what
cognitive processing may cause obvious reactions in physical movement such as
cessation of gait or directly causing falls. Future studies will no doubt require a larger
number of participants in order to provide an appropriate external validity and
generalization of performance of the elderly population and neurologically disordered
populations. The risk of injurious falls among the healthy elderly and non-healthy
populations continues to be a challenging issue. Shedding further light on this crucial
16
issue especially regarding factors that cause and remediate fall risk remains an important
set of question for researchers in the future.
17
APPENDIX A
Intake Information
Neuro-Cognition & Neuro-
Gait and Cognitive-
Linguistic Laboratory at TMH
Linguistic Distraction
Florida State University
Summer-2006
LaPointe, Stierwalt, Heald, Cicchitto
Name: __________________________
Subject Code: ____________________
Date of Birth: ____________________
Gender: M F
Handedness: L
Height: ______
R
Weight:_____
Medical Diagnosis (es): ___________________________________________________
Do you currently have or have you ever been diagnosed with any of the following:
Speech problems:
Yes
No
Tx: ______________________________________________________________
Respiratory problems:
Yes
No
Tx: ______________________________________________________________
Special Diet:
Yes
No
Tx: ______________________________________________________________
Neurologic Trauma:
Yes
No
Tx: ______________________________________________________________
Neurologic Disease:
Yes
No
Tx: ______________________________________________________________
Neurologic insult (vascular): Yes
No
Tx: ______________________________________________________________
Gait Mechanics Trauma:
Yes
No
Tx: ______________________________________________________________
Balance Problems:
Yes
No
Tx:
_____________________________________________________________
18
APPENDIX B
Subject Directions for High Cognitive Linguistic load – Letter Number Sequencing
Please repeat the same walk you just performed, but this time recite a letter-number
sequence while walking. Here is an example of what I would like you to say:
B
5
C
6
D
7
E
8
F
9
G
10
Do your best to recite the correct letter-number sequence while walking from the
doorway to the window. Continue the sequence that starts with (
). Ready? (allow
limited time to pass between revealing sequence and commencing walk) Go.
19
APPENDIX C
Load Counterbalancing Form
Subject 1
Gait Session
Subject: _____ Date: _____
Low:
10
20
30
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
26
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
26
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
31
32
33
34
35
26
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
5
C
6
D
7
E
8
F
9
G
10
H
11
I
12
J
13
K
14
L
15
M
7
E
8
F
9
G
10
H
11
I
12
J
13
K
14
L
15
M
16
N
17
0
9
G
10
H
11
I
12
J
13
K
14
L
15
M
16
N
17
O
18
P
19
High:
B
D
18
F
20
Subject 2
Gait Session
Subject: _____ Date: _____
High:
G
10
H
11
I
12
J
13
K
14
L
15
M
16
N
17
0
18
P
19
Q
20
R
11
I
12
J
13
K
14
L
15
M
16
N
17
0
18
P
19
Q
20
R
21
S
12
J
13
K
14
L
15
M
16
0
18
P
19
Q
20
R
21
S
22
T
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
26
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
26
27
28
29
30
31
32
33
34
35
26
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
26
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
21
H
22
I
N
17
23
Low
15
25
35
21
APPENDIX D
INFORMED CONSENT FORM FOR LEGAL GUARDIANS
Date: _______________
I, _________________________________, freely and voluntarily and without element of
force or coercion, consent for _____________________________________ to
participate in the research project entitled, “The Effects of Linguistic Load on Posture,
Balance, and Gait in Individuals with Neurological Impairment” conducted by Dr. Julie
Stierwalt, Dr. Leonard LaPointe, Dr. Gerald Maitland, & Dr. Tonya Toole, all of whom
hold faculty positions at Florida State University. I understand that the purpose of this
research project is to investigate the effects of different speaking tasks while standing and
walking.
I understand that if I agree to participate in the project I will be asked to partake in
a single data collection session that will last approximately 90 minutes. During the
session the following procedures will be completed, clinical checklists that examine
physical and motor performance, a test that examines cognitive ability, a depression
questionnaire, and several brief balance and walking tasks (6-8 total). One of
investigators or a research assistant will be readily available to answer any questions that
I have about my participation or the study in general.
I understand that my participation is totally voluntary and that I may stop my
participation at any time without prejudice, penalty, or loss of benefits to which I might
otherwise be entitled. I understand that I will receive no financial compensation for
participating in this research. However, the knowledge gained from this study may be of
value to persons
I understand that any information obtained during this study regarding my
performance or anything that could identify me will be kept confidential to the extent
allowed by law. The only exception to this statement is if suicidal tendencies are
identified in the course of the study (Beck Depression Inventory), in which case an
22
immediate referral will follow to the appropriate agency to ensure the safety of the
participant. No other information would be released. The information obtained in this
study may be published in professional journals or presented at professional meetings,
but my name will not be used. I understand that I may be videotaped by the
investigators. These tapes will be kept in a locked cabinet along with the other data
sheets obtained in this study. Only the aforementioned investigators and research
assistants will have access to the data. All material gathered in this investigation will be
destroyed after publication of the study results or within 5 years of the end of the study.
I understand that there is minimal risk involved if I agree to participate in this
study. However, I also understand that every effort will be made to minimize the risk
(safety harness, a gait belt, and a spotter to monitor my balance) and ensure that I am safe
and comfortable during my participation.
I have been given the right to ask and answer any questions regarding the study.
Any questions have been answered to my satisfaction. I understand that I may contact
Dr. Stierwalt at the Department of Communication Disorders (644-2238), Florida State
University or a representative from the Human Subjects Committee (644-8633) for
answers to questions about this research or my rights. Group results will be sent to me at
my request. I certify that I have read the preceding or that it has been read to me and that
I understand its contents. My signature below means that I have freely consented to
participation in this experimental study.
______________________________________
__________________________
Legal Guardian
Date
23
REFERNCES
Alarming Increase In Falls by Elderly Prompts National Educational Campaign. (2005,
February 14). Retrieved April 12, 2006, from www.seniorjournal.com
/NEWS/Eldercare/5-2-14ElderlyFalls.htm.
CIR Systems, Inc. (1996). GAITRite: The World Leader in Temporospatial Gait
Analysis. Retrieved October 20, 2006, from http://gaitrite.com/downloads/index.html
Fuller, G.F. (2002). Falls in the elderly. American Family Physician, (61)7, 2159-2168.
Gruber, O., Indefrey, P., Steinmetz, H., Kleinschmidt, A. (2001) Dissociating neural
correlates of cognitive components in mental calculation. Cerebral Cortex, 11(4),
350-359.
Karst, G.M., Hageman, P.A., Jones, T.F., and Bunner, S.H. (1999). Reliability of foot
trajectory measures within and between testing sessions. Journal of Gerontology:
Medical Sciences, 54(A), M343-M347.
Mills, P.M. & Barret, R.S. (2001) Swing phase mechanics of healthy young elderly
men. Human Movement Science, 20(4-5), 427-466.
Rosengreen, K.S., McAuley, E., & Mihalko, S.L. (1998) Gait adjustment in older adults:
Activity and efficacy influences. Psychology and Ageing 13(3), 375-386.
Springer, S., Giladi, N., Peretz, C., Yogev, G., Simon, E.S., Hausdorff, J.M. (2006).
Dual-tasking effects on gait variability: The role of aging, falls, and executive
function. Movement Disorders, 6(4), 110-118.
Steffen, T.M., Hacker, T.A., Mollinger, L. (2002). Age- and gender-related test
performance in community-dwelling elderly people: Six-Minute Walk Test, Berg
Balance Scale, Timed Up & Go Test, and gait speeds. Physical Therapy, 2(82),
128-137.
Stierwalt, JAG, LaPointe, LL, Maitland, CG, Toole, T, Wilson, K. (2006). The Effects of
Cognitive/linguistic Load on Gait in Individuals with Parkinson’s Disease. World
Parkinson Congress, Washington, DC, Feb
Whelan, B.B., Murdoch, B.E., Theodoros, D.G., Silburn, P.A., & Hall, B. (2005).
Borrowing from models of motor control to translate cognitive processes:
24
Evidence for hypokinetic-hyperkinetic homologues? Journal of Neurolinguistics,
18(5), 361-381.
Winter, D.A. (1983). Biomechanical motor patterns in normal walking. Journal of Motor
Behavior, 15, 302-330.
Winter, D.A. (1991). Biomechanics and motor control of human gait: normal, elderly,
and pathological (2nd ed.) University of Waterloo Press, Waterloo, ON.
25
BIOGRAPHICAL SKETCH
Derek Cicchitto was born in Boynton Beach, Florida on October 29th, 1981. His
collegiate education began at Tallahassee Community College, where he received his
Associate of Arts Degree. Derek completed his undergraduate studies at Florida State
University earning a Bachelors of Science in Communication Disorders. He is currently
pursuing higher education and will receive a Masters Degree from FSU during the
summer of 2007.
26