Vol.1, No.2, 17-21 (2013) Open Journal of Therapy and Rehabilitation
http://dx.doi.org/10.4236/ojtr.2013.12004
The effects of functional electrically stimulated
(FES)-arm ergometry on upper limb function and
resting cardiovascular outcomes in individuals
with tetraplegia: A pilot study
Jennifer Ptasinski, Hisham Sharif, David Ditor*
Department of Kinesiology, Brock University, St. Catharines, Canada; *Corresponding Author: dditor@brocku.ca
Received 10 September 2013; revised 12 October 2013; accepted 19 October 2013
Copyright © 2013 Jennifer Ptasinski et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
Background: Functional electrically stimulated
(FES)-arm ergometry has been shown to in-
crease peak power output and aerobic capacity
in individuals with cervical SCI. However, the
functional benefits remain unknown. Objective:
To determine the effects of FES-arm ergometry
on exercise performance, upper limb function
and resting cardiovascular function in individu-
als with tetraplegia. Methods: Five individuals
(43.8 ± 15.4 years old) with SCI (C3-C5, AIS C-D,
14.0 ± 1 1.1 years post-injury) completed 12 weeks
FES-arm ergometry. Exercise performance (time
and distance to fatigue), perceived upper limb
function [Capabilities of Upper Extremity Ques-
tionnaire (CUE), short form-Quadriplegia Index
of Function Questionnaire (sf-QIF) and Spinal
Cord Injury Spast icit y Ev a lu a t io n To o l ( SC I - SE T )]
and resting mean arterial pressure (MAP) and
heart rate (HR) were measured pre and post.
Results: Following training, MAP significantly
decreased (91.1 ± 14.0 to 87.7 ± 14.7 mmHg; p =
0.04), and there was a trend for an increased
time to fatigue (804.6 ± 359.4 to 1483.8 ± 1110.2
sec; p = 0.08), distance to fatigue (3508.4 ±
3524.5 to 7412.6 ± 7773.1 m, p = 0.08) and the
CUE scores pertaining to hand function (31.6 ±
12.8 to 38.0 ± 17.7; p = 0.07). Conclusion: Twel ve-
week FES-arm ergometry was associated with
decreased resting MAP in individuals with tetra-
plegia, and may show promise as a means to
increase exercise performance and hand func-
tion. Further research is required to verify these
preliminary findings.
Keywords: Exercise; Spinal Cord Injury; Exercise
Performance; Arm Function; Blood Pressure
1. INTRODUCTION
For individuals with cervical SCI, reductions in hand
and upper limb function can be particularly debilitating.
In a study conducted by Anderson, 681 individuals with
SCI were surveyed, and for those with tetraplegia, the
return of arm and hand function was ranked as the
highest therapeutic priority [1]. This is understandable as
recovery of even partial hand and arm function could po-
tentially have a great impact on independence. Anderson
also found that 96.5% of individuals with a SCI consi-
dered exercise to be important for functional recovery,
however, only 56.9% had access to exercise, and only
12.2% had access to a trained therapist. These findings
demonstrate a need for therapies which are targeted at
upper limb and hand musculature, and have the potential
to improve function and independence.
Manual arm ergometry has been shown to result in
physical improvements in individuals with SCI [2]. Un-
fortunately, the potential benefits attained from this form
of exercise are limited to those with at least partial upper
limb mobility. However, functional electrically stimula-
ted (FES) exercise is a therapeutic option for individuals
with SCI and FES-arm ergometry which has recently
become available. This form of exercise involves
electrical stimulation of the upper limb musculature,
which is in such a sequence as to cause a fluid arm-
cycling motion. A recent study found that 12 weeks of
thrice-weekly progressive FES-arm ergometry resulted in
increased peak power output and peak aerobic capacity
in individuals with cervical SCI [3]. Although these
results are very encouraging, the functional benefits of
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J. Ptasinski et al. / Open Journal of Therapy and Rehabilitation 1 (2013) 17-21
18
FES-arm ergometry have yet to be fully determined.
Therefore, the purpose of the present study was to
investigate the effects of a 12-week, thrice-weekly, FES-
arm ergometry program on exercise performance, upper
limb function and resting cardiovascular outcomes in
individuals with chronic incomplete tetraplegia. We hy-
pothesized that 12 weeks of FES-arm ergometry would
improve participants’ exercise performance, upper limb
function and resting cardiovascular measures.
2. MATERIALS AND METHODS
2.1. Participants
Five individuals (4 male, 1 female; 43.8 ± 15.4 years
old) with chronic, incomplete SCI (C3-C5, AIS C-D,
14.0 ± 11.1 years post-injury) were recruited to partici-
pate in this study. Participant characteristics are detailed
in Table 1. All participants received medical approval
before enrolment into the study, and no participant had
undertaken FES-exercise training, or any other structured
exercise training, in the three months prior to the study.
Individuals were excluded from the study if they had do-
cumented cardiovascular disease, a tracheostomy, uncon-
trolled autonomic dysreflexia, or any other medical con-
dition contraindicating exercise. Participants were not re-
quired to discontinue their medications during the testing
or training sessions, and no participants made any change
in their medications during the course of training. This
study was approved by the Research Ethics Board of
Brock University and all participants provided informed
and signed consent before participating. All procedures
conformed with The Code Ethics of the World Medical
Association (Declaration of Helsinki) of July 1964.
2.2. Intervention
FES-arm ergometry was completed on the RT300 er-
gometer (Restorative Therapies; Baltimore, MD), with
surface electrodes (2 × 3.5 inch; PALS Platinum) being
placed on the biceps, triceps, medial deltoids, and supra-
spinatus muscles. For participants with inadequate grip
strength, tensor bandages were used to secure the hands
Table 1. Participant characteristics.
Participant Age Sex Level of Injury AIS Years Post Injury
1 26 Male C4 C 7
2 46 Male C5 C 20
3 30 Male C5 C 11
4 58 Female C3 D 30
5 59 Male C3 C 2
AIS: ASIA impairment scale, ASIA denotes American Spinal Injury Asso-
ciation.
to the grips of the RT300. The training protocol included
12 weeks of FES-arm cycling, at a frequency of three
sessions per week, with a minimum of 30 minutes and a
maximum of 45 minutes of active exercise per session.
There was 48 hours of rest between exercise sessions
whenever possible. The RT300 includes a motor that can
be used to assist the pedaling motion or provide resis-
tance as participants progress over time. Each exercise
session began with a two minute passive, motor-driven
warm up, followed by 30 - 45 minutes of active FES-arm
ergometry, and was completed with a two minute passive,
motor-driven cool down. The stimulation pulse width
was set at 250 µs, and the stimulation frequency was set
at 50 Hz for the biceps and triceps electrodes, and 25 Hz
for the deltoid and supraspinatus electrodes. The stimula-
tion current amplitude was adjustable between 0 to 140
mA, however, for the present study the current was set,
as individually tolerated by comfort, between 15 and 50
mA.
The exercise sessions were progressed as individually
tolerated by increasing the duration of exercise, followed
by increasing the resistance provided by the motor of the
arm ergometer. Specifically, each exercise session was to
include at least 30 minutes of active exercise, and no
more than 45 minutes of exercise. If the upper limbs fa-
tigued before 30 minutes, then a 5 minute rest period was
allowed and a subsequent bout would be performed. This
would continue until at least 30 minutes of exercise had
been accomplished. When a participant was able to per-
form two consecutive sessions of 30 minutes continuo-
usly, the resistance would be increased by one unit as
indicated on the RT300. The RT300 stimulates the mus-
cles such that a target cadence of 50 revolutions per mi-
nute is maintained, and fatigue was determined automa-
tically by the RT300 when, despite maximal stimulation,
the cadence of pedaling dropped below 35 revolutions
per minute for 2 seconds. Although no maximum ca-
dence was set, the revolutions per minute did not exceed
55.
A maximum of five bouts per session were allotted to
complete the 30 - 45 minutes of exercise per session.
Participants had to maintain an exercise adherence of at
least 75% for their data to be included in the analysis.
2.3. Outcome Measures
Exercise performance measures were collected via an
exercise to fatigue test. This test was conducted at base-
line and again following the completion of the 12-week
training program (48 hours following the final training
session), and the resistance used for each individual was
held constant for each test. These measures of perform-
ance included time to fatigue and distance to fatigue.
Functional outcomes included self-reported measures
of upper extremity function and independence as deter-
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J. Ptasinski et al. / Open Journal of Therapy and Rehabilitation 1 (2013) 17-21 19
mined by the Capabilities of Upper Extremity Question-
naire (CUE) [4], and the short form of the Quadriplegia
Index of Function Questionnaire (sf-QIF) [5]. The CUE
is a 32-item questionnaire that evaluates how well an
individual can perform movements with his or her arms
and hands. The left and right limbs are scored separately
on a seven point scale with 1 = totally limited and 7 = not
at all limited. The sf-QIF is a 6-item questionnaire that
evaluates an individual’s level of independence when
performing activities of daily living that require upper
limb function. Items are rated on a 5-point scale with 0 =
dependent and 4 = independent.
Self-reported muscle spasticity was determined by the
Spinal Cord Injury Spasticity Evaluation Tool (SCI-SET)
[6]. This 35-item, 7-day recall questionnaire does not
evaluate the amount of spasticity per se, but rather, it
evaluates how spasticity affects (either positively or ne-
gatively), certain activities of daily living. The SCI-SET
questionnaire employs a 7-point scale with 3 = extre-
mely problematic, 0 = no effect, and 3 = extremely help-
ful. All functional outcome measures were made at base-
line and following the 12-week exercise training pro-
gram.
Resting mean arterial blood pressure (MAP) and heart
rate (HR) were conducted at baseline and following
twelve weeks of FES-arm ergometry exercise (48 hours
following the final training session). Resting cardiova-
scular measures were conducted in the supine position
following 10 minutes of rest in a dark, quiet room. MAP
and HR were determined via an automated cuff placed
over the left brachial artery, and measures were taken
twice per test and averaged to determine the true resting
value.
2.4. Statistical Analysis
All statistical analyses were conducted with the Statis-
tica software program. Due to the relatively small sample
size and high amount of baseline variability between par-
ticipants, outcome measures were compared pre and
post-testing with non-parametric statistical analysis. Spe-
cifically, the Wilcoxon test was used to compare means
at pre and post-testing. Effect size (ES) calculations were
also conducted on all outcome measures for the baseline
and 12-week values. Statistical significance was set at p
< 0.05, and all values are expressed as mean ± standard
deviation (SD).
3. RESULTS
Participants completed the 12-week exercise training
program, without any adverse events or exercise-induced
injury. The average adherence rate was 85%, with
adherence being defined as the percentage of scheduled
sessions attended and completed.
3.1. Exercise Performance
Following the 12-week exercise program, there were
no significant changes in exercise performance, however,
there were trends towards improvement in both time to
fatigue (804.6 ± 359.4 to 1483.8 ± 1110.2 sec; p = 0.08;
ES = 1.14) and distance to fatigue (3508.4 ± 3524.5 to
7412.6 ± 7773.1 m, p = 0.08; ES = 1.24) during the ex-
ercise performance test (Table 2).
3.2. Functional Outcomes
Following the 12-week exercise program, there was no
significant change in the composite score for the CUE
(Table 3). Likewise, when considering the subscales of
the CUE, there was no significant change in shoulder,
biceps, wrist extensor, triceps, or trunk function (Table
3). However, there was a trend towards an increase in the
CUE subscale pertaining to hand function following the
12-week exercise program (Table 3). There was no sig-
nificant change in upper limb function as determined by
the sf-QIF, or the SCI-SET, following the training pro-
gram (Table 3).
Table 2. Measures of exercise performance before and after 12
weeks of FES-arm ergometry.
Pre Post p-value ES
Time to
fatigue (sec)804.6 ± 359.4 1483.8 ± 1110.2 0.08 1.14
Distance to
fatigue (m)3508.4 ± 3524.57412.6 ± 7773.1 0.08 1.24
ES: Effect Size.
Ta bl e 3 . Measures of upper limb function before and after 12
weeks of FES-arm ergometry.
Scale Pre Post p-value ES
CUE (Composite )119.6 ± 49.4 127.6 ± 54.2 0.58 0.31
CUE (Subsets)
Shoulders 20.4 ± 11.122.2 ± 9.6 0.67 0.25
Biceps 21.0 ± 8.218.8 ± 8.1 0.35 0.48
Wrist Extensors19.2 ± 9.718.4 ± 9.5 0.78 0.21
Triceps 23.8 ± 10.123.0 ± 9.9 0.58 0.26
Hands 31.6 ± 12.838.0 ± 17.7 0.07 1.16
Trunk 5.2 ± 3.6 6.4 ± 5.0 0.18 1.01
sf-QIF 7.8 ± 9.8 9.2 ± 11.0 0.2 0.72
SCI-SET 122.6 ± 14.9 129.8 ± 9.2 0.23 0.72
CUE: Capabilities of Upper Extremity Questionnaire; sf-QIF: short form-
Quadriplegia Index of Function Questionnaire; SCI-SET: Spinal Cord Injury
Spasticity Evaluation Tool; ES: Effect Size.
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J. Ptasinski et al. / Open Journal of Therapy and Rehabilitation 1 (2013) 17-21
20
3.3. Cardiovascular Outcomes
There was a statistically significant decrease in resting
MAP following the 12-week FES-arm ergometry pro-
gram (91.1 ± 14.0 to 87.7 ± 14.7 mmHg; p = 0.04; ES =
1.63), but there was no change in resting HR (66.8 ± 7.9
to 70.0 ± 10.1 beats/min; p = 0.14; ES = 1.06) (Table 4).
4. DISCUSSION
The current pilot study was preliminary in nature, and
thus the results should be interpreted with caution. Still,
the main finding of the current study was that individuals
with incomplete tetraplegia may experience decreases in
resting MAP following 12 weeks of FES-arm ergometry,
and although only trends were detected, this form of the-
rapy may also show promise for improving exercise per-
formance and self-reported hand function. Improvements
in exercise performance and hand function would have
obvious practical benefit. However, whether or not the
observed cardiovascular effects are clinically significant
is questionable. Individuals with SCI do experience
higher rates of cardiovascular disease, however, our par-
ticipants were normotensive both before and after the
training program and the magnitude of the reduction in
MAP was not profound. Still, this finding does hold pro-
mise for cardiovascular improvement following FES-arm
exercise and research in hypertensive participants with
SCI is warranted.
4.1. Exercise Performance
As mentioned, there were no significant changes in
exercise performance in the present study, although there
were trends for an increased time and distance to fatigue.
In related work, Coupaud and colleagues conducted a
pilot study investigating the effects of FES-arm ergome-
try on two individuals with tetraplegia [3]. In that pilot
work, the authors found variable results on exercise per-
formance that seemed to depend on functional ability.
Specifically, their more able participant (C6, AIS B, 18
years post-injury) showed increases in peak oxygen
uptake (0.7 to 1.1 L/min) and peak power output (7 to 38
Watts) following 12 weeks of progressive FES-arm ergo-
metry, while their less able participant (C6, AIS A, 8
months post-injury) made no improvement in peak oxy-
gen uptake and a smaller increase in peak power output
Table 4. Cardiovascular outcomes before and after 12 weeks of
FES-arm ergometry.
Pre Post p-value ES
MAP (mmHg) 91.1 ± 14.0 87.7 ± 14.7 0.04 1.63
HR (beats/min) 66.8 ± 7.9 70.0 ± 10.1 0.14 1.06
ES: Effect Size; HR: Heart Rate; MAP: Mean Arterial Pressure.
(3 to 8 Watts). The present study lacked the statistical
power to formally assess correlations between baseline
function and exercise-induced improvement. However,
anecdotally, our two most able participants did experi-
ence large improvements in exercise performance (289%
and 87% in time to fatigue; 336% and 78% in distance to
fatigue), while the others made little to no change. Fur-
ther research with larger samples is required to determine
the relationship between baseline function and the poten-
tial for benefit following FES-arm ergometry.
4.2. Upper Limb Function
There were no significant changes in the CUE when
considering the composite score for the group as a whole,
however, analyzing the separate subscales yielded more
encouraging results. Most notably, there was a trend for
an increase in hand function following the 12-week FES-
arm ergometry program, and these improvements were
observed in 4 of the 5 participants, while one participant
showed no change. This was an interesting finding, es-
pecially given that the biceps, triceps and shoulders were
electrically stimulated and not the hands or forearms.
Anecdotally, spinal cord injured individuals in our reha-
bilitation center, who did not participate in this study,
also reported improved hand function after using FES-
arm ergometry for their weekly therapy. It is not clear
why hand function improves despite no stimulation of
the hands or forearms. However, stimulating and strength-
ening the shoulders, biceps and triceps, may increase
upper limb stability while performing tasks that involve
the hands. Regarding the range of perceived benefits for
hand function, they seemed to encompass a fairly wide
array of gross and fine motor abilities, as the questions
pertained to a wide array of tasks. Further research is
certainly warranted to determine who may yield clini-
cally important benefits in hand function following FES-
arm ergometry, and what the optimal training stimuli are
to realize these results. Unfortunately, however, there
were no significant changes in biceps, triceps or shoulder
function, and this finding was surprising since those are
the muscles stimulated during the FES-arm ergometry.
Still, the lack of significant results for these data may be
due, in part, to the ceiling effect inherent in the CUE
questionnaire, as three of our participants had relatively
high baseline scores for the biceps and triceps. Nonethe-
less, there were participants with room to improve who
still showed no benefit in biceps or triceps function, and
further research is required to determine who may yield
upper limb benefit from FES-arm ergometry and to what
degree. There were also no significant changes on the sf-
QIF following the 12-week training program. This lack
of improvement may be due in small part to the ceiling
effect inherent in the questionnaire, as one participant
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J. Ptasinski et al. / Open Journal of Therapy and Rehabilitation 1 (2013) 17-21
Copyright © 2013 SciRes.
21
5. CONCLUSION
was either independent, or independent with devices, in
all 6 items at baseline. Still, consistent with the results of
the CUE, there were participants with room to improve
on the sf-QIF who showed no benefit following the trai-
ning. Furthermore, the lack of functional improvements
could be due to the nature of the exercise program, as it
was not intense enough to elicit functional improvements.
Training with FES at a continuous moderate intensity in-
creases cardiovascular function, as shown previously by
improvements in total aerobic capacity [3] and MAP in
the present study, but clearly, not functional tasks. Ac-
cordingly, our lab is currently experimenting with high
intensity FES training modes as a means for potentially
improving functional outcomes. Regarding the SCI-SET
scores, there were no significant changes for the group as
a whole, however, three of our five participants did ex-
perience moderate increases. This finding is interesting
as it illustrates that any functional improvements that
may ultimately be demonstrated with larger trials may be
due to increases in strength and muscular endurance, or
alternatively, decreases in muscle spasticity; or possibly
a combination of all three factors. Other studies with
larger sample sizes and a focus on strength, spasticity
and function will be required to answer these questions.
The current study demonstrated that individuals with
incomplete tetraplegia may experience positive changes
in resting blood pressure following 12 weeks of FES-arm
ergometry. In addition, although only trends were found,
our data justify further studies examining the potential
benefits of FES-arm ergometry on exercise performance
and upper limb function, and which individuals are most
likely to realize such benefits.
6. ACKNOWLEDGEMENTS
The authors would like to acknowledge the participants of this study
for their efforts and dedication. H. Sharif was supported by the Ontario
Neurotrauma Foundation.
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The main limitation of the current study was the small
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