#12

CLINICAL NOTE
Outcomes of a Home Cycling Program Using Functional
Electrical Stimulation or Passive Motion for Children With
Spinal Cord Injury: A Case Series
Therese E. Johnston, PT, PhD, MBA; Brian T. Smith, MS; Oluwabunmi Oladeji, PT; Randal R. Betz, MD;
Richard T. Lauer, PhD
Shriners Hospitals for Children, Philadelphia, Pennsylvania
Received May 24, 2007; accepted October 11, 2007
Abstract
Background/Objective: Children with spinal cord injury (SCI) are at risk for musculoskeletal andcardiovascular complications. Stationary cycling using functional electrical stimulation (FES) or passive
motion has been suggested to address these complications. The purpose of this case series is to report theoutcomes of a 6-month at-home cycling program for 4 children with SCI.
Methods: Two children cycled with FES and 2 cycled passively at home for 1 hour, 3 times per week.
Outcome Measures: Data collected included bone mineral density of the left femoral neck, distal femur,
and proximal tibia; quadriceps and hamstring muscle volume; stimulated quadriceps and hamstring muscle
strength; a fasting lipid profile; and heart rate and oxygen consumption during incremental upper extremity
ergometry testing.
Results: The 2 children cycling with FES and 1 child cycling passively exhibited improved bone mineraldensity, muscle volume, stimulated quadriceps strength, and lower resting heart rate. For the second childcycling passively, few changes were realized. Overall, the lipid results were inconsistent, with some positiveand some negative changes seen.
Conclusions: This case series suggests that cycling with or without FES may have positive health benefits
and was a practical home exercise option for these children with SCI.
J Spinal Cord Med. 2008;31:215–221
Key Words: Spinal cord injuries; Tetraplegia; Paraplegia; Child; Exercise; Functional electrical stimulation;
Cycling; Pediatrics; Bone mineral density
INTRODUCTION
The incidence of pediatric spinal cord injury (SCI) is
approximately 1.99 per 100,000 children (1). Because of
improvements in health care, life expectancy for thesechildren has increased (2). With age, they face the same
health problems experienced by the general population,in addition to the neuromuscular effects of SCI, which
can lead to decreased quality of life and significant
lifetime medical costs (3).
One means to address the neuromuscular effects of
SCI is through exercise, particularly cycling. For adults
with SCI, studies have shown that cycling with functional
electrical stimulation (FES) increases muscle cross-secPlease address correspondence to Therese E. Johnston, PT, PhD,
MBA, Research Department, Shriners Hospital for Children,
3551 North Broad Street, Philadelphia, PA; phone:
215.430.4089; fax: 215.430.4141 (e-mail: tjohnston@shrinenet.org).
Q 2008 by the American Paraplegia Society

tional area (4,5), lean body mass (4,5), voluntary andelectrically induced muscle force (4,5), muscle endurance(6,7), and the body’s utilization of oxygen (energy
expenditure) (8–11) and causes improvements in heartrate, stroke volume, and cardiac output during exercise
and at rest (12). Bone mineral density (BMD) has beenshown to increase following a program of FES cycling insome studies (13–15), but not in others (16,17). In
addition, FES cycling with more than 1,500 revolutions
per week has also led to reductions in spasticity (18,19).
Less research has focused on the benefits of passive
cycling in individuals with SCI. Improvements have beenreported in spasticity (20), cardiac output and strokevolume (21), and muscle atrophy (22) after a program ofpassive cycling.
The aforementioned studies have focused on cycling
for adults with SCI, with no information on the potential
benefits for children. This is the first study to examine theoutcomes of these interventions in children with SCI. We
report the results after 6 months of home cycling with
FES or passively for 4 children with SCI.

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215

Figure 1. A child with a spinal cord injury using thefunctional electrical stimulation cycle.
METHODS
The children in this case series were selected from thoseparticipating in a randomized controlled trial (RCT)comparing the 2 cycling modes to a noncycling electricalstimulation program. A nonintervention control group
was not included, and the larger RCT was registered withthe clinicaltrials.gov database. The 4 children presented
in this case series were selected as a convenience sample
to provide a representative sample of the children in the
RCT. One child with tetraplegia and one child withparaplegia were selected for each intervention. The
children were also matched as closely as possible by age.
Parents and children signed informed consent andassent forms, respectively, which were approved by thegoverning institutional review board. Inclusion criteria
were at least 12 months post injury, cervical or thoracic
level SCI with an American Spinal Injury Association(ASIA) A or ASIA B classification, age 5 to 13 years, andinnervated lower extremity muscles. Exclusion criteria
included chronic steroid treatment, history of seizures,cardiac disease, lower limb stress fractures, uncontrolledautonomic dysreflexia, heterotopic ossification, and hip
dislocation.
Children cycled at home with parental assistance for
1 hour, 3 times per week for 6 months. If more than 6sessions were missed over the 6 months, subjects added
1 session per week until the targeted number of overallsessions was reached. Subjects using FES cycled at 50rpm using an RT300-P FES cycle (Restorative-Therapies,
Inc., Baltimore, MD) while seated in their wheelchairs(Figure 1). The cycle provided bilateral cyclical stimulation to the quadriceps, hamstring, and gluteal muscles
using the largest surface electrodes (Axelgaard Manufacturing Co, Inc, Fallbrook, CA) appropriate for the child’sleg. Stimulation pulse duration (150 ls) and frequency(33 Hz) were fixed, and current amplitude (maximum of216

140 mA) increased automatically to generate sufficient
force to maintain the cadence. Children cycling passively
used the RT100 (Restorative-Therapies, Inc., Baltimore,MD) motorized cycle, which passively moved the legs at
50 rpm.
To standardize cycling mechanics across children,
adjustments were made to accommodate children’s sizes
and wheelchair configurations. For example, crank arm
length was shortened to accommodate smaller legs, andthe calf support could be manipulated to prevent it fromhitting the wheelchair. The cycle’s height was raised witha custom-made wooden platform so the children’s feetwould reach the pedals.
Prior to exercising, children participated in lower
extremity muscle stretches. Children were permitted tocontinue their previously established activities including
standing and walking with braces but were not permitted
to participate in non–study-related lower extremity
repetitive motion tasks or electrically stimulated exercise.
It was decided not to alter the prestudy exercise routine
as declines from baseline values might have occurred if
these activities were stopped. Throughout the study, 3
children (1 FES, 2 passive) participated in standing
activities and 1 child (passive) participated in upper
extremity strengthening exercises. None of these activities were new to the children prior to study participation.
Outcome Measures
Musculoskeletal and cardiovascular/respiratory measures
were collected. Musculoskeletal measures included bonemineral density (BMD) of the left femoral neck, distal
femur, and proximal tibia; left quadriceps muscle volumeusing magnetic resonance imaging (MRI); electricallystimulated strength of the left quadriceps; and spasticityof the quadriceps and hamstrings muscles. Cardiovascular and respiratory measures included a fasting lipid
profile and an incremental upper extremity (UE) ergometry test to assess heart rate (HR) and oxygen
consumption (VO2/kg). The investigators performing
testing were blinded to the measures of BMD, muscle
volume, and lipid levels, but not to the other measures.
Musculoskeletal Measures. To assess BMD, dual-energy
x-ray absorptiometry (DEXA) (Hologic, Inc., Bedford,MA) was used with the child in the supine position. The
femoral neck was analyzed using the standard hipalgorithm, and a modified lumbar spine algorithm (23)was employed for the distal femur and proximal tibia.
Measurement error has been determined to be as high as
20% for assessing BMD using DEXA (24).
Magnetic resonance imaging was performed for theleft thigh (most proximal to most distal quadriceps
femoris) in 0.7-cm slices using a 1.5-tesla magnet (GEMedical Systems, Waukesha, WI) and a torso coil.
Chemically selective fat suppression enhanced definition
between muscles. The MRI data were processed using acustom program in Interactive Data Language (Version
6.2) (ITT Visual Information Solutions, Boulder, CO) (25).

The Journal of Spinal Cord Medicine Volume 31 Number 2 2008

The head of the femur was used as the reference starting
point, and the rectus femoris, vastus lateralis, vastus
medialis, and vastus intermedius muscles were outlined
separately to determine cross-sectional area. Muscle
volume was calculated by multiplying the crosssectional area of each muscle by 0.7 cm (26).
Measurement error for this technique has beenreported to range from 6% to 13% (26).
To assess stimulated isometric quadriceps strength,
the children were seated with the hip and knee flexed at
808 and 608, respectively, on an isokinetic dynamometer(Chattex Corp, Chattanooga, TN). The dynamometer’saxis was aligned with the knee joint’s axis, and the distal
attachment was made approximately 3 cm above thelateral malleolus. Surface electrodes were used, andmaximum stimulation levels were determined byincreasing the current until the force output plateaued.
After a 3-minute rest, 3 trials were performed with 2minute rest periods between trials, and the highest value
was selected. Measurement error for this technique is
unknown.
Quadriceps and hamstring spasticity was assessedusing the Ashworth Scale, which was performed withchildren seated on the isokinetic dynamometer. The
examiner (same for all testing) quickly moved each leg 3times into extension and flexion. All 3 scores wererecorded per leg, and the mode was then calculated foreach muscle group. Intrarater reliability of the Ashworth
Scale for muscles around the knee has been shown torange from 0.27 to 0.54 (Kappa) and 0.44 to 0.66
(Kendall’s s-b) in individuals post stroke (27).
Cardiovascular Measures. The fasting lipid profile
included cholesterol, high-density lipoproteins (HDL),
low density lipoproteins (LDL), and triglycerides. Children
fasted overnight for at least 10 hours prior to the blooddraw, which is consistent with other studies (28).
Measurement error has been reported to be 6.1 mg/dL
for cholesterol, 2.3 mg/dL for HDL, 7.4 mg/dL for LDL,
and 18.2 mg/dL for triglycerides in a sample of 19
children (29).
During the upper extremity ergometry test, HR andVO2/kg data were collected using a breath-by-breath
technique with a SensorMedics VMax29 metabolic cart
(Viasys Healthcare, Yorba Linda, CA). The children wore asmall airtight facemask (Hans Rudolph, Inc, Kansas City,MO) over the mouth and nose that held the flow sensor
that measured the volume of oxygen (VO2 in mL) per
kilogram of body weight (VO 2 /kg). VO 2 /kg wasmeasured under 4 consecutive conditions: (a) sitting
quietly for 5 minutes (baseline), (b) UE cycling at 10 W at
a self-selected cadence for 1 minute (warm-up), (c) UE
cycling at 10 W with increases of 10 W every minute until
self-determined fatigue, and (d) sitting quietly for 3
minutes (recovery). Resting HR was averaged frombaseline data, and peak HR and peak VO2/kg were
calculated by determining the highest 15-second averagevalue. Due to potential power output differences

between baseline and 6 months, peak HR was
compared at the highest resistance level that wasachieved at both data collection points. Measurement
error for this test is unknown for children with SCI.
Parent Reports and Program Adherence
Throughout the 6-month period, biweekly phone calls
were made to the parents to assess program adherence
and to identify any problems. Parents were asked
whether the child had exercised 3 times in each of theprevious 2 weeks and also were asked whether they
noticed any changes in their child during that same time
period. The answers to these questions were recorded ona data sheet. If the child had not exercised enough during
the 2 weeks, the parents were asked why and were
instructed to resume the regular schedule as soon as
possible.
CASES
FES Cycling
Participant 1. Participant 1 was a 7-year-old white girlwho sustained a T4-T6 ASIA A SCI in a motor vehicle
crash at the age of 2 years. The maximum stimulation
current amplitudes were set at 115 mA (quadriceps), 130mA (hamstrings), and 100 mA (gluteals). Gluteal
stimulation was set lower as higher amplitudes led to adysreflexic response. Participant 1 had a 92.5%
adherence rate and experienced improvements in BMD
at the femoral neck, distal femur, and proximal tibia;
quadriceps muscle volume; stimulated strength of thequadriceps muscles; HDL cholesterol; resting HR; peakVO2/kg; and peak HR (Table 1). However, cholesterol,
LDL, and triglyceride levels and the cholesterol/HDL ratio
increased as compared to baseline. There were nochanges in her Ashworth scores, but her parents
reported decreased spasticity and looser muscles.
Participant 2. Participant 2 was a 9-year-old white girlwho sustained a C7 ASIA A SCI in a motor vehicle crash at
the age of 4 years. During the study, the maximum
stimulation current amplitudes were set at 60 mA(quadriceps), 50 mA (hamstrings), and 10 mA(gluteals), as higher levels caused autonomic
dysreflexia. Participant 2 had a 100% adherence rateand experienced improvements in BMD at the femoral
neck, distal femur, and proximal tibia; quadriceps muscle
volume; stimulated quadriceps muscle strength; andhamstring muscle spasticity (Table 1). However,cholesterol, LDL, HDL, and triglyceride levels and thecholesterol/HDL ratio worsened as compared to baseline.
Her parents reported bigger, firmer muscles; decreased
bowel program completion times; increased appetite;and increased spasticity that did not require medical
intervention.
Passive Cycling
Participant 3. Participant 3 was a 7-year-old Hispanic boy
who sustained a T3 ASIA A SCI in a motor vehicle crash at

Home Cycling Program for Children

217

Table 1. Results for Children Participating in FES Cycling
Participant 1

Participant 2

MeasureBaseline

6 Months% Change

Baseline

6 Months% Change

Height (cm)Weight (kg)Femoral neck BMD (g/cm3)
Distal femur BMD (g/cm3)
Proximal tibia BMD (g/cm3)
Quadriceps muscle volume (cm3)
Stimulated quadriceps strength (N)Quadriceps spasticity (Ashworth)
Hamstrings spasticity (Ashworth)
Triglycerides (mg/dL)
Total cholesterol (mg/dL)
HDL (mg/dL)
LDL (mg/dL)
Cholesterol/HDL ratio
Resting HR (beats/min)
Peak HR (beats/min)
Peak VO2/kg (mL/kg)

119
27.5
0.171
0.264
0.318
198.5
45.6
1
1
98
188
36
133
5.2
105
185
6.2

126.5
32.8
0.397
0.386
0.382
289.0
177.5
1
1
103
231
40
171
5.8
96
173
15.7

6.3
19.3
132.2
46.2
20.1
45.6
289.3
NA
NA
5.1
22.9
11.1
28.6
11.5
8.6
6.5
153.2

130
23.7
0.257
0.234
0.225
148.1
27.3
0
1
45
143
38
96
3.8
111
129
6

134.5
22.6
0.544
0.258
0.248
225.5
74.7
0
0
48
147
36
102
4.1
94
129
6

3.5
4.6
111.7
10.3
10.2
52.3
173.6
NA
NA
6.7
2.8
5.3
6.3
7.9
15.3
0.0
0.0

NA indicates not appropriate for that measure.

the age of 3 years. He was taking spasticity-reducing
medication, which remained unchanged during thestudy. Participant 3 had a 100% adherence rate andrealized improvements in femoral neck BMD, hamstring
spasticity, and triglyceride levels (Table 2). Distal femur
and proximal tibia BMD and stimulated quadriceps
strength were lower as compared to baseline, and LDL
levels and the cholesterol/HDL ratio were elevated. Hisparents reported decreased bowel accidents and newsensation in his knees and stomach.
Participant 4. Participant 4 was an 11-year-old whiteboy who sustained a C7 ASIA A SCI in a motor vehicle
crash at the age of 3 years. Participant 4 had a 100%
adherence rate and experienced improvements in BMD
at the femoral neck, distal femur, and proximal tibia;
quadriceps muscle volume; stimulated quadriceps
strength; hamstring spasticity; cholesterol; LDL
cholesterol; resting HR; and peak VO2/kg (Table 2).
HDL cholesterol decreased as compared to baseline but
the cholesterol/HDL ratio was unchanged. His parents
reported decreased spasticity, looser muscles, increased
energy, decreased lower extremity swelling, andincreased appetite.
DISCUSSION
The results suggest that cycling can be performed athome with parental assistance. Reported adherence tothe exercise program was greater than 90%, indicatingthat families saw exercise as important and were able toincorporate exercise into their busy lives. For a study
examining longer-term effects of cycling, it was important for the participants to cycle at home to remove
potential barriers to participation. With an at-home218

program, children and parents had the flexibility to
exercise at times convenient for them, potentiallyresulting in improved adherence and outcomes.
Both children cycling with FES showed BMD
improvements. A systematic review examining BMD
changes following exercise for children with typicaldevelopment found BMD gains of 0.3% to 5.5%
depending on pubertal status (30). In our study, theBMD changes for the 2 children cycling with FES greatly
exceeded these values, indicating a substantial improvement. These children also showed comparable or greater
increases than those reported for adults with SCI cycling
with FES who had knee BMD improvements of approximately 10% (14,31), with no effects at the femoral neck
(14,31).
For children cycling passively, femoral neck BMD
improved, with Participant 4 having a large change(297.8%) and Participant 3 having a small change (2.7%)
consistent with that expected from exercise (30).
Similarly, Participant 4 experienced large gains in knee
BMD while Participant 3 did not. This may represent aceiling effect for the influence of passive cycling on BMD.
Participant 4, the child with large gains, had 31% to 60%
lower baseline values compared to the other child cycling
passively. Perhaps passive cycling provided a musculoskeletal load that was influential with smaller BMD values.
Greater loads, such as those provided by FES, may beneeded to further increase BMD. For example, atbaseline, Participant 1 (FES cycling) had distal femur
and proximal tibia BMD values that were within 70% and88%, respectively, of Participant 3 0 s values (passive
cycling). However, Participant 1 realized distal femur
and proximal tibia BMD increases of 46% and 20%,The Journal of Spinal Cord Medicine Volume 31 Number 2 2008

Table 2. Results for Children Participating in Passive Cycling
Participant 3

Participant 4

MeasureBaseline

6 Months% Change

Baseline

6 Months% Change

Height (cm)Weight (kg)Femoral neck BMD (g/cm3)
Distal femur BMD (g/cm3)
Proximal tibia BMD (g/cm3)
Quadriceps muscle volume (cm3)
Stimulated quadriceps strength (N)Quadriceps spasticity (Ashworth)
Hamstrings spasticity (Ashworth)
Triglycerides (mg/dL)
Total cholesterol (mg/dL)
HDL (mg/dL)
LDL (mg/dL)
Cholesterol/HDL ratio
Resting HR (beats/min)
Peak HR (beats/min)
Peak VO2/kg (mL/kg)

118.5
19.7
0.441
0.372
0.358
197.5
32.4
0
2
219
181
30
108
6.0
101
136

122.5
20.5
0.453
0.319
0.338
196.4
23.3
0
0
155
182
26
125
7.0
99
141
Not tested*

3.4
4.1
2.7
14.2
5.6
0.6
28.1
NA
NA
29.2
0.6
13.3
15.7
16.7
2.0
3.7

144.5
29.1
0.138
0.206
0.212
243.1
16.2
0
1
75
219
65
139
3.4
85
116
13.6

146
30.4
0.549
0.255
0.295
280.4
50.6
1
0
75
181
53
113
3.4
79
116
17.1

1.0
4.5
297.8
23.8
39.2
15.3
212.3
NA
NA
0.0
17.4
18.5
18.7
0
7.1
0.0
25.7

NA indicates not appropriate for that measure.
*This child could not tolerate mask used for testing.

respectively, while Participant 3 experienced no changes.
Further study is needed to determine the mechanism forincreased BMD with passive cycling. It also needs to be
determined whether there are significant increases in
BMD with FES cycling and whether these increases are
significantly different than those obtained throughpassive cycling.
For children without disability, normative values areavailable for femoral neck BMD based on age and sex(32), but not for BMD around the knee. While thefemoral neck normative values can be used for comparison, these comparisons should be made cautiously as
they were performed on a different scanner than used inthis study. Using these normative values, the children
cycling with FES improved from 3.3 to 1.4 (Participant 1)
and 2.8 to 0.8 (Participant 2) standard deviations below
the mean, and the subjects cycling passively improved
from 1.8 to 1.7 (Participant 3) and 3.8 to 1.4 (Participant4) standard deviations below the mean. In adults, each
unit of standard deviation decrement at the femoral neckas compared to age-matched controls increases the riskof fracture in the lower extremity by 2.8 (33).
There were large increases in quadriceps muscle
volume and stimulated strength for children cycling with
FES. In adults with SCI, improvements in muscle crosssectional area with FES cycling of approximately 38% in
the quadriceps muscles have been reported (4,5).
Another study reported significant increases in stimulated
quadriceps strength following 3 months of FES cycling in
adults with SCI (16), although they did not report themagnitude of this increase. Clinically, increasing muscle
mass may be very important, as decreased muscle mass isrelated to insulin resistance in adults with SCI (34) and
can decrease the metabolic rate and increase the risk ofmetabolic disease (35). In a small sample of adults withtetraplegia, a decrease in insulin-mediated glucose
utilization showed a direct linear relationship with adecrease in muscle mass (36).
One child cycling passively experienced large
increases in stimulated quadriceps strength but only amodest increase in muscle volume. The large increase instrength may be due to spasms that occurred duringbaseline testing, which may have underestimated themuscles’ potential. During testing, the force would
increase and then decrease simultaneously with a visible
flexor spasm. A topical anesthetic was applied to decreasereflex activity due to cutaneous stimulation, and the child
was retested; however, the problem continued. At
follow-up, flexor spasms did not occur, which may berelated to self-reports of decreased spasticity. The otherchild cycling passively showed no gains in muscle volume
or strength.
There was no apparent correlation between Ashworth scores and self-reported changes in spasticity. This
is not surprising since the Ashworth Scale measures
spasticity at one moment during the day at a specificjoint position, while the participants’ reports are theirrecollection of how spasticity affects their everyday
function. For example, Participant 3 (passive) reported
no change in spasticity, but a 2-point drop was noted forthe hamstring muscle using the Ashworth Scale. In
addition, Participant 1 (FES) reported decreased spasticity, but no change was noted in Ashworth scores.

Home Cycling Program for Children219

Data suggest that both children cycling with FES
experienced exercise effects on the cardiorespiratory
system, including a decline in resting HR for both children
and a decrease in peak HR for the child with paraplegia,
indicating that the heart did not have to work as hardduring exercise. The child with tetraplegia experienced
no change in peak HR. This finding is consistent with theliterature, as adults with tetraplegia have a blunted HR
response to exercise due to alterations in sympathetic
drive (37), which likely is also true for children withtetraplegia. The child with paraplegia also experienced a
153% increase in peak VO2/kg, which likely cannot be
explained by her other activities, which only included
passive standing in a standing frame. A study examining
VO2 max changes following a 12-week aerobic exercise
program for 10- to 12-year-old children with typicaldevelopment showed average VO2 max increases of
6.5% (38), indicating that the child in our study made asignificant gain. For the children cycling passively, 1child’s resting HR declined. Peak VO2/kg also increased,
which was unanticipated. However, an exercise response
may have occurred, as his parents reported fatigue after
passive cycling and improved overall energy level
throughout the study.
A meta-analysis of lipid profiles post aerobic exercise
in typically developing children and adolescents (5–19
years) reported changes only in triglyceride levels(average change 12%). The confidence intervals for lipidchanges were found to be 4.4 to 3.3 mg/dL forcholesterol, 4.8 to 1.9 mg/dL for HDL, 4.3 to 6.7
mg/dL for LDL, and 22.8 to 0.8 mg/dL for triglycerides(39). Using these confidence intervals, 1 child cycling
with FES had positive HDL changes (4-point increase), 1
child cycling passively had decreased cholesterol (38point decrease) and LDL levels (26-point decrease), and 1
child cycling passively had decreased triglyceride levels(64-point decrease). In addition, 3 of the 4 children
showed an increase (negative change) in their cholesterol/HDL ratios. When taking measurement error into
account, the only positive changes in lipids wereexperienced by subjects in the passive cycling group.
However, the American Academy of Pediatrics reportsthat in children and adolescents, even a small reduction
in total cholesterol and LDL levels in children andadolescents could have a large impact on decreasing
the incidence of coronary heart disease, if these lower
values are carried over into adulthood (40).
Due to the overall inconsistent changes in lipid
profiles seen, a different approach may be needed to
improve lipid levels in children with SCI. Diet was notaddressed in this study, and an intervention combining
diet and exercise may be more effective in altering lipid
profiles as compared to exercise alone.
There are several limitations of this study. First, acontrol group not receiving intervention was notincluded in the RCT; therefore, the results may havebeen influenced by the developmental stage and growth220of the children in the study. It is unknown how these
impacted this study. Due to this, normative values forchildren without disability and data from adults with SCI
following exercise programs were used to assist in theunderstanding of the results. The physical developmentof children with SCI for the measures tested is not known
and warrants further investigation. A second limitation isthat the parents provided the information on program
adherence through biweekly phone calls, and theirreports of changes in their children were subjective.
There did not appear to be a relationship between
reported adherence and satisfaction with the results ofthe program. Typical reasons for not exercising werefamily and school obligations. Another limitation is thatmeasurement error is not known for all tests performed inthis study, as some of these techniques have not beenpreviously used for children with SCI. Future work should
address the issues of reliability and measurement error forchildren with SCI. Finally, this report is a case series, so
the data represent a small sample of children. Larger
studies are needed to determine the effects of FES andpassive cycling for children with SCI.
CONCLUSIONSFor the 2 children who cycled with FES for 6 months,
improvements in BMD, muscle volume, muscle strength,
and resting HR were realized. Improvements of similar
magnitude were realized for 1 of the children participating in passive cycling. These results provide preliminary
data on the outcomes of FES and passive cycling forchildren with SCI. Stationary cycling appeared to be ahome exercise option for these children.
ACKNOWLEDGMENTS
This study was funded by Shriners Hospitals for Children,
Grant 8540.
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