Case Report

䢇

Gait Training of Patients After Stroke
Using an Electromechanical Gait
Trainer Combined With Simultaneous
Functional Electrical Stimulation

Key Words: Cerebrovascular accident, Electrical stimulation, Gait, Rehabilitation, Stroke.

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Raymond KY Tong, Maple FW Ng, Leonard SW Li, Elaine FM So

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Background and Purpose. This case report describes the implementation of
gait training intervention that used an electromechanical gait trainer with
simultaneous functional electrical stimulation (FES) for 2 patients with acute
ischemic stroke. Case Descriptions. Two individuals with post-stroke hemiplegia of less than 6 weeks’ duration participated in a 4-week gait training
program as an adjunct to physical therapy received at a hospital. After the
4-week intervention, both patients were discharged from the hospital, and
they returned after 6 months for a follow-up evaluation. Outcomes. By the end
of the 4-week intervention, both patients had shown improvements in scores
on the Barthel Index, Berg Balance Scale, Functional Ambulation Categories
Scale, 5-m timed walking test, and Motricity Index. In the 6-month follow-up
evaluation, both patients continued to have improvements in all outcome
measures. Discussion. This case report shows that, following the use of an
electromechanical gait trainer simultaneously with FES, patients after acute
stroke had improvements in gait performance, functional activities, balance,
and motor control in the long term. [Tong RKY, Ng MFW, Li LSW, So EFM.
Gait training of patients after stroke using an electromechanical gait trainer
combined with simultaneous functional electrical stimulation. Phys Ther.
2006;86:1282–1294.]

This case report describes the

I

Early, intensive, and gait-focused training has been
shown to be effective in some studies of ambulatory
ability in patients after stroke.3,5– 6 These studies indicated that repetitive, task-oriented (ie, gait-focused)
exercise programs improved functional capabilities in
people with neurological deficits. However, conventional gait training alone, without the use of other
interventions such as body weight support (BWS), often
leads to an asymmetrical gait pattern in many patients
after stroke.7 One study8 showed that bone loss in the
lower femoral neck on the paretic side was related to
when the patients relearned to walk after stroke as well as
to asymmetrical weight bearing when standing. Moreover, bone adaptation was driven by dynamic loading
rather than static loading, and the influence of weight
bearing on the paretic leg during walking may be
important to prevent bone loss. Treadmill ambulation
training with support of a percentage of the patient’s
body weight to reduce the load on the legs has been
developed to provide controlled gait weight shifting,
balance, and stepping.9 In their studies of patients who

combined use of functional electrical
stimulation with a gait trainer in a gait
training protocol to generate active
movement in patients’ paralyzed
lower-limb muscles.
had sustained acute strokes less than 6 weeks earlier, da
Cunha and colleagues10,11 concluded that body weight–
supported treadmill ambulation training is a feasible
and safe technique and has a promising role to play in
gait training.
Treadmill training, however, has several disadvantages.
Kosak and Reding12 stated that the physical therapists in
their study preferred patient rehabilitation involving
floor walking with aggressive bracing over treadmill
walking alone, because gait training on a treadmill
requires 2 or 3 therapists to assist with setting the paretic
limb and controlling the trunk movements, especially in
patients who are severely affected by stroke. In order to
reduce therapists’ efforts, Hesse and colleagues13 developed an electromechanical gait trainer (GT II*) that
enabled patients who were unable to walk independently
to practice a gait-like movement with minimal human
assistance. The main feature of this electromechanical
gait trainer was the simulation of stance and swing, with
a ratio of 60%/40% between stance and swing phases.
This ratio was based on normal walking speed, and the
aim of the rehabilitation was to train the patients to walk
with a normal gait pattern by the end of the training. On

* Reha Stim, Kastanienalle 32, 14050 Berlin, Germany.

RKY Tong, PhD, is Assistant Professor, Department of Health Technology and Informatics, Hong Kong Polytechnic University, Hung Hom, Hong
Kong. Address all correspondence to Dr Tong at: k.y.tong@polyu.edu.hk.
MFW Ng, PT, is a student in the Department of Health Technology and Informatics, Hong Kong Polytechnic University.
LSW Li, MD, is Director, Rehabilitation Unit, and Consultant Physician in Rehabilitation Medicine, Tung Wah Hospital, Hong Kong.
EFM So, PT, is Department Manager, Department of Physiotherapy, Tung Wah Hospital.
Dr Tong and Ms Ng provided concept/idea/project design and writing. Dr Tong, Ms Ng, and Ms So provided data collection. Dr Tong, Ms Ng,
and Dr Li provided data analysis and project management. Dr Tong provided fund procurement. Ms Ng and Dr Li provided the patients. Dr Tong,
Dr Li, and Ms So provided facilities/equipment and institutional liaisons. Ms Ng and Ms So provided clerical support. All authors provided
consultation (including review of manuscript before submission). The authors thank the patients and are grateful to the Hong Kong Polytechnic
University Research Grant Committee for their financial support for this project (A-PE62).
This work was supported by the Institutional Review Board of the University of Hong Kong/Hospital Authority Hong Kong West Cluster (UW
03-089 T/89).
This article was received June 7, 2005, and was accepted March 16, 2006.
DOI: 10.2522/ptj.20050183

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n general, gait is greatly altered after people are
affected by a stroke. More than half of patients in
the acute phase after stroke are not able to walk,
and walking impairments are still present 3 months
after stroke.1,2 Greater effectiveness in gait training has
become one of the goals in post-stroke neurological
rehabilitation. Early physical therapy intervention in gait
training is believed to be beneficial for patients after a
stroke.3 For 197 elderly patients after hemiplegic stroke,
Friedman4 showed that almost all of the patients who
had attained the ability to ambulate independently by
day 7 were more likely to maintain gait independence in
the few months afterward than those who could not walk
without human assistance by day 7.

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the gait trainer, only minimal help from the therapist
was needed for shifting weight onto the stance limb,
whereas hip extension was achieved mainly by the moving footplates. In case reports14,15 and a randomized
crossover study16 by Hesse and colleagues, the gait
trainer was shown to be an effective alternative in intense
post-stroke gait rehabilitation to treadmill therapy with
partial BWS in terms of improvement in gait performance and walking speed. Hesse and colleagues also
stated that the advantages of using the gait trainer for
rehabilitation were a reduction in effort by physical
therapists and a more independent and highly symmetrical walking pattern for patients who are nonambulatory.

Because the therapeutic effects of using a gait trainer
coupled with simultaneous FES have not yet been studied in patients after acute stroke, the purpose of this case
report is to describe and discuss the gait training and
performance details of 2 patients who underwent combined FES and gait training intervention in their rehabilitation, with a focus on the application of daily FESgait training intervention sessions and follow-up
methods.
Case Description
Two patients were recruited to examine the feasibility
and effects of using the gait trainer with FES in the
rehabilitation of patients with acute stroke.
Patient A
Patient A (male, 75 years of age) was affected by a
first-time ischemic stroke in the mid-pontine region and
the left centrum semiovale with right-sided hemiparesis.
His body weight was 57 kg, and his height was 162 cm.
He was a former smoker and had a history of gout, and
he had been newly diagnosed with hypertension and
diabetes mellitus. He was totally independent in all
activities of daily living (ADL) before the onset of stroke.

1284 . Tong et al

Patient A had received daily physical therapy, occupational therapy, speech therapy, and sessions with a
psychologist for 2 weeks before being admitted into our
gait training program. The physical therapy consisted of
regular, weekday 40-minute sessions of training based on
the principles of proprioceptive neuromuscular facilitation and the Bobath concept, with the sessions conducted by the patient’s therapist in the hospital’s physical therapy department. The Bobath treatment aimed to
improve the patient’s posture and movement. In addition, patient A received 1.5-hour multidisciplinary treatment sessions, which comprised occupational therapy,
speech therapy, and psychological consultations. The
time between patient A’s onset of stroke and admission
to our gait training program was 4 weeks. His lower-limb
motor power and balance did not change considerably
in the first 4 weeks after stroke. Before the gait training
intervention, he could walk at a speed of 0.09 m/s
(Functional Ambulation Categories [FAC] scale level 1)
with the assistance of one physical therapist providing
firm, continuous support for balance and placement of
the paretic limbs. Limited knee flexion on the affected
side was observed during the single-leg stance and swing
phases of gait. Right hip extension decreased at the end
of the stance phase. Step length and single-leg support
time were shorter than for the unaffected side.
The inclusion criteria for this program were that the
individual had to have normal communication and
cognitive skills and a moderate to severe ambulatory
deficit (FAC scale level ⬍3) within 6 weeks of the first
unilateral stroke. Patient A met the criteria, and he gave
his informed consent to take part in the gait training

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In this case report, we describe the combined use of
functional electrical stimulation (FES) with a gait trainer
in a gait training protocol to generate active movement
in patients’ paralyzed lower-limb muscles. Functional
electrical stimulation has been shown to have therapeutic benefits in the early phase of gait rehabilitation,
enabling patients with brain injuries to achieve a better
functional result in a shorter period of time.17,18
Although FES and the use of a gait trainer have been
separately demonstrated to have positive therapeutic
effects in post-stroke rehabilitation, both techniques
have never been applied in the same study of stroke
recovery. Current theories of perceptual learning and
recovery of function in people with brain damage recommend that meaningful, graded stimuli with active
participation (ie, sensorimotor coupling) and accurate
feedback should be applied.19,20

After stroke, before beginning the 4-week intervention
program, he was only able to turn over in bed and
unable to rise from bed without assistance, he could not
maintain his balance when sitting up or standing, and he
tended to lean on his right side. His Berg Balance Scale
(BBS) score was 4 out of 56, which indicated a high risk
for falling. He was totally dependent on others for all
self-care needs (Barthel Index [BI] score⫽10), which
were complicated by urine retention and a urinary tract
infection. His total Motricity Index leg score was 59 out
of 100. No increase in muscle tone (velocity-dependent
resistance to stretch) was found in the limb muscles, and
there was no loss in sensation. He could not communicate well verbally because he was affected by left facial
nerve palsy, which slurred his speech. However, his score
on the Mini-Mental State Examination (MMSE) at
admission was 22 out of 30, which indicated that he had
enough cognitive ability to understand our instructions
and explanations of the intervention protocol.21 His
main difficulties were controlling the placement of his
paretic lower extremity, controlling his trunk in a midline orientation, and balancing.

Table 1.

Summary of Outcome Measurementsa
Patient A
Before Intervention
(Baseline)

After 4-Week
Intervention

6-Month
Follow-up

Before Intervention
(Baseline)

After 4-Week
Intervention

6-Month
Follow-up

BI (maximum score⫽100)

10

40

75

35

60

90

BBS (maxmum score⫽56)

4

30

42

16

40

50

FAC (maximum score⫽5)

1

3

4

1

3

5

MI leg score (maximum
score⫽100)
Hip
Knee
Ankle

59

92

84

38

48

78

19
14
25

25
33
33

25
25
33

14
14
9

14
19
14

25
33
19

Walking speed over 5 m
(m/s)

0.09

0.33

0.35

0.08

0.31

0.56

BI⫽Barthel Index, BBS⫽Berg Balance Scale, FAC⫽Functional Ambulation Categories scale, MI⫽Motricity Index.

program. The gait training program was approved by the
Institutional Review Board of Hong Kong Polytechnic
University. Outcome measurements of patient A were
taken before the 4-week gait training intervention commenced and are shown in Table 1.
Patient B
Patient B (male, 59 years of age) was affected by a
first-time ischemic stroke (right pontine infarct) with
left-sided hemiparesis. His body weight was 54.5 kg, and
his height was 164 cm. Prior to the stroke, he had been
an independent, retired construction worker. He was a
chronic smoker and had a history of gout, pneumoconiosis, and pulmonary tuberculosis. He was independent
in all ADL before being affected by the stroke. After the
stroke, he had received conventional treatment from the
hospital for 3 weeks before being admitted to our gait
training program. The time between the stroke and
admission to the gait training program was 4 weeks. He
could sit unsupported but required help during transfers and standing. The muscle tone of the left wrist
flexor, elbow flexor, and plantar flexor were increased to
1 on the modified Ashworth scale. Sensation in the foot
and shank was normal using the sharp/blunt discrimination test.
During walking, he needed continuous support by a
physical therapist to help with limb placement, balance,
and weight bearing (FAC scale level 1). His maximum
walking distance was about 7 m, and his walking speed
was 0.08 m/s (Tab. 1). His affected left upper limb was
paralyzed and without motor control, and his left lower
limb had weakness with a Motricity Index leg score of 38
(lack of motor control on the left ankle). He needed
major help in all self-care activities, but he was continent
(BI score⫽35). He had a high risk for falling, as indicated by a BBS score of 16. Observational gait analysis
was performed as the patient walked with a quadripod at
Physical Therapy . Volume 86 . Number 9 . September 2006

a self-selected pace with continuous support from a
therapist for fall prevention. He had left knee hyperextension during the left stance phase in order to preserve
stability during weight bearing, and equinovarus with the
foot drop dragging during the left swing phase. He had
hip hiking and circumduction compensation maneuvers
of the contralateral limb during the left swing phase
because of the insufficient foot clearance in the midswing phase due to a lack of ankle dorsiflexion. He also
had poor left knee control, probably because of quadriceps femoris muscle weakness. His gait and mobility
were disturbed occasionally by the clonus reflex of the
left ankle plantar flexor when the affected calf muscles
(gastrocnemius and soleus) were stretched suddenly
during movement. In this situation, patient B had to stop
walking and wait for the clonus to diminish. His cognitive condition was sufficient (MMSE score⫽24/30) to
understand the gait training program’s instructions and
purposes. He satisfied the inclusion criteria for participation in the program, and he gave his informed consent to be involved.
Assessment Tools
The functional level of each patient after stroke was
evaluated in terms of independence in ADL, balance,
ability in ambulation, overground walking speed, and
motor impairment. The outcome parameters were evaluated on 3 occasions by a physical therapist who was
registered with the Physiotherapists Board of Hong
Kong: 1 day before the commencement of the 4-week
FES-gait training intervention program, 1 day after the
4-week intervention finished, and 6 months after the
end of the intervention. The 2 patients were to be
discharged from the hospital after completing the
4-week intervention.
If the patients gained independence in ambulation from
the intervention, then they also may have gained more
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a

Patient B

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Table 2.
Functional Ambulation Categories Scale26
Patient cannot ambulate, ambulates in parallel bars only, or
requires supervision or physical assistance from more
than one person to ambulate safely outside of parallel
bars.

1

Patient requires manual contacts of no more than one
person during ambulation on level surfaces to prevent
falling. Manual contacts are continuous and necessary to
support body weight as well as maintain balance or
assist coordination.

2

Patient requires manual contact of no more than one person
during ambulation on level surfaces to prevent falling.
Manual contact consists of continuous or intermittent light
touch to assist balance or coordination.

3

Patients can physically ambulate on level surfaces without
manual contact of another person but for safety requires
standby guarding of no more than one person because
of poor judgment, questionable cardiac status, or the
need for verbal cueing to complete the task.

4

Patient can ambulate independently on level surfaces but
requires supervision or physical assistance to negotiate
any of the following: stairs, inclines, or nonlevel surfaces.

5

Patient can ambulate independently on nonlevel and level
surfaces, stairs, and inclines.

independence in everyday activities such as self-care;
therefore, we used the BI to assess the patients’ performance of ADL. The BI covers actions such as walking,
dressing, going to the toilet, and continence, in which a
score of 100 represents independence and 0 represents
total dependence. The BI has been shown to be a
reliable (Cronbach ␣ ⱖ.84), valid (FIM motor subscale
versus BI: Spearman correlation coefficient ⱖ.92), and
responsive (FIM motor subscale versus BI: change
score⫽0.88) measure of basic ADL in patients after
stroke.22 Balance was assessed with the BBS, which is an
ordinal measure of balance performance. The BBS has
been shown to yield data with excellent interrater and
intrarater reliability in elderly subjects23 and in subjects
after stroke (interrater intraclass correlation coefficient[2,1]⫽.98 and intrarater intraclass correlation coefficient[2,1]⫽.97).24 The BBS has been used to predict
falls in elderly people in previous studies22,23 and was
able to detect changes in status of patients after stroke.25
We measured the patients’ gait performance using the
FAC scale (Tab. 2).26 The 6-point FAC scale is designed
to assess a person’s ability to walk, regardless of whether
an assistive device is used, and the score is based on the
amount of support needed. The patients were asked to
stand and take some steps if possible, and their gait
performance was scored on the FAC scale (kappa⫽.85
for interrater comparisons27). Motor function was measured using the Motricity Index leg score, which has a
score range of 1 to 100. The leg score for a patient
comprised 3 joint movements (hip flexion, knee extension, and ankle dorsiflexion) and was used for analysis of
motor loss of the paretic lower limb after stroke. Validity
and reliability have been shown on patients after stroke
1286 . Tong et al

Overground walking speed was evaluated by timing a
5-m walk with a stopwatch, with 1 m before and 1 m after
the 5-m region untimed for the acceleration and deceleration phases of each patient. Walking speed was calculated in meters per second. Both patients were asked
to walk as fast as possible on a measured walkway, with
any assistive aids if necessary and whatever assistance
required from a physical therapist. The walking test was
conducted twice, with the average walking speed of the 2
trials used for further comparison. The 5-m walking test
was designed by da Cunha et al10 for people with recent
strokes, with the short distance enabling people with
relatively poorer aerobic fitness, balance, and lower-limb
strength to complete the test more readily. Because
spasticity in a lower limb or upper limb can affect a
person’s stability and balance during walking, we used
the modified Ashworth scale to measure muscle tone
(kappa⫽.84 for interrater comparisons and .83 for
intrarater comparisons on patients with acute stroke31).
The knee, ankle, wrist, and elbow ranges of motion were
graded from 0 to 5, with 0 representing no increase in
muscle tone and 5 representing rigid flexion or extension. Sensation was evaluated by the sharp/blunt discrimination test on the foot and shank segments.
Intervention
The 4-week gait training intervention that patient A and
patient B underwent separately comprised a 20-minute
training session every day from Monday to Friday on the
electromechanical gait trainer coupled with simultaneous FES, with optional rest breaks after 10 minutes if
the patients requested any. The patients stayed in the
hospital during the 4-week intervention of a total of 20
training sessions. During this period, they also received
40-minute sessions of physical therapy and 1.5-hour
sessions of the multidisciplinary rehabilitation program.
The gait trainer was designed by Werner and colleagues16 to simulate gait phases in a symmetric manner
with a ratio of 60% to 40% between the stance and swing
phases. This ratio was based on normal walking speed,
and the gait training was aimed at training patients after
a stroke to attain as close to a normal gait pattern as
possible by the end of their rehabilitation programs.
The gait trainer supported each patient via a harness
attached to ropes, which were in turn connected to a
gearing system that was adjusted according to the
patient’s ability in lifting each foot during the swing
phase. Pulleys supported part of the body weight

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0

(Cronbach alpha⫽.77, Pearson correlations between
Motricity Index scores and dynamometer scores⫽.78 –
.91).28 –30 In all of these assessment scales, a higher
number represents a higher degree of motor function
and muscle strength (force-generating capacity).

Table 3.

needs at different stages of recovery
(Tab. 3). A pair of self-adhesive electrodes (PALS 5- ⫻ 5-cm square elecQuadriceps Femoris
Common Peroneal
trodes, model Platinum Blue 901220)†
Muscle
Nerve
were attached over the patient’s quadriceps femoris muscle on the paretic
Stimulation phase
Stance phase
Swing phase
Stimulation frequency (Hz)
40
40
side and stimulated in the stance phase
400
400
Pulse width (␮s)
to facilitate weight acceptance. Another
Rising edge ramp (s)
0.3
0.3
pair of electrodes (PALS 38-mm round
Falling edge ramp (s)
0.3
0.3
electrodes, model Ultraflex 881150)†
Waveform
Rectangular pulse
Rectangular pulse
were attached over the patient’s comExtension (s)
0.1
0.1
Current (mA)
50–85
50–70
mon peroneal nerve on the paretic side
and stimulated during the swing phase
to generate ankle dorsiflexion and
knee flexion. The stimulation sites were
through the harness-secured system. The harnessdetermined while the patient was in a seated position
secured patient was positioned upright with each foot
and until a correct functional response was obtained.
placed on a footplate, and the propulsion of the footThe patient’s knee was extended when the quadriceps
plates helped the movement of the legs and feet during
femoris muscle was stimulated, and the patient’s ankle
the stance and swing phases. Furthermore, the gait
was dorsiflexed when the common peroneal nerve was
trainer assisted in weight shifting and keeping the trunk
stimulated. Stimulation intensity was increased until the
erect by controlling the horizontal and vertical movefunctional movement over the required range of motion
ments of the center of mass.16 The strategy was to get the
(knee angle less than 20° from full extension, ankle in
patient walking in an upright posture with proper limb
neural or doriflexed position) was achieved but the
alignment and proper weight shifting and weight bearpatient still felt comfortable with the stimulation sensaing, especially by the paretic lower limb during the
tion, and the sites then were marked on the skin with
loading response phase and the mid-stance phase. In our
nonconductive, semipermanent ink. Electrodes were
gait training program, step length and walking speed
attached to the same marked sites throughout the
could be adjusted from 34 to 48 cm and from 0 to
4-week intervention. Intermittent electrical stimulation
0.70 m/s, respectively. Other training variables included
then was tested continuously for at least 10 minutes
the percentage of partial BWS and the use of the gait
before the first training session started in order to rule
trainer’s front horizontal bar for hand support by the
out skin allergy contraindication.
patient to increase stability. The target training gait
speed was relatively slow (0.20 – 0.60 m/s) to avoid
Figure 1 shows one patient on the gait trainer with 2
overexerting the patient.32 Body weight was partially
pairs of electrodes attached to the paretic lower limb.
supported by the harness to compensate for the paresis
Excessive stimulation at the beginning could cause disof the affected lower limb, and this relief was reduced as
comfort or disturb the patient instead of providing
soon as the patient could support more of his body
assistance. Therefore, the physical therapist gradually
weight. The clinical criteria were that the patient have
increased the intensity until the functional responses
the ability to extend his hips and that the patient have
from the stimulated muscles were observed and the
the ability to carry his body weight sufficiently on the
patient still felt comfortable with the stimulation sensaaffected lower limb. Additional physical therapist help
tion. When a training session started, the amplitudes of
was available during the gait training according to the
the stimulating pulses were raised to the predefined
patient’s needs (eg, for correcting hyperextension of the
stimulation intensities that induced the required ranges
paretic knee during the stance phase). If a patient
of motion while still being comfortable for the patient.
achieved adequate balance while on the gait trainer, he
Caution was practiced on electrode placement because
then was trained not to grasp the front horizontal bar in
the muscle response from FES in a standing position
order to further exercise his balance and postural conmay be different from that in a seated position, and
trol for walking.
placement of electrodes was adjusted to take this into
account. Two connection wires linked the gait trainer
While on the gait trainer, each patient received electrical
control box and the 2 single-channel FES stimulators
stimulation modalities such as waveform and pulse width
(model R01– 0093‡) that were developed to synchronize
with fixed values and with only the stimulation intensity
adjusted (50 – 85 mA for the quadriceps femoris muscle,
50 –70 mA for the common peroneal nerve) by the
†
Nidd Valley Medical Ltd, Knaresborough, United Kingdom.
‡
supervising physical therapist, according to the patient’s
Jockey Club Rehabilitation Engineering Centre, The Hong Kong Polytechnic
Functional Electrical Stimulation Parameters During 4-Week Intervention

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University, Hong Kong SAR, China.

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allowed after 10 minutes into a session. A daily log sheet
was kept to record measurements of blood pressure,
heart rate, gait speed generated by the gait trainer,
percentage of BWS by the harness, total distance walked,
and number of rests during the session.

Figure 1.
One of the patients on the electromechanical gait trainer wearing 2
functional electrical stimulation (FES) devices. Electrodes were attached
over the quadriceps femoris muscle and the common peroneal nerve of
his paretic lower limb.

between the gait phases and the stimulation timing for
the quadriceps femoris muscle and the common peroneal nerve. The therapist assisted the patient on the gait
trainer in knee extension according to need and provided verbal cueing to facilitate the patient’s keeping his
head and trunk in an upright position. The patient also
needed to be aware of the midline orientation of his
posture in case he leaned to his paretic side or increased
kyphosis during a session. Figures 2 and 3 show the
paretic lower limb in the sagittal plane together with the
gait trainer footplate during the stance and swing phases
of one gait cycle, which was synchronized with the FES
pattern.
Blood pressure was measured before and after each
session for monitoring of the patient’s health condition.
Guidelines for cessation of intervention included complaints of headache, confusion, onset of angina, and
excessive blood pressure before and during training
(systolic blood pressure greater than 220 mm Hg, diastolic blood pressure greater than 110 mm Hg). Upon
request from the patient, a rest break for fatigue was
1288 . Tong et al

Patient A completed 19 out of 20 possible sessions over
the 4-week intervention period. One session was not
undertaken because of the patient’s schedule conflict
with a medical assessment. Intervention details of each
session are listed in Table 4. Patient A progressed
gradually, with a reduction in BWS and an increase in
gait speed, which are plotted in Figures 4 and 5, respectively. The initial set walking speed on the gait trainer
was 0.14 m/s, and the speed was steadily increased to
0.34 m/s toward the end of the 4-week period. Body
weight support decreased from 5.3% on day 1 to 0% on
day 15, by which time he had demonstrated he could
bear his body weight on both legs when walking on the
gait trainer. Other observable progressions during the
sessions were more coordinated trunk control and a
decrease in holding the front horizontal bar for support.
On day 10, he was able to walk with one hand on the
horizontal bar for support; on day 16, he had continuously progressed to walk without any hand support. After
day 16, he began walking with an upright trunk and arm
swings; by the last session, he was able to walk independently on the gait trainer with FES.

§

Velcro USA Inc, 406 Brown Ave, Manchester, NH 03103.

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Patient A
Patient A received gait training with simultaneous FES
for 4 weeks, with one session per weekday for 20 minutes
each session. For the first 10 sessions, he put on the
harness while in a wheelchair positioned in front of the
gait trainer and was transferred onto the gait trainer with
the help of a quadripod and 2 physical therapists. While
he was seated on a foldable chair, his feet were then
secured to the adjustable footplates with Velcro straps,§
and pairs of self-adhesive surface electrodes were put on
the quadriceps femoris muscle and the common peroneal nerve on the affected side. Patient A then stood up
with the help of the pulley system, and the gait training
started at a speed of 0.14 m/s, step length of 45 cm, and
5.3% BWS. One therapist sat in front of the patient to
further stabilize the affected knee during the single-leg
stance phase. The patient completed the 20-minute
training sessions without requesting a rest break. At the
end of each session, he was transferred back to his
wheelchair with the help of the pulley system. After 10
sessions, he was able to step onto the gait trainer with the
help of one therapist and then put on the harness by
holding on to the front horizontal bar.

Position of the paretic leg (sagittal plane) on the gait trainer footplate during a stance phase. The colored muscle represents the quadriceps femoris
muscle that was stimulated during the stance phase. The “-ve” and “⫹ve” represent the positions for the active electrode and the indifferent electrode,
respectively.

Patient B
Patient B received the same intervention protocol on the
gait trainer with FES as patient A. He underwent 18
sessions of intervention over the 4-week period. Two
sessions were not undertaken because of a schedule
conflict with an appointment for a phenol block injection to his left calf muscles for clonus reflex control on
day 11 and an appointment with a clinical psychologist
on day 18. Intervention details of each session are listed
in Table 5. Patient B showed large improvements during
the first week’s sessions in terms of an increase in gait
speed and reduced BWS. His progress for the 4-week
period in terms of BWS and walking speed is shown in
Figures 4 and 5, respectively. Body weight support
decreased from 13.0% on day 1 to 1.8% at the last
session, and gait speed increased from 0.17 to 0.31 m/s
during the 4-week period. Patient B was short of breath
during the first 5 sessions, probably because of his past
history of pneumoconiosis. The relatively high number
of rest breaks he requested as well as termination prior
to completion of each 20-minute session (Tab. 5) indicated poor exercise endurance. He also said that his left
calf muscles were painful and swollen after his phenol
Physical Therapy . Volume 86 . Number 9 . September 2006

block injection on day 11, and he developed gout on day
16, which manifested in a slight increase in BWS and a
reduction in gait speed on days 12 and 16. Nevertheless,
he had made overall progress by the end of the 4-week
intervention, and in his last session was able to walk
independently on the gait trainer with FES without
holding the front horizontal bar for support.
Outcomes
Patient A
After the 4-week intervention, patient A said he was more
confident in overground walking and more aware about
his midline orientation and upright trunk posture. His
balance, functional mobility, and ambulation ability had
improved, as indicated by all measurements (Tab. 1). He
was able to walk overground with a quadripod and with
minimal assistance from a physical therapist. His maximum walking distance and gait speed on an indoor floor
were 160 m and 0.33 m/s, respectively. His balance in
standing had improved, and he could stand with his legs
shoulder width apart without physical assistance for
more than 2 minutes under supervision. His dynamic
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Figure 2.

ўўўўўўўўўўўўўўўўўўўўўў
Position of the paretic leg (sagittal plane) on the gait trainer footplate during a swing phase. During the swing phase, the common peroneal nerve
was stimulated. The colored muscle represents the tibialis anterior muscle that was activated after stimulation. The “-ve” and “⫹ve” represent the
positions for the active electrode and the indifferent electrode, respectively.

Table 4.
Patient A: Daily Record of Intervention Sessions

Day
1
2
3
4
5
6
7a
8
9
10
11
12
13
14
15
16
17
18
19
20
a

Body Weight
Support (%)

Gait Speed
(m/s)

No. of Rest
Breaks

Total Distance
Walked (m)

Total Session
Time (min)

5.3
7.0
7.0
5.3
1.8
5.3

0.14
0.20
0.20
0.20
0.22
0.22

0
0
0
0
0
0

235
248
284
279
282
302

20
18
20
20
17
20

5.3
5.3
5.3
5.3
5.3
3.5
1.8
0
0
0
0
0
0

0.22
0.22
0.22
0.25
0.25
0.25
0.28
0.31
0.31
0.31
0.31
0.34
0.34

0
0
0
0
0
0
0
0
0
0
0
0
0

326
330
310
347
360
350
380
390
400
360
395
385
430

21
20
18
20
21
20
20
18
21
18
20
20
20

No data because of a missed training session due to a conflicting scheduled medical assessment.

1290 . Tong et al

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Figure 3.

BBS score improved to 42 out of 56,
and he could stand unsupported with
feet together for 1 minute with eyes
open or 10 seconds with eyes closed
with supervision. He could walk independently using a cane and had a gait
speed of 0.35 m/s. He still required
physical support for climbing up stairs
and for walking up a steep slope (FAC
scale level 4). His independence in
ADL improved, as shown by his BI score
of 75.

The percentage of body weight support (BWS%) given in the 20 sessions of intervention to the
2 patients in the gait training program.

Figure 5.
Walking speed in the 20 sessions of intervention by the 2 patients in the gait training program.

balance also was better, and he could pick up a pen in
front of him from the floor as well as reach forward
under supervision. He became partially independent in
self-care and required only a little help when putting on
shoes and buttoning and unbuttoning clothing. He was
fully continent (BI score⫽40).
We asked patient A to return for a follow-up assessment
6 months after the end of the FES-gait training intervention and discharge from the hospital (Tab. 1). He had
received approximately 48 hours of postdischarge physical therapy and occupational therapy in a day rehabilitation center after the FES-gait training intervention. His

Physical Therapy . Volume 86 . Number 9 . September 2006

In a follow-up assessment 6 months
after the end of the FES-gait training
intervention and discharge from the
hospital, patient B could walk independently with the
help of a cane, including climbing up stairs, and had a
FAC scale level of 5. He had received outpatient postdischarge stroke rehabilitation for 2 months and acupuncture treatment twice a week for 2 months after being
discharged. Clonus reflex was still present, but the
frequency was lower. He was independent in most ADL
tasks, except in some activities such as tying shoelaces
and fastening fasteners (BI score⫽90).

Discussion
In our gait training program, 2 patients with motor
deficits secondary to stroke demonstrated improved

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Figure 4.

Patient B
At the end of the 4-week intervention,
patient B could walk independently
and required only verbal encouragement or supervision by one physical
therapist (FAC scale level 3). His walking speed had improved to 0.31 m/s
(Tab. 1). Patient B was independent in
all transfers and maintained balance in
standing without support with feet
together. His BBS score increased from
16 to 42. Motor function showed
improvement, especially in his knee
extension and ankle dorsiflexion control and the muscle strength on the
paretic side. His total Motricity Index
leg score increased from 38 to 48.
Observational gait analysis showed
improvements in foot clearance and
trunk control. Moreover, flexion in the
hip increased in the swing phase, and
therefore a larger step length was
observed for both sides during walking.
He was partially independent in selfcare as well as in ambulation, and his BI
score was 60.

ўўўўўўўўўўўўўўўўўўўўўў
Table 5.
Patient B: Daily Record of Intervention Sessions

Day

a

Gait Speed
(m/s)

No. of Rest
Breaks

Total Distance
Walked (m)

Total Session
Time (min)

13.0
9.2
7.3
3.7
3.7
3.7
1.8
1.8
1.8
1.8

0.17
0.20
0.22
0.22
0.25
0.25
0.25
0.25
0.25
0.25

0
0
0
1
0
0
0
0
0
0

108
243
288
225
259
310
320
347
380
250

10
17
19
15
16
18
19
20
20
16

3.7
1.8
1.8
1.8
3.7
3.7

0.28
0.25
0.25
0.28
0.28
0.28

1
1
1
0
2
1

260
270
310
380
380
320

15
18
20
20
20
20

1.8
1.8

0.28
0.31

0
0

315
374

17
20

No data because of a missed training session due to a conflicting scheduled phenal block injection appointment and a clinical psychologist appointment.

ambulation and balance during and after gait training
on an electromechanical gait trainer coupled with simultaneous FES. These outcomes are consistent with those
of previous studies that evaluated gait training on a gait
trainer alone in patients following stroke,13–16 as well as
a study that investigated gait training on a gait trainer
with simultaneous FES in patients following spinal cord
injury.33
Before being admitted into our gait training program,
patient A and patient B had already undergone 2 and 3
weeks of the hospital’s conventional rehabilitation program, respectively, but they did not display much
improvement in their walking and motor abilities. During our 4-week FES-gait training intervention, both
patients received an additional repetitive activity of 500
to 800 steps per session via the gait trainer with simultaneous FES. As they went through more sessions, they
showed improvements in balance and gait. Both patients
made progress mostly on the BBS and in overground
walking speed. In their 6-month follow-up assessments,
patient A showed less improvement than patient B, but
both patients had a faster walking speed and displayed
better functional performance than at the end of the
4-week FES-gait training intervention and discharge
from the hospital. Their independence in ADL also
improved compared with that before the intervention.
Although the gait trainer helped with movement of the
legs and feet during the stance and swing phases as well
as assisting in weight shifting and control of the center of
mass, the gait trainer was unable to provide knee control
1292 . Tong et al

during weight bearing or ankle dorsiflexion during the
terminal swing of the paretic lower limb.15 With the help
of synchronized FES, the knee extensors and ankle
dorsiflexors were used to generate more capacity for
weight bearing on the affected side. During gait training,
we found that the stance phase was supported effectively
by FES-induced muscle activations and without continuous manual support by a physical therapist. The patients
also reported they were willing to put more weight on
their paretic lower limb because they felt that the
FES-induced contraction brought additional strength to
their leg during the single-leg stance phase. In addition,
the tingling sensation of FES served as a cue for when to
extend their knee and to dorsiflex their ankle during the
gait cycle, which may have helped them to actively try to
walk during the gait training, compared with perhaps
passively reacting to the repetitions of electrical stimulation of their paretic muscles during their conventional
rehabilitation program.
We used FES to promote muscle strength, lower-limb
circulation, and bone mineralization.34 The novelty and
value of using a gait trainer together with FES was to
enable gait practice for more than 500 steps in a
walking-like movement with corresponding muscle contraction. Patients who were nonambulatory could train
in a highly symmetric gait pattern without the need for
an enormous amount of physical help from a therapist,
which in turn we believe increased their confidence and
provided more exercise in the gait training. Patient B
also may have gained a cardiopulmonary training effect
after the intervention because the total number of rest
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1
2
3
4
5
6
7
8
9
10
11a
12
13
14
15
16
17
18a
19
20

Body Weight
Support (%)

breaks that he requested in the latter sessions was
smaller than during the initial sessions, and his endurance had increased so that he was able to complete the
last 20-minute gait training session without a rest.

The outcomes of our gait training program demonstrate
that it may be practical to integrate FES into electromechanical gait training without adverse effects. However, further randomized controlled studies are needed
to evaluate whether the patient outcomes of combined
training are superior to those of electromechanical gait
trainer treatment alone or conventional gait training
alone.
This case report presented the details of a new gait
training intervention that combines the use of a gait
trainer with simultaneous FES, and this may be useful
information for possible implementation of the combined method within a clinical setting. As such, the
emphasis of this case presentation was to lay out details
of the application of this new intervention combination
in rehabilitation training for patients who are nonambulatory in the early stage after stroke within a hospital
setting.
Conclusion
After the end of the 4-week FES-gait training intervention, the 2 patients showed improvements in their functional activities, balance, motor control, ambulation
ability, and gait pattern. This case report showed that
FES-gait trainer intervention is feasible for use in rehabilitation. That is, the 2 independent modalities of using
a gait trainer and FES can be coupled for gait training
with no prohibitive adverse effects encountered based
on the positive outcomes from the 2 patients during the
acute post-stroke stage as well as 6 months after the end
of the FES-gait trainer intervention. In addition, both
patients were satisfied with the combination of modali-

Physical Therapy . Volume 86 . Number 9 . September 2006

References
1 Clifford J. Managing disability from stroke. Can Fam Physician.
1986;32:605– 614.
2 Wade DT, Wood VA, Heller A. Walking after stroke: measurement
and recovery over the first three months. Scand J Rehabil Med. 1987;19:
25–30.
3 Richards CL, Malouin F, Wood-Dauphinee S, et al. Task-specific
physical therapy for optimization of gait recovery in acute stroke
patients. Arch Phys Med Rehabil. 1993;74:612– 620.
4 Friedman PJ. Gait recovery after hemiplegic stroke. Int Disabil Stud.
1990;12:119 –122.
5 Hesse S, Bertelt C, Jahnke MT, et al. Treadmill training with partial
body weight support compared with physiotherapy in nonambulatory
hemiparetic patients. Stroke. 1995;26:976 –981.
6 Visintin M, Barbeau H, Korner-Bitensky N, Mayo NE. A new
approach to retrain gait in stroke patients through body weight
support and treadmill stimulation. Stroke. 1998;29:1122–1128.
7 Visintin M, Barbeau H. The effects of parallel bars, body weight
support and speed on the modulation of the locomotor pattern of
spastic paretic gait: a preliminary communication. Paraplegia. 1994;32:
540 –53.
8 Jorgensen L, Crabtree NJ, Reeve J, Jacobsen BK. Ambulatory level
and asymmetrical weight bearing after stroke affects bone loss in the
upper and lower part of the femoral neck differently: bone adaptation
after decreased mechanical loading. Bone. 2000;27:701–707.
9 Hesse S, Bertelt C, Schaffrin A, et al. Restoration of gait in nonambulatory hemiparetic patients by treadmill training with partial bodyweight support. Arch of Phys Med Rehabil. 1994;75:1087–1093.
10 da Cunha IT Jr, Lim PA, Qureshy H, et al. Gait outcomes after acute
stroke rehabilitation with supported treadmill ambulation training: a
randomized controlled pilot study. Arch of Phys Med Rehabil. 2002;83:
1258 –1265.
11 da Cunha IT Jr, Lim PA, Qureshy H, et al. A comparison of regular
rehabilitation and regular rehabilitation with supported treadmill
ambulation training for acute stroke patients. J Rehabil Res Dev.
2001;38:245–255.
12 Kosak MC, Reding MJ. Comparison of partial body weightsupported treadmill gait training versus aggressive bracing assisted
walking post stroke. Neurorehabil Neural Repair. 2000;14:13–19.
13 Hesse S, Sarkodie-Gyan T, Uhlenbrock D. Development of an
advanced mechanised gait trainer, controlling movement of the centre
of mass, for restoring gait in non-ambulant subjects. Biomed Tech (Berl).
1999;44:194 –201.
14 Hesse S, Uhlenbrock D, Werner C, Bardeleben A. A mechanized
gait trainer for restoring gait in nonambulatory subjects. Arch Phys Med
Rehabil. 2000;81:1158 –1161.
15 Hesse S, Uhlenbrock D. A mechanized gait trainer for restoration of
gait. J Rehabil Res Dev. 2000;37:701–708.
16 Werner C, Von Frankenberg S, Treig T, et al. Treadmill training
with partial body weight support and an electromechanical gait trainer
for restoration of gait in subacute stroke patients: a randomized
crossover study. Stroke. 2002;33:2895–2901.

Tong et al . 1293

Downloaded from https://academic.oup.com/ptj/article/86/9/1282/2805258 by guest on 12 April 2024

The basic training process and progression definition
that we followed in our gait training program were those
set by the designers of the gait trainer, and we made
adjustments to the training gait speed, electrical stimulation parameters, amount of hand support, and percentage of BWS. In our gait training program, the
percentage of BWS and the FES intensity could be
reduced based on the patient’s progress in the training
session. For example, patient B did not demonstrate
adequate knee control, so we reduced the percentage of
BWS in the first 7 sessions of the 4-week intervention. We
then increased the amplitude of the stimulation current
to his quadriceps femoris muscle on his affected side on
day 8 to achieve better knee extension and to help his
weight bearing during the stance phase of the paretic
lower limb. Patient B performed better and was able to
complete the 20-minute sessions after day 8.

ties. Further randomized controlled group studies would
be invaluable to determine the efficacy of comparing
FES-gait trainer intervention with conventional treatment alone or usage of a gait trainer alone in gait
rehabilitation after stroke.

ўўўўўўўўўўўўўўўўўўўўўў
17 Malezic M, Kljajic M, Acimovic-Janezic R, et al. Therapeutic effects
of multisite electric stimulation of gait in motor-disabled patients. Arch
Phys Med Rehabil. 1987;68:553–560.

26 Holden MK, Gill KM, Magliozzi MR, et al. Clinical gait assessment in
the neurologically impaired: reliability and meaningfulness. Phys Ther.
1984;64:35– 40.

18 Kralj A, Acimovic R, Stanic U. Enhancement of hemiplegic patient
rehabilitation by means of functional electrical stimulation. Prosthetic
Orthotics Int. 1993;17:107–114.

27 Stevenson TJ. Using impairment inventory scores to determine
ambulation status in individuals with stroke. Physiother Can. 1999;51:
168 –174.

19 Gibson EJ. Principles of Perceptual Learning and Development. New York,
NY: Meredith: 1969.

28 Demeurisse G, Demol O, Robaye E. Motor evaluation in vascular
hemiplegia. Eur Neurol. 1980;19:382–389.

20 Schmidt RA. Motor Control and Learning: A Behavioral Emphasis. 2nd
ed. Champaign, Ill: Human Kinetics Inc; 1988.

29 Cameron D, Bohannon RW. Criterion validity of lower extremity
Motricity Index scores. Clin Rehabil. 2000;14:208 –211.

21 Folstein MF, Folstein SE, McHugh PR. “Mini-mental state”: a
practical method for grading the cognitive state of patients for the
clinician. J Psychiatr Res. 1975;12:189 –198.

30 Collen FM, Wade DT, Bradshaw CM. Mobility after stroke: reliability
of measures of impairment and disability. Int Disabil Stud. 1990;12:6 –9.

23 Bogle Thorbahn LD, Newton RA. Use of the Berg Balance Test to
predict falls in elderly persons. Phys Ther. 1996;76:567–583; discussion
584 –585.
24 Berg K, Wood-Dauphinee S, Williams JI, et al. Measuring balance in
the elderly: preliminary development of an instrument. Physiother Can.
1989;41:304 –311.
25 Wood-Dauphinee S, Berg K, Bravo G, Williams JI. The balance scale:
responsiveness to clinically meaningful changes. Can J Rehabil. 1997;
10:35–50.

1294 . Tong et al

31 Gregson JM, Leathley M, Moore AP, et al. Reliability of the Tone
Assessment Scale and the modified Ashworth scale as clinical tools for
assessing poststroke spasticity. Arch Phys Med Rehabil. 1999;80:
1013–1016.
32 Pohl M, Mehrholz J, Ritschel C, Ruckriem S. Speed-dependent
treadmill training in ambulatory stroke patients: a randomized controlled trial. Stroke. 2002;33:553–558.
33 Hesse S, Werner C, Bardeleben A. Electromechanical gait training
with functional electrical stimulation: case studies in spinal cord injury.
Spinal Cord. 2004;42:346 –352.
34 Wade TD, Wood VA, Hewer RL. Recovery after stroke: the first 3
months. J Neurol Neurosurg Psychiatry. 1985;48:7–13.

Physical Therapy . Volume 86 . Number 9 . September 2006

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22 Hsueh IP, Lin JH, Jeng JS, Hsieh CL. Comparison of the psychometric characteristics of the functional independence measure, 5 item
Barthel index, and 10 item Barthel index in patients with stroke.
J Neurol Neurosurg Psychiatry. 2002;73:188 –190.