Robot-assisted locomotor training in incomplete SCI
RESULTS
It was not possible to recruit the predetermined number
of subjects within a reasonable time. After 9 years, only
24 of the planned 30 subjects had been randomized.
Four subjects had an early dropout from the interven-
tion group, and 1 was non-compliant (completed only
one-third of sessions). Thus, the study population
included only 7 intervention and 12 control subjects.
There was no significant group difference at baseline,
although the intervention group was older (mean 9
years), had a larger proportion traumatic SCIs, and had
less walking function at baseline (Table I).
The intervention was well tolerated with no adverse
events, except for minor issues such as small leg abra-
sions. In the control group, no change in the frequency
of physical therapy sessions was noted. The interven-
tion subjects had a mean of 59 days (standard deviation
SD 2 days) of RALT, and sessions lasted 48 min (SD
8 min). The mean distance walked was 2,271 m (SD
465 m), and the mean body-weight support was 40%
(SD 21%), with a guidance force of 82% (SD 8%) per
training session.
Recovery of walking function. This goal was not ac-
hieved in any subject.
Walking speed and endurance. Despite randomization,
the groups differed in several respects. All subjects in
the intervention group had some walking function,
whereas 3 subjects in the control group were unable
to walk. Also, the controls with some baseline walking
function had twice the walking speed and endurance
compared with the I-group. Both groups improved or
maintained their walking speed (10MWT) at post-test.
However, the group difference in improvement was
small and not statistically significant. Mean endu-
rance (distance walked), as measured by the 6MWT,
improved more in the control group (23.1 vs 6.6 m,
not significant) than the intervention group (Table II).
Lower extremity motor score. In the intervention group,
LEMS increased by 5.4 points, vs 0.2 in controls
(Table II).
Balance. Changes measured by BBS, were minimal,
but there was a statistically significant group difference
in postural control (MFR), which declined 8.6 cm
more in the intervention compared with the control
group (Table II).
Table I. Baseline demographics of the final sample of subjects
according to the Intervention or Control group with robot-assisted
locomotor training
Variables
Sex, n (% males)
Age, years, mean (SD)
Post-injury time, years,
Mean (SD)
Median (range)
Traumatic injury, n (%)
Injury level, n (%)
Cervical
Thoracic
Lumbar
ASIA classification, n (%)
AIS C
AIS D
Marital status, n (%)
Married
Other
Smoker, n (%)
Education, n (%)
< 7 years
Elementary school
High school
College
University
At work, yes, n (%)
Use of antispasmodics, n (%)
BMI (kg/cm 2 ), mean (SD)
Walking function, n (%)
Wheelchair dependent with some or without
walking function
Wheelchair independent – walking function with
assistive device
SD: standard deviation; BMI: body mass index.
Intervention Control
group
group
n = 7
n = 12
4 (57)
55 (8) 5 (42)
46 (15)
21 (23)
8 (2–54)
6 (86) 15 (18)
7 (2–48)
6 (50)
4 (57)
3 (43)
0 (0) 6 (50)
6 (50)
0 (0)
1 (14)
6 (86) 5 (42)
7 (58)
3 (43)
9 (57)
2 (29) 4 (33)
8 (67)
5 (42)
0
1
2
2
2
2
3 0
0
3
2
7
4
5
(0)
(14)
(29)
(29)
(29)
(29)
(43)
25.9 (3.8)
(0)
(25)
(17)
(58)
(33)
(42)
25.0 (5.4)
6 (86) 12 (100)
1 (14) 0 (0)
387
DISCUSSION
This study is among the first RCTs to include only
subjects with chronic incomplete SCI (AIS C and D)
> 2 years post-injury, when spontaneous recovery is
no longer expected. Furthermore, the study includes
a control group that received low-intensity usual care.
The effects of RALT were small and not statistically
significant. Similar to previous studies, RALT was well
tolerated and safe with no serious injuries reported (8).
Effects on walking
Our results confirm those of previous studies: Field-
Fote and co-workers reported non-significant impro-
vements in walking parameters both for RALT and
other interventions, except over-ground training, in a
group with baseline gait function similar to our study
(11), as did Duffell et al. (7) and Niu et al. in their
non-blinded RCTs (5). However, the latter study de-
monstrated significant improvements in walking speed
and endurance in the higher functioning group, and
Varoqui et al. reported 0.08 m/s improvement in their
I-group, against no effects in controls (6).
Effect on lower extremity muscle strength
LEMS scores > 30 are common in subjects with fun-
ctional walking, whereas scores < 20 are associated
J Rehabil Med 51, 2019