Body-weight supported locomotor training in incomplete SCI
of subjects, since 2 subjects missed the baseline tes-
ting, and 3 were unable to perform the post-test due
to technical problems.
DISCUSSION
To the best of our knowledge, the present study is the
first RCT to include only subjects with longstanding
incomplete SCI (AIS C and D), > 2 years post-injury,
i.e. when spontaneous improvement is no longer ex-
pected. In addition, the study included a control group
that received usual treatment. The treatment effects
were modest, and not statistically significant.
Are the present results poor compared with previous
studies?
There are a number of previous RCT training studies
in SCI (13). However, they merely compare various
training forms without a control group receiving
the non-intensive training that is usual at this stage
post-injury. In the present context, these studies must
therefore be regarded as observational, presenting the
sum of spontaneous improvements and true training
effects. Only one non-randomized study from 1995 has
a control groups similar to ours (3). The positive results
of this study sparked interest in conducting training
studies, but the findings have not been replicated. A
large observational multicentre study recruited 146
patients early after SCI (8 weeks post-injury). The
patients were unable to walk, or needed assistance
to ambulate (15). Similar to our study, authors report
measured, but not statistically significant, improvement
in walking speed. A meta-analysis of the effects of
training is inconclusive (13), but methodological is-
sues complicate comparison of the studies. In general,
uncontrolled studies achieve better results, probably
due to spontaneous recovery, assessors’ bias etc. (2–6).
The majority of subjects in the current study had
some walking function at baseline, and both their
walking distance and speed increased or were main-
tained in the intervention group. However, the im-
provements were modest. The small improvement in
walking speed (0.1 m/s) may, however, be clinically
relevant (15, 22), but this is uncertain, since a walking
speed of at least 0.44 m/s is required for community
walking (7, 22, 23). A minimum of 46 m (22) or 31
m (13) increase in the 6MWT is considered clinically
meaningful, but the improvement in both of the groups
in the current study was smaller.
In line with this research, most previous studies
report small effects. Some found increased walking
speed of magnitude similar to the current study (0.2
m/s increase for the intervention group) (4, 5, 7, 13), 2
117
studies report greater (6, 24), and 2 somewhat poorer
improvement (8, 21). On average, our subjects impro-
ved distance walked/endurance by 25 m, comparable
to the findings of 2 other studies (8, 21). Two studies
have reported better results among those with post-
injury time from 8 weeks to < 3 years (5, 15) and one
reports poorer improvement (24).
Similar to 3 observational studies (5, 6, 21), subjects
in the current study who were unable to establish
walking function, had poorer baseline neurological
status (5, 6, 21) and balance (5) than the rest of the
group. On the other hand, and in line with previous
findings (5, 6, 21), subjects in the current study with the
weakest walking function tended to make the largest
percentage improvement.
Lower extremity muscle strength can predict
walking function in subjects with SCI, and scores of
30 or more are common in subjects with functional/
community walking ability, whereas scores < 20 are
associated with poor walking ability (7, 25, 26). LEMS
improved 2.7 points more in the intervention group
than among controls (not significant). Several studies
have shown that BWSLT improves lower limb strength
in subjects with SCI (3, 7, 8, 15, 21). Two studies (4,
21) report improvement of similar size as in the pre-
sent study, whereas another study (7) found as much
as 9.1 points improvement in LEMS in the BWSLT
group vs 2.9 points reduction in the physical therapy
group, possibly due to early onset of training and bet-
ter baseline function. In contrast to our study, others
have found that those with higher baseline LEMS
experience most improvement in walking speed (7,
25, 26). An improvement of > 6 points in LEMS may
be needed to detect a significant clinical change. It is
thus questionable whether the present small, border-
line significant improvement in LEMS contributes to
subjects’ walking ability. However, it is possible that
BWSLT can improve postural stability in standing and
sitting positions, through increased muscle strength
and coordination. The clinical importance of the cur-
rent findings seems to be modest, but even a small
improvement may be important to an individual who
struggles to cope with activities of daily living (5, 13).
Was the function too poor at baseline?
We chose to study subjects with poor baseline walking
function since data on their training effects are scarce.
Previous studies included no, or only a few, subjects
who were unable to stand or to move at least 1 step (4,
7, 15). In the large observational study the majority of
non-responding subjects were among those with poor
baseline function (5). However, in addition, a large
proportion (13 of 19 AIS D and 15 of 50 AIS C) who
were unable to ambulate at baseline, had regained some
J Rehabil Med 51, 2019