Journal of Rehabilitation Medicine 51-2 | Page 42

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