Influence of a locomotor training approach on walking speed and distance in people with chronic spinal cord injury: a randomized clinical trial

Abstract

Background: Impaired walking limits function after spinal cord injury (SCI), but training-related improvements are possible even in people with chronic motor incomplete SCI.

Objective: The objective of this study was to compare changes in walking speed and distance associated with 4 locomotor training approaches.

Design: This study was a single-blind, randomized clinical trial.

Setting: This study was conducted in a rehabilitation research laboratory.

Participants: Participants were people with minimal walking function due to chronic SCI.

Intervention: Participants (n=74) trained 5 days per week for 12 weeks with the following approaches: treadmill-based training with manual assistance (TM), treadmill-based training with stimulation (TS), overground training with stimulation (OG), and treadmill-based training with robotic assistance (LR).

Measurements: Overground walking speed and distance were the primary outcome measures.

Results: In participants who completed the training (n=64), there were overall effects for speed (effect size index [d]=0.33) and distance (d=0.35). For speed, there were no significant between-group differences; however, distance gains were greatest with OG. Effect sizes for speed and distance were largest with OG (d=0.43 and d=0.40, respectively). Effect sizes for speed were the same for TM and TS (d=0.28); there was no effect for LR. The effect size for distance was greater with TS (d=0.16) than with TM or LR, for which there was no effect. Ten participants who improved with training were retested at least 6 months after training; walking speed at this time was slower than that at the conclusion of training but remained faster than before training.

Limitations: It is unknown whether the training dosage and the emphasis on training speed were optimal. Robotic training that requires active participation would likely yield different results.

Conclusions: In people with chronic motor incomplete SCI, walking speed improved with both overground training and treadmill-based training; however, walking distance improved to a greater extent with overground training.

Figures

Figure 1.

Flow of participants through the locomotor training study. LR=treadmill-based training with robotic assistance, OG=overground training with electrical stimulation, TM=treadmill-based training with manual assistance, TS=treadmill-based training with electrical stimulation.

Figure 2.

Proportions of “less impaired” and “more impaired” participants in each training group who achieved a minimally important difference in walking speed. Dark gray bars represent participants classified as more strength impaired. Light gray bars represent participants classified as less strength impaired. Values represent the proportion of participants in a category whose walking speed had improved by at least 0.05 m/s after training. LR=treadmill-based training with robotic assistance, OG=overground training with electrical stimulation, TM=treadmill-based training with manual assistance, TS=treadmill-based training with electrical stimulation.

Figure 3.

Proportions of less impaired and more impaired participants in each training group achieving a minimally important difference in walking distance. Dark gray bars represent participants classified as more strength impaired. Light gray bars represent participants classified as less strength impaired. Values represent the proportion of participants in a category whose walking distance on the 2-minute walk test had improved by at least 4 m after training. LR=treadmill-based training with robotic assistance, OG=overground training with electrical stimulation, TM=treadmill-based training with manual assistance, TS=treadmill-based training with electrical stimulation.

Figure 4.

Changes in walking speed overall and by training group. Data were obtained before training, at the conclusion of training, and at follow-up (retention) from 10 participants who had improved by the conclusion of training, overall and by training group. All 10 participants returned for follow-up retention testing at least 6 months (mean=20.3 months, SD=14.3 months) after completing training. LR=treadmill-based training with robotic assistance, OG=overground training with electrical stimulation, TM=treadmill-based training with manual assistance, TS=treadmill-based training with electrical stimulation.