Serial Backward Locomotor Treadmill Training Improves Bidirectional Walking Performance in Chronic Stroke

Abstract

Background and research question: Walking impairment remains a major limitation to functional independence after stroke. Yet, comprehensive and effective strategies to improve walking function after stroke are presently limited. Backward Locomotor Treadmill Training (BLTT) is a promising training approach for improving walking function; however, little is known about its mechanism of effect or the relationship between backward walking training and resulting overground forward walking performance. This study aims to determine the effects of serial BLTT on spatial aspects of backward and forward walking in chronic post-stroke individuals with residual walking impairment.

Methods: Thirty-nine adults (>6 months post-stroke) underwent 6 days of BLTT (3 × /week) over 2 weeks. Outcome measures included PRE-POST changes in backward and forward walking speeds, paretic and non-paretic step lengths, and single-support center of pressure distances. To determine the association between BLTT and overground walking, correlation analyses comparing training-related changes in these variables were performed.

Results: We report an overall improvement in BLTT and overground walking speeds, bilateral step lengths, and single-support center of pressure distances over six training sessions. Further, there were weak positive associations between PRE-POST changes in BLTT speed, BLTT paretic step length, and overground forward walking speed.

Conclusion and significance: Our findings suggest that individuals with chronic post-stroke walking impairment experience improvements in spatial walking measures during BLTT and overground. Therefore, BLTT may be a potential adjunctive training approach for post-stroke walking rehabilitation.

Keywords: backward locomotion; backward treadmill training; gait rehabilitation; post stroke walking rehabilitation; walking impairment.

Figure 1

Backward locomotor treadmill training (BLTT) protocol. Study participants underwent six, 30-min sessions of BLTT over a 2-week period (red cubes). Outcome measures were obtained prior to training at baseline (D2), subsequent training days (D3–D7), and ~24 h following the completion of training (D8).

Figure 2

Backward locomotor training (BLTT) speed and step length over six training sessions. Mean progression in BLTT speed (A) paretic and non-paretic step lengths (B) per training session from baseline (D2) through session 6 (D7), (error bars show standard error, ****indicates significance level <0.001).

Figure 3

Ten meter walk test (10-mWT). Mean change in 10-mWT speed relative to baseline [dotted line signifies the minimal clinically important difference (MCID)- ≥0.15 meters/s] (A). Mean training-related change in paretic and non-paretic step lengths (B), and percent single support times (C) (error bars are standard error, ****indicates significance level <0.001, ***level <0.01).

Figure 4

Correlation analysis of backward locomotor treadmill training change in BLTT speed (A) and paretic Step Length (B) and overground walking speed on the 10-meter walk test.