SWEAT2 study: effectiveness of trunk training on muscle activity after stroke. A randomized controlled trial

Abstract

Background:Trunk training after stroke is an effective method for improving trunk control, standing balance and mobility. The SWEAT² study attempts to discover the underlying mechanisms leading to the observed mobility carry-over effects after trunk training. Aim: A secondary analysis investigating the effect of trunk training on muscle activation patterns, muscle synergies and motor unit recruitment of trunk and lower limbs muscles, aimed to provide new insights in gait recovery after stroke. Design: Randomized controlled trial Setting: Monocentric study performed in the rehabilitation hospital RevArte (Antwerp, Belgium) Population: Forty-five adults diagnosed with first stroke within five months, of which 39 completed treatment and were included in the analysis. Methods: Participants received 16 hours of additional trunk training (n=19) or cognitive training (n=20) over the course of four weeks (1 hour, 4 times a week). They were assessed by an instrumented gait analysis with electromyography of trunk and lower limb muscles. activating trunk muscles in isolation, as compared to 5% in the control group. Motor unit recruitment of the of trunk musculature showed decreased fast-twitch motor recruitment in the erector spinae muscle after trunk training: for the hemiplegic (t(37)=2.44,p=0.021) and nonhemiplegic erector spinae muscle (t(37)=2.36,p=0.024). Conclusions: Trunk training improves selective control and endurance of trunk musculature after sub-acute stroke. Clinical Trial Registration: Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT02708888 Clinical rehabilitation impact:  Trunk training does not alter muscle activation patterns or the amount of muscle synergies over time.  A decrease in fast-twitch motor recruitment in the erector spinae muscle was found during walking after trunk training  Trunk training seems to increase the fatigue-resistance of the back muscles and enables more isolated activation.

Unbiased estimation of the population-level motor module

“…Characterizing motor modules at the population level is a crucial step towards translating experimental findings into clinical applications. For example, evaluation of intervention effects on motor function before and after intervention [38][39][40][41][42][43][44][45][46][47][48][49] , and large cross-sectional clinical studies 38,50,51 need to capture effects as a population. The present study is the first to investigate the motor module estimation algorithm from a population-level perspective.…”