Feasibility of lower-limb muscle power training to enhance locomotor function poststroke

Abstract

Abstract-Poststroke motor control is characterized by greatly reduced muscle power generation. To date, the extent to which muscle power limits walking performance or whether its remediation should be a primary component of locomotor rehabilitation has yet to be established. The purpose of this study was to examine the feasibility and the effects of Poststroke Optimization of Walking using Explosive Resistance training, an intervention aimed at improving poststroke muscular and locomotor function. Twelve subjects (6-60 mo poststroke) participated in 24 training sessions (3 sessions/wk for 8 wk). Exercises included leg press, calf raises, and jump training, all performed at high concentric velocity, as well as trials of fast walking. We measured selfselected and fastest comfortable walking speeds as well as knee extensor and plantar flexor strength and power at pretraining, posttraining, and 8 wk follow-up time points. In addition, we also performed a number of clinical assessments commonly used in poststroke rehabilitation trials. Following training, significant improvements in lower-limb muscle strength and power were realized and accompanied by improvements in self-selected as well as fastest comfortable walking speeds. No changes in clinical assessments resulted from training.

A systematic review of mechanisms of gait speed change post-stroke. Part 2: exercise capacity, muscle activation, kinetics, and kinematics

“…Four of the included studies utilized a strength training intervention through power training, 26 by comparing eccentric and concentric resistance training, 29,44 or strength training exercises. 34 The change in gait speed effect sizes range from 0.4 to 0.67.…”

POWER training in chronic stroke individuals: differences between responders and nonresponders

“…34 The majority of rehabilitation research has focused on traditional resistance training in individuals post-stroke, 22,35–37 with only one other study focusing on power training. 21,38 Therefore, it is difficult to compare our results to previous studies, however comparisons have been made to higher intensity resistance training programs and the one study found that focuses on the time component needed for proper power training.…”

“…This criterion was used because differences in lower limb maximal velocity occur at relatively low external forces and are most closely associated with gait velocity in older individuals. 21,29 Peak isotonic paretic (PKP) and non-paretic knee power (NPKP) were normalized to bodyweight (kg) for data analysis.…”

“…16 treadmill walking with or without body weight support, 17–19 biofeedback therapy, 20 and progressive strength training. 21,22 However, a critical review of post-stroke walking rehabilitation interventions found no differences in post-treatment self-selected walking speed (SSWS) changes across widely used rehabilitation modalities. 23 This lack of superiority amongst intervention approaches may reflect the heterogeneity of the post-stroke population and the various deficits that likely contribute to post-stroke walking dysfunction.…”

“…21,24 To better understand which individuals respond to this type of training, our interest in the current study was in analyzing subgroups of “responders” and “non-responders” to this training intervention. Specifically, the purpose of this paper was to determine baseline and training response differences in individuals who achieved a minimal clinically important difference (MCID) of ≥0.16 m/s in walking speed to those who achieved only minimal gains following POWER training.…”