Exploration of arm weight effects on hemiparetic stroke participants' gait performance.

Background: This study explores the potential benefits of an arm weight intervention for improving gait performance in stroke survivors. Consistent with an interlimb neural coupling mechanism, the investigators hypothesized that arm weight would improve gait performance.

Methods: Nine stroke and nine healthy participants (1 female; age: 58.0 ± 6.8 years) participated. Participants walked over-ground at their preferred speed in four conditions: no weight (C1), non-hemiparetic (healthy: dominant) side weights (C2), hemiparetic (non-dominant) side weights (C3), and bilateral weights (C4). Statistical analyses included repeated analysis of variance (ANOVA) and paired t-test planned comparisons to explore the effects of added weight on gait speed, step width, step length, cadence, and arm swing amplitude. Single-subject analyses used randomization tests to delineate further the weight's effect on gait speed.

Findings: The stroke group walked significantly faster with arm weight (p = 0.048), exhibiting large ANOVA (η = 0.28) and C1 vs. C4 planned comparison (p = 0.021; d = 0.95) effect sizes. Four of nine stroke participants significantly increased gait speed in at least one condition, and seven of nine exhibited large effect size increases (d = 0.85-4.71). The stroke group's hemiparetic-side step length and cadence significantly (p = 0.008) increased in C4 compared to C1, exhibiting large effect size increases (r = 0.96). Four of nine healthy participants significantly increased gait speed in at least one condition, with five of nine exhibiting large effect size increases (d = 0.80-6.63).

Interpretation: This study's exploratory results demonstrate arm weight's potential for improving higher-functioning stroke survivors' gait performance. Arm weight addition merits further investigation as a possible rehabilitation intervention in the stroke population.