Aerobic Endurance and Leg Strength are Predictive of Gait Velocity among Community-Dwelling Stroke Survivors

Background: Gait velocity is an objective, fundamental indicator of post-stroke walking ability. Most stroke survivors have diminished aerobic endurance and paretic leg strength, with one or both of these conditions affecting their gait velocity. Other reported underlying factors affecting gait velocity include functional disability, balance and cognitive impairment.

Objective: To examine potential independent predictors of gait velocity in chronic stroke.

Methods: Cross-sectional design using baseline data from the first 100 community-dwelling stroke survivors enrolled in an exercise intervention study. Eligible subjects included men and women aged ≥ 50 years and at ≥ 3 months post-stroke. Subjects completed a comprehensive, self-administered health survey prior to their baseline study visit. At the baseline visit, functional disability (Modified Rankin Scale), aerobic endurance (2-minute step-test), leg strength (timed 5-chair stand test), balance (single-leg stance) and cognitive impairment (Mini-Mental Status Exam) were assessed. Gait speed was assessed using a valid and reliable timed 4-meter walk test designed for older adults with disabilities; to calculate gait velocity (meters/second). Multiple linear regression was conducted to explore potential independent predictors of gait velocity.

Results: Subjects (n=100) were on average 70±10 years old, and 39±49 months post-stroke. The majority reported an ischemic stroke (68/100) with hemiparesis (80/100); and were married (59/100), White/European-American (78/100), college-educated (79/100), men (54/100). Subjects had an average gait velocity of 0.75±0.23 meters/second, categorized as limited community walkers. Approximately 37% of the variance in gait velocity, could be explained by the optimal combination of the independent variables in the model: functional disability, aerobic endurance, leg strength, balance, and cognitive impairment (R2=0.37, F5,74=8.64, p<0.01). Only better aerobic endurance (t1,74=3.41, p<0.01) and leg strength (i.e. faster chair stand time) (t1,74=–2.23, p=0.03) contributed uniquely and significantly to faster gait velocity.

Conclusion: A hallmark of gait dysfunction in chronic stroke is slow gait velocity, even among well-educated, community-dwelling survivors. Gait velocity is simple to measure requiring only a stopwatch and flat surface for walking. Our findings are similar to reports by others that diminished aerobic endurance and leg strength are major contributors to slow gait velocity in chronic stroke. Long term rehabilitation efforts are needed to improve gait velocity in chronic stroke, and may need to incorporate multifaceted strategies concurrently, focusing on aerobic endurance and leg strength, to maximize community ambulation and reintegration.