Two weeks of ischemic conditioning improves walking speed and reduces neuromuscular fatigability in chronic stroke survivors

Abstract

This pilot study examined whether ischemic conditioning (IC), a noninvasive, cost-effective, and easy-to-administer intervention, could improve gait speed and paretic leg muscle function in stroke survivors. We hypothesized that 2 wk of IC training would increase self-selected walking speed, increase paretic muscle strength, and reduce neuromuscular fatigability in chronic stroke survivors. Twenty-two chronic stroke survivors received either IC or IC Sham on their paretic leg every other day for 2 wk (7 total sessions). IC involved 5-min bouts of ischemia, repeated five times, using a cuff inflated to 225 mmHg on the paretic thigh. For IC Sham, the cuff inflation pressure was 10 mmHg. Self-selected walking speed was assessed using the 10-m walk test, and paretic leg knee extensor strength and fatigability were assessed using a Biodex dynamometer. Self-selected walking speed increased in the IC group (0.86 0.21 m/s pretest vs. 1.04 0.22 m/s posttest, means SD; P 0.001) but not in the IC Sham group (0.92 0.47 m/s pretest vs. 0.96 0.46 m/s posttest; P 0.25). Paretic leg maximum voluntary contractions were unchanged in both groups (103 57 N·m pre-IC vs. 109 65 N·m post-IC; 103 59 N·m pre-IC Sham vs. 108 67 N·m post-IC Sham; P 0.81); however, participants in the IC group maintained a submaximal isometric contraction longer than participants in the IC Sham group (278 163 s pre-IC vs. 496 313 s post-IC, P 0.004; 397 203 s pre-IC Sham vs. 355 195 s post-IC Sham; P 0.46). The results from this pilot study thus indicate that IC training has the potential to improve walking speed and paretic muscle fatigue resistance poststroke.