Abstract 557: Stretching With Ankle Dorsiflexion Splint Improves Measures Of Microvascular Reactivity And Oxygen Extraction In Patients With Peripheral Artery Disease

Abstract

Peripheral Artery Disease (PAD) is a vascular disease that affects over 8 million Americans. PAD patients commonly have difficulty walking due to pain in the legs during physical exertion. Supervised walking therapy has been recommended to improve walking performance and attenuate disease progression; however, this therapy remains underutilized in PAD patients. Recently, there has been evidence to suggest that stretching accomplished via an ankle dorsiflexion splint may improve vascular health and walking performance in PAD; however, it is currently unknown how this protocol affects tissue oxygenation (StO 2 ). The purpose of this study was to determine the impact of 4 wks of ankle dorsiflexion stretching on measures of tissue oxygenation in patients with PAD. Thirteen PAD patients (67.7 ± 7.9 years) were randomized to a stretch (n = 9) or a non-stretch control (n = 4) group. Patients in the stretch were instructed to wear the splint for 30 min/day, 5 days/wk for 4 wks. A 5-min vascular occlusion test was administered before and after the intervention. Measures of StO 2 recovery were calculated following the vascular occlusion test and while completing a 6-minute walk test (6MWT). All measures of StO 2 were derived via Near-Infrared Spectroscopy. Repeated measures ANOVA was used to analyze data. There was a significant improvement in StO 2 recovery in the stretch group compared to the control (Stretch: 0.35 ± 0.25 %/sec vs 0.53 ± 0.29 %/sec; Control: 0.57 ± 0.43 %/sec vs 0.32 ± 0.19 %/sec; p = 0.002). During the 6MWT, patients completing the stretching protocol significantly improved oxygen extraction in the first minute of the test (-0.63 ± 0.05 StO 2 vs -0.73 ± 0.09 StO 2 ); however, this improvement was not significantly different compared to changes in the control group. These results indicate an improvement in microvascular reactivity and oxygen extraction following 4 wks of splint-based stretching. This stretching intervention holds potential therapeutic value for PAD patients and warrants further investigation.