Abstract 289: Abnormal Gait Pattern at Comfortable and Fast Walking Speed in Patients With Peripheral Arterial Disease

Abstract

Background: Characteristics of gait in peripheral arterial disease (PAD) patients are short step length and slow walking speed. It was reported that reduced walking speed was associated with increasing mortality in PAD patients. However, the detail of gait in PAD patients has not been fully clarified. We hypothesized that PAD patients show abnormal gait pattern, in particular in late stance phase (propulsion phase), at comfortable and fast walking speed. Methods: Sixteen symptomatic PAD patients (71±9 years old), who were 11 bilateral and 5 unilateral intermittent claudication (27 claudication limbs), and 7 healthy controls (14 healthy limbs) were recruited. With a 3-dimensional motion analysis system, peak hip joint generated power (HJP: pull-off power) and ankle joint generated power (AJP: push-off power) in late stance were analyzed at comfortable and fast walking speed. Ankle/hip (A/P) peak power ratio was calculated to determine whether hip or ankle power was dominantly used in late stance during walking. Results: Mean ankle-brachial index was 0.63±0.20 in claudication limbs. Pain lesions were buttock, thigh and calf in 8, 3 and 16 limbs, respectively. Compared with healthy controls, the PAD patients showed significant slower walking speed and shorter step length at comfortable and fast walking speed (p< 0.001). The peak HJP and AJP in late stance were significantly lower in the PAD patients at both walking speed. However, when gait speed adjusted, only peak HJP in late stance was significantly lower in the PAD patients at comfortable walking speed (p=0.025). The A/P peak power ratio was higher in the PAD patients at comfortable and fast walking speed (p=0.020, p=0.045, respectively). Among the PAD patients, the HJP, AJP and A/P peak power ratio were not significantly different between buttock pain and calf pain. Conclusions: PAD patients used relatively ankle planter flexors to compensate a muscle weakness of hip flexor at comfortable and fast walking speed. These results suggest that exercise training for hip flexor muscle may increase walking distance and mitigate calf pain during walking in PAD patients.