Gait alterations associated with walking impairment in people with peripheral arterial disease with and without intermittent claudication

Abstract

OBJECTIVES: To describe gait alterations associated with impaired walking endurance in patients with and without lower-extremity peripheral arterial disease (PAD) and determine whether the Caltrac accelerometer provides a valid measure of physical activity in PAD. DESIGN: Cross-sectional. SETTING: Academic medical center. PARTICIPANTS: PAD (n = 40) and non-PAD patients (n = 22) from two Chicago hospitals. MEASUREMENTS: Participants underwent measurement of the ankle brachial index (ABI), leg length, and 6-minute walk. Steps per minute and step length were measured during the first and last 100 feet of the 6-minute walk. Participants wore a Caltrac accelerometer, sensitive to vertical acceleration, during the 6-minute walk and for 7 continuous days. RESULTS: Five PAD participants (13%) and one non-PAD participant (5%) ceased walking before the end of 6 minutes. Among the remaining participants, distance walked in 6 minutes was more highly related to walking velocity during the last 100 feet of the walk than walking velocity during the first 100 feet. ABI was associated significantly with cadence (20.77 steps/minute per unit ABI, P