Peripheral arterial disease (PAD) is a vascular disorder resulting from atherosclerosis of the lower extremities and subsequently leading to decreased blood flow to the legs. This dissertation evaluates potential mechanisms contributing to gait dysfunction in PAD patients, age and reduced blood flow. Gait variability from joint angle data was used to compare normal walking with walking following an induced vascular occlusion in healthy young and older subjects. It was shown that amount of variability increased post occlusion and values of temporal structure of variability also increased in both healthy young and older individuals. Thus, reduced blood flow does contribute to the alterations in the variability of joint angle gait patterns of PAD patients.

The amount of change in the joint angle gait variability from baseline to post occlusion was compared between healthy young and older individuals to assess the effect of age. Results showed gait variability post occlusion was similar between the young and older groups when adjusted for baseline values. In both groups however, the amount of change from baseline to post vascular occlusion was not as severe as previously documented in symptomatic patients with PAD during pain free walking. Therefore, this dissertation also compared joint angle variability of healthy older adults with that of PAD patients during rested and reduced blood flow conditions. Again, amount of variability of joint angle patterns and values of temporal structure of variability of joint angle patterns were increased in PAD patients compared to healthy controls and in the reduced blood flow conditions compared to the rested conditions. Gait variability was affected both by PAD and by the presence of reduced blood flow, confirming our previous suggestions that reduced blood flow does not account for all of the gait variability differences between healthy individuals and those with PAD. Future studies should utilize gait variability to explore other potential mechanisms behind gait impairment in PAD patients.