Amount of Step Width Variability is Increased in Patients with Peripheral Arterial Disease

Introduction: Peripheral Arterial disease (PAD) involves blockages of arteries in the legs and affects up to12 million Americans, most of whom are elderly. These individuals also have increased incidence of falls compared to healthy older without PAD. Abnormally high or low step width variability has also been linked to falls and may play a role into mechanisms of falls in patients with PAD. This study investigates the step width variability in patients with PAD. Methods: Patients with PAD and healthy, age matched controls walked at a self-selected pace in a pain free condition. To calculate step width, medial-lateral distances were taken from the heel strike of the right foot to the heel strike of the left foot and vice versa for 212 steps. Standard deviation, coefficient of variation and sample entropy were calculated and differences between the two groups were measured using independent t-tests. Results: Step width standard deviation was significantly higher for patients with PAD compared with healthy controls (p=0.006). No significant differences were found for the coefficient of variation or sample entropy. Discussion: Patients with PAD have significantly higher step width variability compared to healthy controls prior to the onset of walking pain. This increased variability is consistent with increased falls in patients with PAD. Since PAD causes damage to muscle and nerve fibers, such damage could be contributing to increased step width variability. Future research should examine whether this increased step width variability is caused from the neural or muscular damage to determine effective treatment options