Gait variability in persons with multiple sclerosis

This thesis contains three investigations examining gait variability in people with multiple sclerosis (MS), which is a neurological disease that can result in significant walking impairment. Gait variability, i.e. fluctuations in the mechanics and kinematics of steps during walking, has been associated with motor control function, stability and falls in other populations but has not been thoroughly documented in people with MS. In this thesis, gait variability is documented in different samples of people with MS using a variety of metrics. The first investigation examines differences in variability of spatiotemporal gait parameters between people with MS and healthy controls and associations between variability of spatiotemporal gait parameters and disability in MS. The second investigation determines variability of lower-limb joint and segment angles at various walking speeds in MS. The third investigation documents a novel metric for quantification of footfall placement variability and subsequent associations between footfall variability and fall history in MS. Results herein include greater variability of step length, step time, and footfall placement variability in people with MS compared to controls, decrease in ankle angle variability with increasing walking velocity in MS, and that increased footfall placement variability, indexed by a novel metric, separates recurrent and non fallers with MS. Additional research into gait variability in MS is warranted to further evaluate differences between MS and controls as well as to investigate underlying factors that may drive gait variability in MS