Multiple sclerosis (MS) a demyelinating disease where an autoimmune response damages the myelin sheaths surrounding sensory and motor neurons of the central nervous system. Fifty percent of the MS population reports decreased mobility while walking and experiences falls in day-to-day activities. Past studies have reported gait impairments, including reduced step length and reduced knee flexion, however, these studies compared individuals with and without MS at preferred speeds. In these studies, people with MS preferred to walk at slower speeds, which could explain the altered gait patterns demonstrated. Therefore, in the current study, we assessed joint kinematics of the ankle, knee, pelvis, and trunk at three matched speeds slow (0.6 m/s), medium (1.0 m/s), and fast (1.4 m/s) and preferred speed, and compared between individuals with and without MS. We found that individuals with MS have decreased sensation during a tuning fork vibration assessment, and longer walking times at both brisk and preferred walking speeds. Individuals with MS tended to restrict their knee ROM across walking speeds, which may have required increased motion of the pelvis, particularly at faster walking speeds. At the knee, the appropriate tuning of knee ROM to walking speed was blunted in the MS group. This is particularly evident at the higher walking velocities and may indicate a freezing of degrees of freedom under increasing task demands. Given the reduced sensation at the foot plantar surface in the MS cohort, which can lead to instability and greater reliance of visual information to guide foot placement, this cohort may be reluctant to increase ROM with faster speeds. Increased knee movement could introduce more variability of foot position at heel strike. With impaired foot sensation, less knee movement may be desirable because it reduces the variability of foot placement that must be detected by the somatosensory system in order to maintain stability. A poster derived from Data Analysis and academic research paper composition with Dr. Stephanie Jones, Assistant Professor of Exercise & Sport Studies.
by Kayleigh Boos ‘21