| dc.description.abstract | Persons with multiple sclerosis often report problems with gait and general instability during walking, possibly due to the disease’s disruption of sensorimotor function. Understanding variability of upper and lower body segments during walking is fundamental for assessing gait and balance, fall risk, and identifying differences in variability between healthy control subjects and persons with MS may help uncover specific control strategies in the healthy dynamic system necessary for maintaining overall stability. The primary purpose of this study is to examine the relationship between movement of upper and lower body segments during walking in healthy adults and in persons with multiple sclerosis. Currently no studies have compared upper and lower segmental control in patients with MS with that of healthy controls during walking. Forty patients with MS and forty healthy control subjects were recruited for gait assessment while wearing wireless inertial sensors. Wireless sensors were attached to the trunk and right foot and subjects walked on a treadmill at self-selected pace. Measures of linear (range, root mean square) and nonlinear (approximate entropy, sample entropy, Lyapunov exponent, recurrence quantification analysis %recurrence) variability were calculated from the acceleration time series recorded by the inertial sensors. Paired t-tests were used to test for differences due to location in healthy controls. Two two-way ANOVAs were used (one for the frontal plane and one for the sagittal plane) to test for main effect of group and main effect of sensor location on each of the variability measures. Pearson’s correlations were applied to evaluate relationships between variability of acceleration at the trunk and at the foot within the frontal and sagittal planes. No main effect of group was found for any variability measures. Main effect of location was found for all variability measures, with magnitudes of variability greater at the feet compared to the trunk and structure of variability showing more predictable variability patterns at the foot compared to the trunk. Significant correlations were found between trunk and foot accelerations in the frontal plane for RMS, range, ApEn, SaEn, and LyE, and in the sagittal plane for RMS, ApEn, SaEn, and RQA %REC in healthy controls. For persons with MS, significant correlations were found between trunk and foot accelerations in the frontal plane for RMS, range, and LyE, and in the sagittal plane for RMS, range, ApEn, and LyE. The current study found that variability of upper and lower body segments was significantly altered in persons with MS compared to healthy controls. MS appears to affect the relationships between motion of the feet and motion of the trunk during walking indicating that underlying control mechanisms which govern gait stability may be altered in persons with MS. These control systems may be affected by the pathophysiology of MS, particularly the slowed conduction velocity in the neurons of the central nervous system which ultimately make up the wiring of these control systems. Examining relationships between upper and lower segment motion during walking may therefore be able to provide more relevant gait assessments across various populations, including those with neuromuscular disorders. Assessments based on these measures may ultimately provide therapists with a tool to measure gait stability and gait function. | |
