Gutierrez, G. M., Chow, J. W., Tillman, M. D., McCoy, S. C., Castellano, V., & White, L. J. (2005). Resistance training improves gait kinematics in persons with multiple sclerosis. Arch Phys Med Rehabil., 86, 1824-1829.
Abstract by:
Sherri L. LaVela, MPH
Purpose: To assess the effects of an 8-week resistance training program on walking ability in individuals with multiple sclerosis (MS). The authors hypothesized that following the 8-week training program, gait characteristics in persons with MS would become significantly more consistent with normal gait patterns that are seen in people who are unimpaired.
Participants: Subject inclusion criteria included: neurologist diagnosis of relapsing-remitting MS (in remission); Expanded Disability Status Scale (EDSS) scores from 2.5 to 5.5; and non-sedentary (involved in light physical activity during the prior 3 months). Individuals were excluded if they were using prednisone or antispasmodic medications or had known metabolic conditions or orthopedic limitations.
Method: A repeated measures design was used to examine an 8-week, twice-weekly progressive resistance-training program. Measures included: low-limb strength, gait kinematics, 3-minute stepping, fatigue (Modified Fatigue Impact Scale (MFIS)), self-reported disability (EDSS), and self-report of more/less-affected limbs in terms of strength, sensation, and/or coordination. Measures were assessed at baseline and repeated within a week following the intervention (post-test). Two visits occurred for each, with gait assessed during one visit and leg strength during the other (order based on availability). Descriptive statistics were calculated for the gait parameters; nonparametric Wilcoxon rank tests were used to assess changes in gait, EDSS, and fatigue. Paired t-tests were used for pre-/post-comparisons in isometric strength. Alpha was 0.05.
Results: Eight subjects who had physician clearance to be in the study were enrolled and completed the program (mean values of age = 46 years; height = 1.66 m; mass = 77 kg; EDSS score = 3.6). Adherence was 100%, with adjustments for missed workouts. Lower-limb strength increased for isometric knee extension (by 7.2%, p = 0.03) and plantarflexion (by 55%, p = 0.04), but did not change for knee flexion or dorsiflexion between pre- and post-measures. Subjects significantly decreased percentage of time spent in the stance phase and increased percentage of time in the swing phase for the more-affected limb. In the less-affected limb, there were significant increases in step length and foot angle, and toe clearance significantly decreased. When both limbs were measured, significant decreases were found in the time and percentage of time spent in double support, and a significant increase was noted in stride length. Three-minute stepping improved by 8.7% (no p-value). Mean MFIS scores changed from 32 to 26 (post-program)(p = 0.04). EDSS scores decreased from 3.7 to 3.2 following 8 weeks of training (n.s.).
Discussion: The authors hypothesized that the 8-week resistance-training program would modify gait characteristics to become more consistent with patterns of individuals without neurologic dysfunction. Findings showed that lower-limb strength increased for some muscle groups/joint angles, but not others, and that many measures of gait improved after the program. The hypothesis was supported in that the improvements that were seen made the gait characteristics of those with MS more closely resemble that of those who are unimpaired. In addition, significant improvements were seen in fatigue, as were improvement trends in 3-minute stepping and self-reported disability.
The study may not be generalizable due to the non-experimental design, small sample, and the restriction to individuals who had already been involved in light physical activity in the past 3 months and who had relapsing-remitting MS. Testing effects (due to repeated measures) and instrumentation effects were possible threats to internal validity. Despite these limitations, it is important to recognize that programs such as resistance training can improve gait characteristics and ultimately lead to improved walking ability in persons with MS. The 100% adherence in this sample suggests that this type of program is feasible in a similar cohort of persons with MS. Finally, comments offered by study participants indicated that this training program allowed them to participate in activities they had previously given up (e.g., shopping, hiking), suggesting, at least anecdotally, that the benefits of this type of program can indirectly improve participation in desired activities and lead to a better quality of life.