Middle Eastern Journal of Disability Studies

Abstract
Background & Objectives: Multiple sclerosis (MS) is a chronic neurological disorder that commonly affects individuals over the age of 20 and can impair motor control, including walking and balance disorders. Fatigue is a significant symptom among MS patients that can harm their quality of life and ability to perform daily activities. Regarding the deficiencies of posture control and the effect of fatigue on the quality of life of MS patients, the impact of fatigue caused by physical exercise on the posture control of these patients is worthy of consideration. So, this study aimed to investigate how physical exercise–induced fatigue affects MS patient's postural control.
Methods: This quasi–experimental study followed a pretest–posttest design with a control group. The statistical population comprised MS patients in Tehran City, Iran. The samples from among qualified volunteers were purposefully included in the study and were divided into control (20 people) and MS patients (18 people). The study's inclusion criteria for the study patients were as follows: individuals must have a confirmed diagnosis of MS by a qualified neurologist and fall within the age range of 20 to 50 years. Additionally, participants must have an Expanded Disability Status Scale score below 4.5, be able to stand for at least 30 seconds and walk independently for a minimum of 10 meters without the assistance of any devices. They should also be free of any cardiovascular or musculoskeletal disorders, not currently taking any medication that affects balance or fatigue, and without vision, hearing, or mental impairment. Lastly, they must possess the ability to perform active muscle contraction. The exclusion criterion was non–participation and lack of cooperation during the sessions. The indices of anteroposterior and mediolateral sway and sway area were obtained using the Kistler force ‎plate device to evaluate postural control in two stages: before and after fatigue due to physical exercise.‎ The Bruce modified fatigue protocol was used on a Sportec ‎treadmill to induce fatigue. The data analysis used descriptive statistical indicators such as mean and standard ‎deviation. In the inferential statistic, we conducted a multivariate analysis of the covariance test to ‎compare the effect of fatigue on the sway indices, anteroposterior, and mediolateral of the center of pressure (COP) in two groups: patients with MS and control. ‎The data were analyzed using SPSS software version 28, and the significance level of the tests was considered 0.05.
Results: The results of this study showed significant differences between the control and MS patients in the displacement of COP in the anteroposterior and mediolateral directions (p<0.001) and also in the sway area (p=0.003).
Conclusion: Based on the study results, a tiring movement task harms the postural control of people with MS, and it seems that fatigue caused by physical exercise leads to an increase in the displacement of the COP in MS patients compared to healthy people.