Sex differences in strength, functional capacity and mobility in patients with multiple sclerosis: An exploratory analysis

Background: Physical exercise programs are commonly designed without consideration for sex differences. Nevertheless, disease progression exhibits sex -specific patterns, resulting in different functionality and strength performances. Objectives: To analyze sex differences in strength, functional capacity, and mobility, and to evaluate sex-dependent differences in leg strength in multiple sclerosis (MS) patients. Methods: A cross-sectional study was conducted with 35 participants (female: n = 19; Expanded Disability Status Scale (EDSS) = 3.0 +/- 1.2, male: n = 16; EDSS = 3.3 +/- 1.2). Body composition, maximal voluntary isometric contraction (MVIC), explosive strength (rate of force development, RFD), central activation ratio (CAR), functional capacity, and mobility were assessed. Results: Differences were observed between males and females (p = 0.001) in height, lean body mass and MVIC. No differences were observed in the other variables. Regarding the leg asymmetry, men showed higher values in the stronger leg for both MVIC (p < 0.001, d =large) and RFD, whereas women showed higher values only in RFD. Men with MS demonstrated a greater capacity to produce maximal strength than women with this disease. Conclusions: The results found suggest that maximum strength differs between men and women in our sample of patients with multiple sclerosis. Furthermore, the weaker leg, regardless of sex, exhibits poorer results in explosive strength compared to the stronger leg. However, maximum strength only shows differences in men and not in women. Therefore, these findings should serve as a basis for rehabilitation professionals when planning training programs for this population.