Exercise therapy in multiple sclerosis patients: effects of resistance training, additional electro-stimulation and whole body vibration on muscle functional capacity

Abstract

Background: One of the most invalidating secondary consequences of Multiple Sclerosis (MS) is muscle weakness and increased muscle fatigue. This may be due to inactivity and/or impaired motor unit recruitment. Recent literature date indicates that exercise therapy may beneficially affect muscle functional capacity in MS-affected persons. Aim: We examined the effect(s) of long-term standardized (adapted ACSM guidelines) resistance training, either or not in combination with electro-stimulation and whole body vibration on muscle functional capacity. Methods: A randomized controlled trial was performed in 33 MS-affected persons. At baselines and after 12 and 24 weeks of supervised light (12w, 30% 1RM, 2-3 session/w, 1-2 series) to moderate (24w, 60% 1RM, 2-3 session/w, 2 series) resistance training (RES, n=9, EDSS: 4.4±1.4), resistance training combined with electro stimulation (RES+EL, mA range, n=8, EDSS: 4.5±1.0) or whole body vibration training (WBV, 30-45Hz, 1-3 series, 30-60s, n=8, EDSS: 4.7±1.6) on maximal isometric (45°), isokinetic (180°/s) knee-extensor strength and muscle fatigue resistance (20 contractions, 180°/s) was measured on an isokinetic dynamometer and compared to a control group (CON, n=8, EDSS: 4.3±1.2). Results are presented in means±SD. Results: So far, patients have received 23w of supervised exercise therapy and baseline 12-week rehabilitation therapy results are analysed. In CON, maximal isometric and isokinetic knee-extension torque and fatigue resistance remained stable throughout the study. Maximal isometric muscle strength increased (p<0,05) in RES ranging from 136±38Nm to 152±41Nm. In RES±EL nor WBV no changes were detected following 12 weeks of light-intensity training. Maximal isokinetic muscle strength did not vary in RES nor RES±EL yet increased (p<0,05) from 88±25Nm to 97±31Nm in WBV. Finally, 12 weeks of light exercise therapy did not alter fatigue resistance in any group. Conclusion: Light intensity exercise therapy seems to affect some aspects of muscle functional capacity in MS-affect persons. Based on these results further improvements can be expected in the second part (12-24w) of the present exercise therapy program that is being finalised.