Suspension training improves bilateral isometric strength asymmetry of knee muscles in people with multiple sclerosis

Abstract

Introduction: Most people with multiple sclerosis are diagnosed with bilateral strength asymmetry in the lower limbs. Strength asymmetry increases muscle metabolic cost, muscle fatigability, postural instability, gait disturbance, imbalance, and risk of falling, and negatively affects the quality of life in PwMS. So far, the effects of rehabilitation exercises on reducing the asymmetric index in this population has not been studied convincingly. The purpose of this study was to investigate the effect of suspension exercise on bilateral isometric strength asymmetry of knee muscles in patients with multiple sclerosis. Materials & methods: In this randomized controlled trial, twenty-seven female patients were purposively selected as the statistical sample and randomly divided into the control (n = 13, age: 34.72 +/- 5.01 years) and exercise (n = 14, age: 37.62 +/- 4.58 years) groups. The control group received routine care while the exercise group received the suspension exercise protocol. Isometric muscle strength and bilateral asymmetry were measured at baseline and after 8 weeks. The Biodex isokinetic dynamometer was used to measure the maximal voluntary isometric contraction of the flexor and extensor muscles of the knee. The analysis of covariance was used to analyze the data. Results: The isometric strength of the knee extensor muscles in the weak leg at the angle of 20 degrees and in both legs at the angle of 70 degrees in the exercise group improved significantly. Furthermore, the strength of the knee flexor muscles in the exercise group was increased. The amount of bilateral strength asymmetry in the knee flexor and extensor muscles at the angle of 70 degrees significantly decreased in the exercise group. Discussions & conclusions: These data suggest that suspension training is a practical approach to manage bilateral asymmetry in knee flexor and extensor muscle strength in patients with an EDSS of less than four.