Effect of Unilateral and Bilateral Resistance Training on Muscle Force, Power and Asymmetry of Lower Extremity in Elderly Women

Abstract

As a training strategy for prevention of falling of the elderly, this study compared effect of unilateral resistance training with bilateral resistance training on muscle force, power and leg asymmetry during leg press movement. Twenty-three untrained elderly women(65-85 years) were participated in this study. They were randomly assigned to 3 groups: unilateral training group(UTG, n=8), bilateral training group(BTG, n=7), control(CG, n=8). Subjects in training groups followed elastic band protocol(10 exercises, 2-3 sets/exercise, 3 day/week) for 12 weeks. UTG exercised additionally more 1-2 sets in weaker leg than in stronger leg. Leg muscle force, power and leg asymmetry were measured at baseline and after training. Muscle force was increased significantly in BTG and UTG compared to CG in weaker side and bilateral side of low speed test. In high speed test, muscle force was increased significantly in BTG and UTG in weaker side. In power, UTG showed significantly increase in weaker side of low speed and stronger side of high speed. Both BTG and UTG significantly showed increase in bilateral side of low speed and weaker side of high speed. Force asymmetry was significantly decreased in UTG and BTG compared to CG in low speed and in only UTG of high speed. In conclusively, unilateral and bilateral resistance training increased muscle force and power in weaker leg. And force asymmetry was improved in both unilateral and bilateral training groups of low speed test and in only unilateral training group of high speed test.