Strength training improves fall-related gait kinematics in the elderly: a randomized controlled trial.

BACKGROUND Falls are one of the greatest concerns among the elderly. Among a number of strategies proposed to reduce the risk of falls, improving muscle strength has been applied as a successful preventive strategy. Although it has been suggested as a relevant strategy, no studies have analyzed how muscle strength improvements affect the gait pattern. The aim of this study was to determine the effects of a lower limb strength training program on gait kinematics parameters associated with the risk of falls in elderly women. METHODS Twenty seven elderly women were assigned in a balance and randomized order into an experimental (n=14; age=61.1 (4.3)years, BMI=26.4 (2.8)kgm(-2)) and a control (n=13; age=61.6 (6.6)years; BMI=25.9 (3.0)kgm(-2)) group. The EG performed lower limb strength training during 12 weeks (3 days per week), being training load increased weekly. FINDINGS Primary outcomes were gait kinematics parameters and maximum voluntary isometric contractions at pre- and post-training period. Secondary outcomes were training load improvement weekly and one repetition maximum every two weeks. The 1 maximal repetition increment ranged from 32% to 97% and was the best predictor of changes in gait parameters (spatial, temporal and angular variables) after training for the experimental group. Z-score analysis revealed that the strength training was effective in reversing age-related changes in gait speed, stride length, cadence and toe clearance, approaching the elderly to reference values for healthy young women. INTERPRETATION Lower limb strength training improves fall-related gait kinematic parameters. Thus, strength training programs should be recommended to the elderly women in order to change their gait pattern towards young adults.