Effects of lower extremity strength training on functional mobility in older adults

This study evaluated the effects of a 4-month lower extremity strength-training program on mobility in older adults. Eighty-five older adults (43 experimental, ES, and 42 comparison, CS) with a mean age of 72.3 years served as participants. The ES strength-trained plantar flexors (PF), knee flexors (KF), and knee extensors (KE) 1 hr/day, 3 days a week for 4 months. Both the ES and CS were evaluated for PF, KF, and KE strength (1RM) and the time required to complete floor rise, chair rise, 50-ft walk,and walking up and down stairs before and after the training intervention. The ES increased (p <.05) both absolute (51.9%) and relative strength (1RM/body weight, 52.4%) after training. Only chair-rise and floor-rise tasks improved significantly after training. Baseline and posttraining mobility tasks predicted from 1RMs had low to moderate R values. These results suggest that strength is necessary for mobility, but increasing strength above baseline provides only marginal improvement in mobility for reasonably fit older adults.