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 (1 RM) 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 (1 RM/body weight, 52.4%) after training. Only chair-rise and floor-rise tasks improved significantly after training. Baseline and posttraining mobility tasks predicted from 1 RMs 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.
All the authors are affiliated with the Atlanta VA Medical Center, Rehabilitation Research & Development Center, in Decatur, GA 30033. L. Jerome Brandon is also with the Department of Kinesiology & Health at Georgia State University, Atlanta, GA 30303, and he and Lisa W. Boyette are also with the Division of Geriatric Medicine and Gerontology, School of Medicine, at Emory University, Atlanta, GA 30329.