IS LOWER-EXTREMITY STRENGTH GAIN ASSOCIATED WITH IMPROVEMENT IN PHYSICAL PERFORMANCE AND DISABILITY IN FRAIL, COMMUNITY-DWELLING ELDERS

Background: Strength loss is strongly associated with functional decli ne and is reversible with exercise. The effect of increased strength o n function has not been clearly established. The purpose of this study was to determine whether strength gain is associated with improvement in physical performance and disability. Methods: One hundred function ally impaired community-dwelling men and women (77.6 +/- 7.6 yrs) were tested at baseline and outcome for lower extremity strength, physical performance, and disability. After random group assignment, exercise participants received strengthening exercises in their homes three tim es a week for 10 weeks while control subjects continued their normal a ctivities. Using multiple regression techniques, the relationship betw een strength gain and improvement in physical performance and disabili ty was assessed, controlling for age, depression, and baseline strengt h. Results: A significant impact of strength gain on mobility skills ( p = .0009) was found. The impact of strength gain on chair rise perfor mance was significant in participants who were more impaired (p = .04) . Strength gain was associated with gain in gait speed (p = .02) and i n falls efficacy (p = .05), but not with other balance, endurance, or disability measures. Conclusions: Lower extremity strength gain is ass ociated with gains in chair rise performance, gait speed, and in mobil ity tasks such as gait, transfers, stooping, and stair climbing, but n ot with improved endurance, balance, or disability. Strength gain is a lso associated with improvement in confidence in mobility. Factors tha t may influence the ability of strength gain to affect function are in itial level of frailty and specificity of exercise. These results supp ort the idea that strength training is an intervention that can potent ially improve physical health status in many frail elders. (C) 1998 by the American Congress of Rehabilitation Medicine and the American Aca demy of Physical Medicine and Rehabilitation.