RACIAL-DIFFERENCES IN MUSCLE STRENGTH IN DISABLED OLDER WOMEN

This study examines racial differences in muscle strength, and associa tions of muscle strength to level of physical activity and severity of disability, among a community sample of 254 black and 665 white, mode rately to severely disabled women aged 65 and older: Potential confoun ders that were adjusted for in the models included age, body weight an d height, joint pain, number of chronic conditions, and socioeconomic status. Hand grip, hip flexion, and knee extension forces were measure d using portable hand-held dynamometers in the participants' homes. Ha nd grip strength was measured as the maximal isometric force. Hip flex ion and knee extension forces were measured as the greatest force the tester had to apply to break the isometric contraction. A declining st rength gradient was observed with increasing severity of disability an d for decreasing level of physical activity ill both races. At equal l evels of disability or physical activity, blacks had better hand grip and hip flexion strength, but knee extension strength did not differ b y race. The greater hand grip and hip flexion strength found in black women may be related to their greater muscle mass and known racial dif ferences in body dimensions. No consistent racial differences were obs erved in the relationship between physical activity and muscle strengt h, or muscle strength and disability, suggesting that the role of musc le strength in the disablement process does not differ between races. Physical activity and exercise programs may be feasible ways to preven t worsening of disability disability in blacks and whites.