KNEE EXTENSION STRENGTH AND WALKING SPEED IN RELATION TO QUADRICEPS MUSCLE COMPOSITION AND TRAINING IN ELDERLY WOMEN

Knee extension strength, walking speed, quadriceps muscle mass and com position of the muscle compartment were studied in 66 to 85-year-old f emale athletes and controls. Maximal voluntary knee extension force, f orce/body mass, extension torque, torque/body mass and walking speed w ere higher for the athletes than the controls. A muscle index indicati ng intramuscular fat and connective tissue measured using ultrasonogra phy was lower for the athletes than the controls. There were no differ ences between the study groups in knee extension force related either to cross-sectional area (CSA) or lean tissue area (CSA(L)) of the quad riceps. Within the subgroups, there was no significant correlation bet ween knee extension torque and CSA or CSA(L) of the same muscle. In th e athletes high knee extension torque/body mass was related to a low m uscle index and high walking speed to a low relative proportion of fat in the muscle. The muscle index was lower the more kilometers trained during the preceding year. In the controls high knee extension torque /body mass and high walking speed were related to a low relative propo rtion of fat. Knee extension torque and walking speed were higher the more kilometers walked during the preceding year. The results indicate that elderly female athletes have superior muscle performance compare d to their age-peers. Performance in a maximal isometric strength test in elderly women is not clearly related to muscle mass. However, to s ome extent it is related to the composition of the same muscle, especi ally the degree to which fat is infiltrated into the muscle.