Muscle function in 75-year-old men and women. A longitudinal study.

Nine-teen men and twenty-one women, regarded as representative for the healthy seventy-five-year-old urban population were subjected to tests of lower and upper extremity function. The results were compared with those in the same probands at the age of 70. The investigation included tests of muscular isometric and isokinetic strength in knee-extension and flexion, isometric strength in key-grip, transversal volar grip, elbow-extension and flexion. Furthermore muscular coordination in hand and arm and submaximal endurance in hand-grip were measured. The subjects were classified with regard to physical activity. Between the age of 70 and 75 there was a significant decline in muscle strength in both sexes in the knee-extensors and a somewhat smaller in isometric than in isokinetic strength, and a decline also in the elbow-extensors and flexors. In a test of muscular coordination of the upper extremities and of maximal strength and submaximal endurance in hand-grip the results did not differ significantly between the age of 70 and 75. Isokinetic muscle strength in the knee-extensors and flexors was higher in men with a higher level of physical activity than in those with a lower activity. The results may indicate that the decrement of muscle strength in this age in part may be based on a changed activity pattern (note lack of change in hand-grip strength) with lack of fast and forceful movements in the daily living and speaks for the desirability that elderly people be physically active and that this may prevent disability.