Isometric muscle strength and muscular endurance in normal persons aged between 17 and 70 years.

Isometric muscle strength was measured in 63 women and 65 men, randomly selected, aged 17-70 years, using Penny & Giles' hand-held dynamometer. Eight muscle groups as well as the hand grip strength were tested bilaterally. The muscular endurance was measured as time to exhaustion in the abductors of the shoulder and the flexors of the hip. Reference values for muscle strength and muscular endurance are given in the age groups 17-18, 20-29, 30-39, 40-49, 50-59 and 60-70 years of age. The mean strength of females was about 65-70% of that of the men, but when the results were related to weight, the differences almost disappeared. Both men and women seem to have the greatest muscle strength at the age of about 17-18. The strength is rather constant up to the age of about 40 years, after which a discrete decline is seen up to about 60, from where the decline is more obvious. Muscular endurance showed great variability between individuals. However, no decrease in endurance was seen in older ages. For both sexes, lower reference limits of endurance, with the methods used, for arm abductors are suggested as being 3 minutes and for hip flexors, 90 seconds.