An evaluation of the length-tension relationship in elderly human plantarflexor muscles

Abstract

The purpose of this study was to determine the effect of aging on the muscle length-tension relationship in the plantarflexor muscles of 10 subjects aged 2030 yr (Mean = 23; 5 males, 5 females), 10 subjects aged 60- 80 yr (Mean = 72.3; 5 males, 5 females), and 10 subjects over 80 yr (Mean = 84.1, 5 males, 5 females). Isometric twitch properties, maximum voluntary strength, passive tension, and range of motion were measured at five different joint angles [20°dorsiflexion (DF), 10°DF, 0°, 10°plantarflexion (PF), and 20°PF]. Active (evoked and voluntary) and passive torque production were maximal when the ankle was rotated into the DF positions for all three age groups, whereas the lower values were recorded when the ankle was rotated into 20°PF. Males were stronger than females at all joint angles (p < .01). Also, young adults were stronger than both elderly adult groups (p