Kj. Winegard et al., AN EVALUATION OF THE LENGTH-TENSION RELATIONSHIP IN ELDERLY HUMAN PLANTARFLEXOR MUSCLES, The journals of gerontology. Series A, Biological sciences and medical sciences, 52(6), 1997, pp. 337-343
The purpose of this study was to determine the effect of aging on the
muscle length-tension relationship ill the plantarflexor muscles of 10
subjects aged 20-30 yr (Mean = 23; 5 males, 5 females), 10 subjects a
ged 60-80 yr (Mean = 72.3; 5 males, 5 females), and 10 subjects over 8
0 yr (Mean = 84.1, 5 males, 5 females). Isometric twitch properties, m
aximum voluntary strength, passive tension, and range of motion were m
easured at five different joint angles [20 degrees dorsiflexion (DF),
10 degrees DF, 0 degrees, 10 degrees plantarflexion (TF), and 20 degre
es PF]. Active (evoked and voluntary) and passive torque production we
re maximal when the ankle was rotated into the DF positions for all th
ree age groups, whereas the lowest values were recorded when the ankle
was rotated into 20 degrees PF. Males were stronger than females at a
ll joint angles (p <.01). Also, young adults were stronger than both e
lderly adult groups (p <.01). These results illustrate that despite th
e consider able age-associated loss in both voluntary and evoked stren
gth in the plantarflexors, the optimal angle for torque production rem
ains the same for younger and older adults.