Peak concentric torque (PCT) and peak eccentric torque (PET) will be measured at an angular velocity of 30°/s.
A similar degree of loss was reported by Candow and Chilibeck, 10 who also measured peak isokinetic concentric torque at 60° per second for the knee extensors and found an approximate torque loss of 25.3% comparing younger and older subjects.
Twenty four college-age males exerted their maximum torque in both concentric flexion and extension at 60, 120, and 180°/s of angular velocity through a ±60° range of deviation from wrist neutral.
Studies on the Tω relation have generally shown reduced torque capability for concentric velocities for older DF [2], [5] and PF [5], [6] muscles, but some have found that eccentric torque production is preserved in older adults [7], [8].
Based on evidence from previous studies, we anticipated that active community dwelling older adults would have smaller isometric torque capacities, slower concentric muscular properties (i.e. less torque at a given velocity on the Tω relation), and stiffer series elasticity in the aponeurosis TΔL relation when compared to active young adults.
20 The maximum contraction torque for four concentric contractions was used for further analysis.
Maximum voluntary concentric torque of the hamstrings and quadriceps was assessed using a ConTrex-MJ isokinetic dynamometer (ConTrex AG, Dubendorf, Switzerland).
Concentric torque for the elbow flexors was similar between the age groups (younger, 43.3 ± 2.6 Nm (Newton*meter); older, 45.3 ± 6.9 Nm; P = 0.93).
Modern, commercial isokinetic dynamometers allow both isometric and isokinetic measurements of strength as concentric torque at various angular velocities [ 48, 49].
Concentric torque for the knee extensors in the young and old age groups was significantly greater than that of the elbow flexors (P < 0.001 and P = 0.001, respectively).
