Lower-Body Torque and Power Declines Across Six Decades in Three Hundred Fifty-Seven Men and Women: A Cross-sectional Study With Normative Values.

This study presents age-specific and gender-specific patterns and normative values for lower-body isokinetic performance in 195 women and 162 men, 18-80 years of age, using data collected from 1991 to 2004. Peak torque (PT) and average power (AP) during knee extension (KE), knee flexion (KF), ankle plantar flexion, and dorsiflexion (DF) at 1.05, 3.14, and 5.24 rad · s(-1) were compared by decade. Knee extension and KF at all speeds showed a significant main effect by age group (G). Men's KEPT and KEAP at 60 and 70 G were significantly different than 20, 30, and 40 G at all speeds. Additionally, 50 G differed from all other groups. For women, 50, 60, and 70 G KEPT and KEAP at 5.24 rad · s (-1)differed significantly from all other age groups. Men's KFPT and KFAP showed no differences among 20, 30, and 40 G, whereas 50 G differed from all groups except 60 G. For KFPT and KFAP, women 20 and 30 G differed from other age groups at all testing speeds. Plantar flexion and DF performance declines were speed specific mainly occurring at 3.14 rad · s.(-1) The results reflect declines in strength and power beginning during the fifth decade in men, and earlier in women. The study also provides normative values, which may be used to evaluate neuromuscular performances by gender across decades of life.