Maximal isokinetic and isometric muscle strength of major muscle groups related to age, body mass, height, and sex in 178 healthy subjects

The main objective of this study was to establish normative values for maximal concentric isokinetic strength and maximal isometric strength of all major muscle groups in healthy subjects applying sex, age, height, and body mass-adjusted statistical models. One hundred and seventy-eight (178) (93 male and 85 female) healthy non-athletic Danish volunteers aged 15-83 years were recruited. Eighteen test protocols for each sex were applied to determine isokinetic and isometric muscle strength at knee, ankle, hip, shoulder, elbow, and wrist using a dynamometer (Biodex System 3 PRO). Multiple linear regressions were performed with maximal muscle strength (peak torque) as dependent variable and age, height, and body mass as independent variables. Muscle strength significantly related to age in 24, to height in 13 and to body mass in 27 out of the 36 models. In gender-specific analyses, the variables age, height and body mass accounted for 25% (20-29) (95% confidence interval) of the variation (r (2)) in strength for men and 31% (25-38) for women. The r (2) was similar for the isokinetic models and the isometric models [31% (22-40) vs. 28% (23-34)]. Age, height, and body mass related to strength in most muscle groups and gender-specific models with estimated prediction intervals were established for maximal strength of major muscle groups.