Muscle performance in an urban population sample of 40-to 79-year-old men and women

An urban population sample of 40 to 79-year-old men and women was investiga ted to evaluate the influence of age and activity level on muscle strength and endurance and to establish a reference material. During the investigati on 144 persons were tested bilaterally, except for ankle strength, when onl y the right side was examined. Isometric muscle strength was determined in the knee extensors and flexors. Isokinetic (at 60 degrees /s and at 180 deg rees /s) muscle strength was determined concentrically and eccentrically in the knee extensors and flexors. The dynamic and static endurance of the ex tensors was measured. Isometric strength was determined in the ankle planta r and dorsiflexor muscles. Isokinetic ankle plantar flexion strength was de termined concentrically at 60 degrees /s with and without prior eccentric m uscle contraction. Hand-grip strength was evaluated with a dynamometer. Wal king velocity and the number of heel-rises were recorded. Physical activity level was assessed by questionnaire. Muscle biopsies were taken from the v astus lateralis muscle for histochemical and enzymatic analyses. Walking an d the different muscle tests declined with age, and with a slight gender di fference. Muscle biopsies showed a trend toward smaller muscle fibers with age. The results of our study can be used as reference material for clinica l studies in different age groups.