Musculoskeletal capacity and its changes among aging municipal employees in different work categories.

Aging effects on musculoskeletal capacity were studied among 83 subjects over a four-year period beginning at about 51 years of age, and the associations between work demands and musculoskeletal capacity were studied in a cross-sectional investigation comprising 137 subjects (mean age about 55 years). The follow-up study showed significant changes in musculoskeletal capacity, maximal isometric trunk strength having decreased 16-22% and 9-10% among the men and women, respectively, and maximal trunk muscular endurance and back mobility having increased 21 and 14%, respectively, among the men. The cross-sectional study showed statistically significant differences in isometric handgrip strength and leg mobility among the men and in isometric trunk flexion strength and trunk muscular endurance among the women in the three studied work groups. The investigation suggested that changes in musculoskeletal capacity can be marked after the age of 50 years and that physically heavy occupations do not maintain a sufficient level of capacity among elderly workers.