Muscle performance, work ability and physical functioning in middle-aged men.

BACKGROUND Limited data exist on the associations between muscle performance and work ability measures in working age adults. AIMS To evaluate how the results of simple muscle performance tests correlate with self-reported work ability and physical functioning in middle-aged men. METHODS Muscle performance was measured with handgrip, sit-up, arch-up, squatting and lifting tests. The Physical Functioning scale and the Role Limitations due to Physical Health Problems scale of the RAND-36 health questionnaire were used to assess functioning and the Work Ability Index (WAI) questionnaire to assess perceived work ability in a subgroup of 51 subjects. RESULTS A total of 104 men aged 45-55 years employed in physically active work participated. Muscle performance was weakly associated with WAI and functioning measures, accounting for 10% of the variance at most. Dynamic lifting test results for both arms correlated with WAI scores (right: r = 0.31, left: r = 0.34). Scores of the dynamic lifting test for both arms correlated with the Physical Functioning scores (right: r = 0.23, left: r = 0.28) and with the Role Limitations due to Physical Health Problems scores (right: r = 0.25, left: r = 0.28). Results of the squatting test were associated with the Physical Functioning scores (r = 0.24). CONCLUSIONS The study failed to provide support for the use of muscle performance tests in work-related fitness evaluations in middle-aged men employed in physical jobs.