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.