Diminished dynamic performance capacity of back and abdominal muscles in concrete reinforcement workers.

Abstract

A total of 295 male Finnish concrete reinforcement workers, aged 19 to 64 yr and engaged in heavy physical work including prolonged stooping were clinically examined. In 24% of the men both back and straight abdominal muscle performance capacity was reduced, in 18% only the capacity of the straight abdominal muscles, and in 4% only the performance of the back muscle. The prevalence of diminished trunk muscle performance capacity increased rapidly with age. Diminished back muscle performance capacity was asosicated with a history of sciatica (.chi.2 = 16.9, P < 0.001) and diminished performance capacity of the straight abdominal muscles with a history of lumbago (.chi.2 = 5.9, P < 0.02 after adjustment for age. Diminished back muscle performance was associated with backache (.chi.2 = 16.9 P < 0.001) and sharp pain in the back (.chi.2 = 4.5, P < 0.05) during an ordinary workday, as was also diminished performance of the straight abdominal muscles (.chi.2 = 23.8, P < 0.001 and .chi.2 = 7.3, .PI. < 0.01, respectively). No association between length of exposure to the back loads in reinforcement work and the prevalence of diminished trunk muscle performance capacity could be established.