Trunk muscle strength measurements and prediction of low-back pain among workers

A pilot study was conducted to explore the relationship between the occurrence of low-back pain and parameters of trunk muscle strength. Dynamic strength measurements were performed among 53 male workers without low-back pain and 31 male workers with low-back pain. The average torque of lateral right movement was significantly lower for workers with low-back pain compared to those without. The application of discriminant analysis pointed out that another four strength measures contributed to the discriminant function. These measures were average power of lateral right movement, mean torque and maximum velocity during flexion, and isometric strength during right rotation. The results showed that it was possible to find a linear combination of these discriminating variables that successfully allocated 68% to either the group of workers with low-back pain or the group without. Although this discriminatory power is too small to be of practical significance, the discriminant analysis performed reveals some promising features for further research.