Reproducibility of trunk isokinetic strength findings in healthy individuals

Background. Back strength is an important factor in the functional assessment of chronic low back patients and therefore ensuring the reproducibility of the findings is of critical importance. So far the studies were focusing on relative indices that turned out to be an inappropriate method due to possibility of bias. Furthermore the reproducibility of eccentric trunk flexors strength findings that may play a role in numerous sport activities has never been evaluated. Objective. To evaluate the reproducibility of isokinetic eccentric and concentric strength of the trunk flexors and extensors in healthy subjects using the absolute reproducibility indices. Methods. Twenty seven young healthy physical education male students were tested twice over a period of one week using an isokinetic dynamometer. The main outcome measure was isokinetic peak torque. Results. Strength scores of the trunk flexors and extensors evidenced clinically acceptable reproducibility. This conclusion was valid irrespective of the testing velocity or type of contraction. Conclusion. Concentricand eccentric isokinetic testing of the trunk flexors and extensors muscles is a viable option for the testing of healthy subjects.