In sports medicine, disorders of muscle function and muscular imbalance play an important role in both risk of injury and lack of improvement. They are highly important for the trunk muscle function, since low back pain is one of the most common disorders of sportsmen and is usually diagnosed as "functional disorder" without further specification. Despite its relevance, little is known about the specific capabilities of trunk muscle function in elite sportsmen. This study describes the measurement of trunk muscle torque, velocity, endurance and coordination in elite sportsmen. The study was performed by clinical examination and an isoinertial testing device (ISOSTATION-B200, Isotechnologies, Hillsborough, NC, USA). The results of a study of 20 German elite male rowers are presented and the relevance of these results is discussed in respect of their implications for training and therapy in injured athletes. Mean torques in extension and flexion were 319 Nm and 295 Nm, respectively. Elite rowers were stronger in isometric torque in all planes compared to normals and other sports groups, such as tennis players and swimmers. The better the rowing performance was, the lower was the extension/flexion ratio, the coordination and the decrease in velocity during endurance testing. This testing procedure is a useful tool in the measurement of trunk performance in elite sportsmen.