Relationships between preferred and maximum effort low-back motion.

The purpose of this study was to determine if subjects differed in their preferred and maximum effort low-back-movement characteristics, and to determine if preferred low-back-movement characteristics could contribute to the prediction of maximum effort performance parameters. Sixteen subjects performed a flexibility trial, isometric exertions, and both maximum effort and preferred effort repetitive trunk motion against a resistance set at 50% of the recorded maximum isometric torques. All movement directions about all three primary axes were examined. The results showed that the preferred low-back-movement characteristics were different from those when a maximum effort was requested, although the performances were equally consistent. It was possible to reasonably predict maximum effort velocities from a knowledge of the preferred effort velocities.