Postural reaction during maximum grasping maneuvers using a hand dynamometer in healthy subjects.

The purpose of this study was to quantitatively evaluate spontaneous body sway during maximum grasping maneuver with a hand dynamometer, which we sometimes encounter in clinical practice. The postural reaction of the whole body during maximum grasping maneuver was analyzed in 26 right-handed healthy male volunteers using a three-dimensional motion analysis system (VICON system, Oxford Metrics, UK) and force plates. We found that the gravity center of the body moved toward the grasping side. Also, voluntary rotation of the trunk and flexion of the neck was observed during grasping on each side.