The relationship of movement time to hand-foot laterality patterns.

Asymmetries in movement times of the hands in 60 healthy participants with different patterns of hand-foot dominance were investigated. Handedness and footedness were assessed by means of questionnaires and verified by simple motor tasks. Psychomotor performance was evaluated by the use of selected tests from the computerised Vienna Test System (VST, Vienna, Austria). Movement time (MT) was assessed separately for dominant and non-dominant hands in a unimanual simple reaction task. Participants performed significantly better with their preferred hand, and differences in performance between right- and left-handers were not significant, neither was there a main effect of foot dominance on MT of the hands. However there was a significant effect of laterality pattern in hand-foot combination on hands MT: participants with cross-lateral dominance patterns of hands and feet performed significantly better than those with congruent hand-foot dominance. No significant interaction with sex was found. These results provide evidence for a lack of independence of hand and foot dominance in motor performance, suggesting the functional significance of limb laterality pattern in the motor control system. The results support the hypothesis that the quality of human hand movements may be influenced not only by central information processing (hemispheric specialisation) but also by other structures and processes of motor control, such as central pattern generators (CPGs) and biomechanical factors.