Movement Science: Purposefulness and Cross Transfer in a Forearm Supination and Pronation Task

Abstract

The effects of forearm cross-transfer training with materials-based (MB), rote exercise (RE), and control conditions were investigated using a pre-test, training-post test design. The pre- and post-test task involved cranking resistive wing nuts in and out with each hand. The MB participants were given a practice device and were assigned to one of four groups that involved cranking wing nuts in or out with their left or right limb. Participants in the RE group were not given a practice device, but were asked to supinate and pronate their assigned limb for a specified duration. The difference between the MB condition's pre- and post-test movement time (MT) was significantly better than that between the RE and control groups' movement time. Contrast analyses revealed that the MT difference for the MB condition was significantly greater than the control performance when the purpose of the pre- and post-test movements of the untrained limb was similar to the training purpose (cranking the wing nut in or out) but not when compared to the homologous muscle groups (supinators or pronators). These finding suggest that enhanced meaning exerts a powerful influence when coupled with tangible forms. This is congruent with an occupational therapy premise; namely, tasks embedded with greater meaning can be more effective in facilitating improved performance than tasks having less meaning ascribed to them. Key words: bimanual, coordination, interlimb motor control.