Retention of Relative Grip Effort for At-Home Isometric Exercise

The purpose of this work was to determine if subjects initially trained to use a handgrip dynamometer could learn to perform the exercises at the same relative level of effort with a considerably less expensive substitute device. All subjects trained (4, 2-minute contractions, 30% maximal effort) 3 times per week for 12 weeks. In Study I, Group 1 (n = 13) trained using only the dynamometer while Group 2 (n = 14) trained using both the dynamometer and an egg-shaped substitute item for the first 6 weeks. All subjects then trained using only the egg-shaped item. Grip effort was evaluated every 2 weeks using the dynamometer. Group 2 subjects gripped at a level consistently closer to the desired level of effort. Study II investigated the importance of the substitute item's shape. Group 3 (n = 10) trained using the egg-shaped item while Group 4 (n = 10) trained using an item that was similar in shape to the dynamometer. Group 4 subjects gripped at a level consistently closer to the desired level of effort. These results suggest that gradual introduction of a substitute item similar in shape to the dynamometer can significantly improve the transfer of handgrip exercise to a less expensive substitute item by increasing retention of desired level of effort.