2020 Volume 41 Pages 244-251
In this study, we investigated the ability to adjust grip strength in childhood by comparing the characteristics of force generation and relaxation. Twenty-six boys and twenty-five girls in fifth grade （11 years old） performed their strongest grip [maximum voluntary contraction （MVC） task］．adjusted from complete relaxation to their self-perceived half strength [generation task （0% MVC to 50% MVC）］．and adjusted from maximum voluntary strength to their self-perceived half strength [relaxation task （100% MVC to 50% MVC）］．Two trials were performed for each task, and the average value was calculated. In addition, during the generation and relaxation tasks, the relative values were calculated based on the 100% MVC, and the constant and absolute errors from the target value （50% MVC） were evaluated. There were no significant relationships in the constant error among the force levels of maximum, generation, and relaxation tasks for boys and girls. The relative values were significantly smaller during the relaxation task than during the generation task and were smaller in girls than in boys. The constant errors were significantly negatively greater during the relaxation task than in the generation task in boys and girls, and greater in girls than in boys during the generation and relaxation tasks. Moreover, there was a positive correlation in the relative values between generation and relaxation in boys. These results suggest that the ability to exert maximum power and adjust power are different, and the ability of force control is higher in boys than in girls during childhood.
