把握動作に与える動作課題と物体重量の影響

Influence of prehensile task and weight of object on human prehension movement

要旨：本研究は，把握動作における物体重量および動作課題の影響について，主に動作時間と運動軌跡の観点から明らかにすることを目的とした．健常女性10名に，5種類の重さの異なる同型物体を用いて，物体把持後の目的を異にする2種類の把握動作課題を課した．その結果，提示される物体位置が同じでも，物体の重さや把持後の目的が異なることで物体把持までの動作時間が異なることが示された．また，物体重量と動作課題両者に対応した運動軌跡で物体へのリーチが行われることが示された．本研究結果から，物体の重さや課題の内容により，動作時間や物体へのリーチの仕方が変化することを応用した把握動作訓練の可能性が示唆された．

　The purpose of this study was to clarify the effect of movement task and weight of the objects in prehension movement, mainly from the aspect of motion time and trajectory. Ten healthy females were given two kinds of prehension movement tasks with different subsequent objectives using five objects with identical shape and different weight. As a result, it was shown that motion time before prehension differed by the weight of the objects or by subsequent objectives, even if the position of the object presented was the same. Also, it was revealed that reach to the object was made along the motion trajectory, which was determined by the coordination with both weight of the object and content of the task. Consequently, this study suggested the possibility of implementing prehension motion training, implying that motion time and the way of reach can vary depending on the weight of the object and the content of the task.