上肢の把握動作に影響する反対側上肢の感覚情報—対象物のサイズと距離の情報

Sensory information of the contralateral upper limb affecting grasping movements of the upper limb on the size and distance of the object

要旨：上肢の把握動作時の反対側上肢の感覚情報が運動制御に及ぼす影響を検証した．第一実験は，健常者20名の動作を反対側上肢の対象物の把持や視覚の有無から3条件で比較した．結果は，視覚と反対側上肢の把持の組み合わせの条件では手指開口幅が減少した．第二実験は，健常者20名の動作を反対側上肢の把持による対象物の距離とサイズの情報が個別で提供される条件で比較した．結果は，距離の情報が手指開口幅の減少に寄与するが距離とサイズの情報が揃わない場合，手指の開閉に要する時間が増加する傾向であった．このことから，把握動作の制御に寄与するには，対象物の視覚と反対側上肢の体性感覚の統合の空間的明瞭度に依存する可能性がある．

　We investigated the effects of sensory information from the contralateral upper limb on motor control during grasping movements of the upper limb. In the first experiment, movements of 20 healthy subjects were compared in three conditions based on the presence or absence of object grasping and vision in the contralateral upper limb. The results showed that the hand opening width was decreased in the condition of the combination of vision and contralateral upper limb grasping. In the second experiment, the movements of 20 healthy subjects were compared under the condition that the distance and size of the object were individually provided by the grasping of the contralateral upper limb. The results showed that the distance information contributed to the decrease in hand opening width, but the time required to open and close the hand tended to increase when the distance and size information were not aligned. Thus, the contribution to the control of grasping motion may depend on the spatial clarity of the integration of object vision and the somatosensory integration of the contralateral upper extremity.