リーチ運動における2台のデジタルスチルカメラを用いた簡易上肢動作解析システムの妥当性の検討

Validity of a simple upper extremity three-dimensional motion analysis system with two digital still cameras in analyzing reaching movements

要旨：2台のデジタルスチルカメラを用いた簡易上肢動作解析システムの妥当性を検討した．健常者8名を対象に，簡易上肢動作解析システムと三次元動作解析装置を用い，リーチ動作時の肩・肘・股関節の角度とリーチ距離を動画にて撮影した．動画から，動作開始時，開始から1秒後，最大リーチ時の静止画を取り出し，関節角度とリーチ距離の相関係数と測定値の差を求めた．簡易上肢動作解析システムと三次元動作解析装置の相関係数は，肩関節で0.90〜0.99，肘関節で0.97〜0.99，股関節で0.85〜0.99，リーチ距離で0.96であった．関節角度，リーチ距離の平均誤差は，約3.5°，約1.0cmであった．簡易上肢動作解析システムは，妥当性を有し臨床で有用な可能性がある．

　Introduction: This study investigated the validity of a three-dimensional motion analysis system in analyzing upper limb reaching movements using two digital still cameras. Methods: Eight healthy subjects participated in this study, and their reaching movements were simultaneously analyzed using two digital still cameras and a conventional three-dimensional motion analysis system. The joint angles of the shoulder, elbow, hip, and the distance of reach were calculated at reach onset, one second after reach onset, and at maximum reach. The data were analyzed using the Pearson's product-moment correlation and Student's t-test. Results: The detected angle of the joints through the dual camera and the three-dimensional motion analysis system were significantly correlated with the shoulder (r=0.90-0.99), elbow (r=0.97-0.99), hip (r=0.85-0.99) and distance of the reach (r=0.96). The mean error of joint angles was 3.5°. The mean error of the reach distance was 1.0 cm. Conclusion: We demonstrated the validity of a three-dimensional motion analysis system for the analysis of upper limb reaching movements, using two digital still cameras. This system may be useful for clinical application.