Contribution to the Velocity of the End of Upper Limb in Terms of Angular Velocity of Articulations of Upper Limb

本研究ではISBの角度定義を参考に, 上肢3関節の関節運動の7自由度の角度を定義し, その回転軸まわりの角速度ベクトルを考え, 先端速度の内訳を角速度の項の総和であらわした。また各体節座標系の直交三軸まわりの角速度ベクトルを考えた場合や, 肩関節の角度を絶対角度で算出した場合と比較した。本研究の計算方法を用いることによって, 角度定義の回転軸まわりに角速度ベクトルを考えているため各角速度を関節運動と対応づけられる。また肩関節の角度を胴体に対する相対角度であらわしたために上腕の姿位に関係なく各角速度を関節運動に対応づけられる。しかし手首関節の角度定義は, 掌屈・背屈について解剖学的角度定義とはやや異なる。前腕にマークを取り付けない場合には, 橈尺屈と掌背屈の先端速度の貢献は, 両者を合わせて考えるのがよい。The purpose of this study was to calculate contribution to velocity of the end of upper limb including a racket as an example of tennis service. The velocity of racket-head sum up terms of angular velocity which is accurately in accordance with three-dimensional angular definition which is defined in reference to ISB recommendations for standardization in the reporting of kinematic data. Upper limb's articulations have seven degrees of freedom ; horizontal abduction/adduction, abduction/adduction, internal/external rotation, elbow flextion/extension, pronation/supination, ulnar/radial flextion and palmar/dorsal flextion. Each angle is calculated as relative angle between adjacent segment coordinates. Each anguler velocity vector has direction of rotational axis and magnitude of numerical differential. Each term of angular velocity is cross-product of angular velocity vector and vector from joint to racket-head. One male high-performance player's flat service was recorded by two video cameras. By the DLT method three-dimensional displacements of digitized points were reconstracted. Relative forward velocity of racket-head to shoulder resulted mainly from internal rotation, elbow extension and ulnar flextion during racket-head accelerative phase, and from horizontal adduction and pronation during follow-through. Compared with calculation of Sprigings et. al. shoulder joint angular velocity vector are related with anatomical joint movements without reference to position and orientation of upper-arm because shoulder joint angles are relative ones, and contribution of upper-arm movement is divided into terms of body rotation and shoulder joint rotation. Angular definition of palmar/dorsal flextion in this study isn't accordance with clinical or anatomical definition. In case that markers are not attached to the forearm, we may understand contribution of terms of angular velocity of ulnar/radial flextion and palmar/dorsal flextion together, until wrist joint angular definition is published by ISB.5KJ00004196653原著論文Original articledepartmental bulletin pape