3次元的身体角運動量の算出法

Abstract

A technique is presented for determining the angular momentum of the human body about its mass centre for general three-dimensional movements. The three orthogonal components of the angular momentum X, Y, and Z of 15 body segments composed of a transfer term and a local term were computed. The total angular momentum of the whole body was considered to be composed of the sum of the angular momentum of each body segment. The three-dimensional coordinates for determining the angular momentum were computed by a Direct Linear Transformation Method from film data. For calculated individual angular momentum the relative error is estimated to be within 7.2%. The application of the principle of conservation of angular momentum was discussed for the jumping smash of badminton. A large angular momentum was generated by rotation of the smash arm during the airborne phases. The lower limbs react upon the arm with an equal and opposite angular momentum to keep the angular momentum constant. This kind of counter rotation to the smash arm was useful to keep the body balance and reinforce the hitting arm.