Long Bone and Joint Response to Mechanical Loading

The research program presented in this report is concerned with collection of active muscle force and moment response data of the human upper and lower extremities when the extremities are subjected to various external forces. The major components of the specially designed and built experimental apparatus are a subject restraint system, a force application device which employs three sonic emitters, and an upper arm (or upper leg) cuff with four sonic emitters. The sonic emitters are utilized to determine the three-dimensional direction and the location of the force application on the limbs and the orientation of the limbs with respect to the torso. Kinematics of relative motion between two body segments is presented in a format suitable for utilization of four sonic emitters on the moving body segment. The numerical results are presented from a set of experiments conducted on three male and three female subjects to determine their active muscle resistance against the external forces to dislodge their limbs from the initial or so-called stowed position. It is concluded that although there are intra- and inter-subject variations for the maximum values of the resistive muscle force and moment data for the limbs, there are some trends one can establish for the behavior of their magnitudes.