Active muscle force and moment response of the human arm and shoulder

This paper is concerned with collection of active muscle force and moment response data of the human arm and the shoulder complex when the arm is subjected to various external forces. The major components of the specially designed and built experimental apparatus for this research are a subject restraint system, a force application device which employs three sonic emitters, and an upper arm cuff with four sonic emitters. The sonic emitters are utilized to determine the direction and the location of the force application on the arm and the orientation of the upper arm with respect to the torso. The numerical results are presented from experiments conducted on three male and three female subjects to determine their active muscle resistance against the external forces to dislodge their arms from several initial configurations. Some representative results determining the active muscle force capability of the subjects when their arms are dislodged from the initial configuration are also presented. Incorporation of the results of the present research into the multi-segmented models of the human body should improve the long-time response of capabilities of these models. This type of response capability of the mathematical models is essential for the proper stimulation of the biodynamic events which take place prior to flail injuries.