The forearm-hand complex weights 55N, and the center of mass is 0.17 m from the elbow joint. The weight of barbell is 67N, and the center of mass of barbell is 0.36 m from the elbow joint. The distance between muscle insertion point and joint center/axis of rotation of the elbow flexors is estimated to be 0.044m from the elbow. The insertion angle of the biceps is 55. What force must be exerted by the elbow flexors to keep the forearm at a static 90 flexion angle (in N)