The elbow joint is flexed using the biceps brachii muscle, which remains essentially vertical as the arm moves in the vertical plane. If this muscle is located a distance a from the pivot point A on the humerus, determine the variation of the moment capacity about A if the constant force developed by the muscle is F. Plot these results of M vs. θ for −60 ≤ θ ≤ 80.
Units Used:
kN = 103 N

Given:
a = 16 mm
F = 2.30 kN
θ = (−60 ... 80)