1. A worker, from a seated position, reaches to their side (with the arm extended at a 45 degree angle) to pick an item from a bin to place on their worktable as shown in Figure 1a. The item weighs 5 lb. The angle between the deltoid muscle and the humerus (a) (see Figure 1b) changes with the angle between the body and the humerus (e) as shown in Table 1. If the worker is 6ft. tall and weighs 185lb. what is the force Fm exerted by the deltoid muscle at the moment of pickup? What are the reaction forces R, and Ry at the shoulder joint? Assume that the insertion point of the deltoid muscle muscle into the humerus is .05H from the shoulder joint axis of rotation. 0 Elbow angle O-05 AB = AC = 0.20 .05 W We Figure la Figure 1b Table 1 90 30 180 90 65 25 45 21 25 17 0. 13