315 Unit 2: Lecture 1-5

A woman of mass mbody and height h flexes her elbow to raise the ball in her hand due to biceps muscle force FM. Theta (t) is measured relative to the xaxis and is positive in the counter-clockwise direction. Assume that m is the combined mass of the forearm, hand, and ball and l is the COM of the forearm, hand, and ball. Assume here that FM acts purely in the y-axis. Solve for elbow joint forces in terms of l, theta, and FM. STEPS

1. FBD 2. Kinetics 3. Kinematics 4. Solve

For anatomical segments, if you'd like to compute I about a nearby proximal or distal joint, you can compute this directly from anthropometry table GIVE AN EXAMPLE

For a rigid body, I computed about its COM is the smallest. I computed about the farthest point away from the COM is the largest.