I'm very confused with this problem and need some help and direction on how to write dynamic equations of motion. The problem is as follows:
Write the dynamic equations of motion for muscle force Fm, hip force Fj in the normal direction n towards rotation center along the -r direction and in the tangential direction t perpendicular to that direction. The equations should be written in terms of weight of the leg W,Fm, Fj appropriate angles and distances. Assume the entire leg moves as a rigid body about hip O. Assume the muscle force acts at 2/3 of the length of the thigh on the axis, making 15 degree angle with axis shown.
The rest of the information is in the attachment provided. Thank you in advance for your help.-Nivek