I've been running a simulation of a bionic arm. Basically it's like a human arm, it has a forearm and upper arm that's connected by a pin hinge. On the elbow, there is a hydraulic that controls the extension and retraction of the arm. When I move the object and hit physical dynamics, the arm bends for about 100 degrees until it stops due to collision. However, when I run the simulation the arm does a 360 degree turn through itself, even when I make contact between the upper arm and forearm. I'm not sure what I'm doing wrong. Can someone help me please?