Character joint springs

The springs for character joint don't seem to do anything. Can anyone explain how they work?

Thanks.

 

<crickets and tumbleweeds for two years>

The springs in character joints are not analogous to the springs in hinge joints. In a hinge joint, as you show in the video, the spring moves the joint around its axis of rotation toward a designated rest position. The spring in a character joint is a linear (not angular) spring connecting the anchor and the connected anchor. It's not unusual, for example, for these to be separated by character animations, so that they have to be restored when you activate a ragdoll on the character. If you leave the "spring" value at 0, they will snap together, but if the joint was too separated this essentially exerts tremendous force on the rest of the ragdoll and can make it twang around violently. Set it to a non-zero value to specify how forcefully the joint position gets restored.