How do hands and feet joints work?

Sometimes hands and feet are connected to the joint by magnets. Sometimes the ball joint and the hands/feet are connected and there is a wire going horizontally through the foot and hands ball joint. An s-hook would be attached to the wire and the elastic. I think sometimes the hands and feet are separate from the ball joint, but there is a small hook in the hand or foot and the hallow ball joint covers the hook so you can't see it.

I hope this helps.

 

I've seen four methods:
1. Hand attaches to separate wrist ball via magnet; wrist ball has eyehook+S-hook on top that hooks onto arm elastic.
2. Hand has wrist ball molded directly onto hand. Wrist ball has eyehook+S-hook as above.
3. Hand has molded wrist ball with bar across top of wrist ball (resin or metal). S-hook hooks onto bar.
4. Wrist ball is separate. Hand has wrist socket with eye hook; wrist ball has large hole to accommodate S-hook which hooks onto arm elastic.

Hope it helps!