Four joints do most of the hard work when you move each day. Each one trades mobility (how much it moves) against stability (how well it stays in place) in its own way. Tap each one.
Shoulder
Selected jointsmobility vs stability
The four joints
📷 Reference image
A real labeled figure to compare with the interactive above.
Selected Synovial Joints — OpenStax, CC BY 3.0 (via Wikimedia Commons)
