Internal rotation strength is often undertrained yet essential for hip health, knee comfort, and efficient gait mechanics. This supine isometric variation allows you to develop internal rotation capacity while keeping the pelvis grounded and the effort precise. The intention here is clarity, not force. Use lighter resistance than external rotation, stay well below maximal effort, and reduce intensity immediately if lateral knee or IT band tension appears. This drill supports long-term joint resilience by reinforcing control where the body often avoids working.