Lunges with your weight on an unstable base.
This helps all the muscles and core engage from your balancing foot ankle and leg to your core and glutes and tum.
However…on another level
It has just been suggested to me by my hip surgeon that anyone like me who has had a hip re-surface surgery procedure and has metal on metal in their hip -this could be having adverse effects as the flexion movement on the weight bearing leg can cause the metal on metal to rub more than usual.
Metal on metal hip replacements and resurfaces can cause metal ions (cobalt and chromium) to leak into the blood stream and give metal ion readings in the blood above normal levels. This could cause future health issues.