Sit on the floor with your leg bent, your foot flat on the floor, and your upper back against a bench.
Have your prosthetic off.
Hold a barbell on your hips, with a wide grip.
Fully extended your residual leg and lift off the floor.
Rest your upper back against the bench and slightly lift your hips from the floor.
When ready, push your hips towards the ceiling, resisting any rotational movement at the pelvis.
Return to the starting position.
