Perform this exercise without your prosthetic on.
Sit on the floor with your legs bent, feet flat on the floor, and upper back against a bench.
Rest your residual arm for support against the bench if needed.
Press your feet against the floor and lift your hips.
Hold a dumbbell across your hips with your sound arm.
Lift one foot from the floor and straighten your knee.
When ready, lower your hips to the floor and then explosively lift your hips up until you have a straight line from knees to shoulders and your hips are level.
Repeat.
