Don't focus on lifting the knee in this exercise, but move the thigh away from the floor by squeezing your butt. You can also do it without a dumbbell.
- Start on all fours, with your hands directly under your shoulders and your knees directly under your hips.
- Bend your right knee at a 90-degree angle and place a dumbbell in the crook of your knee.
- Slowly pulse your flexed foot toward the ceiling by squeezing your glutes. Your back should remain perfectly still in a neutral spine. The motion should be small and controlled with the muscle, not momentum, doing the work.
- Return to the starting position to complete one rep. Do 15 pulses on each side.