HOW: Get set-up on a surface that will allow you to slide your heels. You can also use something to slide on the floor, like a towel on a hardwood surface. With your knees bent to 90 degrees, perform a bridge on your heels with the front of your feet off the ground. While maintaining your hips high off the ground, slowly let your legs straighten to perform an eccentric curl. Repeat
FEEL: You should feel your glutes, hamstrings, and even your calves working.
COMPENSATION: Do not arch your low back, keep your core engaged by first flattening your low back into the ground before you bridge up. Try to keep your hips high as you perform the eccentric curl out.