Hinge and rise to bulletproof your posterior chain.
Stop at a straight line, don't hyperextend. Drive the movement with your glutes and hams.
Hinging over the pad with your ankles locked in turns the back extension into a hip hinge on rails: the hamstrings lengthen as you lower, then haul your torso back up to a straight line. Your back muscles work the whole time too, holding your spine solid instead of letting it round and flop. It is posterior chain armour that costs nothing but bodyweight.
Mostly the hamstrings and glutes if you are hinging from the hips. If your lower back is doing the lifting, you are probably rounding and unrolling your spine each rep. Set the back in one position and move only at the hips.
Stop at a straight line from head to heels. Cranking into hyperextension shifts stress onto the spine for no extra muscle benefit. Squeeze hard at straight and head back down.
Slow the lowering phase, add a pause at the top, or hold a plate against your chest once bodyweight reps get comfortable. Range and control beat speed here every time.
