The partner bench back extension is a clever way to target the glutes and spinal erector muscles. There are machines and angled benches that allow this exercise to be performed solo, but, lacking those, all you need is a bench and a workout partner. It is usually performed for high reps as a burnout or accessory movement for lower-body training.
Works the spinal erectors, glutes, and hamstrings
Promotes lower back health
Works posterior chain of body without spinal loading
Lie prone on a flat bench with your shoulders and head off the bench. Your midsection and legs should be supported and your partner should firmly press down on your upper hamstrings to keep you in position on the bench.
Once secured, lift your hand off the floor and cross them over your chest. This will be your starting position.
Contract your lower back to rise off the bench as high as you can, hold for 5 seconds, then slowly release and extend down as far as the range of motion will allow.