How to Back extension

What it is

An exercise performed on a bench or roman chair where you hinge at the hips and extend back up, training the spinal erectors along with the glutes and hamstrings. It strengthens the often-neglected posterior side of the trunk.

Muscles worked

Primary: Spinal erectors. Secondary: Glutes, Hamstrings.

How to perform it

Set up on the bench with your hips supported at the pad and feet anchored.
Cross your arms or hold a light weight at your chest, body straight.
Hinge down at the hips under control, keeping the spine neutral.
Extend back up until your body is in a straight line — squeezing the glutes — without over-arching past straight.

Common form faults

Over-extending and cranking the back past a straight line at the top. Stop when the body is straight; there's no benefit to hyper-arching the spine under load.
Rounding the spine to reach lower. Keep a neutral spine and hinge from the hips; reduce the range if the back rounds.

Programming

Strengthens the spinal erectors, glutes and hamstrings and supports bigger hinge lifts. Usually 10–15 reps; add light load at the chest before chasing heavy weight, and keep the top position neutral.

Frequently asked questions

Are back extensions safe for the lower back?

Done with a neutral spine and stopping at a straight-body position (not cranking into hyperextension), they're a productive way to strengthen the lower back and posterior chain. Avoid yanking into an over-arched top position under load.

Do they work the glutes or the lower back?

Both, and you can bias one: rounding the upper back slightly and thinking 'hips' emphasises the glutes and hamstrings, while staying rigid emphasises the spinal erectors. Foot and torso position shift the balance.