Machine 45 Degree Back Extension

Also known as: 45 Degree Back Extension and 45 Degree Hyperextension

Anton YefanovUpdated October 10, 2026

Machine 45 Degree Back Extension demonstration, with the core highlighted

The machine 45 degree back extension is performed on an angled hyperextension bench where the lifter hinges forward at the hips and uses the lower back, glutes, and hamstrings to return to a straight line. The 45 degree angle reduces the load compared to a horizontal back extension, making it the most accessible version of the movement and a clean teaching piece for the hip-hinge pattern.

How to do the Machine 45 Degree Back Extension

Set the pad height so the top edge sits just below your hip crease and step into the machine.
Plant your feet firmly on the foot platform and cross your arms over your chest.
Brace your core and hold a straight line from head to heels at the starting position.
Hinge forward at the hips, lowering your torso toward the floor with a flat back.
Stop when you feel a stretch in the hamstrings and your torso is roughly parallel to the floor.
Drive your hips into the pad and squeeze your glutes to return to the straight starting line.

Muscles worked

The machine 45 degree back extension works your core, chiefly the spinal erectors that run along the lower back, with the glutes and hamstrings helping to raise the torso. The erectors work isometrically for the whole set: their job is to hold the spine flat while the body pivots at the hips, and they feel it most as you approach the straight line at the top.

The glutes and hamstrings handle the hip extension itself. They are stretched hardest at the bottom, when the torso is roughly parallel to the floor, and they drive the first part of the climb. Pad height changes the emphasis. With the top edge just below the hip crease the hips can fold freely, so the hinge is clean. Set the pad too high and the movement turns into spinal flexion, which shifts the work onto the lower back alone.

Primary:: Core

Why train it

Strengthens the lower back, glutes, and hamstrings as a connected chain.
Reinforces the hip-hinge pattern with bodyweight load.
Builds back resilience that protects deadlifts and rowing variations.

Common mistakes

Rounding the lower back at the bottom instead of hinging cleanly at the hips.
Hyperextending the lower back at the top instead of stopping at a straight line.
Adding weight too soon, which compromises the hinge and overloads the lower back.
Rushing the descent instead of controlling the lowering phase for the full range.

Frequently asked questions

What equipment do I need for the Machine 45 Degree Back Extension?

Only a machine. Nothing beyond that is required to run the movement the way it is described above.

Is the Machine 45 Degree Back Extension suitable for beginners?

Yes. The Machine 45 Degree Back Extension is rated beginner, and the machine holds the path for you, so there is little to get wrong once the seat and the pin are set.

Can I do the Machine 45 Degree Back Extension at home?

Only if your home setup runs to a machine. Most do not, so this is usually a gym movement. The alternatives below cover the same muscles with kit you are more likely to have.

How many sets and reps of the Machine 45 Degree Back Extension should I do?

Three to five sets of 5 to 8 reps for strength, or 8 to 12 for size. A hinge is heavy on the lower back, so leave a rep in the tank and rest two to three minutes between sets.

What are good alternatives to the Machine 45 Degree Back Extension?

Barbell Rack Pull, Bodyweight Deadlift, and Abdominals Stretch Variation Four train the same primary muscles as the Machine 45 Degree Back Extension. Pick whichever one suits the equipment in front of you.