How to Do a Machine Back Extension: Proper Form, Variations, and Common Mistakes

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Targets: Lower back muscles

Equipment Needed: Back extension machine or Roman chair

Level: Beginner

The back extension machine or Roman chair is used for an isolation exercise that targets the lower-back muscles, primarily the erector spinae. You lock your heels under a pad or roller with another pad to support your lower body as you recline face-down. This facilitates flexing at the waist. 

The exercise requires that you bend at the waist, and a little at the hips, lowering the torso until approximately the upper and lower body form a right angle. The extension is usually performed as a bodyweight exercise, using only the upper body for the load. The use of the back extension machine is controversial as poor technique can result in an injury. It can be part of a strengthening program.

How to Do a Machine Back Extension

Adjust the back extension machine so that your feet are securely hooked under the footpads. You need to ensure a good fit so that you are held firmly when you start the bend at the hips. Position your lower body across the large pad provided for this purpose. You need to be far enough forward so that you can flex the upper body almost at right angles. Cross your arms beneath your chest.

  1. Brace the abdominals while holding the arms folded and maintaining the body in a horizontal position. Make sure the ankles are well anchored.
  2. Bend slowly at the waist until the upper body is at 90 degrees to the lower body. Avoid arching your low back and squeeze your glutes at the top.
  3. Extend to the starting position and stretch upward just slightly so that the back is in hyperextension. Avoid arching your low back and squeeze your glutes at the top.
  4. Try 3 sets of 5 repetitions—more or less depending on the condition and strength of your back and abdominal muscles.

Benefits of the Machine Back Extension

Back extensions are done when you want to strengthen the lower back. They complement abdominal exercises by providing a reverse movement of the core muscles compared to crunches.

The back extension machine targets the erector spinae, which are three muscles: illiocostalis lumborum, longissimus thoracis, and the spinalis. This bundle of muscles lies in a groove along the vertebral column. These muscles extend your lumbar spine. Synergistic muscles used in the back extension are the gluteus maximus, hamstrings, and adductor magnus. Stabilizer muscles used include the back, shoulder, and neck muscles: biceps, triceps, lats, deltoids, traps, pecs, and rhomboids.

You use these muscles anytime you pick up an object from the ground. They are also key muscles in maintaining good posture.

Other Variations of the Machine Back Extension

You can perform this exercise in different ways to meet your skill level and goals.

Back Extension on the Floor

back extension

Ben Goldstein / Model: Melissa Castro Schmidt

A basic bodyweight floor version of the back extension is a great starting place or alternative for when you do not have gym access.

  1. Lie face down on a solid surface.
  2. Reach your arms straight out over your head, parallel to the floor. Keep your shoulder blades back and down (retracted).
  3. Exhale and lift your arms, head, and chest off the ground.
  4. Hold your neck in a neutral position looking down, do not look up or to the side.
  5. Hold this position for a count of one, squeezing your glutes together and bracing your abs.
  6. Return to the starting position with control.

Stability Ball Back Extension

back extension on ball start

Verywell / Ben Goldstein

back extension on ball finish

Verywell / Ben Goldstein

You can perform a back extension over a large stability ball much in the same way as a machine.

  1. Kneel on the floor in front of a stability ball.
  2. Lean your torso on the side of the ball.
  3. Extend your legs back one at a time and brace yourself by pressing your toes into the floor.
  4. Lean over the ball with your hands by your ears, elbows out.
  5. Exhale and while pressing your feet into the floor to brace you, lift your chest and upper torso off the ball.
  6. Squeeze your glutes and hold for a count of one.
  7. Inhale, lowering back to the starting position with control.

Standard Bench Back Extension

Use a standard bench to perform a back extension exercise.

  1. Place weight plate, kettlebell, or heavy dumbbell on one end of a bench to brace it.
  2. Lay face down on the bench, with your hips resting on the opposite end of the bench, arms crossed in front of your chest.
  3. Exhale and extend your lower back, lifting your torso slightly above parallel.
  4. Inhale, lowering your torso to the starting position with control.

Weighted Machine Back Extension

Adding a weight plate to a machine back extension can increase the challenge, helping you progress the exercise.

  1. Brace the abdominals while holding a weight plate to your chest, arms crossed over it to keep it in place.
  2. Maintain the body in a horizontal position. Make sure the ankles are well anchored.
  3. Bend slowly at the waist until the upper body is at 90 degrees to the lower body. Avoid arching your low back and squeeze your glutes at the top.
  4. Extend to the starting position and stretch upward just slightly so that the back is in hyperextension. Avoid arching your low back and squeeze your glutes at the top.

Common Mistakes

Poor technique can lead to an injury when you use a back extension machine. Avoid these errors.

Too Fast and Jerky

You must keep your movement slow and controlled. Do not bounce or jerk. If you go too fast or you use any forceful motions you can strain your back muscles or compress your discs.

Hyperextension

Only extend until your back is level with your thighs. Do not overextend your back.

Too Heavy of Weight

It is safest to perform this with only your body weight. If you add weights, select a light weight.

Too High of Training Volume

Keep the training volume low, such as no more than 10 repetitions for two sets.

Safety and Precautions

Do not use the back extension machine if you have a herniated disc. If you have any back problems, talk to your doctor or physical therapist to see whether this exercise is appropriate. Muscle engagement is the same as picking up a heavy object from the ground. If you have been told to restrict such activities, you should not use this machine.

One criticism of the back extension machine is that it isolates the lower back muscles too much, so your other muscles don't assist in protecting your back sufficiently. If you feel any back pain or discomfort when doing this exercise, stop.

Aim for 8 to 15 reps, depending on your fitness level, but do not do more than what you can do with proper form and no pain.

Try It Out

Incorporate this move and similar ones into one of these popular workouts:

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5 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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