Back Extension: Benefits, Muscles Worked, and More

published by: Debbie Luna
Last Updated:
January 17, 2023

The back extension is a bodyweight isolation exercise usually performed with the aid of a machine that allows the exerciser to achieve a complete range of motion, though certain versions of the back extension may be performed on the floor instead.

It is most often seen in the recovery phase of periodization utilizing athletic training programs, or combined alongside significantly more intense compound movements such as the deadlift or good morning, both of which require the back extension to “finish off” the muscle groups in a safer manner.

Regardless of its purpose in the training program or recovery plan, the back extension is an excellent exercise that presents a low impact alternative to many back exercises - thereby reducing the risk of injury while still retaining the same muscle group activation pattern.

What are Back Extensions?

Back extensions or hyperextensions, in more technical terms, are an isolation exercise with a closed kinetic chain that may or may not be considered a bodyweight exercise depending on whether the exerciser has chosen to incorporate additional resistance into the movement.

weighted hyperextension

It primarily targets the lower back, with the middle and upper back also being activated subsequently; with a particular focus on the erector spinae muscle groups that are responsible for supporting, protecting and extending the spinal column and entire back itself.

Back extensions are considered one of the most versatile isolation exercises for inducing a hypertrophic or rehabilitative stimulus in the back muscles, as they may be performed entirely without equipment on the ground, or with the addition of kettlebells or weight plates and the use of a hyperextension bench in order to intensity the exercise.

What is the Purpose of Back Extensions?

Back extensions are generally performed in an exercise routine for the purposes of improving the stability and relative strength capacity of the erector spinae muscles, alongside an improvement in the range of motion at which the entirety of the back may enter an extended form.

In certain cases, the back extension may even serve to induce a rehabilitative effect in individuals with poor lumbar or thoracic back posture, or individuals who wish to rehabilitate a back injury with active recovery methods that do not place significant strain on said areas.

What Muscles are Worked by the Back Extension?

The back extension primarily works most of the posterior chain muscle groups, with a particular focus on the two erector spinae muscle groups that run alongside the spinal column - though it does activate the glutes and hamstring muscle groups to a certain extent as well.

The erector spinae are the primary target of the exercise, and as such are also responsible for the majority of the force involved throughout the movement.

This is not entirely applicable at the deepest part of the repetition however, as the hamstrings and glutes will activate to a significant extent so as to draw the torso upwards once more, also working with the oblique muscles to an extent for the purposes of stability.

While on the topic of stability, the quadratus lumborum within the deepest portion of the lower to middle back is also recruited to a certain extent - though only if the exerciser utilizes a proper range of motion, and in sufficient enough volume to shift some small amount of the resistance to said muscle group.

Who Should Perform Back Extensions?

Back extensions are suitable for the majority of regular gym goers or physical rehabilitation patients, though the latter are better left advised by a physician or physical therapist prior to attempting the back extension while still suffering from any injuries.

For athletes and exercisers wishing to improve the stability and strength of their posterior chain, the back extension makes an excellent (if low impact) auxiliary exercise, especially when combined with other exercises that place significant training stimulus on said posterior chain muscles.

How are Back Extensions Performed?

As the back extension is a highly versatile exercise that may be performed entirely without equipment on the ground or with the use of a roman chair stand, it is best to separate each variation’s individual form cues and mechanics so as to avoid confusion.

It is important for the exerciser to note that the back extension machine exercise is a different exercise from the back extension exercise performed with the use of a roman chair, and as such the form cues, mechanics and loading pattern are quite different between the two.

Floor Back Extensions

In order to begin performing a floor back extension, the exerciser simply needs to lie on their stomach in a comfortable and spacious area, with their arms extended outward on both sides.

floor back extensions

Once positioned appropriately, the exerciser will lift their torso from the ground by squeezing their gluteus muscles and contracting their lower back, raising their chest and sternum off the floor and shortening the erector spinae in an concentric capacity.

Pausing at the apex of the repetition and squeezing the lower back muscles, the exerciser will then slowly release their contraction of the glutes and lower back; thereby lowering their chest and sternum back to the ground and completing a repetition of floor back extensions.

Roman Chair Back Extensions

To set up a set of roman chair back extensions, the exerciser will position themselves within the roman chair stand by bending over the padded portion of the roman chair and hooking their ankles in the catches at their rear, thereby securing themselves and allowing them to achieve a full range of motion.

back extension

To begin performing the exercise, the exerciser will bend their torso over the padded portion of the roman chair, hinging at the hip and maintaining a neutral spine position as they do so.

Once at the apex of the repetition, the exerciser will then contract their lower back, glutes, and hamstrings as they draw their torso back upwards, returning to the starting position if performed correctly.

This completes a single repetition of the roman chair back extension, with subsequent repetitions simply requiring the motion to be repeated until the set is complete.

Benefits of the Back Extension

Despite its relatively low impact and small muscle group activation set, the back extension is an exercise capable of inducing a wide variety of benefits that may aid the exerciser or patient in achieving their workout goals.

Apart from the general benefits that are achieved from the very fact that the back extension itself is an exercise, several other positive effects may be induced by regular and proper performance of the back extension, such as a strengthening in the stabilizing capacity of the erector spinae.

1. Improved Back Stability

One of the primary reasons the back extension is performed in the first place is its capacity to greatly improve the exerciser’s various back stabilizer muscle groups, thereby producing better posture adherence, reducing the risk of spinal overextension and even strengthening the back during the performance of other exercises.

The most significant of these back stabilizer muscle groups is the erector spinae, the primary mover muscle involved in the back extension and subsequently also the muscle that receives the most training stimulus - thereby reinforcing the back and protecting it from instability related injuries.

2. Reduced Injury Risk

As a direct effect of the improved back stability and reinforced spinal protection that the back extension offers, it can also reduce the risk of injury not only in athletic endeavors but in general day to day tasks that may otherwise injure the exerciser.

Tangentially related to these factors is the improvement in lower back flexibility that roman chair-based back extensions can provide, also serving to further reduce the risk of spinal column and lower back injury as the tissue adapts to a wider range of stable motion.

3. Body Awareness Improvement

Though the back extension is a low impact exercise with relatively simple to master form, it can greatly improve the exerciser’s bodily awareness during the performance of other exercises that require the lower back and spinal column to remain in a stable and safe position.

This is most noticeable in exercises such as the deadlift or barbell row, wherein the exerciser must learn to maintain a neutral spinal column supported by a braced core and lower back, something that may be learned from regular performance of the back extension exercise.

4. Low Impact Alternative Lower Back Exercise

As the majority of lower back exercises are of a high intensity that may make them unsuitable for novice exercisers or individuals with a history of lower back injuries, the back extension may act as the perfect alternative movement.

Though it is of significantly lesser intensity and thus will provide a less intense training stimulus, the back extension may replace such exercises like the good morning and the rack pull - so long as it is for the purposes of retaining lower back training stimulus with a decreased impact.

Common Mistakes of the Back Extension

The back extension is known as a relatively simplistic and safe exercise - though this does not mean that certain mistakes in its form or mechanics cannot be made, with the most common being an overextension of the back during both phases of the exercise.

A variety of other mistakes are often made in concerns to the back extension, and as such we have chosen to list those that are most commonly made by individuals new to the back extension, or resistance exercise in general.

Overextension of the Back

As previously mentioned, one of the largest mistakes exercisers make when performing a back extension is overextending the back, either by bending too far backwards in the case of the roman chair back extension, or too far forwards in other variations of the back extension.

This will place unnecessary and even dangerous amounts of pressure on the discs of the thoracic and lumbar portions of the spinal column, placing the exerciser at risk of spinal disc fusion, extruded spinal discs or a variety of other injuries related to spinal column compression.

Too Much Volume Utilization

Less of an issue in the mechanics or form of the back extension and more in the programming of the exerciser’s workout routine, utilizing too much volume per set of repetitions is another common mistake related to the back extension exercise.

Though it is low impact and generally utilizes very little resistance, excessive volume of repetitions can lead to strain of the various smaller muscles located deep in the middle and lower back, as well as eventually lead to overuse injuries in the connective tissues of the hips and spinal column.

As such, it is best for the exerciser to stick within the repetition ranges of 8 to 20 per set, thereby keeping the volume of the exercise to appropriate amounts.

Reliance on Momentum During the Repetition

Less of an issue with floor based back extensions and more likely to occur in roman chair back extensions, a reliance on momentum or “swing” during the back extension is another common mistake made by novice exercisers that may result in reduced training stimulus.

This is due to the fact that the muscle groups involved in a repetition of the back extension are recruited to a lesser extent as momentum reduces the total resistance placed on them, not only reducing the training stimulus accrued but also placing the exerciser at greater risk of injury.

A repetition of back extensions should be performed in a slow and controlled manner, with the exerciser bracing their back and core throughout the entirety of the movement.


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2. Matsudaira K, Hiroe M, Kikkawa M, Sawada T, Suzuki M, Isomura T, Oka H, Hiroe K, Hiroe K. Can standing back extension exercise improve or prevent low back pain in Japanese care workers? J Man Manip Ther. 2015 Sep;23(4):205-9. doi: 10.1179/2042618614Y.0000000100. PMID: 26917938; PMCID: PMC4727733.

3. De Ridder, E.M., Van Oosterwijck, J.O., Vleeming, A. et al. Posterior muscle chain activity during various extension exercises: an observational study. BMC Musculoskelet Disord 14, 204 (2013).

4. Steele, James, Stewart Bruce-Low, Dave Smith, David Jessop, and Neil Osborne. “Isolated Lumbar Extension Resistance Training Improves Strength, Pain, and Disability, but Not Spinal Height or Shrinkage (‘Creep’) in Participants with Chronic Low Back Pain.” CARTILAGE, (April 2020), 160–68.

Debbie (Deb) started powerlifting and Olympic lifting in High School as part of her track team's programming; She continues to train in order to remain athletic. Inspire US allows Deb to share information related to training, lifting, biomechanics, and more.
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