What is the back extension?
The back extension is an exercise for the lower back. You can use the back extension machine or the Roman chair spinal extensor in the gym to perform this exercise, or for a similar workout you can also perform the dorsal raise bodyweight exercise, which use the same muscles.
Which muscles does the back extension use?
The back extension uses the lower back (erector spinae) muscles. This exercise also works the extensor muscles at the sides of the spine. The back extension exercise is ideal to combine with the abdominal crunch to create a strong core.
You will usually find the back extension machine next to the abdominal crunch machine in the gym. Both look quite similar in layout with a padded bar that you sit against. To use the back extension machine you push back against the bar, while to use the ab machine you have to pull the bar forward.
How to perform the back extension
To perform the back extension using the back extension machine in the gym, first sit comfortably on the seat and rest your upper back against the padded bar.
You can place your hands either on your legs, across your chest or ideally grasp the handles which will usually be at the sides of the seat.
Keep looking forward and keep your chest up and prepare to push back against the bar. When you push, make sure to use your hips to extend your upper body backwards, keeping your body straight by engaging the lumbar spine. Abs should be tight to give strength and stability to the core.
Pause and hold the weight for a few seconds when you have extended back to a comfortable amount, then slowly move forward again back to your starting point, returning the weight gently to the stack.
Always keep the motion slow and controlled. It is especially important to be careful with a slow movement when working with the lower back as it is an area that is easy to injure with improper technique.
Back extension machine caution
Some people do not like using the back extension machine due to the risk of injury it poses if you overload the weight or lift incorrectly. We urge caution when using this machine and always err on the side of a lighter weight than you can handle.
It is a good idea to use the back extension machine as a flexibility enabler and light strengthener rather than try to max out with heavy loads. The deadlift is far better at building all-over back strength.
However, if used sparingly the back extension works as a complement to the ab crunch for well-balanced core muscles.
Roman chair spinal extensor
An alternative to the back extension machine is the Roman chair spinal extensor. To get into position on this apparatus, you lie forwards across the angled bars, placing the back of your legs behind the padded lower bar and your hips on the padded cushion.
To perform the exercise, bend forward at the hips until comfortably extended at angle of between 45 and 90 degrees, then raise yourself slowly back up to your starting position using your lower back muscles.
To make this exercise more difficult, you can use a resistance band positioned around the base of the machine with the other loop slipped around the back of your neck. Support the band with your hands as you slowly lift to stretch the band.
This back exercise using the Roman chair spinal extensor not only targets the erector spinae muscle, it also recruits your glutes and hamstrings to hold your body still while you lift.
Other exercises for the back
The dorsal raise is a similar exercise which is performed using only your own bodyweight. This exercise moves the back through a much smaller range of motion and is safer to perform than back extensions using gym machines.
The dorsal raise is ideal to use alongside sit ups and planks for a good core strengthening bodyweight workout. In fact, although the plank primarily works the abs, it can also be used as a back strengthening exercise, as it works multiple muscles, including the erector spinae.