The machine back extension is the seated lower back machine: you sit with a pad across your upper back and push backwards against the weight stack, from a forward lean to sitting tall. It trains the same muscles as a back extension on the 45° bench, but the load is set with a pin, so you can start light and add weight in small steps without hugging a plate to your chest. If you have been looking for "the lower back machine" in your gym, this is it.
How to do it
- Set the seat so the pad sits across your upper back, below the neck, with your feet braced.
- Cross your arms over your chest and push back slowly until you are sitting upright.
- Come forward under control rather than letting the stack pull you down.
Common mistakes
- Throwing yourself back with momentum and slamming into the end of the range.
- Pushing far past upright into an arch, which loads the lower back without training anything useful.
What it trains
- Lower back
- extends the spine against the pad — the muscle the machine is built for
- Glutes
- extend the hips as you come upright and help you out of the forward lean
- Hamstrings
- assist at the hips, though less than on a bench — seated with the knees bent, they are too short to pull hard
Variations and alternatives
Common questions
What is the lower back machine called?
Usually the back extension machine or the lower back machine — the label on the frame depends on the maker. It is the seated one, where a pad sits across your upper back and you push backwards against the stack. In StackUp it is Machine Back Extension, and a search for "lower back machine" finds it too.
Is the lower back machine the same as a hyperextension?
No. On a hyperextension you lie face down on a 45° or flat bench with your hips on a pad and move your whole torso against its own weight. The machine sits you upright, puts the load on a pad behind your shoulders and lets you choose it in small steps, which makes it easier to start light and to progress. Both train the lower back; StackUp keeps them as separate exercises because their numbers mean different things.
How far back should I lean on the back extension machine?
To sitting upright, or a few degrees past it, and no further. The work is in coming up out of the forward lean; pushing on into a deep arch at the end loads the lower back without training anything useful. Set the start position so the forward lean feels like a stretch, not a strain.
How heavy should I go on the lower back machine?
Moderate, for 10 to 15 slow, controlled reps. The lower back takes well to steady volume and badly to grinding out heavy low-rep sets, so treat this as an accessory. Set the rep range in StackUp and it suggests the next weight once your heaviest set clears the top of it — the default step is 2.5 kg, and you can set it to match the stack on your machine.
In StackUp. Logged as weight and reps per set, and your heaviest working set decides whether the weight goes up next time. Get the app.
Back
