90-90 Rotation
The 90-90 rotation is a bodyweight mobility exercise targeting the abdominal muscles and obliques. It involves lying on your back with legs bent at 90 degrees and rotating them side to side, improving spinal rotation and core stability.
How to do it
- Lie on your back with your hips and knees bent at 90 degrees, feet off the ground.
- Extend your arms out to the sides for stability, palms facing down.
- Keeping your knees together, slowly rotate your legs to one side until they are just above the floor.
- Pause for a moment, then rotate your legs back through center and to the opposite side.
- Continue alternating sides for the desired number of repetitions.
Form cues
- keep shoulders glued to the floor
- move with control, not momentum
- keep your knees at a 90-degree angle
- focus on the twist coming from your waist
Breathing: Inhale as you prepare, and exhale deeply as you rotate your legs toward the floor.
Common mistakes
- lifting shoulders off the ground, which reduces the stretch in your spine
- moving too quickly, which prevents your muscles from stabilizing the movement
- letting knees separate, which shifts tension away from your core
Muscles worked
Primary: abs. Secondary: obliques, lower back.
Suggested sets & reps
Get fitter
3 sets x 12-15 reps per side, 45s rest
Lose weight
3 sets x 15-20 reps per side, 30s rest
Build muscle
3 sets x 10-12 controlled reps per side, 60s rest
Easier, harder & alternatives
Make it easier
Make it harder
Alternatives
Take care if…
- If you have a history of back pain, perform the movement slowly and avoid forcing the rotation.
General educational guidance, not medical advice. Stop on sharp pain and check with a qualified professional if unsure.
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Start free →Frequently asked questions
Should my knees touch the floor?
Aim for the floor, but don't force it. If your shoulders start to lift, stop just before that point.
I feel this in my lower back, is that okay?
You should feel a gentle stretch. If you feel sharp or pinching pain, stop immediately and use a smaller range of motion.
Can I do this every day?
Yes, it is a gentle mobility movement that can be done daily to help with spinal stiffness.