Hip 90/90 position

Sit with both knees at 90 degrees to simultaneously work internal and external hip rotation.

Why it works

Hip rotation range is a primary limiter in lower-body movement quality, and internal rotation in particular is commonly lost from prolonged sitting. The 90/90 position places both hips at end range simultaneously and allows targeted loading of each direction, directly addressing the rotational mobility that transfers to squatting, walking gait, and low-back comfort.

How to do it

1. Sit on the floor with the front knee at 90 degrees (shin parallel in front) and the back knee at 90 degrees (shin parallel to the side).
2. Sit upright with a neutral spine — do not collapse or round.
3. Hold for 1–3 minutes, working active upright posture the whole time.
4. Switch sides. Add PAILs/RAILs contractions once you can hold the position with a straight spine.

Evidence

Hip rotation restriction is well documented as a contributor to low-back pain and altered movement patterns in clinical populations. The 90/90 stretch is established practice in physical therapy and functional movement systems for addressing this restriction. (clinical)

Strong clinical tradition but limited RCT data specifically on the 90/90 position versus alternatives.

Common mistake

Letting the spine round to fake the appearance of being "flat" in the position, which removes the hip stretch and shifts stress to the lumbar spine.