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90/90 Hip Internal Rotation Stretch

Draftstretch80%intermediate⬤ moderate evidence
View FHIR resourceFHIR R4 ActivityDefinition — the interoperable form of this exercise

Positions & Range of Motion

Start
seated on the floor in 90/90 position — front leg 90° hip flexion and 90° knee flexion, back leg 90° hip abduction and 90° knee flexion, spine tall
End
trunk hinged forward over the front shin with a long spine, feeling a stretch in the front-hip external rotators toward internal rotation
Range of Motion
front-hip external rotators lengthened toward end-range internal rotation via forward trunk lean; sustained stretch

How to Perform

Seated on the floor with front leg at 90° hip flexion + 90° knee flexion, back leg at 90° abduction + 90° knee flexion (the '90/90' position). Lean forward over the front shin to stretch the front-hip external rotators and lengthen toward IR. Switch sides.

Watch on YouTube↗

Opens a YouTube search for “90/90 Hip Internal Rotation Stretch”

Starting position: seated

Coaching Cues

  1. 1

    Sit tall before leaning — don't round the spine to reach the shin

    (verbal)
  2. 2

    Back-leg knee may want to lift — use that as feedback for capsule restriction

    (tactile)

Evidence-Based Dosing & EMG Data

Recommended Dosing

30 s hold × 3 reps each side + 2 × 10 active IR transitions, daily for 6 wk.

Muscles Involved (8)

Stabilizers

Erector Spinae Group— Holds a tall, neutral spine during the forward lean (cue: sit tall, do not round the spine to reach the shin).

Lengthened / Stretched

Obturator Internus— Deep external rotator of the front hip, lengthened by the toward-IR lean.
Obturator Externus— Deep external rotator of the front hip, lengthened toward internal rotation.
Gemellus Superior and Inferior— Gemellus superior/inferior, part of the deep-six external rotators being stretched toward IR.
Piriformis— Deep hip external rotator; key stretched target as the front hip is driven toward IR. Note its ER action diminishes/reverses past ~60-90 deg hip flexion, but it remains a stretched structure in the 90/90 position.
Gluteus Maximus— Strong hip external rotator; posterior/deep fibers stretched by the toward-IR position combined with hip flexion.
Gluteus Medius— Posterior fibers act as external rotators and are lengthened toward IR; secondary stretched structure.
Quadratus Femoris— Deep external rotator lengthened as the front hip moves toward IR.

Easier Variations ↓

1

Seated Cross-Leg IR Hold

Simpler crossed-leg sit if 90/90 is unreachable.

Harder Variations ↑

1

Active 90/90 Transitions

Rotate hips actively from one 90/90 side to the other — trains hip rotation under load.

Target Movements (1)

Hip Internal RotationHip Joint (Coxofemoral)

Why This Exercise Matters

Everyday activities this exercise helps you do — essential means it directly trains the capacity the task needs:

Squat to StandTrunk Rotation & Looking Behind

Goals This Helps With

Rehab, performance, prevention, and mobility goals this exercise supports — essential means it's a cornerstone:

Improve Hip MobilitymobilityHip Osteoarthritisrehab

Research Notes

Standard internal-rotation mobility drill. Add active 90/90 transitions (rotating from one side to the other through both hips simultaneously) to train motor control alongside mobility.