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90/90 Hip Stretch (Shinbox)

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

Positions & Range of Motion

Start
seated on the floor, both hips at 90° flexion, front leg in external rotation and back leg in internal rotation, both sit-bones anchored, spine tall
End
both knees pressed toward the floor with chest reaching gently over the front shin, trunk stationary and sit-bones still anchored
Range of Motion
hip rotators lengthened to comfortable end range in front-hip ER and back-hip IR; sustained myofascial stretch

How to Perform

Seated with both hips at 90° flexion and 90° rotation — front leg in external rotation, back leg in internal rotation. Targets hip capsule, gluteals, and deep rotators. Myofascial stretching improved hip rotation by up to 56% over 6 weeks. No evidence of fascicle lengthening from stretching — improvements come from decreased stiffness (g=0.37) and increased stretch tolerance (g=0.74).

Watch on YouTube↗

Opens a YouTube search for “90/90 Hip Stretch (Shinbox)”

Starting position: seated

Coaching Cues

  1. 1

    Tall, long spine — rotation lives at the hip socket

    (verbal)
  2. 2

    Press both knees toward the floor without moving the trunk

    (verbal)
  3. 3

    Reach the chest gently over the front shin

    (verbal)
  4. 4

    Both sit-bones stay anchored to the floor

    (tactile)

Evidence-Based Dosing & EMG Data

Recommended Dosing

2-4 reps of 30-60 seconds per side, 5-7 days/week, ≥5 minutes total weekly [Thomas 2018]

Muscles Involved (4)

Primary Movers

Piriformis— Stretched in ER position
Gluteus Maximus— Posterior hip stretch

Secondary Movers

Gluteus Medius— IR position — anterior fibers stretched
Gluteus Minimus— Contributes to rotation limitation

Easier Variations ↓

1

Figure-4 Stretch

Supine with ankle crossed over opposite knee. Simpler hip ER stretch.

Harder Variations ↑

1

90/90 with Forward Lean

Lean torso forward over the front shin for deeper hip ER stretch.

Target Movements (2)

Hip External RotationHip Joint (Coxofemoral)
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:

Floor Transfers (Sit-to-Floor-to-Stand)Dressing — Lower Body

Goals This Helps With

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

Improve Hip MobilitymobilityHip Osteoarthritisrehab

Evidence Sources (2)