Clam Shell
The Clam Shell is a foundational hip isolation exercise performed lying on your side that targets the gluteus medius to improve hip stability and prevent knee injury. It involves externally rotating the top hip while keeping the feet touching, resembling a clam opening its shell.
Iridium identifies this as a sub-muscle isolation movement for the glute medius, programming it when you need to accumulate specific volume without adding significant systemic fatigue to your recovery score. Because increasing weight is often impractical for this movement pattern, Iridium relies on RPE feedback to ensure intensity remains high enough to contribute to your Minimum Effective Volume.
Form Cues
- Lie on your side with your hips and knees bent at a 45-degree angle.
- Stack your hips directly on top of each other, perpendicular to the floor.
- Keep your heels touching throughout the entire movement.
- Squeeze your glutes to lift the top knee toward the ceiling.
- Lower the knee slowly to the starting position.
- Don't allow your top hip to roll backward as you lift the knee.
- Don't lift your feet off the floor or separate your heels.
- Don't use your lower back to generate the movement.
- Don't rush the lowering phase; maintain tension.
- Don't rotate your spine to get the knee higher.
Common Mistakes
- Rolling the pelvis backward
- Using the lower back
- Lifting the feet
- Rushing the tempo
- Insufficient range of motion
Muscles Worked
The Clam Shell primarily isolates the gluteus medius and gluteus minimus, which are critical for hip stabilization and abduction. Strengthening these muscles helps prevent knee valgus (knees caving inward) during squats and running, while also reducing strain on the lower back.
Primary
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