Reps Only exercise

Clamshell form, muscles worked, and workout tracking

The clamshell is a side-lying hip external rotation exercise in which the top knee opens like a shell while the feet stay together, targeting the gluteus medius and the deep rotators of the hip. It is one of the most prescribed drills in physical therapy and warm-ups because it wakes up the lateral hip with very low load, improving pelvic control and knee alignment before squats, runs, or lunges.

Clamshell illustration

How to do Clamshell

  1. 1Lie on your side with your hips and knees bent to about forty-five degrees, feet stacked, and your head resting on your lower arm.
  2. 2Place your top hand on your hip and brace your core so your pelvis stays stacked and still.
  3. 3Keeping your feet touching, exhale and lift your top knee toward the ceiling like a clamshell opening.
  4. 4Stop the moment your pelvis starts to roll backward; range should come only from the hip.
  5. 5Lower the knee back down slowly, feel the side of your hip working, and finish all reps before rolling to the other side.

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Track Clamshell in Plates

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