Form Friday: Clamshells


by Devin Sarno, NSCA-CPT

Exercise: Clamshells

Muscle Groups: Gluteus Medius, Gluteus Maximus, Abductors

Importance:  With how often most of us sit, hip tightness and glute weakness is incredibly common. The clamshell is a great exercise to keep the hips moving and assist in strengthening and activating the glutes. By keeping your hips and glutes strengthened, you will be better equipped to perform your squat and deadlift and avoid compensation patterns that could cause back, hip, or knee pain.

Proper Form:

  1. Begin by lying on one side of your body on a floor or padded surface

  2. With your legs and feet stacked on top of one another, bend your legs so that your knees are at a 90 degree angle and your hips are at about a 135 degree angle

  3. Keeping your hips, knees, and ankles stacked on top of one another, hinge slightly at the hip in order to drive your top knee upward to open your legs like a clamshell

  4. Keep your heels touching and squeeze the glutes to drive the movement

  5. Be sure that the movement is slow and controlled, pausing briefly at the top of the movement

  6. Slowly reverse the motion and lower yourself back to your starting position

Progression/Regression: Band resisted clamshells


  • Keep your spine in a neutral position

  • Put your free hand on your glutes to feel that they are working as the prime mover of the exercise rather than the hip flexors

  • Keep your feet in contact with one another, especially your heels

Sample Workout, 2 rounds (Squat warmup):

  • 20 banded glute bridges (with looped band around knees)

  • 10 banded clamshells (each side)

  • 15 Squats (with looped band around knees; driving knees out against band)

  • 15 Hip Hinges