HOW: Begin the exercise by laying on your side. Place your top foot in front of your bottom foot. Push both feet into the ground to lift your body up into a full side plank. Keep your body in one straight line from your heels to your hips to your shoulders.
FEEL: You will feel your shoulder, hip, and core working – specifically the side facing the floor. You will also feel the inner groin region of your top leg as long as you push that side's foot down into the ground as you should.
COMPENSATION: Avoid allowing your shoulder blade to sag back. Avoid allowing your hips to dip towards the floor when holding at the top.