By strengthening your outer hips and glutes with this move, you're providing more support to your hips and lower back, Speir says.
- Lie on your side with your head resting in your hand. Stack your legs in a 90-degree bend.
- Raise your top knee to open the thighs like butterfly wings — your heels should be touching as you maintain the bend in your legs.
- Open and close the top knee while only using your leg muscles to drive the movement — keep the hips still.
- Repeat 20 times.