This is a gentle exercise used to strengthen your inner thigh.

Side Lying Hip Adduction
Step 1
Starting Position: Lie on your side on a mat/floor with your legs lengthened straight away from your body with your feet stacked in neutral position. Your lower arm can be bent and placed under your head for support. Your upper arm rests upon your upper hip. Your hips and shoulders should be stacked up and aligned vertically to the floor. Your head should be aligned with your spine. Engage your abdominal muscles to support your spine. Slowly bring your lower leg forward until it lies in front of your upper leg. Both legs remain straight. Both feet are resting on the floor with the feet in neutral position.
Step 2
Upward Phase: Exhale. Gently raise the lower leg off the floor. Keep the knee straight and the foot in a neutral position. Do not allow the hips to roll forward or back. Both knees should be “looking” straight ahead. Continue raising the leg until the hips begin to tilt, the waist collapses into the floor or until your feel tension develop in your low back or oblique muscles
Step 3
Downward Phase: Gently inhale and return the leg to your starting position in a slow, controlled manner. After completing your set, roll over and repeat with the opposite leg.
Due to the limited movement at the hip joint in this direction, the leg need only rise a few inches off the mat/floor.

Source: AceFitting