Knock knees are usually correctable with exercises that strengthen the outside muscles of the hips. Pilates exercises build strong muscles of the waist and trunk for good posture, balance and stabilization. Certain Pilates exercises target your hip abductors, which are the muscles on the outside of your hips. When these muscles are weak, they cannot pull your knees outwards into their proper alignment, so your knees collapse inwards, creating knock knees.
Pilates exercises require no other equipment but a a mat. Tone your outer thighs to correct knock knees by doing exercises such as the butterfly. The butterfly makes you point your knees outwards, building strength in the opposite direction from a knock-kneed position.
Stand with your feet greater than shoulder-width apart, and turn your feet out at 45-degree angles. Cross your arms in front of your body, and bend your knees until your thighs are parallel to the floor. Push through your heels and squeeze your glutes as you stand up all the way onto the balls of your feet. Swing your arms outward and overhead, crossing your wrists.
Pilates Ring Exercises
The Pilates ring, or magic circle, is a steering-wheel-sized piece of equipment with two padded "handles" on each end to hold onto or place your legs against. The ring is effective for toning inner and outer thighs.
To strengthen the outer thighs, lie on your side with your knees bent at right angles, and place the ring on the outside of your shins. One padded handle of the ring is on the floor beneath your bottom leg and the other handle points toward the ceiling. Lift your top leg toward the ceiling against resistance from the ring. Keep your knee pointing forward to practice proper alignment. Do not let it point inward. Repeat on the other side.
Pilates With a BOSU
A BOSU, or both sides up, ball creates an unstable environment on which to exercise. This increases the challenge to your core, including your hips. The side lying staggered legs on a BOSU is a Pilates exercise that strengthens inner and outer thighs at the same time.
Lie sideways with your right hip on the center of the round side of the BOSU, your legs straight and your upper torso supported by your right elbow on the floor. Squeeze your legs together and stacked with your knees pointing straight ahead. Raise both legs toward the ceiling. Repeat on the other side.
Pilates Machine Exercises
One exercise you can do on an appropriate Pilates or similar machine is the seated hip abduction. To perform this exercise, sit on the seat facing the upright frame with your legs straight in front of you. Grasp the handles connected to the cables with your arms straight, and put the insides of your feet against the cables. Open your legs to push against the cables. Your arms move with your legs to hold the cables in place but do not do any of the work.