One of the main postural deviations that cause pain and injury in the foot and ankle area (and resultant compensations in the rest of the body) is overpronation.
Pronation is a normal function that occurs when the foot rolls inward toward the midline of the body. This movement causes the heel to collapse inward and the medial arch of the foot to elongate and flatten. Overpronation, however, is when the foot collapses too far inward for normal function. This directly affects the ability of the foot to perform and can disrupt proper functioning through the entire body.
Apart from the problems overpronation causes in the feet, it can create issues in the calf muscles and lower legs. The calf muscles, which attach to the heel via the Achilles tendon, can become twisted and irritated as a result of the heel rolling excessively toward the midline of the body. Over time, this can lead to the inflexibility of the calf muscles and the Achilles tendon, which will likely lead to another common problem in the foot and ankle complex, the inability to dorsiflex. As such, overpronation is intrinsically linked to the inability to dorsiflex.
Joint Strengthening Exercises
Some exercises can strengthen and retrain the foot and ankle complex to correct overpronation. The overpronation exercises may be performed while wearing shoes, or for an even greater challenge, in bare feet.
[Read: Simple Strengthening Exercises For Knee Pain]
Big Toe Push down
Stand with the feet facing forward. Spread the big toes away from the second toes on both sides. If your client does not have enough strength or coordination to spread the big toes toward the midline of the body, have the client manually move them to the correct starting position. With the big toes spread, gently raise the arches of the feet so the body weight shifts toward the outside of the feet.
As arches lift up, be sure the big toes stay in contact with the ground and do not slide toward the second toes. In this position, gently push the big toe down into the ground until the muscle under the arch of the foot contracts.
Once your client becomes accustomed to the feeling of this muscle contracting isometrically, progress this exercise by gently rocking the body weight forward. As weight transfers forward, push the big toes down hard into the ground to contract the muscles in the arches of the feet to stop the foot from collapsing (i.e., overpronating). Perform this exercise for 8 to 10 repetitions at least two to three times per day.
The gluteus maximus muscle works concentrically to extend the hips and externally rotate the leg. It works eccentrically to slow down hip flexion, internal rotation of the leg and subsequent pronation of the foot. Strengthening the gluteus maximus muscle with this isometric, concentric exercise will help prepare it for the more dynamic eccentric strengthening exercise, Lunge With Knee Pull, to help decrease overpronation (Price, 2010).
Stand with the heels together and feet turned out like a duck. Tuck the pelvis under (i.e., posteriorly rotate) and gently try to rotate the legs outward without moving the feet. As the legs rotate outward, the gluteus maximus muscle on both sides should contract, causing the ankles to roll out slightly and the arches of the feet to raise. Hold this contracted position for three to five seconds, relax and repeat eight to 10 times once per day.
When you can control the activation of the gluteus maximus muscle, progress to this more complex movement. It involves both concentric (i.e., lifting the leg) and eccentric (i.e., lowering the leg) contraction of the gluteus maximus muscle while stabilizing the lumbar spine.
Lie over a stability ball and balance the body with the hands on the ground. Use the muscles of the right gluteal complex to lift the right leg off the ground without arching the lower back. Once your client can lift the leg without arching the lower back, progress by turning the right leg outward and/or inward on subsequent repetitions to activate different fibers of the glutes. Perform 10 to 12 repetitions on each side once per day.
Side-lying Leg Lift
The gluteus minimus and gluteus medius muscles act eccentrically to slow down the leg as it travels toward the midline of the body across the foot and ankle. When these muscles are weak and not functioning correctly, the leg collapses, causing the foot to overpronate. Strengthening these muscles helps decrease the effects of overpronation (Price, 2010).
Lie on the left side of the body with the head supported. Bend the right knee and position the instep of the right foot on the inside of the left knee. Posteriorly rotate the pelvis (i.e., tuck it under) and gently lift the right knee without arching the lower back or rotating the hips. Perform this exercise slowly, allowing plenty of time for the nervous system to connect kinesthetically to the muscles on the sides of the hips and buttocks. Progress this exercise by slowing down the lowering of the leg so that the eccentric portion of this exercise takes twice as long as the lifting (e.g., concentric) phase. Perform 10 to 12 repetitions on each side, once a day.
Lunge With Knee Pull
This exercise combines isometric, concentric and eccentric movements, and is designed to strengthen the muscles of the foot, ankle, lower leg, quadriceps, gluteal complex, abdominal and spine to retrain the entire kinetic chain and decrease overpronation.
Stand in a staggered lunge position with the left foot forward. Bend at the hips (without rounding the spine), rotate the torso and grab the outside of the left knee with the right hand. Slowly bend the knees and lunge gently while pulling the left knee toward the midline of the body. As the left knee pulls inward, rotate the left shoulder backward so the spine and rib cage turn behind the left hip.
As the weight is transferred forward into the left leg, push the left big toe down into the ground (as described in the Big Toe Push down exercise) to help stabilize the foot and ankle. The client should feel all the muscles in the left gluteal complex contract as they work to steady the pelvis, spine, hips, and leg. Return to the starting position and repeat six to 10 repetitions on each side for one to two sets at least three times per week.