Pronation is a turning outward of the foot at the ankle, so that one has a tendency to walk on the inner border of the foot. (Pronation is the opposite of supination). When a foot and ankle pronates to a great degree, we call it over-pronation. During the normal gait cycle, we all pronate and then rapidly recover. It is over-pronation that patients are concerned with. This is a static deformity associated with flat feet and sometimes with foot and arch pain.
Chief Diagnostic Sign: You can test for pronation by looking at the leg and foot from the back. Normally you can see the Achilles Tendon run straight down the leg into the heel. If the foot is pronated, the tendon will run straight down the leg, but when it lies on the heel it will twist outward. This makes the inner ankle bone much more prominent than the outer ankle bone.
Because pronation is a twisting of the foot, all of the muscles and tendons that run from the leg and ankle into the foot will be twisted. If left untreated, pronation may be the cause of heel spurs, plantar fasciitis, frequent ankle sprains, shin splints, weak and painful arches, and eventually knee, hip, and lower back pain.
A common cause of pronation is heredity — we can inherit this biomechanical defect. The second most common cause is due to the way our feet were positioned in the uterus while we were developing; this is called a congenital defect. In either instance, the following occurs in our feet during our development:
The muscles, ligaments, and other soft tissue structures that hold our bones together at the joints become looser than normal. When the bones are not held tightly in place, the joints are not aligned properly, and the foot gradually turns outward at the ankle, causing the inner ankle bone to appear more prominent. The foot moves in this direction because it is the path of least resistance. It is more difficult for the foot to move in the opposite direction (this is called supination). As we develop, the muscles and ligaments accommodate to this abnormal alignment. By the time growth is complete, the pronated foot is: abnormally flexible, flat, and its outer border appears raised so that as you step down you do not come down equally across the entire foot; instead, you come down mostly on the inner border of the foot. Normal aging will produce further laxity of our muscles that causes the pronation to become gradually worse.
Pronation can also occur as an overuse syndrome in active runners, where a great deal of stress is placed on ligaments and tendons that support the medial column.
Obesity is another predictor for pronation and deterioration of the medial ligaments and posterior tibial tendon due to excessive stress on these tissues.
Acute Trauma can also lead to over-pronation when ligaments are torn or tendon is ruptured. Once again this can lead to a collapse of the medial column.
Arthritic conditions involving the knee joint when the joint is in varus (inner collapse) posture, this places the center of gravity over the ankle joint rather than the foot causing undue pressure on the inner ankle.
Results of Pronation:
Due to the laxity of the soft tissue structures of the foot, and the fact that the joints are not held together properly, the bones of the feet shift. When this occurs, the muscles that attach to these bones must also shift, or twist, in order to attach to these bones. The strongest and most important muscles that attach to our foot bones come from our lower leg. So, as these muscles course down the leg and across the ankle, they must twist to maintain their proper attachments in the foot. This twisting of these muscles will cause: shin splints, Achilles Tendonitis, generalized tendonitis, fatigue, muscle aches and pains, cramps, ankle sprains, and loss of muscular efficiency (reducing walking and running speed and endurance).
The problems we see in the feet, which are due to over-pronation include: bunions, heel spurs, plantar fasciitis, fallen and painful arches, hammertoes, metatarsalgia (ball of foot pain), and calluses.
- Children: If pronation is diagnosed before the age of five it can usually be treated in such a manner that the bones and joints will be aligned properly as growth continues. This may prevent the arch from collapsing, as well as allowing the muscles of the leg to enter the foot without twisting. With proper and early treatment, the foot will not turn out at the ankle, and the child’s gait will improve. Treatment for pronation in children may include: night braces, custom-made orthotics, and exercises. These treatments usually continue until growth is complete, and then the adult may need to wear custom-made orthotics to prevent the pronation from returning (the foot, as every other part of our body, tends to return to its original form if preventive measures are not taken). One side note: frequently, pediatricians will wait too long, hoping that the child will “outgrow” the problem. By the time they realize that the child’s feet will not improve, it is too late to change the foot. In these cases, custom-made orthotics is used to prevent the pronation from becoming worse.
- Adults: The only effective conservative treatment for pronation is custom-made orthotics.
How custom-made orthotics for pronation and over-pronation work:
- Pronation forces us to bear most of our weight on the inner border of our feet. Custom-made orthotics gently redistributes the weight so that the entire foot bears its normal share of weight with each step we take. The foot will not twist out at the ankle, but will strike the ground normally when the orthotics is used. This action of the custom-made orthotics will help to prevent: shin splints, ankle sprains, knee and hip pain, lower back pain, nerve entrapments, tendonitis, muscle aches, bunions, generalized fatigue, hammer toes, and calluses.
- Custom-made orthotics supports not only the arch as a whole, but also each individual bone and joint that forms the arch. It is not enough to use an over-the-counter arch support, as these generic devices will not provide the proper support to each specific structure of the arch and foot. Each pronated foot’s arch collapses differently and to different degrees. The only way to provide the support that you may need is with a custom-made device. This action of the custom-made orthotic will help to prevent: heel spurs, plantar fasciitis, calluses, arch pain, and weakness of the entire foot.
- Custom-made orthotics will reduce the twisting of the leg muscles as they enter the foot, by maintaining a normal alignment of the bones and joints of the foot. If the bones and joints are aligned properly, by reducing the pronation, the muscles can run straight to their attachments in the foot, without twisting to get to these bones. This action of custom-made orthotics will reduce Achilles Tendonitis; shin splints; ankle, knee, hip, and lower back pain; and leg cramps. This action will also allow the leg muscles to work more efficiently, thus allowing you to walk and run with less effort.
- With every step we take, we place at least half of our body weight on each foot (as we walk faster, or run, we can exert more than twice our body weight on each foot). As this amount of weight is applied to each foot there is a significant shock passed on to our body. Custom-made orthotics will absorb some of this shock, helping to protect our feet, ankles, knees, hips, and lower back.
Our custom-made orthotics for pronation and over-pronation are constructed of thin, comfortable, modern shock absorbent materials. These materials compress as you place your weight on the orthotic, thus absorbing the shock of each step, rather than passing on these shocks to the foot, leg, and spine. When you remove your weight from the orthotic, the orthotic returns to its original shape and height. This occurs because the materials we use have a “memory,” and can remember their original shape and height, and return to it. These materials will comfortably keep the foot in its proper alignment, relieving the pronation and its symptoms, while helping to prevent further associated problems from occurring .
Based on impressions of your feet and information you provide on a comprehensive self-examination form, we can design and construct a pair of orthotics that will help to reduce your pronation, muscle imbalances, foot and leg pain and fatigue, and foot abnormalities. These orthotics will fit into any shoe with a heel height up to 1 1/2 inches.