When a foot over-pronates stress is unduly placed on the inside of the ankle and the knee, and over a long period of time, particularly if a person is involved in sports and running, this added stress starts to damage structures in the knee and ankle. The result is usually pain, particularly when running, which typically varies in severity. If the arch of the foot is weak, usually due to a lack of strength in supporting muscles of the foot, it can collapse over time, so people who aren?t flat footed can sometimes start to over-pronate in time. This can stress tissues on the underside of the foot, causing painful conditions like bunions (the abnormal inflammation and protrusion of the big toe?s joint) and Plantar Fasciitis (painful inflammation of connective tissues in the sole of the foot).
Excess stress on the inner surface of the foot can cause injury and pain in the foot and ankle. Repeated rotational forces through the shin, knee, thigh and pelvis also place additional strain on the muscles, tendons and ligaments of the lower leg.
Overpronation may have secondary effects on the lower legs, such as increased rotation of the tibia, which may result in lower leg or knee problems. Overpronation is usually associated with many overuse injuries in running including medial tibial stress syndrome, or shin splints, and knee pain Individuals with injuries typically have pronation movement that is about two to four degrees greater than that of those with no injuries. Between 40% and 50% of runners who overpronate do not have overuse injuries. This suggests that although pronation may have an effect on certain injuries, it is not the only factor influencing their development.
Bunions, calluses and crooked toes may indicate alignment problems. So, it is important to ascertain the condition of a client's toes. Check the big toe to determine if the first joint of the toe is swollen, has a callus or bunion, and/or looks as though it abducts (i.e., hallux valgus) rather than pointing straight ahead. Also, look to see if the lesser toes seem to "curl up" (i.e., the person has hammer or claw toes). This may be indicative of damage to, or inflexibility of the plantar fascia caused by excessive flattening of the foot.
Non Surgical Treatment
Overpronation of the feet can be corrected in some cases and in others it can be effectively managed. Overpronators can train themselves to change their running gait, wear arch supports, orthotic insoles or specialist shoes for overpronators. In order to determine exactly what is happening during the stride, it is necessary to have a gait analysis conducted by a professional. The extent of overpronation can then be determined, and the causes can be identified and corrected directly. The main corrective methods used for excessive pronation are orthotics. Orthotics are the most straightforward and simplest solution to overpronation. Orthotics are devices which can be slipped into shoes which will offer varying degrees of correction to the motion of the foot. Orthotics help to support the arches and distribute the body weight effectively, and are usually the best treatment choice for moderate to severe overpronation. Orthotics may require existing insoles to be removed from your shoes to accommodate them; although most running shoes will have a removable insole to accommodate an orthotic insole.
Hyperpronation can only be properly corrected by internally stabilizing the ankle bone on the hindfoot bones. Several options are available. Extra-Osseous TaloTarsal Stabilization (EOTTS) There are two types of EOTTS procedures. Both are minimally invasive with no cutting or screwing into bone, and therefore have relatively short recovery times. Both are fully reversible should complications arise, such as intolerance to the correction or prolonged pain. However, the risks/benefits and potential candidates vary. Subtalar Arthroereisis. An implant is pushed into the foot to block the excessive motion of the ankle bone. Generally only used in pediatric patients and in combination with other procedures, such as tendon lengthening. Reported removal rates vary from 38% - 100%, depending on manufacturer. HyProCure Implant. A stent is placed into a naturally occurring space between the ankle bone and the heel bone/midfoot bone. The stent realigns the surfaces of the bones, allowing normal joint function. Generally tolerated in both pediatric and adult patients, with or without adjunct soft tissue procedures. Reported removal rates, published in scientific journals vary from 1%-6%.