Excess pronation usually causes overuse type injuries, occurring most frequently in runners. When a neutral foot pronates during walking or running, the lower leg, knee and thigh all rotate internally (medially). When an athlete with an overpronates this rotation inwards movement is exaggerated. This in turn increases the stresses on the muscles, tendons and ligaments of the foot, lower leg including shin and knee as the limb rotates in too far.
There are many biomechanical issues that can contribute to excessive pronation, including weak foot intrinsic muscles, limited ankle dorsiflexion mobility and calf flexibility, weak ankle invertor muscles (e.g. posterior tibialis), weak forefoot evertor muscles (peroneus longus), poor hip strength and control, Anterior pelvic tilting, heel InversionIn a person who overpronates, the heel bone goes into an everted position meaning that it turns out away from the midline of the body. The opposite motion of eversion is inversion. Inversion is a motion that needs to be controlled to prevent the foot from excessively pronating.
Common conditions seen with overpronation include heel pain or plantar fasciitis. Achilles tendonopathy. Hallus Valgus and/or bunions. Patellofemoral pain syndrome. Iliotibial band pain syndrome. Low back pain. Shin splints. Stress fractures in the foot or lower leg.
A quick way to see if you over-pronate is to look for these signs. While standing straight with bare feet on the floor, look so see if the inside of your arch or sole touches the floor. Take a look at your hiking or running shoes; look for wear on the inside of the sole. Wet your feet and walk on a surface that will show the foot mark. If you have a neutral foot you should see your heel connected to the ball of your foot by a mark roughly half of width of your sole. If you over-pronate you will see greater than half and up to the full width of your sole.
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%.