Over-pronation, or flat feet, is a common biomechanical problem that occurs in the walking process when a person?s arch collapses upon weight bearing. This motion can cause extreme stress or inflammation on the plantar fascia, possibly causing severe discomfort and leading to other foot problems.
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.
If you overpronate, your symptoms may include discomfort in the arch and sole of foot, your foot may appear to turn outward at the ankle, your shoes wear down faster on the medial (inner) side of your shoes. Pain in ankle, shins, knees, or hips, especially when walking or running are classic symptoms of overpronation. Overpronation can lead to additional problems with your feet, ankles, and knees. Runners in particular find that overpronation can lead to shin splints, tarsal tunnel syndrome, plantar fasciitis, compartment syndrome, achilles tendonitis, bunions or hallux valgus, patello-femoral pain syndrome, heel spurs, metatarsalgia.
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
Get a gait analysis of your running style, this will highlight if you overpronate, oversupinate or have a neutral gait. Most podiatrists, physio’s and sports therapists will offer this service, as do some specialist sports shops. Find a clinic. If you overpronate, get orthotics with extra medial support. Many running shoes have a harder material on the inside of the midsole (the thick hard foam part of the running shoe). This means the inside of the shoe will be compressed less under load and support the inside of the foot preventing it from rolling in or flattening. For people with considerable overpronation, another option is to have an orthotic device fitted. Orthotic insoles come in many types and prices. Some are pre-molded and can be bought off the shelf. These are ok for the majority of problem feet. However some cases may require specially casted orthotics from a relevant sports injury therapist or podiatrist.
Calcaneal “Slide” (Sliding Calcaneal Osteotomy) A wedge is cut into the heel bone (calcaneus) and a fixation device (screws, plate) is used to hold the bone in its new position. This is an aggressive option with a prolonged period of non-weightbearing, long recovery times and many potential complications. However, it can and has provided for successful patient outcomes.