To understand “overpronation” it’s important to first understand pronation. Pronation is a normal function of the foot. It is the inward motion of the ankle bone and outward motion of the rest of the foot bones, which occurs naturally when the foot hits the ground and weight is applied. Pronation is a good thing; it cushions the foot and the entire body during the walking cycle. It keeps the foot and ankles protected from hard impact and an uneven ground surface. Overpronation occurs when too much pronation is present. In other words, overpronation occurs when the inward motion of the ankle bone is excessive and goes past the healthy point necessary for its intended functions. This excessive motion is caused by a misalignment between the ankle bone and the hindfoot bones. It creates an imbalance of forces and weight distribution in the foot that propagates throughout the entire body. Over time, this functional imbalance causes repetitive damage to joints, ligaments and bone structures. Left untreated, overpronation can lead to foot ailments such as bunions, heel pain (plantar faciitis), hammertoes, etc. Furthermore, the excessive motion in the foot can travel up the body and cause knee, hip and lower back pain.
There are many possible causes for overpronation, but researchers have not yet determined one underlying cause. Hintermann states, Compensatory overpronation may occur for anatomical reasons, such as a tibia vara of 10 degrees or more, forefoot varus, leg length discrepancy, ligamentous laxity, or because of muscular weakness or tightness in the gastrocnemius and soleus muscles. Pronation can be influenced by sources outside of the body as well. Shoes have been shown to significantly influence pronation. Hintermann states that the same person can have different amounts of pronation just by using different running shoes. It is easily possible that the maximal ankle joint eversion movement is 31 degrees for one and 12 degrees for another running shoe.
It is important to note that pronation is not wrong or bad for you. In fact, our feet need to pronate and supinate to achieve proper gait. Pronation (rolling inwards) absorbs shock and supination (rolling outwards) propels our feet forward. It is our body?s natural shock-absorbing mechanism. The problem is over-pronation i.e. the pronation movement goes too deep and lasts for too long, which hinders the foot from recovering and supinating. With every step, excess pronation impedes your natural walking pattern, causing an imbalance in the body and consequent excessive wear and tear in joints, muscles and ligaments. Some common complaints associated with over-pronation include Heel Pain (Plantar Fasciitis) ,Ball of foot pain, Achilles Tendonitis, Shin splints, Knee Pain, Lower Back Pain.
When sitting, an over-pronating foot appears quite normal, i.e. showing a normal arch with room under the underside of the foot. The moment you get up and put weight on your feet the situation changes: the arches lower and the ankle slightly turns inwards. When you walk or run more weight is placed on the feet compared to standing and over-pronation will become more evident. When walking barefoot on tiles or timber floors over-pronation is more visible, compared to walking on carpet or grass.
Non Surgical Treatment
Heel counters that make the heel of the shoe stronger to help resist/reduce excessive rearfoot motions. The heel counter is the hard piece in the back of the shoe that controls the foot?s motion from side-to-side. You can quickly test the effectiveness of a shoe?s heel counter by placing the shoe in the palm of your hand and putting your thumb in the mid-portion of the heel, trying to bend the back of the shoe. A heel counter that does not bend very much will provide superior motion control. Appropriate midsole density, the firmer the density, the more it will resist motion (important for a foot that overpronates or is pes planus), and the softer the density, the more it will shock absorb (important for a cavus foot with poor shock absorption) Wide base of support through the midfoot, to provide more support under a foot that is overpronated or the middle of the foot is collapsed inward.
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%.