Overview
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.
Causes
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.
Symptoms
Because overpronation affects the entire lower leg, many injuries and conditions may develop and eventually cause problems not only in the leg and foot, but also the knee, hips and lower back. Pain often begins in the arch of the foot or the ankle. Blisters may develop on the instep, or on the inside edge of the heels. As overpronation continues and problems develop, pain will be felt elsewhere, depending on the injury.
Diagnosis
The best way to discover whether you have a normal gait, or if you overpronate, is to visit a specialty run shop, an exercise physiologist, a podiatrist or a physical therapist who specializes in working with athletes. A professional can analyze your gait, by watching you either walk or run, preferably on a treadmill. Some facilities can videotape your gait, then analyze the movement of your feet in slow-motion. Another (and less costly) way is to look at the bottom of an older pair of run shoes. Check the wear pattern. A person with a normal gait will generally see wear evenly across the heel and front of the shoe. A person who overpronates will likely see more wear on the OUTside of the heel and more wear on the INside of the forefoot (at the ball). A person who supinates will see wear all along the outer edges of the shoe. You can also learn about your gait by looking at your arches. Look at the shape your wet feet leave on a piece of paper or a flat walking surface.
Non Surgical Treatment
Anti-Pronation Insoles provide a unique foot support system that aligns the lower body. The major cause of foot and leg pain is over pronation (rolling over of the feet) which causes excessive pressure on the muscles, ligaments and bones of the lower body. Running insoles treat the underlying cause of over pronation and prevent future occurrences of the associated foot or leg condition. A project conducted at the NIKE Sport Research Laboratory studied the effects of orthotics on rear foot movement in running. Nine well-trained runners who wore orthotics were chosen as subjects. The results of the study indicated that orthotics reduced rear foot movement by roughly one degree or approximately nine percent of the amount found in runners not using orthotics. The average reduction of the maximum velocity of pronation was fifteen percent. Thus this study indicates that orthotics and insoles control over pronation which will treat and prevent many sporting injuries.
Prevention
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.
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.

Causes
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.
Symptoms
Because overpronation affects the entire lower leg, many injuries and conditions may develop and eventually cause problems not only in the leg and foot, but also the knee, hips and lower back. Pain often begins in the arch of the foot or the ankle. Blisters may develop on the instep, or on the inside edge of the heels. As overpronation continues and problems develop, pain will be felt elsewhere, depending on the injury.
Diagnosis
The best way to discover whether you have a normal gait, or if you overpronate, is to visit a specialty run shop, an exercise physiologist, a podiatrist or a physical therapist who specializes in working with athletes. A professional can analyze your gait, by watching you either walk or run, preferably on a treadmill. Some facilities can videotape your gait, then analyze the movement of your feet in slow-motion. Another (and less costly) way is to look at the bottom of an older pair of run shoes. Check the wear pattern. A person with a normal gait will generally see wear evenly across the heel and front of the shoe. A person who overpronates will likely see more wear on the OUTside of the heel and more wear on the INside of the forefoot (at the ball). A person who supinates will see wear all along the outer edges of the shoe. You can also learn about your gait by looking at your arches. Look at the shape your wet feet leave on a piece of paper or a flat walking surface.

Non Surgical Treatment
Anti-Pronation Insoles provide a unique foot support system that aligns the lower body. The major cause of foot and leg pain is over pronation (rolling over of the feet) which causes excessive pressure on the muscles, ligaments and bones of the lower body. Running insoles treat the underlying cause of over pronation and prevent future occurrences of the associated foot or leg condition. A project conducted at the NIKE Sport Research Laboratory studied the effects of orthotics on rear foot movement in running. Nine well-trained runners who wore orthotics were chosen as subjects. The results of the study indicated that orthotics reduced rear foot movement by roughly one degree or approximately nine percent of the amount found in runners not using orthotics. The average reduction of the maximum velocity of pronation was fifteen percent. Thus this study indicates that orthotics and insoles control over pronation which will treat and prevent many sporting injuries.
Prevention
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.