What is foot pronation?

Pronation is the movement of the subtalar joint (between the talus and calcaneus) into:

• Eversion (turning the sole outwards)
• Dorsiflexion (pointing the toes upwards) and
• Abduction (pointing the toes out to the side).

When standing, pronation occurs as the foot rolls inwards and the arch of the foot flattens. Pronation is a normal part of the gait cycle (walking/running) which helps to provide shock absorption at the foot.

The opposite movement to pronation is supination. This is also a normal part of the gait cycle and can be excessive (oversupination)

What is overpronation?

The problem with pronation is when it is excessive, here the term overpronation (or hyper-pronation) is used. This is quite a common problem and can lead to a number of injuries, especially in runners, including:

• Shin Splints
• Anterior compartment syndrome
• Patello-femoral pain syndrome
• Plantar fascitis
• Tarsal tunnel syndrome
• Bunions (Hallux valgus)
• Achillies tendonitis

The picture on the right shows someone with this problem. The right foot is rolling in. This causes the lower leg to turn inwards which puts the knee and hip out of alignment and can cause the back to be rotated.

The left foot is corrected with an orthotic device. This is inserted into the running shoe and controls the position of the heel allowing the rest of the foot to fall into place.

How Does this Cause Injury?

Abnormal foot biomechanics usually causes over-use type injuries. When a neutral foot pronates during walking or running, the lower leg, knee and thigh all rotate internally (medially). When an athlete with an overpronated foot runs, this rotation movement is exaggerated and becomes more marked.

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.

How Can I tell if I Overpronate?

• Firstly, look at your feet in standing, have you got a clear arch on the inside of the foot? If there is not an arch and the innermost part of the sole touches the floor, then your feet are overpronated.
• Secondly, look at your running shoes. If they are worn on the inside of the sole in particular, then you probably overpronate when you run
• Thirdly, try the wet foot test. Wet your feet and walk along a section of paving and look at the footprints you leave. A normal foot will leave a print of the heel, connected to the forefoot by a strip approximately half the width of the foot on the outside of the sole. If you’re feet are pronated there may be little distinction between the rear and forefoot.

What can you do?

• Get an assessment of your gait, this will highlight if you overpronate, oversupinate or have a neutral gait. 
• If you overpronate, get an generic orthotic or sandal with extra medial support. Many generic orthotics have a harder material on the inside of the midsole (the thick hard foam part of the running shoe). This means the inside 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.
• Orthotics and 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 Chiropractor.