Pronation is the term used to describe a natural movement of the foot when walking. When the gait is normal, the heel strikes the ground first. As weight is transferred forward, the arch of the foot flattens and the foot rolls slightly inwards. Body weight is then placed on the ball of the foot and toes, and the foot straightens and turns outwards as the toes push off. Overpronation occurs when the foot rolls inward too far. This causes all the muscles and tendons of the lower leg to twist excessively. Regular overpronation is believed to contribute to the development of many knee, lower leg and foot injuries such as heel spurs, plantar fasciitis, tendinitis and bunions. It is thought that as much as 60% of the population may overpronate.
Overpronation often occurs in people with flat feet, whose plantar fascia ligament is too flexible or too long, and therefore unable to properly support the longitudinal arch of the foot.
People tend to inherit the foot structure that leads to overpronation. In a normal foot the bones are arranged so that two arches are formed, the longitudinal and the transverse. Ligaments hold all the bones in their correct positions, and tendons attach muscles to bones. If the bones are held together too loosely, they will tend to move inwards as this is the easiest direction for them to go. Over time the soft tissue structures will adjust to the misalignment and the foot will become permanently over-flexible, with a flat arch.
- Hormonal changes during pregnancy cause ligaments to weaken.
- Rapid weight gain can weaken the arches.
- Running on hard surfaces can lead to damaged arches.
- The normal aging process will exacerbate the condition as ligaments and muscles weaken.
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.
One of the easiest ways to determine if you overpronate is to look at the bottom of your shoes. Overpronation causes disproportionate wear on the inner side of the shoe.
Another way to tell if you might overpronate is to have someone look at the back of your legs and feet, while you are standing. The Achilles tendon runs from the calf muscle to the heel bone, and is visible at the back of the ankle. Normally it runs in a straight line down to the heel. An indication of overpronation is if the tendon is angled to the outside of the foot, and the bone on the inner ankle appears to be more prominent than the outer anklebone. There might also be a bulge visible on the inside of the foot when standing normally.
A third home diagnostic test is called the ‘wet test’. Wet your foot and stand on a surface that will show an imprint, such as construction paper, or a sidewalk. You overpronate if the imprint shows a complete impression of your foot (as opposed to there being a space where your arch did not touch the ground).
If a young child is diagnosed with overpronation braces and custom orthotics can be, conjunction with strengthening and stretching exercises, to realign the bones of the foot. These treatments may have to continue until the child has stopped growing, and orthotics may need to be worn for life in order to prevent the foot reverting to an overpronated state.
Wearing shoes that properly support the foot, particularly the arch, is one of the most effective treatments for overpronation. Custom-made orthotic inserts can also be very beneficial. They too support the arch and distribute body weight correctly throughout the foot. Motion-control shoes that prohibit pronation can be worn, so may be useful for those with severe overpronation.
One good treatment is to walk barefoot as often as possible. Not relying on shoes to support the arch will encourage proper muscle use. Practicing yoga can help to correct poor posture and teach you how to stand with your weight balanced evenly across the whole foot.
Exercises to strengthen and stretch supporting muscles will help to keep the bones in proper alignment.
Stand with your heels together and feet turned out. Tighten the buttock muscles, slightly tilt your pelvis forwards and try to rotate your legs outwards. You should feel your arches rising while you do this exercise.
Stand facing a wall and place hands on it for support. Lean forwards until stretch is felt in the calves. Hold for 30 seconds. Bend at knees and hold for a further 30 seconds. Repeat 5 times.
While drawing your toes upwards towards your shins, roll a golf ball under the foot between 30 and 60 seconds. If you find a painful point, keep rolling the ball on that spot for 10 seconds.
Big toe push:
Stand with your ankles in a neutral position (without rolling the foot inwards). Push down with your big toe but do not let the ankle roll inwards or the arch collapse. Hold for 5 seconds. Repeat 10 times. Build up to longer times and fewer repetitions.
Place a ball between your foot and a wall. Sitting down and keeping your toes pointed upwards, press the outside of the foot against the ball, as though pushing it into the wall. Hold for 5 seconds and repeat 10 times.
Stand on one foot on the floor. The movements needed to remain balanced will strengthen the arch. When you are able to balance for 30 seconds, start doing this exercise using a wobble board.