Underpronation and Supination of the Foot

Pronation of the foot is the rolling motion it goes through when in contact with the ground. Normal pronation involves the inward rolling of the foot during walking, running or jogging and it helps to ensure that the weight of the body is evenly distributed and the forces generated are dealt with effectively. There are various degrees of pronation which depends on how the tendons, ligaments, bones and muscles operate in an individual. Normal pronation will see the foot move slightly inwards, and overpronation sees this happen to an excessive degree. Then there is overpronation the foot rolls too much, with the force on the push off more concentrated on the big toe and second toe. On the other hand, underpronation sees too little roll. When the heel strikes the ground, most of the body weight remains on the lateral side of the foot, with the push off taking place from the fifth metatarsal (the little toe). This phenomenon is more accurately called supination, because the foot tends to remain in a supine position throughout the stride.
An underpronator or supinator will tend to see the knees move laterally and often results in a bow-legged gait. An underpronator will not be able to deal with the forces from walking and running effectively. Stress tends to be concentrated more on the lateral side of the foot. This can easily be seen on a pair of old running shoes, which show wear on the outside edge more than the central or medial side.

Several predisposing factors influence the occurrence of underpronation. People with internal rotation of the hips, ankles and knees are more likely to be underpronators as opposed to external rotation which leads to overpronation. Bow-legged individuals also have the tendency to be underpronators.

Signs of Underpronation

• Pain in the arches of the feet
• Heel pain
• Gait instability
• Knee pain
• Back pain
• Rigid feet
• High foot arches

Treatment of underpronation tends not to focus on correction of the gait, but with helping the feet cope with the shocks and forces generated when walking – essentially adding extra cushion to make up for what is naturally lacking. Treatments help the feet to bear weight more effectively. The primary treatment is wearing shoes with adequate support and extra cushioning. Although there are no running shoes which are created specifically to deal with this particular gait abnormality, the best choice is to wear neutral running shoes. Neutral running shoes are the most lightweight and flexible, and they encourage pronation of the foot. Since most running shoes tend to be in the stability category, particular care should be taken when choosing exercise shoes. Stability shoes should never be worn, as they will tend to limit what little pronation there is. Similarly motion control shoes should not be worn as these will limit pronation to an even greater degree.

Orthotics designed for underpronators are often a good choice. These usually take the form of insoles which can be slipped inside shoes which will correct any faults in the gait to promote a more natural movement. Surgery is often not advised since supination can be managed with these more conventional treatments. Only when there is considerable pain would surgery usually be recommended. Prevention of underpronation involves stretching before exercising or training to help the structures of the foot cope with activity, and when muscle imbalances are the cause it is beneficial to perform strengthening exercises to address the imbalance directly.