What Is Supination?
The foot is capable of undergoing 2 basic motions – one of which is supination. Supination is a complicated joint motion involving movement of several joints in several different planes. The motion results in a lifting of the arch or a “falling” to the outside. The entire lower extremity is in fact tilted out. A supinated foot may be associated with bow leggedness, an increased tendency to sprain ankles, a bump on the back of the heel and very high arches. If you are a supinator, you are also most likely a pronator. The foot hits the ground in a supinated position but is followed by pronation.
What Causes Excess Supination?
As the foot contacts the ground in gait (walking) the entire foot is supinated (the heel is turned in and the outside of the foot hits the ground). By the time your body weight is transferred to the front of the foot, the arch has lowered and weights bearing has been spread out over the rest of the foot (i.e. – pronation has occurred). In a supinated foot, pronation occurs but the weights bearing remains on the outside of the foot. If it sounds complicated, it’s because it is. High arched feet are often called supinated feet. This is an oversimplification. The most common cause of excess supination is high arches (cavus foot type) or an inverted lower extremity (such as in bow leggedness).
What Does Excess Supination Cause?
If the body was a rigid structure that required nothing but a solid base of support, the supinated foot would be ideal. However, as soon as we walk or run the foot must function as a mobile adaptor, so that shock can be absorbed. If a foot is overly supinated, it usually tends to be rigid and is not capable of undergoing adequate pronation (to absorb shock). Unlike pronated feet which can be made more stable by an orthotic, supinated feet cannot be easily made more flexible. The lack of proper shock absorption and excessive tilting to the outside can result in frequent ankle sprains, peroneal tendonitis, tailor’s bunions (on the 5th toe), excessive callousing on the outside of the foot, knee and back pain (due to lack of shock absorption) and iliotibial band syndrome.
How Is Excess Supination Treated?
Treating the supinated foot type is not at all straightforward. Once the reason for the excess supination is determined, steps can be taken to improve shock absorption (well-cushioned shoes and insoles), to accommodate the natural position of the foot (using an arch support or custom orthotic or wedges), and sometimes to encourage pronation (using custom orthotics and wedges). Supinated feet do not necessarily need curve-lasted shoes. The key to treating this foot type is an accurate identification of all contributing biomechanical factors.