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supination
Supination is roughly the opposite of pronation. Supination
involves a lifting of the arch and a tilting to the outside. Supinated
feet are often referred to as cavus (high arched) feet. This is not
a common foot type.
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People who wear out the outside of their heels
are not necessarily supinators. Supinators often sprain their
ankles and are generally unstable while walking.
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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, 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 weightbearing has been spread
out over the rest of the foot (i.e. - pronation has occured). In a supinated
foot, pronation occurs but the weightbearing 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 straight forward. Once
the reason for the excess supination is determined, steps can be taken
to improve shock absorption (well cushioned shoes and insoles), to accomodate
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 accurate identification of all
contributing biomechanical factors.
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