Gabe Mirkin, M.D.
Runners with high arches are at increased risk for
suffering stress fractures, small cracks in the bones of their feet
and lower legs; and those with low arches are at increased risk
for knee cap pain. When you run at six miles per hour, your foot hits the ground with a force greater than three times body weight. The
faster you run, the harder your foot strikes the ground. This force
can break bones, damage joints and tear muscles. The human
body is designed so you never land flatfooted when you run. The majority of people land on the outside (lateral) bottom of the foot and roll inward toward the big toe. This helps to distribute the force of your foot strike throughout your foot and leg and protect you from injury. The further you roll inward, the greater the protection against this
force. However, when you roll in too much, your lower leg twists
inward excessively, causing your kneecap to rub against the long
femur bone behind it and cause pain. This is called Runner’s Knee.
If you have pain behind the knee cap during running or
walking, ask your podiatrist to look at your feet. If your arches
appear to be flat, you usually will have a normal arch, but you roll
inward so far that your arch touches the ground. Your treatment
is to place special inserts, called orthotics, in your running shoes
and to do special exercise that strengthen your vastus medialis
muscle that pulls your knee cap inward.
If you develop pain in the medial side of your lower leg or
your feet, your podiatrist will probably order a bone scan to check
for stress fractures, small cracks in the bones of your feet. If you
have stress fractures and high arched feet, you will need
specially padded running shoes and have to learn to try to
hit the ground with less force when you run.
Physician and Sportsmedicine, January, 2005
Checked 9/15/06