by Ayne Furman, D.P.M.

The old song, "Foot bone is connected to the ankle bone, the ankle bone is connected to the leg bone and the leg bone is connected to the knee bone," is pretty close to an accurate biomechanical description of the synergy of the lower leg and foot that occurs during running.

When there is extra or limited motion of the foot, limited flexibility of the ankle, or incompatible effects from the external environment, i.e., running surface or shoes, the joints, tendons and muscles closer to the body can be effected. The joint most commonly effected by the foot and ankle is the knee.

The knee is the most effected joint because of the "screw type" torque that occurs with every step. As the foot goes from heel-strike landing on the back outer portion of the heel to mid-stance, i.e., when the foot is flat on the ground, the lower leg twists toward the mid-line of the body. While the lower leg is rotating the upper leg is twisting in an opposite direction. This simultaneous opposite motion of the upper and lower leg creates a torque effect on the knee.

With each step excessive rolling in, or pronation of the foot, can lead to injuries on the inside or front of the knee by virtue of repetitive stresses or over stretching of the pes ansurine tendon on the inside of the knee or patellar tendon on the front of the knee cap.

The pes ansurine tendon runs down the inside aspect of the knee, it is not actually located inside the knee joint. A group of three muscles make up the pes ansurine tendon. One of the roles the tendon is to resist the knee from collapsing inward due to the torque type stress.

Initial warning signs that the pes ansurine tendon may be inflamed in a runner are: some pain on the inside of the knee the first thing in the morning when getting out of bed, pain at the beginning of the run and later on in the day. As the pes ansurine tendinitis worsens the time the pain is noticed throughout the day is greater and soon running is no longer an enjoyable activity.

The patellar tendon connects the knee cap to the tibia bone of the lower leg. When the patellar tendon is inflamed it is called "jumper’s knee," or patellar tendinitis. Basketball players often get this condition from jumping and particularly from the landing stress of a jump. For a runnner jumper’s knee can develop from the over stretching of

"Often trying an over-the-counter sports type arch support can reduce the internal rotation of the foot and leg."

the patellar tendon as the lower leg rotates in and the knee cap moves in an opposite direction.

Jumper’s knee can be painful the first thing in the morning, more noticeable going down steps, getting up from a sitting position and running down hills. On self examination pain can be found by pressing at the bottom of the knee cap.

The biomechanical malaignment that can precipitate the above injuries can be caused by poor foot mechanics. Often changing to a more stable and supportive shoe, both for running and work, is an effective treatment.

Very often patients are left only partially treated if they change to supportive running shoes but do not alter their "working/walking life" shoe gear. This means loafers, topsiders and women’s dress flats should be worn a limited amount of time, as well as limiting walking bare-foot.

Often trying an over-the-counter sports type arch support can reduce the internal rotation of the foot and leg. Arch supports that are slightly rigid in the arch area are going to provide more support but could also be the hardest to get used to wearing.

Patellar tendinitis sometimes will improve with the use of a counter force brace such as a Chopat knee brace. Quadriceps stretching is also beneficial for this problem. The quadriceps are the muscles on the front of the upper leg.

Both of the above injuries respond well to icing. Ice should be applied 2-to-3 times a day for 12-to-15 minutes. Do not ice immediately before running. In fact, moist heat prior to a run may be helpful. Try placing a damp wash cloth in a microwave oven for 45-to-60 seconds and applying it to the injured area.

If the knee pain does not respond to the above suggestions you should seek professional care and evaluation from a sports oriented medical professional.