Chronic Knee Pain In The Runner
by Dr. Jeffrey Ross, D.P.M., F.A.C.F.A.S.
Clinical Assistant Professor, Baylor College of Medicine
Fellow, American College of Foot and Ankle Surgeons
one point or another, runners eventually ask
the question, "Will all that running eventually
hurt my knees and cause arthritis so I'll never
be able to run again?"
The answer is usually no!
When knee pain is ignored, permanent, even crippling
damage may occur. By seeking early expert advice
and following corrective measures, however, knee
pain can often be eliminated without continuous
Proper biomechanical evaluation of the knee, lower
extremity and foot can draw attention to the underlying
cause of a knee problem. Overuse training, running
on unrelenting road surfaces and wearing improper
or worn-out shoes are a few possible contributing
Patellofemoral pain syndrome (PFPS) is the leading
cause of chronic knee pain in adolescents, and
one of the most common causes in adults. Malalignment
of the knee joints is not only caused by biomechanical
problems in the knee, but more accurately in the
entire lower extremity, usually brought on by excessive
pronation. An abnormal amount of pronation in the
subtalar joint of the foot during the stance phase
in running creates an extreme amount of lower leg
rotation that disrupts the normal relationship
of the knee joint. Remember, this knee joint is
riding on a cushion of cartilage only three millimeters
thick that must absorb impact three to six times
the body weight of the runner. To make matters
worse, the knee joint happens to be one of the
most unstable in the body, subject to twisting
as well as impact injury. Excessive pronation not
only causes the foot to roll inwards, but allows
the knee to be out of alignment with every stride.
The result of this biomechanical imbalance is patellofemoral
stress syndrome, or "runner's knee."
There are many approaches to runner's overuse
knee pain. The relationship of the pelvis to the
knee, and then the lower extremity and foot (referred
to as Q-angle) is an important biomechanical consideration.
High Q-angle combined with excessive pronation
can cause a "pendulum swing" of the knee. Over
a period of time, this patellofemoral imbalance
can cause articular (cartilage) damage due to increased
local stress, and decrease in the amount of normal
loading of the articular cartilage.
There are other causes of patellofemoral pain
syndrome as well. One of these is weakness or atrophy
of the inside quadriceps muscle. Another is wearing
shoes where the outer soles are worn down, causing
the runner to roll outwards (supinate) excessively
during heel strike, then roll in (pronate) excessively.
Changing shoes every five hundred miles or every
six months is a helpful rule of thumb. Choosing
a shoe with good stability and proper motion control
is another tip to help avoid this injury.
The use of prescription orthodic devices has been
shown to significantly reduce excessive pronation,
establish more of a neutral subtalar joint, and
allow the foot to function more effectively. The
body will then require less forward propulsion,
and provide for improved shock absorption. The
Q-angle (one of the measures of lower extremity
alignment we described) will be altered with a
foot orthodic. It has been shown that by altering
the Q-angle, a prescription orthodic allows for
more normal loading and contact pressure. By affecting
the rotations of tibia on the femur, the pressure
in the knee joint is more easily distributed between
the condyles of the femur. This creates a more
normal alignment. Thus, the runner is more biomechanically "correct," and
with the entire lower extremity (femur, knee, tibia,
foot) in more proper alignment, the runner suffers
less risk of injury.
A less expensive soft orthodic can often work
just as easily as the harder prescription device.
For the runner who needs minimum control for pronation,
the softer device may be all it takes. However,
the softer device will eventually break down, and
could cause a resumption of symptoms. Therefore,
a trial period of at least four weeks is necessary
in order to evaluate whether the runner should
progress to a more permanent foot orthodic.
Strengthening exercises, particularly of the quadriceps
muscle group, is essential. Cross-training exercise
- i.e. swimming, aqua-running, cycling, and, later,
stair-stepping and roller-blading - can maintain
training effect and conditioning, while allowing
for rest and recuperation of the knee joint. Another
suggestion is taking extra time off between running
days. The compulsion to run a marathon, especially
two to three a year, can have its destructive affects
upon the body, its muscles and joints. When we
run every day, we do not allow the body to enjoy
the rest it deserves. Often we do not observe the
rule to keep weekly mileage increases to 10 percent
or less; runners training for marathons often try
to boost there mileage during the weekend after
too many inactive weekdays. Use cross-training
during alternative days to keep in shape, and,
simultaneously, give overused muscles and knees
a much deserved rest.
The next time you experience a twinge of knee
pain with no previous injury, think of overuse
runner's knee and seek the proper sports medicine
specialist. Don't continue to "run through" knee
Prompt treatment and corrective measures now could
prevent injury down the road.
Dr. Ross is a Podiatrist, M.D.
in private practice in Houston, TX. To book
an appointment with Dr. Ross or find out about
his services he can be reached at 713.791.9521.