Factors such as weak thigh muscles, excessive pronation, and tight leg muscles and tendons can cause pain in the front part of the knee.
People may feel pain when running downhill but eventually may have pain during walking.
Magnetic resonance imaging (MRI) and arthroscopy may be needed for diagnosis.
People should stop running until there is no pain and then use exercise to strengthen and balance muscles around the knee.
If excessive pronation causes pain, shoe inserts can help.
(See also Overview of Sports Injuries Overview of Sports Injuries Sports injuries are common among athletes and other people who participate in sports. Certain injuries that are traditionally considered sports injuries can also occur in people who do not participate... read more 
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The kneecap (patella) is a circular bone that is attached to ligaments and tendons around the knee and normally moves up and down the thighbone during running.
When the Front of the Knee Hurts
Normally, the kneecap (patella) moves up and down the thigh bone during running. People may feel pain in the kneecap because thigh muscles are weak or the feet roll in too much (pronation). As a result, the kneecap rubs abnormally against the thigh bone, causing increased wear and tear.  |
Pain in the front of the knee (anterior knee pain) may be caused by
A kneecap located too high or too low in the front of the knee joint
Off-center insertion of the muscles around the knee cap
Tight, shortened hamstring muscles
Tight Achilles tendon
Weak thigh muscles—which normally help stabilize the knee
Runner’s knee
Weak thigh muscles are a common cause of runner’s knee, a treatable cause of anterior knee pain. Weak thigh muscles allow the kneecap to move sideways and rub abnormally against the thighbone. Runner’s knee usually starts out with knee pain when running downhill. Later, any running or walking, especially down steps, is painful.
Excessive pronation
Excessive pronation of the foot (rolling of the foot inward) when walking or running can cause knee pain. Pronation forces the thigh muscles (quadriceps) to pull the kneecap outward and rub abnormally against the end of the thighbone.
Diagnosis of Knee Pain
A doctor's evaluation
Doctors ask about symptoms and examine the person. Sometimes magnetic resonance imaging (MRI), arthroscopy (looking inside the joint with a flexible viewing tube), or both are needed.
Treatment of Knee Pain
Rest
Rehabilitation
Running is avoided until it can be done without pain. Ice applied to the affected area, nonsteroidal anti-inflammatory drugs (NSAIDs), and temporary use of a knee sleeve or elastic support also help. Other exercises, such as riding an exercise bike (with high seat position, low repetition, and low resistance) or swimming, can be done to protect the knee and maintain physical fitness during recovery. Exercises to strengthen and balance the muscles in the back (hamstrings) and front (quadriceps) of the thigh are helpful.
In runner’s knee, stretching before exercise can help balance the abnormal forces caused by tight muscles and reduce injury.
A shoe insert can help correct excessive pronation.
Courtesy of Tomah Memorial Hospital, Department of Physical Therapy, Tomah, WI; Elizabeth C.K. Bender, MSPT, ATC, CSCS; and Whitney Gnewikow, DPT, ATC.
Courtesy of Tomah Memorial Hospital, Department of Physical Therapy, Tomah, WI; Elizabeth C.K. Bender, MSPT, ATC, CSCS; and Whitney Gnewikow, DPT, ATC.
Courtesy of Tomah Memorial Hospital, Department of Physical Therapy, Tomah, WI; Elizabeth C.K. Bender, MSPT, ATC, CSCS; and Whitney Gnewikow, DPT, ATC.
Courtesy of Tomah Memorial Hospital, Department of Physical Therapy, Tomah, WI; Elizabeth C.K. Bender, MSPT, ATC, CSCS; and Whitney Gnewikow, DPT, ATC.
Courtesy of Tomah Memorial Hospital, Department of Physical Therapy, Tomah, WI; Elizabeth C.K. Bender, MSPT, ATC, CSCS; and Whitney Gnewikow, DPT, ATC.
Courtesy of Tomah Memorial Hospital, Department of Physical Therapy, Tomah, WI; Elizabeth C.K. Bender, MSPT, ATC, CSCS; and Whitney Gnewikow, DPT, ATC.
Courtesy of Tomah Memorial Hospital, Department of Physical Therapy, Tomah, WI; Elizabeth C.K. Bender, MSPT, ATC, CSCS; and Whitney Gnewikow, DPT, ATC.
