How to treat PFS runner's knee

November 27, 2013

By Sara Jurek, MD
Orthopedic Surgeon

Patellofemoral pain constitutes a quarter of the injuries to the knee. Kneecap pain can be both debilitating and frustrating; prolonged pain can limit physical activity and cause those suffering from it to abandon their recreational and sporting activities.

Patellofemoral pain usually manifests as a gradual onset of pain around the edge or underneath the kneecap during physical activities. Common activities such as descending hills or stairs, squatting, running, or sitting for long periods of time can all aggravate the pain and cause soreness.

How your knee works

patellofemoral pain image from knee joint is made up of three bones: the femur (thigh bone), the tibia (shin bone), and the patella (kneecap). The patellofemoral joint refers to the kneecap and the groove (trochlea) in the femur in which the patella sits. The four muscles of the quadriceps all attach to the patella. The patella is a sesamoid bone (the bone is embedded within the tendon) and it plays a crucial role in the function of the leg by lengthening the lever arm of the muscles and tendons of the quad to maximize power and function and by acting as a shield to protect the knee from direct trauma. The cartilage covering the kneecap within the knee joint acts as a shock absorber, protecting the underlying bone from stress.  With running and jumping, the knee (and its overlying cartilage) can experience forces up to 8 times bodyweight. The cartilage itself does not have a nerve supply, but the bone underneath has an extensive nerve supply and these nerves become painful when the cartilage is not functioning properly to pad and protect the bone.

In patellofemoral syndrome, or PFS (also known as runner’s knee), the cartilage undersurface of the patella become angry, inflamed, irritated, and the kneecap hurts.

How to treat PFS or runner’s knee

  1. Loosen things up. Use a foam roller to roll out the quad muscle and the illiotibial (IT) band. These tissues all hook into the kneecap and can contribute to pain when they are tight.
  2. Make things stronger. In the early recovery period (the first several weeks when you are just starting out on your recovery journey), exercises that improve the muscle tone of the quad should be performed to begin strengthening without putting undue stress on the kneecap. Exercises that use the quad with the knee straight (so as not to stress the knee joint) and those that strengthen the outer hip (try these exercises) and hamstrings are the best to begin your recovery. As the pain and inflammation diminish, functional exercises (exercises that mimic natural movement instead of isolated, single-movement exercises facilitated by weight machines at the gym) such as wall sits and air squats (or, if you really want a challenge when your knee feels significantly better, plyometric jump squats) are optimal. These strengthen your hip abductors (butt muscles) as well as your quads, which have both been identified in scientific research as being key contributors to knee pain (if they are weak) or to the lack of knee pain (if they are strong). Once your pain has nearly or completely resolved, you can gradually ease back into your normal recreational and athletic activities (and/or try out those plyometric jump squats), taking care to build back up in terms of volume, intensity, and mileage. Physical therapy is an excellent option to formally guide you through this aspect of your recovery.
  3. Ice and use anti-inflammatories (but only if your GI system can tolerate these). Try icing your knee for 20 minutes at a time and be careful to protect your skin from frostbite. Both icing and anti-inflammatories will help to diminish swelling and reduce inflammation.
  4. Support your feet and they will support you. Options to accomplish this include wearing shoes with arch support, in particular, shoes with “medial posting.” This helps unload the inside (medial) part of your foot if you are prone to pronating (which loads excessive force on the inner part of the kneecap). Running stores are a good resource to find shoes with this feature. Over-the-counter orthotics (shoe inserts) with a firm arch also help unload the patella and are another excellent option for increased support.
  5. Prevent it. A holistic approach works well; strengthen your kinetic chain. Your kinetic chain is the interrelated system of all of your bones and muscles that work together to make you move. The gym where I like to work out preaches that “everything is everything” and this is simplistic but true; being well-rounded in a physically-fit sense will serve you well in terms of avoiding injury in the future. Again, utilizing functional movements in your strength program is optimal. Cross train and try new sports. A strong foundation is your best bet for a pain-free existence.