The most common causes of running related knee pain is patellofemoral pain syndrome (PFPS) or runner’s knee.  Though there are other causes of knee pain from running, patellofemoral pain account for most running related knee injuries.  This is a repetitive strain injury and often become a chronic problem if not treated properly. 

Also know as anterior knee pain, knee pain from also a large number of cyclists and other athletes.  PFPS is an injury with pain mainly in front of the knee (anterior knee pain), but also around and underside of the kneecap.  This is mainly due to repetitive wear and tear of the tissues around the kneecap and the cartilage on the underside of the kneecap.  

Though patellofemoral pain syndrome is often considered the same as chondromalacia patella which also causes pain in the front of the knee, chondromalacia is softening or erosion of the cartilage on the underside of the kneecap.  Knee pain from running can also be due to chondromalacia patella.  

The patellofemoral joint is the joint created by the kneecap (patella) and the groove on the femur (thigh bone).  It functions like a pulley increasing the mechanical leverage for the action of the quadriceps muscle via the patellar tendon.  

Common presentation of patellofemoral pain syndrome:

This injury is much more common in female runners and often develops into a chronic problem.

People with runner’s knee injury are able to handle their daily activities like walking and sit-to-stand because these activities put less load on the tissue.   Running, jumping and squatting put much more load on the knee making it harder to handle the higher demands of these activities.  If the demand on the tissue is more than it can handle, it will break down and get injured.    To make matters worst, once it’s injured and in a weakened state it won’t be able to handle the demands of running or other athletic activities.  

Thus it’s important to determine the amount of load the injured tissue can handle when one is designing a rehabilitation program for an injured knee.  If the pain starts after running two miles, the distance was too much for the joint to handle.  If there is no immediate pain after running, but later in the day or the next day there is more pain, the distance was too much.  

What structures are actually painful?  

There are 4 main pain generators or injured tissues in runner’s knee.

1.  The medial retinaculum and the lateral retinaculum that attaches to along the kneecap.  

2.  Knee synovial tissue is the membrane that lines and lubricates the joint.  

3.  Infrapatellar fat (Hoffa’s fat pad): It’s the fat tissue which sits just below your kneecap.  

4.  Subcondral bone injury and articular cartilage damage.  

 Common symptom of PFPS:

•    Pain in front of the knee, along the kneecap or behind the kneecap. 

•    Pain with clicking, popping, catching or grinding sensation when walking or with knee                  movement.

•    Knee giving out or buckling.

•    Swelling, painful to touch, burning and ache.

•    “movie goers sign” pain with sitting for a long time and when you first stand up.

•    Pain with squatting, lunges, stairs, hills, running or jumping activities.  

•    With going up and down stairs or hills.

Assessing if you have patellofemoral pain syndrome

1.  Single leg squat

Hold on to the edge of a table or back of chair, do a single leg squat and see if you have pain along the kneecap.

2.  Press down along the border of the kneecap looking for painful spots.

3.  Hopping on one leg for 30-60 seconds.  This test will put a lot more stress on the knee and is replicating the single leg hopping which takes place while running.  (Avoid this test if the other two tests reproduce your symptoms).

These tests are indicative for patellofemoral pain, but not all runners with patellofemoral pain will have these symptoms. There are additional assessments a physical therapist can use to determine if you have PFPS.

Patellofemoral pain syndrome treatment

Patellofemoral pain syndrome exercises are one main solution to treat this problem.  Though there are a lot of exercises for strengthening the knee and surrounding tissues, one has to be careful to not overload these injured tissues resulting in further injury and pain.  Thus Patellofemoral pain syndrome exercises should focus on a non-weight bearing exercise program combined with other solutions like massage, heat therapy, taping and herbal supplements.  

In addition to targeted Patellofemoral pain syndrome exercises, I have found specific cross friction massage techniques to be very effective for treating this injury.  Massage is helpful for improving circulation, breaking down scar tissue and adhesions while improving tissue mobility.  Here a specific scar tissue mobilization technique I have used to treat my patients: