Anterior knee pain is common among active adults and adolescents.
It usually involves a dull ache behind the patella (kneecap) in one or both knees. This pain may be felt during or after an activity.
It can be caused by conditions such as patellofemoral pain syndrome, patellar instability, Osgood-Schlatter’s disease, patellar tendonitis (aka Sinding-Larsen-Johansson disease), Hoffa’s disease (of the fat pad), and poor positioning of the patella.
Patellofemoral pain syndrome is the most common knee condition caused by an imbalance of muscles surrounding the knee.
There can also be a structural cause such as improper rotation of the femur (the thigh bone).
The muscular imbalance involves a weak vastus medialis, which is part of the quadriceps muscle on the inner part of the knee.
Other tissues on the outside of the knee, such as the lateral retinaculum, may become tight and pull the patella, causing it to track improperly and create pain.
The structural cause can usually be evident during activity. The femur can be improperly rotated which leads to weak rotational moments of the hip. This too creates improper tracking of the patella along the femur.
Possible causes include overuse/overtraining, sudden changes in sport/training, improper footwear, and rapid growth in adolescents causing alignment changes.
Patellar instability may include subluxation or dislocation of the patella.
This usually occurs with sudden twisting, rotating, or foot plant and pivot movements. There is often a sudden clicking, followed by immediate swelling and loss of movement and possibly inability to weight bear.
Osgood-Schlatter’s is an overuse condition where the tibial tuberosity (attachment of patellar tendon) becomes enlarged and inflamed.
This usually accompanies a growth spurt. It can be often associated with excessive exercise and loading and is three times more common in males than females.
Patellar tendonitis can be another overuse condition involving inflammation of the attachment of the patellar tendon on the patella, causing pain.
Hoffa’s disease is a condition that involves inflammation and enlargement of the fat pad that lies beneath the patellar tendon.
This fat pad may also be pinched during knee movements if it becomes quite enlarged.
Poor positioning of the patella can predispose the patella to track along the femur in a non-optimal pattern that creates abnormal friction beneath. A result is often pain and inflammation, and sometimes crepitus or joint noise. The patella can sit higher than normal, Patella Alta, or can situate lower than normal, Patella Baha.
Physical therapy treatment of anterior knee pain will often involve controlling inflammation/swelling around the knee.
There is often a need to temporarily reduce or even discontinue activities that continue to aggravate the pain.
A physical therapist can also provide proper exercises to strengthen the muscles around the hip and knee, particularly those groups that influence patellar tracking.
Stretching and desensitizing the tight tissues and muscles of the hip and knee will also assist in regaining balance and restoring patellar alignment and tracking during activity.
It is important to consider overuse and revisit training principles to ensure your exercise plan can maximize recovery.
Other techniques such as taping or bracing can be beneficial, and perhaps consideration of proper equipment and footwear.