SPORTS MEDICINE

Jumpers Knee

 

With girl’s high school volleyball season in full swing and boys/girls basketball season just around the corner, it is prime time for patellar tendinopathy, or “Jumper’s Knee.” The patellar tendon is the soft tissue just below the patella, or knee cap, that connects on to the tibia, or shin bone. The patellar tendon is the connection of the quadriceps muscle that allows for the knee to extend when the quadriceps contracts. With repetitive use of the quadriceps muscle, the tendon can begin to undergo excessive micro trauma, resulting in pain that is localized to the tendon. Patellar tendinopathy can be separated into two main categories; patellar tendonitis and patellar tendinosis. Patellar tendonitis is the more acute of the two diagnoses, taking place when the condition is less than 6 weeks old. At this stage, there is a significant inflammatory process occurring at the tendon, but the tendon is still strong. This is an important stage to treat the injury, as the tendon itself is still strong and can recover more quickly. However, when the injury persists for 2+ months, the patellar tendonitis transitions in to patellar tendinosis. With tendinosis, the pain is no longer due to an inflammatory process occurring at the tendon, but rather from a breakdown of the tendon fibers themselves. With an absence of an increased inflammatory process, which is vital for regeneration of healthy tendon fibers, the patellar tendinopathy can become much more difficult to treat and can become a chronic condition.

So how do we treat patellar tendinopathy? The first step is to look at weaknesses/inefficiencies in the rest of the kinetic chain, which can result in excessive stress on the tendon. These inefficiencies may include poor flexibility of the gastrocnemius/soleus complex (calf) or the quadriceps muscles. Tightness of the calf can result in decreased dorsiflexion range of motion (ROM), resulting in increased pressure on the patella with knee flexion and forces the patella tendon to absorb more force when running, jumping, or squatting. Meanwhile, poor flexibility in the quadriceps muscle can increase the strain on the patella tendon, as the tendon is forced to account for the lack of quadriceps length. Additionally, strength of muscles throughout the lower extremity, most notably the gluteus max/med/min muscle group, must be evaluated for weakness. Glute strength is vital for proper movement mechanics, as the glute muscles not only function as hip extensors, but also function to stabilize the pelvis over the leg. Without stabilization from these gluteal muscles, further strain is put on the quadriceps muscle to attempt to stabilize the leg, for which the quadriceps are at a mechanical disadvantage. This increased strain can be another contributor to patellar tendinopathy, and must be addressed by strengthening the hip abductors and extensors.

Ideally, the individual experiencing patellar tendinopathy should rest and avoid performing the action/activity that is causing the symptoms. However, this may not be a very appealing option for an athlete that is in the middle of his/her season and does not want to miss any games. While the aforementioned interventions (stretching, strengthening) will address some of the causes and minimize stress on the tendon, pain will likely continue to occur without allowing the tendon to rest and heal. However, there are a couple things that an athlete can do to minimize pain/stress on the tendon while continuing to compete in their athletic event. The first, and easiest solution, is the use of an infrapatellar strap. These straps can be purchased at a relatively cheap price, or can be made by rolling athletic tape pre-wrap up on to the patella tendon, as pictured. The pressure from the strap disperses the force on the tendon away from the vulnerable area to the rest of the knee, resulting in decreased pain at the patella. Additionally, isometric holds of the quadriceps have been seen to substantially decrease patellar tendonitis related pain. Isometric contractions occur when the quad muscle exerts force, but the leg does not move. This can be performed by pushing the toe in to a wall or holding a knee in extension against a resistive band that is pulling the knee into flexion. A single isometric hold has shown to significantly decrease pain at the patella tendon for 45 minutes during athletic activity. A combination of patella tendon strapping, isometric holds, and accessory stretching/strengthening are the keys to allowing an athlete suffering from patella tendinopathy to continue playing while minimizing pain/breakdown of the tendon.

Rio E, Kidgell D, Purdam C, et al. Isometric exercise induces analgesia and reduces inhibition in patellar tendinopathy. British Journal of Sports Medicine Br J Sports Med. 2015;49(19):1277-1283. doi:10.1136/bjsports-2014-094386.

Rutland M, O’Connell D, Brismee J-M. Evidence-supported rehabilitation of patellar tendinopathy. North American Journal of Sports Physical Therapy. 2010;5(3):166–178.