Patellar tendonitis is an injury that affects the tendon that connects the patella (knee cap) and the tibia (shin bone). The patellar tendon is a continuation of the quadriceps muscles, which are responsible for knee extension. Also known as jumper’s knee, patellar tendonitis is prevalent in athlete’s who perform a great amount of forceful knee extension (ex. volleyball, soccer, and basketball). Although this specific injury is highly noted in jumpers, all types of athletes are susceptible to it.
Patellar tendonitis is a common overuse injury. An overuse injury is a certain condition that materializes over time due to repetitive stresses. In the case of patellar tendonitis, repetitive forceful knee extension begins to cause micro tears in the patellar tendon, which accumulate over time and result in inflammation of the tendon. Along with repetitive jumping, a sudden increase in the frequency of activity is also a culprit.
Tightness of the quadriceps or hamstrings may also contribute to the occurrence of patellar tendonitis. In either case, the first resulting in possible hyperextension and the second resulting in slight knee flexion, the patellar tendon will be placed under an increased amount of strain.
Alignment of the pelvis, femur, patella, and tibia may also attribute to the development of jumper’s knee. Genu valgum (knock knee) and genu varum (bow leg) both put shear forces on the patellar tendon resulting in increased stress. Another bony abnormality, patella alta (raised kneecap), can add additional stress to the tendon by elongating it.
As with other injuries, immediate care of patellar tendonitis is to follow the R.I.C.E. protocol (Rest, Ice, Compression, Elevation), which is explained in full detail in February 15th’s posting entitled, Immediate Care of Acute Ankle Sprains. The main purpose of the R.I.C.E. protocol is to control swelling and minimize pain. To build onto the rest component, athletes who are experiencing patellar tendonitis should attempt to stay away from activity that exacerbates the pain such as jumping, sprinting, and kicking.
Once swelling and the pain associated with swelling is resolved, range of motion and strengthening exercises (Strengthening and stretching exercises) may be included in the treatment. As noted earlier, patellar tendonitis is a result of subsequent micro tears. To accompany the natural healing properties of the body, knee extension exercises should be incorporated to strengthen the quadriceps and the patellar tendon. Dependent on the underlying cause, different types of stretches and overall knee strengthening exercises should be performed.
Along with strengthening and stretching, proprioceptive exercises may be performed to increase neuromuscular control. Proprioception, a joint’s ability to position itself in the correct position while in space, may help to maintain a neutral position of the knee during activity and therefore decreasing shear forces on the tendon. A popular proprioceptive exercise for the lower extremity is a stork stand. To perform this exercise stand on the involved leg with the contralateral leg raised and your hands on your hips, hold this position for thirty seconds staying as still as possible. If this becomes too easy try closing your eyes.
When returning to activity patellar tendon straps may be used to assist in the function of the tendon. Average time for return to participation can rely on the severity of the injury and may even cause issues for an extended amount of time as long as activity is continued. For the competitive athlete however, these procedures will assist in recovery and more than likely make a speedier recovery.
Additional Resources:
Wright State University Sports Medicine Blog 
I think this blog is great- it’s always good to review even the most basic injuries to brush off some of the cobwebs. That being said, I thought there were a few critical things missing from this entry. What about the idea that the knee joint is the middle of the kinetic chain and that thus it is critical to look at both hip and ankle function when examining it? This is particularly true when the problem is chronic.
In CKC activities the ankle is the primary shock absorber and the knee functions as it’s back up- therefore if there is a problem at the ankle, the knee will suffer too. “Jumper’s knee” as such, is not only a problem with repetitive flexion and extension at the knee- it could stem from decreased ankle ROM and thus decreased ability to absorb shock that transmits up the kinetic chain. An athletic trainer would be remiss not to examine ankle ROM in the athlete presenting with patellar tendonitis. Further, the blog mentions hamstring and quadriceps strength as contributing factors but similarly, if calf strength is compromised by either an ankle or knee injury, patellar tendonitis can result.
Lastly, we can not ignore the top of the kinetic chain and the effect weak hip abductors or extensors may have downstream. Lack of abductor strength creates the potential for abnormal valgus stresses at the knee and over pronation at the ankle both of which affect the functioning of the patellar tendon. Weak hamstrings and glutes will create similar problems that should not be overlooked.
For more information check out:
Cook, J.L., Khan, K.M., and C.R. Purdam. (2001). Conservative treatment of patellar tendinopathy. Physical Therapy in Sport, 2, 1-12.
Penny,
Thanks for the additional information and great feedback! You brought up a very good point that we failed to mention. There are a multitude of areas that could play a part in anterior knee pain and specifically, pain in the patellar tendon. While it is no excuse, the goal of this post was to provide basic information for the general population about what could be causing their knee to hurt and basic remedies to help with acute pain.
Thanks again Penny, we hope all is well for you!
Please