Patella Tendinopathy: Known As Jumper's Knee

Patella Tendinopathy Commonly Known As Jumper’s Knee

What Is Jumper’s Knee?

The term jumper’s knee describes an insertional tendinopathy, a tendon complaint where injury, degeneration, or inflammation occurs at the point where the tendon attaches to bone. With regard specifically to a patella tendinopathy, it is where the site of discomfort and injury is experienced at the attachment of the tendon to the lower pole of the kneecap. The term jumper’s knee refers to a patella tendinopathy where overload occurs at this point, commonly the result of excessive jumping or running activities and frequently experienced on both sides of the body, however jumper’s knee is also often experienced on only one side of the body.

What Causes Jumpers Knee?

The patella tendon joins the kneecap (patella) to the shin bone (tibia). The patella tendon is extremely strong and transmits the force of the powerful quadriceps muscle contraction to pull at the tibia, straightening the leg/knee. When your quadriceps contraction pulls on the patella tendon actively straightening the knee (as with jumping motions), huge forces are transferred through the tendon. Henceforth the patella tendon is placed under significant stress during sports involving rapid explosive changing of direction and repetitive jumping or bounding movements. Sports including, but not limited to, basketball, volleyball, or track events like high jumping or long jumping. Associated with the repetitive strain of jumping type activities, over time micro-tears as well as collagen degeneration may occur, as a result of this consistent micro-trauma to the tendon it can lead to the developing of a patellar tendinopathy. As with most tendon complaints, the majority of chronic cases of jumper’s knee are degenerative conditions of the tendon, rather than acute inflammation (or tendonitis).

Risk Factors For Developing Patella Tendinopathy

Beyond being involved in above mentioned activities, some risk factors associated with developing jumper’s knee include:
  • Increased body weight.
  • Being bow-legged.
  • Having an increased Q angle of the knee (being knock-kneed).
  • Having an abnormally high kneecap, or conversely an abnormally low kneecap.
  • Having a leg-length inequality (a difference between right and left leg lengths).
  • Poor quadricep and hamstring flexibility.
  • Being Male (males are more likely than females to have one sided patella tendinopathy).
  • Training surface and footwear are potential contributing factors, where playing on hard surfaces, or playing in poor footwear are also considered risk factors for jumper’s knee
Other factors worth looking at include, vertical jump ability, as well as jumping and landing technique, as these can all influence tendon loading. When jumping the kneecap tendon experiences greater mechanical load during landing than during push off, therefore, eccentric muscle action and control during landing is important to assess. This phase of the jump may well exert mechanical and tension loads that lead to injury.

What Does Jumper’s Knee Feel Like?

The symptoms of jumper’s knee typically come on slowly and may not be associated with a specific injury where the individual can trace back the onset of pain to a specific incident. The athlete is first likely to experience aching and stiffness after exercise. With jumper’s knee the pain is normally felt at the bottom front of the kneecap, over what is called the lower pole of the patella. The pain is normally an aching quality and the bottom of the patella is frequently very tender with palpation of the area.

Classification Of Patella Tendinopathy

A simple way to classify jumpers knee is categorize it into one of 4 stages:
  • Stage 1 – Is pain only after training or activity, without any functional impairment.
  • Stage 2 – Pain before and after training, but pain eases during activity once warmed-up and the individual is able to perform satisfactorily during training or playing.
  • Stage 3 – Where pain during training limits performance, as well as the individual suffers with prolonged pain both during and after activity.
  • Stage 4 – Is where the pain is experienced during every day activities not just during or associated with physical activity.
Disclaimer: Sydney Physio Clinic does not endorse any treatments, procedures, products mentioned. This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific advice or assistance regarding Patella Tendinopathy Commonly Known As Jumper’s Knee should consult his or her orthopaedic surgeon, general practitioner, sports medicine specialist or physiotherapist.