Jumper’s knee

Jumper’s knee

Jumper’s knee is a condition whereby inflammation and tendinopathy of the patellar tendon (and to a lesser degree the quadriceps distal tendon) occurs in athletes with a mature skeletal system. As the name suggests, this tendinopathy occurs due to repetitive excessive stress from overloading through jumping (although the specific mechanics of injury is still uncertain). In rare cases, it has been found in non-jumping sports such as weightlifting and cycling.

Risk factors making athletes more prone to developing jumper’s knee include the following:

• Increased body weight.
• Structural biomechanics – being bow-legged or knock-kneed; having an increased Q-angle at the knee joint; elevated or depressed patella; or having a leg-length discrepancy (uneven stress placed through the knee joint).
• Muscular biomechanics – reduced hamstring and quadriceps flexibility; jumping as well as landing technique affect load through the tendon. Landing (eccentric loading through the tendon) tends to be more indicative of resulting in the tendinopathy so poor eccentric strength could also be a factor.
• Over-training (resulting on poor muscular control) and playing/jumping on hard surfaces have also been implicated as risk factors.

Classification of Jumper’s knee

There are 4 classifications of Jumper’s knee depending on the severity of the symptoms experienced. Athletes will usually complain of pain on the front side of the knee, usually with an aching sensation. Symptoms can often have a slow onset of pain with no association with a specific injury or trauma.

Stage 1: Athlete experiences pain after the activity with no functional limitations.

Stage 2: Athlete experiences pain during as well as after the activity but will still have the ability to perform the activity to a competent level.

Stage 3: Athlete suffers from prolonged pain during and after the activity and suffers from a progressive inability to perform their activity.

Stage 4: A complete tendon tear or rupture occurs which requires surgical intervention.

Jumper’s knee will usually be diagnosed by the medical specialist via a complete history taking and clinical assessment. Further tests/scans (X-rays, MRI’s) are not usually necessary but could be ordered to eliminate any other complications.

Treatment of Jumper’s knee

Most athletes will respond to a conservative rehabilitative regime. Depending on the classification the athlete will be diagnosed, it will include all the following in various forms:

• Modification of activity – eliminating activities that place excessive repetitive load through the quadriceps/patellar tendon.
• Cryotherapy – ice is essential in reducing swelling and inflammation especially after performing activities.
• Biomechanical assessment should be performed to assess hip, knee and ankle ROM to see if limited mobility is evident – which can then be addressed.
• Stretching – stretching of the (a) flexors of the hip and knee (hamstrings, ilio psoas, rectus femoris, adductors, and hamstrings), (b) extensors of the hip and knee (quadriceps, gluteals), (c) the ITB, and (d) surrounding tissues and structures around the knee joint. What is important to develop a balance between the musculature to ensure even load through the skeletal structures during stress.
• Strengthening exercises – these will be specific to what is required and once again is prescribed to ensure even load through the body/joints.
• Other modalities such as specific knee braces or strapping to ensure correct patellar tracking could be used; arch supports or orthotics can be prescribed to improve foot and leg stability which can help to produce even load through the joints as well as to prevent further injury.
• A functional, progressive sport-specific strengthening programme needs to be adhered to before return to sport. This is essential in ensuring re-injury does not occur.