Adolescent knee pain

Among adolescent populations, particularly those who are very active, knee pain is a very common complaint limiting their everyday activity or chosen sport. We’ve all heard of growing pains, but what does this actually mean?

Relevant anatomy and impact of growth

The knee joint is made up of the shin bone (tibia) joining the thigh bone (femur) with the kneecap (patella) positioned at the front. The muscles at the front of our thigh are known as the quadriceps and act to straighten the knee. The bump we can all feel below our knee is where the quadriceps attach to. This bump is anatomically referred to as the tibial tuberosity.

In our body, muscles are connected to bones via connective tissue known as tendons. When a muscle contracts, it will pull on the tendons to produce movement. The quadriceps tendon attaches the quad muscles to the top of the kneecap, and the patellar tendon attaches the bottom of the kneecap to the bump on the top of our shin.

When the quads contract to straighten the knee, the kneecap moves slightly upwards along the surface of the femur, whereas bending of the knee causes the quads to stretch and compresses the patella tendon.

How does growing cause knee pain?

Located at the ends of adolescent bones are areas of cartilage called growth plates. As young individuals experience growth spurts, full bone maturation has not yet been achieved. Meaning that the growth plate is continuing to grow and has not yet hardened into solid bone as seen in adults. Male and female growth spurts tend to occur between the ages of 12-14 and 10-12 years respectively.

Growing pain can arise when the developing bone cannot withstand the tractional forces produced by the tendon. Resulting in an inflammatory response at this area causing swelling, pain, and tenderness. In severe cases, the tendon may pull away a bony fragment from its attachment, this is known as an avulsion fracture.

Most commonly, the complaint of knee pain, as a result of growing, is most prevalent in active adolescents who participate in sports that involve repetitive movements like jumping and sprinting. Such repeated movements cause excess traction of the tendon over its attachment, leading to further aggravation of this area. The two most common injuries are Osgood-Schlatters and Sinding-Larsen Johanssen disease.

Osgood-Schlatters and Sinding-Larsen Johansson

Osgood-Schlatters refers to pain and tenderness directly over the bump below our knee, whilst Sinding-Larsen Johansson refers to pain over the lower aspect of the knee cap.

Both conditions present as a gradual worsening of pain in the absence of any trauma or acute mechanism. Pain is reported with activities such as bending the knee, kneeling or post activity once the body has cooled down. These individuals may experience swelling and increased temperature over the site of pain at the knee.

Both conditions subsequently cause tightness of the surrounding muscles in the leg. In the case of Osgood-Schlatters, the bump may become more pronounced due to the formation of a bony callus as the bone attempts to heal itself.

Both conditions will eventually self-resolve once bone tissue has fully developed.

What can Physiotherapy do to help?

Physiotherapy can have a significant impact in the management of adolescent knee pain whilst awaiting its resolution. Through conducting accurate assessment and an understanding of a wide variety of other knee pathologies, we can provide an accurate diagnosis on what is going on, identify the severity of the injury as well as recognise more serious pathology.

Physiotherapy can also:

  • Discuss load management to optimise patients’ activity participation as well as their condition.
  • Recommend easy at home management strategies.
  • Identify and treat associated biomechanical factors, muscle weakness or tightness which may be contributing to further knee aggravation.
  • Formulate a tailored strengthening program to better support the knee joint.
  • Provide particular taping techniques to reduce pain levels during activity by offloading the knee joint.
  • Facilitate a safe return- to-sport plan.
  • Refer patients for scans or specialist sports physicians for more severe cases who may require further investigation.

Be sure to speak to your Physio, if you, or your loved one is experiencing knee pain – as there are treatment and management options available.