Overuse knee injury in younger athletes

Knee                       Knee1

By Jason Wells
Sports and Spinal Physiotherapist

The young athlete has a very different skeleton and muscle system when compared to the mature athlete due to the immature growing skeleton and developing muscle system, and therefore will often have quite a different injury profile. The young athletic knee is particularly prone to overuse injuries especially during times of rapid growth. Sudden growth is a strong predictor of knee pain especially as the cartilage of young athletes is less resistant to repetitive strain. Soft tissues about the younger knee become tighter due to the sudden lengthening of the bony skeleton. The “growth pains” that children get are real areas of inflammation in bone and soft tissues. Although a lot of the growing pains eventually resolve spontaneously with time, if left untreated the young athlete will often spend several years struggling with unnecessary pain. We can divide the profile of young athletic injuries into traumatic or overuse causes. Overuse injuries in young athletes is the focus of this series of articles. Lets start with the knee anatomy of the younger athlete. Diagram 1 demonstrates the common cartilage areas that are involved in childhood knee pain.

Overuse injuries occur when there is an increase or change to the volume, intensity or type of activity. Growth plates are particularly vunerable to overuse injuries. Growth plates at the end of the long bones provide the source of cartilage and bone cells that drive skeletal growth and injuries to these areas can alter bone development. Pain is often deep within the knee and poorly localised. There is accompanying swelling and pain during and after activity including during sleep. A Sports Physio will often order an Xray or MRI scan to check for any deformities and advise on the correct active rest and rehabilitation program. More commonly though, growth plates outside the knee are implicated with pain on the front of the knee (Osgood Schlatter’s Disease) in which a definite local pain can be elicited where the patella tendon inserts into the shin bone below the knee cap. Although painful and often swollen leading to the characteristic bump, these injuries are less concerning because they do not affect bone growth. These can be managed with changes to the running load, stretching and strengthening and use of appropriate bracing.

In addition to changes to sporting volume and the stage of growth and development, other factors will influence the development of overuse injuries in the younger athlete including the type of stretching, the type of shoe and boot, the presence of any malalignments, sporting technique and quality of movement, previous injuries, and the proficiency and vigilance of the coaching staff. If you are concerned about your son or daughter’s knee, get it checked out by our Sports Physios who have the skills to diagnose and manage this condition. The next article in this series will focus on what stretches to do around the knee.