By: Dr. Kevin McIntyre B.Kin., DC
Our clinic sees many different sports injuries in people of all ages. Athletic injuries in younger patients sometimes occur for reasons related to being younger, though, so their management may be different than when we are seeing adult patients. Examples include growth plate injuries, injuries that are influenced by growth and maturation, as well as injuries related to frequent training, as often seen in youth athletes. It is impossible for one blog entry to cover the entire topic of the influence of growth and maturation on athletic injury and performance. This blog simply aims to give our readers some insight into the complexity of this topic and why we need to recognize why active kids might be in pain.
Specialization in Sport
One factor that influences injury is specialization in sport, which is increasingly common among young people.
It is generally accepted that training for more than eight months per year, choosing a single main sport and quitting other sports to focus on one sport suggests that an athlete has “specialized.”
Interestingly, it has been shown that athletes with low specialization have a lower risk of injury but a more moderate risk of acute injury. In contrast, the specialized athlete has a moderate and high risk of injury but a low risk of acute injuries. This makes sense; the untrained athlete might be less skilled or less familiar with a sport and, therefore, more likely to hurt themselves with an event of injury. A skilled athlete could avoid those injury events through better skill acquisition and practise, but because they train so often, they are at risk of an overuse injury. Since participating for more than sixteen hours in a week is also a risk factor for injury it is prudent for parents and coaches to appreciate this risk and watch for the early signs of overuse injury.
Most Common Injuries in Youth Athletes
For youth athletes, most injuries occur in the lower limb. Specifically, the knee and ankle with ankle sprains being the most common sports injury for all ages. Girls are at a much higher risk of ACL injury when compared to boys. There are some injuries that are specific to youth athletes and don’t occur in adults, such as growth centre irritations like Osgood Schlatter’s and Sever’s apophysitis. These conditions are irritations of growing areas in the bone (knee and foot, respectively), and once a person is skeletally mature, they generally resolve.
Part of managing these conditions is being aware of training volume and perhaps reducing or modifying the training plan to allow symptoms to settle down and not worsen.
Treatment and Prevention
Treating and preventing injuries are perhaps more complex in a youth athlete. This is because kids grow at different rates and at different times, and this has a big influence on the development of many conditions.
Thankfully some research has given us a better understanding of growth trends. For girls, the typical “peak” growth spurt is twelve, and in boys, it is fourteen. For most kids, the legs grow first, and then the torso grows after. Bones seem to grow before soft tissues. This will relate to pain and performance changes in young athletes (discussed in more detail later), but it will also cause kids to “stretch out” during bone growth and perhaps appear leaner, then they “fill in” when the soft tissue growth catches up.
Performance of Young Athletes
As we age, our ability to interpret sensory signals and control our muscles and joints improves. As mentioned above, at around twelve to fourteen years of age, a child experiences a spurt in growth rate affecting different tissues at different times. Bone grows before soft tissue, which alters force production. In conjunction with this, the young athlete is dealing with a changing ability of the brain to coordinate movements. Especially in girls, this effect is more common as the timing of improvement in neuromuscular control occurs at a different rate and time than growth in tissues. In simple terms, it’s like a moving target. Different tissues experience bursts of growth at different times while our brain is trying to learn motor control. Not surprisingly, during this period of rapid and extensive growth, you are likely to see a change in athletic performance. It’s important for parents and coaches to recognize this so that they can help the young athlete understand why performance may plateau or regress for a period of time.
Another reason for poor performance is that growing athletes experience a delay from muscle activation to force production along with poorer motor control and tendon stiffness. As the athlete gets older, these factors should improve. The neuromotor control should improve and catch up to the growth curve; the tendons should stiffen and thicken, which aids in force transmission from the muscle. Combined with a reduction in the lag between muscle activation to force production, athletic performance should improve once these growth spurts end. Again, it’s important for parents and coaches to understand these normal deficits in performance during periods of growth (and the year after) and support young athletes so they don’t get frustrated with this.
The year after peak height velocity (the ‘growth spurt’) is a year of adaptation. After bones have lengthened, muscles get longer, thicker and tendons get stiffer. Neuromotor control changes as well. Coaches, athletes and parents should therefore understand that performance may suffer. More importantly, overuse injuries can occur when bones are relatively longer and soft tissues are trying to “catch up,” all while a young athlete may be asking these areas to perform at their normally high intensity.
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