However, teens participating in sports run an increased risk of injury. These injuries can carry lifetime consequences. Adolescents are at higher risk from sport-related injuries for several reasons. Teens vary in their development and are different sizes. The skeleton is also immature. Injury from overuse is a particular concern in this age group. Overuse is likely due to increased skill levels, intensity of training and competition in sport at younger ages, and longer (often year round) training seasons.
Adolescents suffer a high rate of injuries while playing sports. Sport injuries have a significant effect on the teen, their parents and the health care system. In Canada, sport injury is the leading cause of injury in adolescents. It is also the highest cause of injury leading to emergency hospital admission for this age group. In Alberta, it is estimated that one in three teens requires medical attention, and one in ten goes to a hospital emergency department with a sport injury every year. These numbers likely reflect the high number of teens participating in sports and their associated risk of injury. Sport specific injury rates are even higher in sports such as football, hockey, basketball, soccer and gymnastics.
Sport injuries, specifically knee and ankle injuries, can increase the risk of developing osteoarthritis later in life. An estimated eight per cent of adolescents drop out of recreational sporting activities each year because of an injury. Such injuries may reduce future physical activity, leading to less than ideal future health.
Extrinsic Risk Factors
Intrinsic Risk Factors
Even before an actual injury happens, many risk factors for injury in sport can exist. The mechanism of injury (how an injury happens) might involve a pivot maneuver on the court or contact in hockey. Extrinsic risk factors can include weather or field conditions, while intrinsic ones might be the athlete’s age or conditioning level. Modifiable risk factors (see sidebar) can be affected by injury prevention strategies.
Knowing which kids may be at higher risk can help us target them with appropriate prevention strategies. Teen boys playing sports may be at a greater risk of injury. They can be more aggressive, have larger body mass, and make greater contact compared to girls in the same sports. Greater force may be used when running, jumping, pivoting and contacting other players, increasing the risk for injury. In soccer and basketball, however, studies show that girls are more likely to be injured. This may be due to different skill levels or may be physiological in nature.
Studies suggest left-handed teens may also be at more risk of injury. This may be due to the development of the nervous system or simply related to a sports environment biased for right-handed players, especially equipment.
Previous injury clearly increases the risk of injury in sport. Perhaps symptoms persist or the teen needs more rehabilitation. The body may not have healed from physiological problems, associated with a previous injury, such as lax ligaments, decreased muscle strength, endurance, and proprioception. Proprioception is the body’s awareness of joint position and movement and its ability to react to external forces. This includes the ability to co-ordinate muscle effort and sense body-space relations such as maintaining balance.
Hockey, basketball and football are always among the top-rated sports for injury in male athletes. There is certainly significant contact involved in hockey and football, and some in basketball. All three involve jumping, sprinting and pivoting, actions often involved in the mechanism of injury in sport. Gymnastics, basketball and soccer are always among the top-rated sports for injury in female athletes. They also include lots of jumping, sprinting and pivoting.
The risk of injury in child and adolescent sport grows with age. As kids get older, the level of competition, amount of contact, body size, and time spent participating in sport increase. Taller and heavier athletes often do gymnastics or play football, soccer and baseball. They may be more at risk for injury since greater force is absorbed through their soft tissue and joints. In hockey, a contact sport where there is no weight classification, smaller players are more at risk for injury. In Australian Rules football, a larger field size and fewer players likely reduce contact - perhaps why the game in such a venue is associated with a lower risk of injury.
Organized sport and tournament play, including competitions, have higher injury rates than unorganized sport. Athletes are more likely to play at greater intensity and speed in competitions and tournaments than in practice and regular season play. The risk of being injured is heightened.
Since the skeleton is growing rapidly in children and teens, there are physiological reasons why children and adolescents may be at greater risk of injury. For instance, sudden intense traction from a muscle may be placed on an immature skeleton during a period of rapidly increasing muscle strength. This may cause a ligament or tendon to tear away a small piece of bone to which it is attached. The result can be a fracture of the growth plate where bone growth occurs. This injury is not possible in an adult.
Chronic, repeated muscular traction can also be exerted on an immature skeleton, usually during a growth spurt. It can result in traction apophysitis, an inflammation caused by repeated irritation of the growth plate. Osgood-Schlatter and Severs disease are examples of this type of injury that can happen only in children and adolescents.
If pre-season training is limited, the resulting lower endurance and strength can mean a higher rate of injury. In some team sports like rugby or soccer, less than half of the athletes competing at a club or school level have done any pre-season conditioning.
Some athletes may benefit more from the protective effects of training programs than others. For instance, lower skill division adolescent female soccer players may benefit more than those in the higher skill divisions.
Many coaches emphasize stretching as part of a regular warm-up routine. However, lower flexibility has not been shown as a risk factor for injury in most adolescent sports. Increased flexibility seems to be important in gymnastics and figure skating, which demand a high degree of flexibility for many of the moves.
The absence of protective equipment in sport certainly increases the risk of injury in some sports. In hockey, full face shields are often required. Research evidence has found their use does protect against head and face injuries.
A recent high school survey in Alberta suggests that more than half of teens never wear a helmet while skateboarding, scootering and rollerblading. While helmet use has apparently increased in cycling, skiing and snowboarding, less than half of the surveyed teens doing these activities wore a helmet more than 75 per cent of the time. Research evidence has found that helmets protect from head injury in these sports. Some may argue that using a helmet may increase risk-taking behaviour, but this is not supported by research.
The same survey estimates that other protective equipment, such as wrist guards, is rarely used by youth in snowboarding, skateboarding and rollerblading. All of these activities have relatively high rates of wrist fracture.
It is impossible to eliminate all injury in youth sport. However, injury prevention strategies can reduce the number and seriousness of injuries in many sports.
More research evidence on injury prevention exists for adult and elite sport than for youth sport. However, sport injury is so significant to adolescents that it warrants specific attention. The long-term effect on sport participation, early osteoarthritis and future risks of obesity and disease is a huge health concern. Still, immediate benefits regarding self-esteem, socialization, teamwork and motor skill development come from participating in sports.
Using protective equipment can help prevent injury in many sports. Such equipment includes full face masks and mouth guards in hockey, shin pads in soccer, and helmets in cycling, skiing and snowboarding. The challenge is to get kids using the equipment. Despite ongoing controversy, combining education, legislation and facility/sport association requirements may be the best way to encourage the use of protective equipment.
Sport-specific injury prevention strategies can help reduce the risk of injury. In particular, risk associated with intrinsic factors including previous injury, decreased strength, endurance, flexibility, and neuromuscular (nerve and muscle) control including balance can be reduced. Prevention strategies have typically focused on adults and elite sport athletes. Neuromuscular training, including balance training like using a wobble board, can have a protective effect for kids involved in high school physical education.
Proprioceptive balance training is an important part of rehabilitation in sport medicine. It is also part of pre-season injury prevention programs for many athletes, including kids. In adult soccer, decreased balance is a risk factor for recurring ankle sprain injury. Injuries can be prevented by improving dynamic posture control and balance and producing more co-ordinated and consistent movement patterns during activities.
Balance training, combined with other training techniques such as strengthening, warm-up, and plyometrics, may reduce ankle and knee sprains in certain elite and adult sports. (Plyometrics are exercises where the muscle is stretched immediately before it is contracts.) Neuromuscular training, with an emphasis on how to jump and land, may also reduce knee injury in some teen sports.
A recent survey in Alberta suggests that prevention strategies targeting certain adolescent sport groups may have the greatest health impact. The sports include basketball, hockey and soccer. Recently, the Sport Medicine Centre at the University of Calgary began a Sport Injury Prevention Research Centre program. Researchers and clinicians from many different backgrounds work together here to reduce injuries in sport. The centre focuses on prevention of injury in adolescent sports. Current projects include a survey examining sport participation, sport injury and sport safety practices for kids, developing injury surveillance and examining risk factors for youth soccer and hockey, and developing prevention strategies for high school basketball.