It is great to see so many children active in the fall, however, toward the end of the sports season, many are complaining of knee pain. Why does it seem more prevalent with soccer?
The fall air brings soccer games, and almost every field is filled with children of all ages running, cutting and jumping for balls. It is great to see so many children active, however, toward the end of the season, many are complaining of knee pain.
Why does it seem more prevalent with soccer? The sport demands speed and stability to maintain control with running, stopping and cutting, which means to quickly change direction. Is it the new turf that is on the new fields being built today?
There are many opinions on turf, and more research is being done on how it affects the body. Is it overuse syndrome? Many soccer players play all year, so they may be over-training, or they be improperly trained. All of these questions are appropriate, but one of the most important questions is who are these injuries happening to and how can we prevent them?
The research has identified the athletes most at risk for knee injuries are girls. The Cincinnati Children's Hospital Department of Sports Medicine Biodynamics Center shows "there is a 4-6 fold higher incidence of serious knee ligament injuries in females participating in jumping and cutting sports than males."
There are many reasons these injuries are seen more in girls than boys and most often seen in soccer and basketball. Recent evidence points toward myriad factors that influence a gender-related bias toward knee injuries. These factors include structure (bony alignment), neuromuscular control (how well the body knows how to move), hormone levels and overall strength. All of these reasons place the typical female athlete at increased risk for knee pain or injury.
Although some of these factors clearly cannot be changed, recent research and rehabilitation approaches seek to modify the two that can: neuromuscular control and biomechanical control of the body structure.
Some studies have shown that teaching a young girl to land properly, with flexed hips and knees, can change their outcome of power and stability. It can also significantly reduce stress through the legs. Increased force and poor absorption of impact because of poor alignment may lead to anterior knee pain and traumatic injuries, such as anterior cruciate ligament tears.
Based on this research, ACL injury prevention and knee awareness programs have been developed nationwide. The programs show enhanced performance, decreased landing impact and improved strength and power. These all lead to the ability to excel in sports.
A large factor in prevention of knee injuries is to look at training and development of the athlete. Research shows athletes positively respond to instruction and feedback of proper technique, balance training, strengthening and plyometrics, or jump training. Teaching them how to move quickly with agility drills that involve provocative positions of the knee once they are strong can lead to improved leg control.
Jump training is important for power, but instructing athletes to land softly, bend the knees at landing, control knee position and practice good habits make more resilient players. Biofeedback, such as watching their own leg and knee positioning, improves an athlete's awareness and allows them to accommodate to faults and use them to strengthen techniques.
Power and stability are what athletes need to jump, land, cut and change directions safely. Strong hip stability allows an athlete to plant on one leg and strike a ball with the other. Staying strong and not letting knees fall together while holding off a defender is another good example of why strength and stability are important.
Children and adolescents generally have more flexibility in their muscles and more laxity in their joints than adults. This excessive mobility at their joints makes them more vulnerable to both traumatic and over-use injuries of the soft tissues, such as tendonitis or ligament injuries.
Athletes spend a lot of time stretching and basing their flexibility on their hamstring length (e.g. "I can put my hands to the floor!"). However, increased flexibility, most often seen in girls and young women, directly relates to decreased muscle stiffness, which correlates to poor power and stability. Less stability at the knee, weakness at the hip and core and poor body positioning may all lead to knee injuries or pain.
We want our children to be active and to play the sport that they love without injuries leaving them on the sidelines. There is a need for increased emphasis placed on strength and conditioning programs targeting the trunk and core muscles and their influence on lower extremity biomechanics for athletes, especially for girls.
In addition, enhancing performance of functional and sport-specific activities, such as cutting or changing direction, by training the motor control and timing of specific muscle group activation is essential for prevention of injury in this population.
If an injury does occur, receiving the proper rehabilitation in a timely manner to treat the injury and then teaching safe exercises for the return to the sport is the best way to keep athletes playing their sport.
Jennifer Green, P.T., is an expert clinician physical therapist at Spaulding Outpatient Center Framingham and Physical Therapist for the New England Revolution. She is coordinator of Sports Programming for the Spaulding Rehabilitation Network and has a special interest in treating adolescent athletes.