Development of Injuries in Junior Tennis Players
A multinational study (Kiebler et al. 1988) showed a high incidence of injuries in elite junior players. Annual injuries of up to 70% have been reported with overload injuries being the predominant type. The two main causes of injuries are Macrotrauma and Microtrauma.
Macrotrauma includes acute sprains, acute joint injuries, fractures, dislocations and contusions. They occur most frequently in the lower extremity and result from a one time event.
Microtrauma is more silent and results from a process that occurs over time. There are many causes for microtrauma but in general it is associated with overuse and biomechanical alterations which slowly affect the young athlete and may result in tendinitis/tendinopathy, muscle strains, bone contusions, stress injuries to the growth plates, joint instability and others. They may occur in the upper extremity, lower extremity or spine.
The adolescent growth spurt is a critical time for athletic specialization and overuse. During this period there is a high incidence of injuries in particular at the growth plates ( physis and apophysis). In this rapid growth phases, muscles and tendons need to generate increased forces which are then transferred to the growth plates. If the activity is performed repetitively during long periods it may potentially lead to overuse injuries. Overuse injuries occur as a result of repetitive sub maximal loading of the musculoskeletal system with inadequate rest not allowing for structural adaptation and healing.
Although there is no way of completely avoiding this from happening, there are several principles that need to be understood by the tennis coach and parents in order to minimize the risk of overuse injuries and microtrauma. Overuse injuries can be diminished by developing proper sport techniques and training methods, performing adequate warm-up and cool-down exercises, implementing adequate rest and recovery periods as part of the training schedules, developing good sleeping and nutrition habits and using proper equipment. There is also extensive scientific data demonstrating that intense year round single sport specialization without any cross training subjects the body to the same constant pattern of repetitive microtrauma and overuse.
The 4 stages of overuse in increasing severity include: 1) pain in the affected area after physical activity; 2) pain during the activity without restrictive performance; 3) pain during the activity that restricts performance and 4) chronic unremitting pain even at rest.
Each athlete is different and these strategies must be implemented on an individualized basis. In elite players a careful athletic and health assessment and creating appropriate and detailed periodization planning schedules is essential in order to achieve long term success.
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