INJURY PREVENTION

By Dr M Goss-Sampson BSc, PhD, Dr S Parsonage BSc, PhD, J M Strickland, MCSP

When an athlete has an injury problem, either traumatic or overuse, much time is quite rightly spent on clinical assessment and diagnostic testing before a diagnosis is made. This of course is fundamental to prescribing and implementing the correct treatment regime, where both the subjec- tive and objective findings are dealt with, eg. pain and dysfunction, together with improving quality and control of motion (1). It is very satisfying to see athletes returning to their full playing perfor- mance.

Highly successful careers in tennis are often curtailed by injuries induced by inappropriate technique - the abbreviated take-back of the racket as in Pat Rafter’s serve is the focus of much discussion and may have played a part in the shoulder injury which forced his retirement from the professional game. In the women’s game, which produces world class players in their teens, a spectrum of overuse injuries resulting from high intensity training and competitive play during the critical years of growth often result in retirement in the early 20s eg. Martina Hingis. And the recreational weekend player, with a lower level of both fitness and technique, in attempting to imitate the strokes of the professional player, can suffer injuries which play a major part in curtailing long term enjoyment of the game.

So in the long term it is far more effective to prevent injuries from occurring in the first place, and this requires a team approach involving technical coaches, fit- ness trainers, physiotherapists and sports scientists. Biomechanics plays a crucial role in the prediction of injuries by analy- sis of sports-specific movements, such as the tennis serve or forehand, which impose high loads on the body, are high- ly repetitive, and are an essential part of a winning game at any level.

THE SCIENTIFIC ANALYSIS OF MOVEMENT Biomechanics, described as ‘the study of the internal and external forces affecting human performance’ is an important area of analysis in many professional sports (2). Using biomechanical techniques we can gather information on areas ranging

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BIOMECHANICS AS A TOOL FOR IN TENNIS

from how movement skills are learned and performed, to causative factors underlying sports related injuries. In tennis, biome- chanical analysis can help players to both perform more efficient and consistent strokes and also reduce the incidence of injuries relating to poor or inappropriate technique.

There are two complementary areas of study, kinematics and kinetics. Kinematics is the analysis of general movement and more specifically the movements of body segments relative to each other resulting in co-ordinated body movement. Kinetics is the analysis of the forces underlying movement, such forces include those pro- duced by the action of muscles around joints (internal forces), ground reaction

INJURY PREVENTION

forces and ball/racket impacts (external forces).

In many movements there are kinetic and kinematic chains in which force produc- tion and body segment movements occur in a co-ordinated sequence. In the tennis stroke, for example, coordinated activa- tion of the body segments starting from the ground reaction forces at the contact point of the player with the court, through the hips, torso, and shoulder, culminating with the acceleration of the racket head at ball contact, should pro- duce efficient force to create maximal ball velocity (3). Any changes in this sequence of events may lead to a reduction in the effectiveness of the stroke and increase the possibility of injury.

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