PREVENTION OF SPORTS INJURIES

by Dr Peter Thomas MB BS, DObst RCOG, Sports Physician, Reading, Berkshire

Prevention is a vital and often neglected aspect of sports injuries. A few well-chosen words at the right time may reduce the number of injuries, and the workload of the general practitioner. The article deals with prevention of common injuries and gives practical tips on how to reduce and alleviate symptoms in future.

An understanding of the classification of sports injuries is helpful in both prevention and treatment. The injury may be of sudden or gradual onset, and may be extrinsic or intrinsic. Extrinsic injuries are caused by external forces applied to the body. Intrinsic injuries are caused by excessive or inappropriate forces applied within the body.

Injuries can then be classified according to the body component involved - muscle, tendon, ligament or bone. However, management of a partially torn ligament is very different from that of a completely ruptured ligament.

Injuries may also be classified according to the particular type of sport being played and the particular activity being undertaken within that sport. For example, sprinters generally experience different injuries from endurance runners, because of the variation in technique and training involved.

Prevention of extrinsic injuries

If the rules of competition and training were strictly applied and adhered to, extrinsic injuries should not occur. Many of the rules in various sports have been made in order to prevent and reduce injuries. For example, rugby union has recently changed the laws on scrummaging in order to protect players from neck injuries.

To minimise extrinsic injuries, athletes may need to protect themselves (e.g. helmet, padding, strapping, box, shin guard, gum shield). Although many sports people use strapping to add strength and stability to joints, it may also prevent or reduce the severity of injury by absorbing shock.

Equipment used in sport may itself produce injury if it is faulty or inappropriate for the size, age, or ability of an individual. The facilities used by the sports person may also add to the risk of injury. Loose or sharp stones or other objects on the field of play are potential hazards that are easily avoided. Indoor training facilities should be cleaned regularly to clear water or dust from the surfaces, and to remove sharp objects from the surrounding area.

Prevention of intrinsic injuries

Although intrinsic injuries may occur without any apparent cause, invariably they are the result of inappropriate training loads. Screening may be necessary to ascertain whether it is safe for some patients to undertake a particular activity. For example, it would be unwise to allow an epileptic to race motor cars or a patient with a history of a spontaneous pneumothorax to do sub-aqua diving. Diabetic and asthmatic patients should be encouraged to partake in sports, but their condition should first be controlled. Older patients who have not taken exercise for a long time may benefit from having their pulse rate, blood pressure, heart rate, body fat and flexibility checked.

Training regimes

The purpose of training is to increase or enhance fitness. Fitness is a combination of speed, endurance, power, flexibility, skill, mental attitude, and tactical awareness. Good training involves controlled progression of the frequency, duration, and intensity, of the training load. A rapid increase in one or all of these parameters can cause injury. However, overload is necessary to improve function.

Specificity is a key word in training; if the training is not specific, then it too is a potential hazard. Training regimes may consist of short, high-intensity activity, prolonged, low-intensity "steady-state" activity or interval training and Fartlek. Interval training uses a combination of periods of work and rest. Fartlek is a system of training originally used by Scandinavian runners, and involves alternating periods of speed at irregular intervals, as in cross-country running.

Resistance training is now being used by many athletes. The resistance may be provided by free weights, fixed weights (as on a "multi-gym"), isometrics, isokinetics or the individual's own body weight. Training muscle groups eccentrically (controlled lengthening of a muscle or extension of a joint) produces good results but is also more hazardous. Recently, pliometric training has been incorporated into regimes. This involves rebounding - for example, jumping down from a box and rebounding up onto another box. The purpose of this exercise is to improve the elastic recoil of tendons and muscles. Pliometrics, however, are a potential cause of intrinsic injuries.

Precautions for older athletes

Veteran athletes need to take special precautions because of their reduced strength, flexibility, and powers of recovery. Their cardiovascular efficiency is also reduced, and this, combined with possible increased obesity, will make them more vulnerable to injury. A pre-existing condition such as osteoarthritis in a knee joint will not only expose them to further risk of injury in that joint, but will also increase the risk of other injuries. For instance, the back or feet may be injured as a result of moving abnormally to overcome the pain or reduced range of movement in the knee. However, regular bouts of moderate exercise improve the health of articular cartilage and increase the muscle function and therefore the stability of an osteoarthritic joint.

Precautions for young athletes

Children are at increased risk of injury if they partake in training that is inappropriate for their age. Prepubertal children in particular should not lift heavy weights, as they do not have the ability to improve muscle power. Even after puberty, because they lack intrinsic anabolic steroids, boys up to 16-18 years old and girls up to 14-16 years old should not lift weights that exceed half their body weight. They may develop hot, painful and swollen joints after prolonged bouts of exercise. If the symptoms and signs do not disappear after a few days of rest, further investigation may be indicated.

Problems of overtraining

Overtraining is an abnormal physical or psychological response to over-stressing an athlete, either physically or mentally. It is a risk factor for intrinsic injury, and may also lead to increased susceptibility to illness.

Fatigue from overtraining may be a result of glycogen depletion, increased lactate levels, or a failure of temperature and fluid regulation (Box 4). Environmental factors such as heat, humidity, altitude, and time-zone changes increase the risk of developing an overtraining syndrome, as do travel fatigue, inadequate nutrition, inadequate rest and intercurrent illness or injury. The result is a reduction in performance, an increase in recovery time, extreme fatigue during exercise, and prolonged fatigue after exercise.

Treatment includes rest, either complete or relative (e.g. changing to another sport or activity for a few days), together with an increase in food and fluid intake, an increase in sleep, suitable diversion from sport, and a reduction in the intensity, frequency, and duration of training. The athlete, coach and parents may need to be counselled concerning the type, quantity and quality of training.

Prevention of specific injuries
Shoulder joint injuries

One of the most common injuries of the shoulder joint is a supraspinatus tendinitis, caused by repeated use of the shoulder above 90 degrees of abduction. Swimmers and racquet players are particularly susceptible to this injury. Management involves reducing the number of times that the joint is put through the range of movement that causes the tendon to be squeezed. Swimmers can be encouraged to change strokes, or to use their legs only for a short time, while tennis players can be advised to avoid serving or overhead volleying for a while when training.

Tennis elbow

Tennis elbow is another common injury, and is seen not only in athletes. It may be caused by the equipment being used (e.g. a racquet handle that is too big or too small, or racket strings that are too tight). The increasing use of carbon fibre in sports equipment increases the likelihood of injury, as it does not absorb or dissipate energy, and instead transmits it directly to the body.

Back problems

Fifty per cent of patients requiring physiotherapy present with painful backs. The injury may not be a direct result of the sport itself, but caused by other forms of training undertaken in association with that sport.

Weight training frequently causes injury, particularly if not supervised adequately. It is worth enquiring whether an injured athlete with a back problem is training in a gymnasium. For example, international rowers are ten times more liable to injure themselves when land training than when training on the water.

Athletes should consider whether the type of training they undertake is improving their performance, or whether the returns are nullified by the increased risk of injury, which may prevent them from competing.

Knee injuries

An injured knee that has been treated and rehabilitated should be protected from unnecessary stress to avoid prolonged disability. Other forms of exercise may prolong the pain. The knee should not be loaded unnecessarily by doing squats beyond 90 degrees of flexion and kneeling should be avoided. The stability of the joint can be greatly improved by building up the quadriceps and hamstrings. The vastus medialis in particular needs special attention. This muscle comes into play in the last 10 to 20 degrees of extension, so if the athlete is using a bicycle, the saddle should be high enough to allow full extension.

Ankle sprains

Lateral ligament sprains of the ankle occur in all sorts of sports and are invariably inadequately rehabilitated. Typically, a football player will sustain a lateral ligament sprain and will then rest for about two weeks before trying to play again, only to re-injure the ankle after a few minutes. This might be repeated a number of times before the athlete seeks advice. The repeated relapses are caused by poor muscle function around the ankle joint and poor proprioceptive feedback.

Graduated exercise regimes are required, starting with walking without a limp, followed by alternating periods of jogging and brisk walking, leading to faster bouts of running and sprinting. This is followed by hopping, bounding and weaving, before the footballer can start dribbling and then kicking a ball. He is fit to return to competitive football only when he is able to do this for at least 20 minutes. Balance drills, including standing on one leg and using a wobble board, will help prevent recurrence of the injury by improving proprioceptive feedback lost as a result of the original injury.

Conclusion

Prevention is better than cure, but in order to give advice to patients, an understanding of the mechanisms of injury is desirable. In theory, extrinsic injuries should not happen, and intrinsic injuries should be reduced by appropriate training regimes. Special precautions should be taken with the young and the old. Injuries need both proper rehabilitation and advice on avoiding unnecessary stress when performing activities related to the injury.

Practical points

• Extrinsic injuries are caused by an external force being applied to the body; intrinsic injuries are caused by excessive or inappropriate forces being applied within the body.
• To minimize extrinsic injuries, the athlete may need to wear protective equipment
• Intrinsic injuries may occur without any apparent cause; invariably, they are the result of inappropriate training loads
• Older people who have not taken exercise for a long time may benefit from having their blood pressure, heart rate, body fat and flexibility checked
• Children have an increased risk of injury if they partake in training that is inappropriate for their age; prepubertal children should not lift heavy weights
• Fifty per cent of patients requiring physiotherapy present with painful backs
• The sport that an individual plays may not be the cause of the injury; it is more likely to be a result of other forms of training undertaken in association with that sport
• It is worth enquiring whether an injured athlete with a back problem is training in a gymnasium.
• An injured knee that has been treated and rehabilitated should be protected from unnecessary stress, in order to avoid prolonged disability