But are there general rules for sport injury prevention which apply to all sports? Fortunately, yes: scientific investigations concerning the causes of injuries have yielded a number of important points about who gets injured -and why.
Most of the studies have focussed on running, even though running is NOT the most injury-producing sport. In terms of the total number of injuries produced per year, soccer is actually number one with volleyball close behind and running in third place. Sports scientists suggest that injury rates could be cut by up to 25 per cent if athletes took the proper preventative steps.
However, sports participants are confused about what to do about injury prevention, and in fact there are many misconceptions about injuries. For example, coaches and athletes often believe that males have higher injury rates than females, but male and female athletes actually have about the same injury rate per hour of training. Among runners, it's popular to believe that training speed is a critical cause of injuries ('Speed kills,' according to one popular adage), but research actually indicates that there' s no link between training velocity and injury risk.
Another common belief is that stretching before workouts helps to reduce one's chances of injury, but research again says no. In a very recent study, 159 Dutch athletes were taught how to stretch effectively before training sessions, while a second group of 167 similar athletes received no stretching instruction at all. Although the stretching did a good job of loosening up the athletes' calves, hamstrings, and quadriceps muscles, actual injury rates were identical in the two groups, averaging about one injury per 200 hours of training. The stretching had no protective effect at all!
Don't overdo it
On the other hand, the AMOUNT of training you actually carry out plays a key role in determining your real injury risk. Studies have shown, for example, that your best direct injury predictor may be the amount of training you completed last month. If May is a heavy training period, for example, watch out in June! This relationship may seem strange at first, but it simply reflects the fact that vigorous training produces tired muscles which may not be able to stand up to further training stresses. Fatigued muscles also do a poor job of protecting their associated connective tissues, increasing the risk of damage to bones, cartilage, tendons, and ligaments.
If you're a runner, the link between training quantity and injury means that total training mileage is an excellent indicator of your injury risk. The more miles you accrue per week, the higher your chances of damage. One recent investigation found a marked upswing in injury risk above about 40 miles of running per week.
The two best predictors of injury
However, it's important to bear in mind that many injuries are actually NOT new trouble areas; they are recurrences of previous problems. That brings to mind an important point: the absolute-best predictor of injury is a prior history of injury. In other words, if you've been injured before, you're much more likely to get hurt than an athlete who's been trouble-free. Again, this is logical: regular exercise has a way of uncovering the weak areas of your body. If you have slipshod hip muscles, for example, or knees that are put under heavy stress because of your unique biomechanics during exercise ('poor form'), your hips or knees are likely to be hurt when you engage in your sport for prolonged periods of time. After recovery, if you reestablish your desired training load without changing your biomechanics or strengthening your hip muscles, those areas are very likely to be injured again.
Strangely enough, the second-best predictor of injury, after total training time, is probably the number of consecutive days of training you carry out each week. Consecutive days are counted as follows: if you train on Monday, Tuesday, Wednesday, and Friday, you are training on three consecutive days each week (Friday doesn't count because it has a rest day before and after it). Scientific studies strongly suggest that reducing the number of consecutive days of training can lower the risk of injury. For example, instead of working out for one hour from Monday through Friday (five consecutive days), you could probably reduce your risk of injury by completing 75-minute workouts, four days per week (Monday, Wednesday, Friday, and Saturday, for example). Your total training time would be the same in each case, but the second strategy would reduce your consecutive days from five to two, giving you much more average recovery time between sessions and lowering your risk of injury. Recovery time reduces injury rates by giving muscles and connective tissues an opportunity to restore and repair themselves between workouts.
Type A's should take care
Psychological factors seem to play a role in producing injuries, too. Some studies have shown that athletes who are aggressive, tense, and compulsive have a higher risk of injury than their relaxed peers. Such worried, 'Type-A' individuals also have more multiple injuries and lose twice as much training time when an injury actually occurs. So, relax! Tension may make muscles and tendons tauter, increasing the risk that they will be harmed during workouts.
Almost finally, remember that many injuries are caused by weak muscles which simply aren't ready to handle the specific demands of your sport. This is why people who are starting a running programme for the first time often do fairly well for a few weeks but then - as they add on additional mileage -suddenly develop foot or ankle problems, hamstring soreness, or perhaps low-back pain. Their bodies simply aren't strong enough to cope with the demands of the increased training load. For that reason, it's always wise to couple progressive resistance (weight) training with your regular training. Resistance exercises can fortify muscles and make them less susceptible to damage, especially if the strength- building exercises involve movements that are similar to those associated with the preferred sport. For example, runners who want to improve leg-muscle strength are probably better off performing 'closed-chain' (weight- bearing) exercises such as lunges and squats, instead of carrying out non-weight-bearing routines on weight machines while in a seated position. The latter activities are as unlike running as exercises can possibly be!
Make it specific
Strength training should also be specific to your sport. If you play tennis or squash, for example, or participate in a sport which involves throwing an object, you should devote lots of time to developing the muscles in front of the shoulder (anterior deltoids, pectoralis major, pectoralis minor, etc.) which increase the force with which you can strike or throw the ball, but you should also work systematically on the muscles in the back of the shoulder, including the trapezius and 'rotator cuff' muscles which control and stabilize the shoulder joint during ball-striking actions (and provide most of the force for 'backhand' strikes).
Finally, remember that the absolute-best predictor of future injury is a past history of injury, so if you were hurt sometime during 1994, be careful! Your chance of an injury in 1995 is about 25-50 per cent greater, compared to the lucky athlete who managed to stay injury-free this past year.
Injury prevention tips
( l ) Avoid training when you are tired. Tired muscles provide inadequate support for tendons, ligaments, and bones, increasing the risk of strains, sprains, and stress fractures.
(2) Make sure that you increase your consumption of carbohydrate during periods of heavy training. Muscles which are low on carbohydrate are tired muscles, leading to the problem mentioned in recommendation No. 1. If you're an endurance athlete, you need about 200-225 calories of carbohydrate per stone of body weight during strenuous training.
(3) Continuing to build on the 'fatigue produces injury' theme, you should bear in mind that increases in training necessitate increases in resting, too. Anytime your training volume increases by more than 2-3 per cent, you need to make sure that you're getting more sleep and taking more time to rest during the day. Otherwise, you're not really training; you're trying to tear yourself down.
(4) Remember a key principle of training: total training time doesn't automatically build upon itself. If you've been training for three hours per week, for example, that does NOT mean that you're ready to step up to three and one-half hours per week. Any increase in training should be preceded by an increase in strengthening so that your body is really ready to take on the new load. Runners, for example, should go through a strengthening period emphasising drills to boost leg-muscle power before they attempt a significant upswing in mileage. Tennis or squash players should work on their shoulders and legs before they upgrade their playing time.
(S) Be especially careful if you're a relative newcomer to your sport. If you've only been participating in it for a few months, you're much more likely to be injured, compared to someone who's been active for several years, simply because the latter individual has had more time to strengthen the appropriate muscles and connective tissues.
(6) Treat even seemingly minor injuries very carefully to prevent them from blowing up into big problems. Remember the time-honored acronym RICE--rest, ice, compression, and elevation--when a small injury strikes. Rest gives the afflicted area time to heal, ice reduces inflammation and swelling, and compression and elevation lessen swelling, promoting healing.
(7) Working with your doctor, take anti-inflammatory medications to control pain and reduce inflammation and swelling which occur as a result of your sports activity.
(8) If you experience pain during a workout, stop your training session immediately. A temporary loss in training time and fitness is far better than long-term damage to your body. Many athletes produce chronic deterioration of a knee joint or another anatomical region by insisting on training through pain. Remember that you're in sport for the long run; a lost month of training to rehabilitate a damaged knee is much better than having to quit your sport completely sometime in the future because of joint degeneration.
(9) If you want to toughen your training without raising your risk of injury too much, another good strategy is to slightly raise your average training intensity (speed), instead of tacking on lots of additional volume (miles) of running, cycling, swimming, or walking.