Each year, about 1 in every 25 people will seek medical help for a "sports" injury, but not all of those injuries are sustained while playing sports. Any repetitive physical activity, even walking, can injure muscles and joints.
People who participate in sports are more likely than others of the same age to have muscle and tendon injuries and bone fractures. This certainly doesn't mean you should avoid sports - the health benefits far outweigh the cost in terms of sports injuries.
Sports injuries are most commonly caused by poor training methods; structural abnormalities; weakness in muscles, tendons, ligaments; and unsafe exercising environments. The most common cause of injury is poor training. For example, muscles need 48 hours to recover after a workout. Increasing exercise intensity too quickly and not stopping when pain develops while exercising also causes injury.
Everyone's bone architecture is a little different, and almost all of us have one or two weak points where the arrangement of bone and muscle leaves us prone to injury. Common predisposing factor in injuries to the ankles, legs, knees, and hips include:
Uneven leg length may lead to awkward running and increases the chance of injury, but many people with equal-length legs suffer the same effects by running on tilted running tracks or along the side of a road that is higher in the centre. The hip of the leg that strikes the higher surface will suffer more strain.
Pronation is the inward rolling of the foot after the heel strikes the ground, before the weight is shifted forward to the ball of the foot. By rolling inwards, the foot spreads the shock of impact with the ground. If it rolls too easily, however, it can place uneven stress on muscles and ligaments higher in the leg.
While an overly flexible ankle and foot can cause excessive pronation, a too-rigid ankle will cause the effects of cavus foot. Although the arch of the foot itself may be normal, it appears very high because the foot doesn't flatten inwards when weight is placed on it. Such feet are poor shock absorbers and increase the risk of fractures higher in the legs.
Bowlegs or knock knees add extra stress through knees and ankles over time, and may make ankle sprains more likely.
Other structural conditions that make sports injuries more common include:
Having some muscles that are very strong and others that are weak can lead to injury. If your quadriceps (front thigh muscles) are very strong, it can increase the risk of a stretched or torn hamstring (rear thigh muscle). Tight iliotibial bands may be the cause of knee pain for many athletes in running sports.
Overuse injuries are caused by repeated, microscopic injuries to a part of the body. Many long distance runners experience overuse injuries even after years of running. For road runners, the surface is hard and sometimes uneven, and the running movements are repetitive. In addition, there are usually both up- and downhill elements, and these increase the stress on tendons and muscles in the lower leg. You will more likely develop running injuries if you wear the wrong shoes or sneakers. You should use footwear that doesn't allow side-to-side movement of the heel, and that adequately cushions the foot.
People who play racquet sports tend to injure their upper body. The need to firmly grasp the racquet and the shock of impact with the ball can cause various injuries to the tendons of the wrist and elbow, such as "tennis elbow," which may extend into the muscles of the forearm. In addition, the human arm really isn't designed to handle strenuous activity above the head. Tennis is a leading cause of rotator cuff (shoulder joint) tendinitis. This is potentially one of the most difficult sports injuries. If you continue to play tennis when you have a sore shoulder, the rotator cuff tendons can fray or tear and may require surgery.
There are several common sports injuries.
Shin splints: Shin splints have a number of causes and may occur on the outside or the inside of the shin. With anterolateral shin splints, pain around the front of the shin starts immediately when your heel strikes the ground awkwardly. In posteromedial shin splints, the pain is felt on the inner part of the shins and is worse when you stand on your toes. If you keep running on a regular basis when you have a shin splint, the pain tends to spread toward the knee. Tests are often required to understand the exact nature and cause of shin splints.
Achilles tendinitis: The Achilles tendon (the tough sinew that attaches the calf muscle to the back of the heel bone) is most likely to be damaged if you participate in running or jumping sports. The injured Achilles tendon feels tender when squeezed between the fingers. Pain is usually at its worst in the morning and improves with walking. Vigorous exercise will increase the pain for a bit, then improve it. However, you should never exercise a damaged Achilles tendon without the supervision of a sport medicine physician or therapist, or until it's healed.
Lumbar strain: The standard weightlifter's injury can also occur in sports that involve sudden twisting of the back, such as golf and baseball. Sudden lower back pain appears with twisting or lifting. It may seem fairly minor for an hour or two, but carrying on the exercise will usually bring a sudden deterioration with extreme pain and back spasms.
Lateral and medial epicondylitis: More commonly known as backhand and forehand tennis elbow. Backhand tennis elbow can also occur with overuse of a screwdriver, but tennis may be more problematic because not only are you gripping hard, but there are also repetitive shocks being transmitted to the flexed wrist tendons. Forehand tennis elbow is also common in golfers, baseball players, and people who have to lug heavy suitcases around. You feel pain when you flex the wrist backward (lateral tendons) or forward (medial tendons).
Metatarsal stress fracture: The second to fourth toes are vulnerable to breakage if you push off with your toes when sprinting or running long distances. Army cadets doing running and marching drills are likely to suffer stress fractures during training camps. Dancers and gymnasts experience stress fractures because of frequent jumping. The front of the foot starts hurting during exercise, and the pain usually stops when you finish. With each subsequent bout of exercise, the pain appears earlier and earlier, and gets steadily worse. The fracture can take up to 3 months to fully heal.
Any injured tendon can undergo permanent changes if you continue to exercise it without letting it heal. The normal tendon material can be replaced with inflexible fibrous material in a process called mucoid degeneration. The ligament attaching it to the bone can tear, there may be steady bleeding, and the bone can even change shape where it meets the tendon, forming a spur that may cause pain on movement. In the worst-case scenario, pain can become constant whether you're moving or not, and the affected parts become permanently weak.
It's vital to follow doctor's advice about rest. If you cannot see a doctor, don't exercise the affected area until you're sure it's healing.