Overview of sports injuries

[Jessica]

Sports injuries are common among athletes and other people who participate in sports. Certain injuries that are traditionally considered sports injuries can also occur in people who do not participate in sports. For example, homemakers and factory workers often develop tennis elbow, although they may never have played tennis.
Sports participation always carries the risk of injury. Sports injuries are more likely when people do not warm up properly (exercising and stretching muscles at a relaxed pace before an intense workout—see Warming up).
Muscles and ligaments are injured when subjected to forces greater than their inherent strength. For example, they may be injured if they are too weak or tight for the exercise being attempted. Joints are more prone to injury when the muscles and ligaments that support them are weak, as they are after a sprain.
Individual differences in body structure can make people susceptible to sports injuries by stressing parts of the body unevenly. For example, when legs are unequal in length, forces on the hips and knees are unequal and place more stress on one side of the body.
Excessive pronation—rolling onto the inside of the foot after it strikes the ground—can cause foot and knee pain. Some degree of pronation is normal and prevents injuries by helping distribute the foot’s striking force throughout the foot. In people with excessive pronation, the feet are so flexible that the long arch flattens out, allowing the inner part of the foot to come close to touching the ground during walking or running and giving the appearance of flatfeet. Runners with excessive pronation may develop knee pain when running long distances because the knee caps tend to turn outward when the feet turn inward. This position in turn places excessive pressure across the front of the knee.
The opposite problem—too little pronation—can occur in people who have rigid ankles. In these people, the feet appear to have very high arches and do not absorb shock well, increasing the risk of developing small cracks in the bones (stress fractures) of the feet and legs.
The way in which the legs are aligned can produce pain, particularly in women with wide hips. Such women develop a tendency for the knee caps to be pushed outward from the midline. This force on the knee caps causes pain.
Generally, sports injuries can be divided into four categories:

Overuse
Blunt trauma (for example, falls and tackles)
Fractures and dislocations
Sprains (ligament injuries) and strains (muscle injuries)