About Sports Injuries: The Facts
Each year, about in person in 25 seeks medical help for a "sports" injury, but not all of them are sustained while playing sports. Any repetitive physical activity, including walking, can damage muscles and joints. Although humanity has evolved to walk on two feet, the adaptation isn't perfect, and it will always put more stress on bone, tendon, and muscle than the normal four-footed method. In the same way, our arms have evolved from legs that go backwards and forwards into complex tools that can twist and turn in a variety of ways. Inevitably, some of these positions are hard on the joints and muscles.
As a rule, 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 benefit in terms of cardiovascular well being far outweighs the health cost in terms of sports injuries.