injuries

Question
how can a person hurt their knee in baseball and how does a knee get injured

Answer
Alex,
No offense, but this is a very broad question.  In short, a knee is held together with ligaments and tendons just like every other joint in your body.  The knee takes on a lot of the load of an athlete's body therefore creating injuries, like sprains, torn ligaments, ruptured tendons, etc.

Baseball is a "non-contact" sport, so most knee injuries in baseball are caused by the ground and not another individual, as in football.  Constant stopping and starting, changing directions quickly, and of course sliding while base running are the leading causes of knee injuries in baseball.

Hope this helps, Alex.

Donovan