Physical Danger
In the immortal words of House of Pain, "Jump around. Jump up, jump up and get down. Rreeeeeeeee."
By our estimates, basketball is approximately 40% jumping, 40% jumping, and 20% flopping, which is definitely a recipe for foot and leg injuries.
Common injuries for basketball players include twisted or sprained ankles and muscle or ligament tears. ACL injuries can be especially serious, so if your knees are acting up, don't ignore them.
Also, we've all jammed our finger playing basketball at least once. It's probably not the most serious injury, but it still hurts. A lot.