Data suggests that the conditioning of our cartilage prevents our joints from damage. If the damage acquired from exercise is greater than the body's ability to repair it, the joints start a degenerative pattern. So if you are just starting to exercise, start gently, and work your way up to the ninja style kicking boards and jumping from extreme heights. Give your cartilage time to get buff too!
This data also indicates starting to go through all ranges of motions at a joint and working up to loading all planes of joint motion. Injury occurs in our joints by loading too much force in positions we rarely go through. So starting to increase the tensile strength of our joints may prevent these occurrences and even prevent osteoarthritis in those joints.
