The body is mainly a biochemical "machine", that can at least partially regenerate itself, which have evolved through 100,000s of years. However our society has, for the last 100 years, progressed much faster than evolution can keep up with, to the point where one hardly has to use one's body at all. However if you do not exercise, you run the &...
Consider a knee:
The meniscus absorbs much of the shock of jumps and landings.
Tears in the meniscus is a common cause of surgery.
Sports with high risk of meniscus tear include american football, soccer, basketball and wrestling.
Altough running is high impact this injury do not seem to be common here.
Rather it seems that rotation of the knee and ...