Double-jointedness is a myth. Though you might be able to stretch your muscles twice as far as others, you owe it to a single, extra-flexible joint.
We've all heard about someone who's torn an ACL, but do we really know what that means?
Can you bend your thumb backwards until it touches your wrist? If you join your hands behind your back, can you lift them over your head without letting go?
Your step the wrong way off a curb and sprain your ankle…or is it a strain? A strain is when you badly stretch or tear a muscle. A sprain is when you stretch or tear ligaments, or part of a ligament. A Moment of Science.