Mystery #2Tier 2-3body / muscles
Why do your muscles only pull, never push?
You can bend your arm up and straighten it back down, but it turns out a muscle can only ever pull, never push. So how do you manage to move a bone in both directions?
Your guess
What's your hunch: if a muscle can only pull, how do you move a bone back and forth?
There's no single magic word to type, have a go in your own words, then reveal the answer to see how close you got.
Make a guess to unlock the hints and the answer.