Why do we have kneecaps on our legs but no “armcaps” on our arms?

Question

Why do we have kneecaps on our legs but no “armcaps” on our arms?

In: 3724

Answer 1

There are good answers in the thread, so I’m just going to share [this interesting video about how kneecaps work.](https://youtu.be/XnYO4TnpTCo)