The Poem!

 Have you ever wondered

 Just how we walk and run?

 and how we bend our arms and legs?

 Well listen, everyone…

 The secret's joints and muscles.

 They make a tiptop team.

 When muscles pull your bones at joints

 You move just like a dream!

 Muscles always come in pairs.

 One shortens, tugs the bone.

 To get the bone back into place

 The other has a tug of its own.

 That, my friends, is how it works

 When you're moving all the time

 All that's left for you is to

 Remember this little rhyme!