Motion Capture

Maya has a great tool for Motion Capture retargeting, which is called humanIK. Kangaroo is simplifying this for you. If just turn on the function humanIkSkeleton(), it'll create this skeleton:

There's nothing for you to do at this point. Just know that it'll use this later under the hood when Animators apply Motion Capture using the Picker.
For more information check: Animator Tools