If you duplicate a capsule or muscle object node manually, certain required connections may not be recreated properly from the transform to the Muscle Object shape node. Selecting Muscle > Muscles/Bones > Fix Invalid Muscle Object nodes from the main menu auto-detects and fixes these for you.

For example, if you manually duplicate a capsule and move it, you may notice that its shape does not appear to follow where the transform is. Using this utility corrects that problem.