How to rig a puppet Arm so that elbow have 360 degree hinge rotati Ion

I worked on a doll puppet and it was listed on okaysamurai website i think some years ago and it had this functionality, The arm could move 360 degree and also the elbow, and it was like upper arm and lower arm are separate layers but connected to each other giving a 360 degree hinge rotation effect at elbow. 

But unfortunately i dont see that puppet anymore on intenet and i need that effect badly, Tried my best but could not get it properly. 

Do anyone know how to do it?