The elbow joint is actually made up of 3 joints. These joints allow the elbow to bend and straighten as well and pronation and supination (turning the palm down and up when the elbow is bent).
To perform this exercise:
Begin with your elbow straight and your palm facing forward. Begin to bend your elbow. During this time supinate (turning the pinky side of the hand up towards the ceiling) the forearm as far as you can.
Once you have bent your elbow completely, turn the palm over towards the floor, att
empting to rotate the thumb to the floor as far as you can (pronating).
While you are pronating straighten out your arm.
Wrist, thumb and finger circles
For the wrist:
Flex the wrist down as far as you can and then try and scribe out the largest circle
For the thumb
If you place your hand down on a table with the palm up your thumb can move up and down (abduction and adduction), in towards the pinky and out away from the pinky (flexion and extension) and it can rotate so that the pad of the thumb can touch each finger (opposition).
Start by lifting your thumb up towards the ceiling as far as you can and then towards your pinky circling around to the pads of the fingers and then away from the pinky finally ending up pointing back up towards the ceiling.
This can be performed in the other direction as well.
For the fingers
The base of each finger can also create a circle as well. The joints in fingers for the most part bend and straighten. To work these joints simply bend and strengthen them as far as you actively can.