In combination with the design of the arms, there are three distinct designs. The hands were designed like crab claws to facilitate posing with circus accessories. 
Click on the photos to see a larger view.

Chamfered, open to front

The earliest arm design featured a crab hand with a chamfered area where the hand comes together near the wrist (see photo). The arm, when dropped to the side, exposes the hand opening to the front.

Chamfered, open to side

The second arm design was made exactly like the first except that the hand was rotated 90 degrees so that the hand opening is not exposed to the front when the arm is dropped to the side.

Not chamfered

The third arm design was like the second style except that the chamfered area of the hand was not made. This hand style is found on one-part head clowns.