Figure 7.24 - Arm positioning

You can apply rotation keyframes to the spheres and make an animation

with the arm. In those animations, you easily go back to the rest position

(Initial position) by clearing all rotations—Press ALT+R to reset a

rotation with a sphere selected.

Use the ALT key with any transformation shortcut to return the object

property to their original value. The same option is also available from

the Object → Clear menu.