Challenge: Specialized Palm Build
Since you do not give a desired size of the palm, I'd like to propose the following solution, consisting of 1x 6222 - Brick, Round 4 x 4 with 4 Side Pin Holes and Center Axle Hole and 4x 6628 - Technic, Pin with Friction Ridges Lengthwise and Towball, arranged like so:



You might need to work on the size of the fingers to make this work with "grip" - but it meets your challenge criteria.

There is also part x872 - Technic, Steering Arm with 4 Ball Joints which would be more compact, however, this part is extremely hard to find (there are no sellers on BrickLink currently).