Does the term "upper extremity" include hands?
As far as I know, and the same is written on Farlex Free Dictionary, the upper extremity or superior limb includes:


the shoulder girdle
the arm
the forearm
the hand


Again, on this Dartmouth Medical School page, the upper limb bones are described and the article includes the bones of the hand.

So, anatomically speaking, the upper limb includes the hand.