Employee was changing out agitator paddles, one fell & struck EE in the back of right hand. EE's hand was in midair, not on any surface. EE noticed mild pain at the time & noticed severe pain, swelling & decreased ability to move fingers at about 0300 on 9/3/21. EE was seen at onsite clinic and referred to ortho. Restricted use, no work. Right hand in rigid splint.