At first I thought he might just be fidgety because he has too much energy, but working him beforehand doesn't seem to do anything to help the matter.
I can think of only a few possible solutions. If I could hang a hay bag for him so that he had something to do while having his feet done, he may be happier (to him, everything is better when hay exists). Or I could try to work in breaks for him; she could work on him for 15 minutes, then let him go back to his stall for a bit, and then work on him some more - although that could end up making him testier. Lastly, I've considered getting a calming paste.
I definitely need a solution, as I think his trims are suffering as a result of this bad behavior.
Thanks in advance for any suggestions you may have!