[dotancohen]

I doubt that there would ever be need to physically overcome the jackscrew motor (trim motor), as there is an electrical cutout switch in ready reach. The issue the GP discusses is when due to whatever reason the trim runs away (electrical or otherwise), the 737 has two physical wheels that the flight crew can turn, _OR CATCH_ while it is turning. That is like stopping a spinning bicycle wheel by grabbing it. It is physically dangerous to the crew member.