[He's only half paying attention to the movie, more focused on how much he's able to feel during the exercises, so he doesn't mind too much when she suddenly pauses it. He just looks back at her before feeling his arm and shoulder a bit.]

The fact that I can feel more than yesterday is already an improvement, no matter how painful it is. But it's fine, I'd tell you if it was more than I can handle.

[Of course, there could be a problem in that he might push what he can "handle," but she probably can guess that.]

These stretches, though... I'm not really familiar with them. They might be more effective than what's been suggested so far.