Strain from repetitive motions/checks

I started developing OCD in august of last year. Since then, I’ve settled into a routine where I physically check multiple things before bed each night. My OCD makes me not trust my eyesight, so I need to have a concrete feeling that, say, the door is locked, so I’ll twist the knob 8 times. Anyway, about a month ago, I began noticing a twinge in the shoulder of the arm I use to check things with. I use a lot of force to convince my brain that whatever I’m checking is right, and I think it’s causing minor shoulder strain. I do this multiple times a night on different objects, so I think my OCD is causing this.

Does anyone else have this problem?