Today I worked for 12 hours and then ended the day with a massage.
By comparison, the Egyptian masseur from two weeks ago was crap. His massage technique was the same as how I would do it, only more forceful. My Google masseur tonight had fancy professional methods, pressing out the stress in a way that said "non-amateur".
When he got to my right shoulder, it became much more painful. "This must be your mouse hand," he said. "Years of stretching forward to use the mouse has caused this muscle to deform. Your rib is sticking out in the back, and your shoulder is contorted forward." He pressed his thumb just below my collarbone, and I yelped. "Feel this knot here?"
"Are you sure you're not just picking a spot and poking me in it?" I asked hopefully, between gasps of breath.
He laughed and continued kneading my shoulder with his knuckle. "You should learn to use the mouse with your left hand, so that you can switch between the two."
"Won't that make me deformed on both sides instead of just one?" I said.
"No, the damage is exponential based on use."
Alas, gentle readers and mouse-users, you probably have the deformity too.