I had a double mastectomy and three lymph nodes removed in March of 2011. Mobility, even now, is still something I work on every day. Even at work, I pause two or three times to stretch. If I forget, I notice the tightening. They are little stretches, like reaching up and touching the door frame every time I walk in or out of my office.
My surgeon suggested this exercise: put a towel over the top shower rail and grab each end, pull the towel back and forth over the rail. He cautioned me to work on mobility for a solid year, and I agree because ten month later, I notice when I slack off even a little.
Everyone is different. My surgery was post chemo. I hope this helps.