I have had my expander in for almost a year. After your expander has been expanded for a while your PS should be able to take some of the fluid back out. If you haven't had chemo yet and are already fully expanded it's no wonder you hurt. The pain does lessen as time goes by. The muscle does stretch and will relax somewhat. Since I was going to under go extended chemo because of a clinical trial my PS had me come back about 8-12 weeks after my last expansion to take some of the fluid back out which greatly relieved the pressure. Remember this will not feel so bad once the permanant implant is in place. Hang in there. Do you have a physical therapist? If so, have them show you exercises to do so you can get back your range of motion in your arms. My left shoulder was very painful due to the axillary lymph node disection, but slowly stretching out my muscles really helped. Get your doctor's permission before beginning any exercises and go slow. It's a process, but you'll like the results once you are finished. Stay strong, it's not easy!