What to expect from an acupuncture treatment for shoulder pain in Morden... Shoulders are complex joints, and often get injured or strained, sometimes even from something unexpected like sleeping in an awkward position one night. Overuse or poor posture can contribute to mild shoulder pain as well, as can age-related degeneration. A mild case of shoulder pain might lead to a bit of discomfort for a couple of weeks, or it could be months of pain and restriction from an injury