The pain that you are describing does sound nervy. However, nerve pain that goes in the shoulder is typically coming from the neck. There are no nerves that travel from the lower lumbar spine that have attachments to the arm. Your physical therapist gave you postural exercises, which is good (since poor posture can essentially crush nerves as they exit). However, you probably need to find a physical therapist who does manual therapy where they actually put their hands on your neck and assess movement to see if a nerve is caught there somewhere. Just speaking from an anatomical perspective. Plus, it's also hard to find a good PT. They are few and far between in my experience.
Jasmin: Severe PE/HELLP and delivered at 24+6 & PCOS (29) Hubby Bubby, Frank (29) Baby Blue
stopped in to say hello and goodbye on 6/3/10Baby Lucas was born on 10/13/11, PE and HELLP-free! Thank you baby aspirin and Lovenoxhttp://www.ehd.org/pregnancy-calendar.php?id=18192