Leah,
I had an adult late in life onset of FSHD. I am a Mechanical Engineer and was able to fully function in my career until I began to notice obvious signs of headaches, muscle pain, poor posture, and fatigue. I knew something was wrong and it was a scary process of doctors to finally get my diagnosis. I was shocked at the news and my family was devastated since I have always been an active and very physically fit individual. My life had changed in a big way when my Doctor sat me and my wife down for the news.
I am still able to work in my profession but on a limited basis. Fortunately my manager has been very supportive but does not understand the complexities of the disease. I have to take frequent breaks to mainly rest my lower back and stretch my shoulders. Being an employee under ADA guidelines scares employers. So, I am thinking of taking early retirement because my stamina is quickly diminishing.