I once asked a coworker who was a supervisor in a sewing plant in her previous job that same question. She said that you need the machine low or chair high, enough to work with your arms not raised. In other words, your elbows at the normal, not raised position. Since I use a cabinet, I have my chair raised all the way up with a bed pillow on the seat. I am tall, 5'9", my arms very long and this has solved the aching shoulder problem.