Group I. Function: Upward rotation of scapula; elevation of arm above shoulder level. Extrinsic muscles of shoulder girdle: Trapezius; levator scapulae; serratus magnus (DC 5301)

Rating levels

• 40% — Your shoulder and upper back muscles that lift your shoulder blade and raise your arm above shoulder height are severely damaged or weakened. You have major difficulty or cannot lift your arm up over your head (like reaching for something on a high shelf), and your shoulder blade doesn't move properly when you try to raise your arm, causing significant functional problems with overhead activities.
• 30% — You have severe problems with the muscles that lift your shoulder blade and raise your arm above shoulder height. These muscles (the trapezius in your upper back/neck, the levator scapulae in your neck, and the serratus magnus along your ribs) are significantly damaged or weakened, making it very difficult to lift your arm overhead or move your shoulder blade properly.
• 30% — You have moderately severe muscle damage or weakness in the muscles that lift your shoulder blade and help you raise your arm above shoulder height. This affects key muscles like the trapezius (the large muscle across your upper back and neck), the levator scapulae (muscle that lifts your shoulder blade), and the serratus anterior (muscle along your ribs that helps push your shoulder blade forward). Your symptoms would include significant difficulty or inability to fully raise your arm overhead, noticeable shoulder blade winging or abnormal movement, and substantial weakness when lifting or reaching above shoulder level.
• 20% — This applies when you have moderately severe problems with the muscles that help lift your shoulder blade up and allow you to raise your arm above shoulder level. The affected muscles include the trapezius (the large muscle across your upper back and neck), the levator scapulae (muscle that lifts your shoulder blade), and the serratus magnus (muscle along your ribs that helps move your shoulder blade). You would have significant difficulty or pain when trying to shrug your shoulders upward or raise your arm overhead, but still have some function remaining.
• 10% — You have moderate difficulty lifting your arm above shoulder height due to problems with the muscles that control your shoulder blade movement. The affected muscles include your trapezius (the large muscle across your upper back and neck), levator scapulae (muscle that lifts your shoulder blade), and serratus magnus (muscle along your ribs that helps rotate your shoulder blade upward). This level of impairment means you can still raise your arm overhead but with noticeable limitation, weakness, or discomfort.
• 10% — You have moderate difficulty lifting your arm above shoulder height due to problems with the muscles that control your shoulder blade movement. The affected muscles include your trapezius (the large muscle across your upper back and neck), levator scapulae (muscle that lifts your shoulder blade), and serratus magnus (muscle along your ribs that helps rotate your shoulder blade upward). This level of impairment means you can still raise your arm overhead but with noticeable limitation, weakness, or discomfort.
• 0% — You have only slight problems with the muscles that help lift your shoulder blade up and raise your arm above shoulder height. The affected muscles include the trapezius (the large muscle across your upper back and neck), levator scapulae (muscle that lifts your shoulder blade), and serratus magnus (muscle along your ribs that helps move your shoulder blade). Your symptoms are minimal and barely noticeable in daily activities.
• 0% — You have only slight problems with the muscles that help lift your shoulder blade up and raise your arm above shoulder height. The affected muscles include the trapezius (the large muscle across your upper back and neck), levator scapulae (muscle that lifts your shoulder blade), and serratus magnus (muscle along your ribs that helps move your shoulder blade). Your symptoms are minimal and barely noticeable in daily activities.