Thoracic Outlet Syndrome What is thoracic outlet syndrome? Often caused by weight gain, weightlifting, injury, accident, or tumor growth, thoracic outlet syndrome is a condition that is caused by tissue growth or change that occurs in close proximity to the thoracic outlet. When the blood vessels are pushed together, it creates a painful irritation. What are the symptoms of thoracic outlet syndrome? Arm, neck, and shoulder pain, weakness and limited range of motion in these areas as well, issues with circulation, and numbness in various parts of the body. How do we treat thoracic outlet syndrome? Since poor posture is often a contributing factor to this condition, we show you the proper way to sit, stand, and move about so that stress is taken off your neck and shoulders, and other parts of your body can stop compensating for this injury. We also show you various stretches that are designed to lower pain, increase range of motion, improve strength, and relieve general discomfort.