"I'm here for tight shoulders. Why are we going to talk about the thoracic spine?" Great Question! What exactly is the thoracic spine you wonder? The thoracic spine is the middle portion of your spine from about the top of your shoulders to the bottom of your rib cage. Why is it important? It is the common culprit for injuries like shoulder impingement and neck pain. Our thoracic spine stiffens into a rounded or kyphotic position because of our environment and our culture.