Chest

The chest is formed mostly by the pectoralis major and minor muscles. These muscles span from the front of the shoulders, across the ribs to the front of the sternum. When the chest muscles are tight, it can be hard to retract or squeeze the shoulder blades and the shoulders can stay rounded and forward, leading to weakness and postural deficits. The chest muscles are also involved in respiration and need to both stretch and contract as the lungs inflate and deflate.