Shoulder pain is the 2nd most common orthopedic reason patients seek out medical care behind low back pain. Shoulder pain has many causes including lack of mobility, shoulder blade and rotator cuff weakness, but posture is often criticized as a risk factor for shoulder pain. Clinicians and patients believe a poor posture places structures such as the rotator cuff at risk for injury or the posture changes the function of muscles in the upper body. In our practice, we often find stiffness or a lack of mobility in the middle back (thoracic spine) either precipitates or perpetuates a patient's shoulder symptoms. Poor mobility in the thoracic spine requires more of the neck and shoulder during a given functional movement.
A recent review article searched the available evidence to determine posture's role on shoulder pain and function. Barrett and colleagues examined 10 studies to determine if posture influences shoulder range of motion or the development of shoulder pain (Man Ther. 2016). They found moderate evidence showing no difference in thoracic posture between those with and without shoulder pain. Conversely, the did find strong support that better posture allows for greater shoulder range of motion compared to a slumped posture. Their final conclusion stated no significant contribution of thoracic posture on the development of future shoulder pain, but further research is needed.