The shoulder joint is a common site of injury due to its increased mobility.  This makes it unstable and prone to injury, and accounts for 8-13% of all athletic injuries.

Acute traumatic shoulder injuries include separation, dislocation, tears, and fracture.  Chronic shoulder injuries due to repetitive movements are likely from overhead activities (e.g. painting ceilings, electrical work, baseball, swimming) and include impingement and tendinitis.  The resultant shoulder injury or pain can lead to shoulder instability or the opposite problem, adhesive capsulitis (frozen shoulder).

Shoulder pain may be fully or partly a result of the cervical (neck) or upper thoracic (upper back) spine, which may be due to nerve irritation or faulty posture.  One study found that manipulation of the neck and upper back could reduce shoulder pain and disability and improve ranges of motion if 3 of these 5 variables were present:

1. Pain-free forward arm-raising <127˚
2. Shoulder internal rotation <53˚
3. Negative impingement test
4. Not taking any medication for shoulder pain
5. Duration of symptoms <90 days

This clinical prediction rule suggests that the neck and upper back have a role in shoulder problems.  One can see that an increased thoracic kyphosis (rounding of the upper back) can lead to a forward posture of the shoulder blade.  This makes it difficult to raise the arm since only 2/3 of arm elevation comes from the shoulder joint and the other 1/3 must come from the shoulder blade moving on the rib cage.

Therefore, if you have shoulder discomfort, first you should get a proper diagnosis because there are numerous causes of shoulder pain which may also include the neck and upper back.  Then, an appropriate and effective treatment for the specific injury and cause can be implemented.  This may include neck and back manipulation in addition to shoulder rehabilitation exercises.  Just like low back pain can be from upper back and hip restrictions, shoulder problems may be a result of faulty posture and not just your shoulder.

Source:  Mintken PE et al.  Some Factors Predict Successful Short-Term Outcomes in Individuals with Shoulder Pain Receiving Cervicothoracic Manipulation:  A Single-Arm Trial.  Phys Ther. 2010 Jan; 90: 26-42.