The various shoulder problems seen by doctors of Chiropractic can be due to one or more of the manifestations of rotator cuff dysfunction. This is generally a biomechanical continuum which begins with dysfunction of the rotator cuff muscles and may progress to rotator cuff syndrome, supraspinatus tendinitis, impingement syndrome, subdeltoid and subacromial bursitis, calcific shoulder bursitis, and even cases of frozen shoulder and bicipital tendinitis. In most cases, there is no direct, acute injury.
Because it is a very mobile joint with little stability in certain positions, the soft tissues of the shoulder region can be injured during athletic and recreational activities, at work, or in a fall. Every acute sprain and strain injury to the shoulder needs an accurate evaluation, treatment and rehabilitation, if future problems are to be avoided. Chronic instability is a real possibility after an injury, since the surrounding muscles and connective tissues are the true source of shoulder joint stability.
The shoulder is made up of several joints that must function together smoothly to provide the extreme mobility which is possible, and is necessary for many activities. The shoulder joint complex includes the sternoclavicular joint, the acromioclavicular joint, the glenohumeral joint, and the scapulothoracic articulation (a pseudojoint). The upper thoracic spine should also be considered a major contributor to shoulder motion, especially during overhead reaching (when reach is extended as the spine tilts away from the shoulder), and during throwing.  The connective and muscular tissues that support and move these joints will need to be assessed, so that support can be provided for the healing of any injured tissues. Eventually, rehabilitation of all injured tissues will be necessary, in order to regain full function.
There are many connective tissues in these joints which can be injured, resulting in a shoulder sprain. The sternoclavicular joint is the only point at which the shoulder girdle is firmly attached to the axial skeleton. The ligaments involved there are the sternoclavicular and costoclavicular. The acromioclavicular (AC) joint is held in place by the coracoclavicular and acromioclavicular ligaments. A thick capsule composed of several ligaments secures the humerus into the labrum of the glenohumeral joint. The scapulothoracic “joint” has muscular connections only; there are no ligamentous attachments.
Any of the numerous muscles and tendons that contribute to the movement and coordinated stability of these joints can become strained in a shoulder injury. The main muscles associated with the shoulder include: the trapezius, latissimus dorsi, pectoralis major, deltoid, rotator cuff (SITS muscles), serratus anterior, and the biceps and triceps muscles. Manual testing can often quickly identify which of these muscles are weakened and painful upon contraction after an injury.
Mechanics of Shoulder Injury
While injuries can be quite individual and complex, several common shoulder injury patterns have been identified: 
- Blow to the anterior shoulder – can cause ligamentous tears resulting in dislocation.
- Fall onto top of shoulder – may cause a ligamentous tear resulting in AC joint separation.
- Fall on an outstretched arm – can result in AC separation, posterior dislocation, labrum or rotator cuff tear.
- Arm forced into external rotation and abduction – anterior dislocation and/or labrum tear.
- Sudden traction to the arm – momentary subluxation or brachial plexus traction injury.
- Sudden pain during activity or lifting – consider rupture of muscle/tendon or labrum tear.
- Rehabilitation of Shoulder Sprain Injuries
Significant damage to one or more of the connective tissues of the shoulder can result in joint instability and chronic dislocations. Treatment of Grade 3 or moderate-to-severe Grade 2 sprains will include some external support (sling or taping) and restricted activities. Once the ligaments have undergone sufficient early repair, controlled passive motion to include PNF routines can help to prevent the formation of adhesions (scarring in areas of movement). Resistance exercises are introduced to stimulate a stronger repair and to assist in the remodeling process. Isometric patterns are progressed to various forms of resistance exercise, based on the patient’s tolerance for joint motion. For athletes, regaining full stability may require advanced forms of exercise in the functional phase of rehabilitation, such as proprioceptive training and plyometrics. These maneuvers help to re-coordinate the sensory receptors and motor controls at the spinal cord (non-thinking) levels. 
Rehabilitation of Shoulder Strain Injuries
Injured muscles and tendons of the shoulder girdle may need a brief period of support and restricted activity, but controlled re-strengthening should be initiated early. Elastic tubing is a safe and effective method of providing progressive resistance exercises.  A very easy and effective program starts with a consistent exercise routine using surgical tubing equipment in the basic forward-back-in-out directions (flexion, extension, abduction, adduction) making certain speed is pain free. This is initially performed within a limited, pain-free range of motion, building to full range as pain subsides. As tolerated, additional shoulder exercises should be performed as indicated, including internal / external rotation, horizontal abduction / adduction and the various complex PNF patterns. This inexpensive rehabilitative program should initially be practiced under supervision to ensure proper performance.
Once good exercise mechanics and control are demonstrated, a self-directed program of home exercises is appropriate. As with sprain injuries, shoulder strains in athletes may require more specific, sports-performance exercises, such as eccentrics and plyometrics. Specific sports skills (such as throwing) may also need to be retrained.
A factor that is too frequently overlooked is the influence of posture on shoulder girdle function. Reports by Hertling and Kessler  and Hammer  support the need to evaluate the patient for specific postural distortions, such as thoracic kyphosis and cervical anterior translation (causing a “forward head”). An additional complicating postural factor can be the alignment of the scapula on the thoracic cage – when the shoulder is “rolled forward” (protracted). Correction of these chronic alignment faults will significantly reduce the biomechanical stress on muscular support for the shoulder.
Outcomes assessment is the collection and recording of information relative to health processe, whereas, outcomes management uses outcome information in a way that enhances patient care. With the dawning, of the “era of accountability,” there are new social mandates directed toward health care providers and health-related facilities. Measurements of quality, satisfaction, efficacy, and effectiveness now serve as essential elements for health care decisions and matters of health policy. The two common outcome assessments in regards to shoulder management available to chiropractors include:
Shoulder Injury Self-Assessment of Function Questionnaire
This is a 15 item ADL tool from American Shoulder and Elbow . The patient fills out the questionnaire. A score of 0 is considered normal whereas scores approaching 60 represent disability.
Shoulder pain and Disability Index (SPADI)
This is a 13 point questionnaire measuring pain and disability. The Scale has been
shown responsive to improved and worsened change over time and treatment.
Both of these questionnaires require permission from the copyright owners to utilize which has been obtained and available. (See OutcomesAssessment.org).
An appropriate and progressive active rehab program should be started early in the treatment of patients with shoulder sprain and strain injuries, generally after ligaments and connective tissues have repaired sufficiently. Simple, yet effective rehab techniques are available, none of which require expensive equipment or great time commitments. A closely monitored home exercise program using exercise tubing is recommended, since this allows the doctor of Chiropractic to provide cost-efficient, yet very effective and specific rehabilitative care. Outcome assessment monitoring is a simple way to document curative progress and treatment during recovery.
The most important aspect is to recognize and address the biomechanical alignment problems and postural factors that are frequently associated with shoulder injuries. This entails screening the patient for forward head and flexed (kyphotic) torso postures. In addition, protracted (forward) shoulders change the angle of the scapula and compress the rotator cuff further. Failure to recognize these complicating factors will result in a patient with recurring shoulder complaints. When the shoulder girdle is properly aligned on the torso, the complex mechanism of the shoulder will be more likely to function optimally.
1. Nordin M, Frankel VH. Basic Biomechanics of the Musculoskeletal System, 2nd. ed. Philadelphia: Lea & Febiger; 1989. 235.
2. Souza TA. Differential Diagnosis for the Chiropractor. Gaithersburg: Aspen Pubs; 1997. 145.
3. Kibler WB, et al. Functional Rehabilitation of Sports and Musculoskeletal Injuries. Gaithersburg: Aspen Pubs; 1998. 157.
4. Roy S, Irvin R. Sports Medicine: Prevention, Evaluation, Management, and Rehabilitation. Englewood Cliffs: Prentice-Hall; 1983. 195.
5. Hertling D, Kessler RM. Management of Common Musculoskeletal Disorders, 2nd. ed. Philadelphia: JB Lippincott; 1990. 177.
6. Hammer WI. Functional Soft Tissue Examination and Treatment by Manual Methods. Gaithersburg: Aspen Pubs; 1991. 31.