By Allison Chambers, PT, DPT, OCS
Physical Therapist
Central Indiana

Over 66% of the general population will experience shoulder pain during their lifetime — and that risk increases with age. Rotator cuff pain is one of the most common causes of shoulder pain. Over 20% of the general population has been found to have a full-thickness rotator cuff tear, with risk factors of age, history of trauma, and dominant arm contributing. Both physical and occupational therapists are able to provide value to patients managing shoulder pain and help improve their quality of life.

The Anatomy of the Shoulder

The shoulder complex is not just one joint, but a group of joints that contribute to a common goal of moving the arm. The shoulder is made up of the glenohumeral, acromioclavicular, sternoclavicular, and scapulothoracic joints, which cover a large area of the upper quarter.

There are many muscles involved to allow these joints to function properly, including 17 muscles that attach to the scapula which functions as the “foundation” of the shoulder girdle. A stable scapula helps the rotator cuff hold the head of the humerus in the center of the glenoid as the arm elevates.

Where Do You Start with Your Shoulder Treatment Evaluation?

Evaluation of the shoulder complex should include a thorough subjective history and physical assessment. Make sure to include a few important items in the patient’s history:

• Mechanism of injury
• Hand dominance
• Location of pain
• functional limitations and impact on performance

Though uncommon, systemic referral should be ruled out. Multiple organs including the liver, stomach, pancreas, gallbladder, lungs, and heart can refer to the shoulders. Additional questioning is warranted if shoulder pain appears non-mechanical and a proper referral is made.

Common Origins of Shoulder Pain and How to Properly Diagnose

In patients over the age of 45, the three most common diagnoses of shoulder pain in order of frequency are:

• A full-thickness rotator cuff tear
• Degenerative joint disease (osteoarthritis)
• Frozen shoulder (adhesive capsulitis)

Physical assessment to determine the most proper diagnosis can help in determining your plan of care. Here are a few key points to consider for differential diagnosis of shoulder pain.

Rotator Cuff Tear

Pain and/or weakness in external (more common) or internal rotation strength. Use clinical prediction rule of 3 special tests to help with confirming diagnosis:

• Positive drop arm sign. Passively abduct the arm to 90 degrees and ask the patient to hold; inability to hold is a positive test.
• Painful arc sign. Pain between approximately 60-120 degrees of active shoulder abduction.
• Positive infraspinatus test. Pain and/or weakness with resisted external rotation.

When two out of these three are present, there is a 69% probability of a tear. And if all three are present that probability increases to 91%.

Degenerative Joint Disease

Gross mobility restrictions, likely both active and passive.

• Crepitus (audible and/or palpable).
• Should have sufficient and pain-free strength of rotator cuff, unless there is a secondary rotator cuff disorder.

Frozen Shoulder

• Mobility restrictions and pain in all planes of motion, both active and passive.
• More common in women over the age of 40 with a history of thyroid dysfunction and diabetes.
• Can be primary (no known cause) or secondary (to a fall or other injury).

Due to the shoulder’s proximity to the spine, both the cervical and thoracic spine should be screened during your evaluation. Assess cervical range of motion, as this is a common point of referral for shoulder and arm pain. Thoracic extension contributes to end-range shoulder flexion by as much as 10 degrees, therefore restrictions in thoracic mobility and posture should also be assessed.

How Structures Around the Shoulder Can Contribute to Shoulder Dysfunction

Anterior translation of the humerus on the glenoid is often present. This can result from a vast array of deficits including rounded/forward shoulders and tight pec muscles, decreased scapular strength/endurance, weakness in the rotator cuff muscles, forward head posture, decreased anterior cervical strength/stability, and decreased thoracic mobility and postural changes/kyphosis.

Establishing a Successful Treatment Plan for Shoulder Pain

Treatment must ultimately depend upon the diagnosis and functional presentation of your patient and the following information may help guide your decision-making. If you find significant limitations in PROM/AROM, working on shoulder mobility is a good place to start. Gentle passive shoulder ROM in areas of stiffness, which may include flexion, scaption, and internal and external rotation, will improve joint integrity and can be helpful with pain management.

Using AAROM for a home exercise program will allow the patient to progress more independently. This can include exercises such as pulleys, supine flexion or external rotation with a cane, and table slides. Start in anti-gravity or gravity-eliminated positions, and progress to more upright postures until the patient is standing. With patients that have high irritability, consider using pendulums, PROM, gentle joint mobilization, soft tissue massage, and isometrics as a starting point. Using heat prior to treatment may improve tolerance to mobility exercises, especially with a frozen shoulder.  Always use your clinical judgment and base all decision-making on your specific patient’s evaluation to determine which interventions would be appropriate.

As the patient progresses with less pain and increased mobility, establishing a solid strength program is crucial. Begin by addressing any postural deficits, as the shoulder needs to have a stable foundation for successful motion. This may involve correcting the patient out of a swaying posture in standing or modifying their position to more upright sitting in their wheelchair (using props if needed). Addressing scapular strength should help improve shoulder mechanics and posture, and allow optimal function of the rotator cuff.

As always, be creative and be sure to include functional exercises and meaningful goals in your plan of care.  It is important to maintain an open line of communication with the referral source and consider any recommendations for follow-up with specialists to obtain specific orders/protocols.