Shoulder joint is one of the most mobile joints of the body that is most vulnerable to develop moderate or severe trauma and damage. Physiologically, our shoulder joint is known as ball and socket joint (the ball-like humeral head is attached to the socket of scapular bone with the help of ligaments, muscles, tendons and other parts of connective tissue that holds the joint capsule together). According to the peer reviewed journal, American Journal Of Orthopedics each year Americans spend almost $7 billion on the management or treatment of acute or chronic shoulder pain or dysfunctional shoulder joint.
Anatomy of shoulder joint and anatomical classification of shoulder joint pain
The causes of shoulder pain may be classified according to the site or source of origin of shoulder pain. Shoulder joint is formed when the humerus of the upper limb articulate with the glenoid cavity of scapula (which in turn is also connected to clavicle or collar bone).
The union of three bones is supported by ligaments, fibrous cords, muscles and tendons or tendon sheaths. In order to promote functional and 3-dimensional motion across upper limb or shoulder joint without causing any injury or discomfort, a rich network of nerves and blood vessels bathe the joint cavity.
Muscular causes: Stress, sprain, tearing or stretching of muscle fibers may also produce characteristic pain and discomfort across shoulder joint.
Articular causes: Fracture, dislocation or damage to bone or joint cavities produces severe excruciating pain, disability and swelling, the cause is mostly traumatic in approximately 70% of the cases.
Extra-articular causes: This include damage, destruction or tearing of tendons, ligaments and associated connective tissue structures that may limit range of motion and produce pain on stretching.
According to the recommendations of American journal of orthopedics, the 3 most common causes of shoulder joint pain are:
- Rotator cuff disorders (that constitute almost 10% of all cases of persistent shoulder pain)
- Adhesive capsulitis constitute 6% of all the cases of chronic shoulder pain
- Glenohumeral OA accounts for about 2% to 5% of all the cases
8 Causes Of Shoulder Pain
According to the report published by Meilisin (1), the most common and notable causes of shoulder pain are classified as:
Inflammation suggests obnoxious tissue response to moderate or severe tissue injury that may have intrinsic or extrinsic origin. The cause of inflammation may be trauma, wear and tear changes in the ligaments or joints, chemicals, foreign body or any other source of irritation. The classic features of tissue inflammation are redness, fever, swelling and limited range of motion. Most common inflammatory conditions that may produce shoulder pain are shoulder bursitis (inflammation of shoulder bursa), tendinitis (inflammation of tendons that pass through or attach at shoulder joint and help in the movement or activity of shoulder joint), adhesive capsulitis (inflammation of primary joint capsule).
- Traumatic injury to shoulder joint
Traumatic injury to shoulder joint is most commonly observed in athletes or sport professionals (especially those who are involved in racquet sports like badminton, table tennis or squash). Other common causes are accidental (in case of falls or road traffic accidents) or assaults.Most common traumatic conditions that may produce shoulder pain include rotator cuff tear (another most common cause of shoulder joint pain and dysfunction due to trauma in most cases) and avascular necrosis of humeral head, fracture or dislocation of shoulder joint and other similar causes.
- Nervous causes
Nervous causes are mostly referred and involve injury or damage to nerves that supply shoulder joint. Most common nervous conditions that may produce shoulder pain include impingement syndrome (also known as nerve entrapment syndrome that involves pressure mediated injury of nerve when it passes through narrow joint cavities. Neoplastic processes and trauma are the most common causes of nerve-related shoulder joint pain.
- Degenerative conditions of shoulder joint
Arthritis refers to inflammation of a joint surface or joint cavity and constitutes a separate variety of shoulder joint diseases or disorders. Arthritis involving shoulder joint may be septic arthritis, glenohumeral osteoarthritis (OA), and other causes of degenerative joint diseases.
- Metabolic conditions of shoulder joints
Certain inherent or acquired metabolic conditions of shoulder joint can also lead to pain, discomfort and limited range of motion of shoulder joint. Chronic medical conditions like osteoporosis, diabetes mellitus and steroid abuse can affect the strength and integrity of bones. As such, this conditions leads to lower bone mineral density, leading to weak or vulnerable bones that are at much higher risk of fractures or/ and dislocations.
- Infectious causes
Shoulder joint is richly supplied with blood vessels and the joint cavity is protected by tendon and muscle sheaths. However, moderate to severe trauma may introduce infectious agents in the joint cavity. Similarly, septicemia (presence of bacterial or fungal agents in the blood) can also lead to septic joint conditions leading to pain, discomfort and infection. If left untreated, infection of joint capsule can lead to abscess formation that may require surgical drainage.
- Neoplastic causes
Neoplasia refers to cancer or malignancy that may produce shoulder pain in some cases. Cancers of lungs and breast are among the most notable ones that may present (or show signs of) moderate shoulder pain due to inflammation (as a result of toxins secreted by cancers), pressure or damage to nerves that supply shoulder joint or other similar reasons.
- Hormonal causes
Excess or deficiency of certain hormones (like thyroid, adrenal hormones, calcitonin and parathyroid hormone) can directly affect the mineralization of bones. Shoulder joint is not among the most commonly affected joints, but serum calcium and phosphate levels should always be assessed periodically in cases where shoulder pain is chronic and unprovoked.
Risks Factors Of Shoulder Pain
Persistent or chronic pain along shoulder joint (that may be associated with other symptoms like stiffness, limited range of motion, inflammation, fever and other features) is usually a trivial symptom that responds very well to rest, relaxation and lifestyle changes. However, in certain cases, the damage may be chronic and permanent that affects the integrity of joint cavities, capsules and ligaments. Here are the most common risk factors that are associated with shoulder pain:
- Advancing age: Physiological aging increases the risk of wear and tear changes since the ligaments and other supportive elements are weaker and vulnerable.
- Highly mobile lifestyle: Individuals who are active in sports are at much higher risk of developing chronic shoulder pain due to stress and pressure. Often times athletes pay more attention to the bulky muscles of the upper limb (or shoulder gurdle) that compromises the integrity or strength of shoulder joint.
- Occupational responsibilities that involve heavy weight lifting like porters, body builders, wrestlers are also at risk of developing chronic shoulder pain as a result of sub-acute injuries.
A number of other factors can also contribute to the pathogenesis of shoulder pain like nutritional discrepancies, immune-mediated damage and other factors.
Treatment Options Of Shoulder Pain
Treatment or management of shoulder pain is dependent on a number of factors and before initiating or devising therapeutic regimens, it is very important to identify the causes of shoulder pain. Here are a few most common strategies to manage shoulder pain:
- Exercise or lifestyle modification
This is the most common, essential and basic approach that is practical in most types of shoulder pain. Exercise is required to strengthen and stabilize shoulder joint as well as other connective tissues elements that support the capsule cavity. Strenuous or unsupervised exercises are contraindicated when shoulder pain is due to fractures, ligamentous strain or tearing of supportive shoulder ligaments. Other modifications that you may introduce in your life are:
- Switch your occupation if the cause of persistent shoulder pain is heavy weight lifting, sports-related activities or any other physical activity that increases the stress or strain on shoulder joint and may interfere with the healing process.
- If you have mild swelling, pain, soreness of muscles (seen mostly in case of acute injury or sprain involving shoulder joint), you can also employ warm and cold compresses to alleviate swelling and pain.
- Therapeutic massage can be performed by therapist or your associates to alleviate pain and swelling. Massage also improves the circulation of blood across inflamed joints and thereby promotes healing.
- Rest is helpful in situations when the pain is caused by over-activity or misuse.
- Physical therapy
Physical therapy is also advised to individuals with moderate to severe pain that affects range of motion and produce characteristic stiffness of shoulder joint. Physical therapy exercises may be active (performed by individuals in the home or office setting under the supervision of physical therapist) or may be passive (performed with the active help and participation of therapist). Research conducted by Bang (9) concluded that manual physical therapy that is performed under the supervision of a therapist is far more superior to unsupervised exercises alone. Physical therapy regimen helps in improving physical strength in patients with frozen shoulder and other ailments like shoulder impingement syndrome.
- Complementary medicine
There are a number of therapies that are considered superior (or comparable) to pharmacological or surgical modalities. A few strategies that may be employed are:
- Acupuncture involve introduction of fine needles at special pressure points to promote the flow of energy. It is one of the ancient methods of managing chronic pain due to degenerative bone disorders.
- Chiropractic therapy involves actual manipulation of dislocated bones or other connective tissue elements. Alternative medicine is associated with least side effects and tremendous benefits.
- Pharmacological options
Depending upon the cause of shoulder pain, different pharmacological options can be employed. In most cases, medications are usually avoided due to poor concentration capacity. However, if pain is severe, intra- articular injections can alleviate symptoms. Common pharmacological options include:
- Non-steroidal anti- inflammatory drugs (NSAIDs) are utilized in acute cases to reduce swelling. Chronic intake should be avoided due to risk of stomach bleeding and development of gastric ulcers. NSAIDs are excellent remedies for all inflammatory conditions like bursitis, capsulitis, arthritis and tendinitis.
- Opoid analgesics are prescription drugs that are advised when pain is most severe (for example if the cause of shoulder pain is a fracture).
- Cortisone injections are mostly employed as the last resort when shoulder pain does not respond to oral analgesics.
- Surgical options
Surgical options are mostly employed in complicated or complex fractures, mal-alignment or undesired healing process. Surgical procedures are quick to show response but the recovery procedure is highly variable and lengthy. In addition, the risk of infection is fairly high in case of surgeries involving shoulder joint that may lead to complete deterioration of upper limb functions. In order to decrease the total tissue damage, many advanced techniques are also being developed (like ultra-sounded operations and laser therapies as discussed by Bingol (6) in his report.
Shoulder pain is a common ailment that significantly compromise basic and daily functions of an individual starting from eating, bathing and basic functional or occupational work. If inciting source of injury is not removed, the resulting damage may be permanent, requiring surgical procedures.
According to the data shared in the report of Urwin (3) approximately 1% of the entire US population seeks medical help for the management of chronic shoulder pain each year and it is considered as the third most common cause of musculoskeletal issues. If your shoulder pain is refractory to ordinary methods of treatment, do not hesitate to see a registered healthcare professional. It is important to understand the root causes of shoulder pain before you seek advice for permanent pain relief.
1. Meislin, R. J., Sperling, J. W., & Stitik, T. P. (2005). Persistent shoulder pain: epidemiology, pathophysiology, and diagnosis. American journal of orthopedics (Belle Mead, NJ), 34(12 Suppl), 5-9.
2. Mitchell, C., Adebajo, A., Hay, E., & Carr, A. (2005). Shoulder pain: diagnosis and management in primary care. BMJ: British Medical Journal, 331(7525), 1124.
3. Urwin M, Symmons D, Allison T, Brammah T, Busby H, Roxby M, Simmons A, Williams G Ann Rheum Dis. 1998 Nov; 57(11):649-55.
4. Mitchell, C., Adebajo, A., Hay, E., & Carr, A. (2005). Shoulder pain: diagnosis and management in primary care. BMJ: British Medical Journal, 331(7525), 1124.
5. Ginn, K. A., Herbert, R. D., Khouw, W., & Lee, R. (1997). A randomized, controlled clinical trial of a treatment for shoulder pain. Physical Therapy, 77(8), 802-809.
6. Bingöl, Ü., Altan, L., & Yurtkuran, M. (2005). Low-power laser treatment for shoulder pain. Photomedicine and Laser Therapy, 23(5), 459-464.
7. Ginn, K. A., & Cohen, M. L. (2004). Conservative treatment for shoulder pain: prognostic indicators of outcome. Archives of physical medicine and rehabilitation, 85(8), 1231-1235.
8. Schulte, K. R., & Warner, J. J. (1995). Uncommon causes of shoulder pain in the athlete. The Orthopedic clinics of North America, 26(3).
9. Bang, M. D., & Deyle, G. D. (2000). Comparison of supervised exercise with and without manual physical therapy for patients with shoulder impingement syndrome. The Journal of orthopaedic and sports physical therapy, 30(3), 126-137.