Work related shoulder disorders

Work Related Shoulder Disorders

Dr. Sanjay Wadhwa Professor, Dept. of Physical

Medicine and Rehabilitation, AIIMS, New Delhi

• Why talk about it?• What is it?• Who gets it?• When does it occur?• Where does it occur?• How can we manage it?


• Introduction• Definition(s)• Classification(s)• Evaluation• Prevention • Management


• Work-related Musculoskeletal Disorders (WMSDs) are common disorders.

• Economic costs are enormous.• Considered by some as an ‘umbrella’ term.• Also known as

repetitive motion disorders, occupational overuse injuries, repetitive strain injuries etc.


• Account for over 50% of all workers’ compensation claims in USA.

• Upper limb disorders are far more common than lower limb disorders.

• The mainstay of management involves ergonomic interventions.


WHO defines these disorders as multifactorial, with work contributing significantly, though not exclusively, to causing the disease.

The term disorder is more appropriate when some of the outcomes are of uncertain pathogenesis and may consist of symptoms without clinical signs.

The term work related musculoskeletal disorders has come to replace repetitive strain injuries or cumulative trauma disorders.


Work-related musculoskeletal disorders are MSDs that may be caused, aggravated, or precipitated by intense, repeated, or sustained work activities with insufficient recovery; they generally develop over a period of weeks, months, and years.


It follows that MSDs can be partially caused by adverse work conditions, can be exacerbated by work place exposure, and can impair work capacity.


The diagnoses of WMSDs consist of

• Trapezial and parascapular myalgia,• Rotator cuff and bicipital tendinitis,• Impingement syndrome, and • Subacromial and subdeltoid bursitis.


Sustained contractions result in increased intramuscular pressure and decreased blood flow.

Ischemic conditions occur when intramuscular pressure exceeds capillary closing pressure at about 30 mm Hg.

The increased metabolic demands of the working muscle and the relative ischemia caused by increased intramuscular pressure can contribute to derangements in intracellular pH, lactic acid, calcium, potassium balance, PGE2 etc.


High levels of muscle enzymes, including creatine phosphokinase and aldolase.





Different Systems of Grading/ Staging

• Japanese Grading System (Japanese Association of Industrial Health)

• Australian Staging System (Occupational Repetition Strain Advisory Committee in Australia)

• Pathophysiologic Grading System (Luck and Anderson)


Japanese Grading System

• Grade I• Grade II• Grade III• Grade IV• Grade V



• Grade I• Subjective complaints without clinical findings



• Grade II• Subjective complaints with induration and

tenderness of the neck, shoulder, and arm muscles



• Grade III Includes grade II and any of the following:• Increased tenderness or enlargement of

affected muscles• Positive neurologic tests• Paresthesia• Decrease in muscle strength• Tenderness of spinous processes of vertebrae• Tenderness of the paravertebral muscles



• Grade III contd. • Tenderness of the nerve plexus• Tremor of the hand or eyelid• Cinesalgia of the neck, shoulder, and arm• Functional disturbance of the peripheral

circulation• Severe pain or subjective complaints of the

neck, shoulder, or upper extremity



• Grade IV• Type I• Severe type of grade III• Type 2• Direct development from grade II without

passing through grade III, but having specific findings as follows:



• Grade IV Type 2• Orthopaedic diagnosis of the neck-shoulder-

arm syndrome• Organic disturbances such as tendinitis or

tenosynovitis• Autonomic nervous disturbances such as

Raynaud’s phenomenon, passive hyperemia, or disequilibrium

• Mental disturbance such as anxiety, sleeplessness, thinking dysfunction, hysteria, or depression



• Grade V• Disturbance at work and in daily life


Australian Staging System

• Stage I• Stage II• Stage III



• Stage I• Aching and tiredness of the affected limb that

occurs during the work shift but subsides overnight and during days off work.

• There is no significant reduction in work performance, and there are no physical signs.

• This condition can persist for months and is reversible.



• Stage II• Symptoms fail to settle overnight, cause a

sleep disturbance, and are associated with a reduced capacity for repetitive work.

• Physical signs may be present.• The condition usually persists for months.



• Stage III• Symptoms persist at rest.• Sleep is disturbed, and pain occurs with

nonrepetitive movement.• The person is unable to perform light duties

and has difficulty with nonoccupational tasks. • Physical signs are present.• The condition may persist for months to years.


Pathophysiologic Grading System

• Grade I (mild)• Grade II (moderate)• Grade III (severe)



• Grade I (mild)• Shoulder girdle muscle pain that occurs during

work or similar activities and resolves a few hours later

• No findings on physical examination



• Grade II (moderate)• Shoulder girdle muscle pain that persists for

several days after work• Muscle belly and insertional tenderness on

examination



• Grade III (severe)• Shoulder girdle muscle pain that is constant for

weeks or longer• Multiple tender areas• Palpable induration indicating muscle fibrosis• Muscle belly contracture• Reduced range of motion of myogenic origin


Internal stress due to exposure to environmental and organizational risk factors in the workplace:

• Poor lighting• High background noise• Cramped working conditions• Inadequate work breaks• Job dissatisfaction• Excessive productivity demands


• Symptoms are common.• Diagnosis is essentially clinical.• Investigations have some role to play.• Recurrence is common if treatment is not

comprehensive.


Dentists seem to be particularly susceptible to work related shoulder disorder as a result of sustained static loads while maintaining the shoulder in a position of flexion and abduction with elevation of the scapula.


In a Finnish study that included 40 dentists, Katevuo and coworkers found that 46% had radiographic evidence of osteoarthritis and 44% had bilateral disease. In contrast, only 13% in the control group- 82 farmers presumably unexposed to static load- had findings consistent with osteoarthritis.


Other groups:

• Musicians• Healthcare workers• Factory workers• Sheet metal workers• Garment workers• Electricians• Fish industry



• According to the WHO approved ICF model OSDs are structural and functional body impairments.

• A disability occurs when various activities are limited.


Management is best carried out by a multidisciplinary team.

The team includes:

• clinical psychologist, • physical therapist, • occupational therapist, • physical education teacher, • vocational counselor, • physician (physiatrist), and • nurse.


Management includes

• Ice/ Heat• Exercises• NSAIDs• Tricyclic antidepressants• Local interventions (steroids)• Stress management• Ergonomic interventions


Conclusion

• A very big challenge for India• ‘Make in India’• Rehabilitation• Prevention



THANK YOU