Kayvan Karamifar, M.DOccupational Medicine Specialist

The Most Important Disorders• Shoulder:

• Rotator cuff tendinitis• Bicipital tendinitis

• Elbow:– Lateral Epicondylitis– Medial Epicondylitis– Olecranon Bursitis– Cubital Tunnel Syndrome

• Forearm:– Pronator Teres Syndrome– Anterior interosseous syndrome– Posterior interosseous syndrome– Intersection syndrome

• Wrist:– Carpal tunnel syndrome– DeQuervain disease– Ganglion cyst– Trigger wrist

• Hand:– Guyon`s canal syndrome– Hypothenar hammer

syndrome– Trigger finger– Trigger thumb– Occupational hand cramp

Occupational Physical Stressors (Job Risk Factors)RepetitionForceAwkward postureContact stressVibration

High-risk JobsSome examples:

Auto assemblers Butchers VDT users Drivers Packinghouse workers Seamstresses Musicians Clerical workers Textile workers Miners Dentists

Diagnosis RequirementsDefinite clinical diagnosis

History Specific physical examination Motor, sensation, reflexes, ….

Ergonomic stressors Taking occupational history Job visit and ergonomic analysis Video recording

Off-the-job exposurePrevious trauma

Treatment MethodsConservative therapy

Specific splint useMedical therapy

Drug therapyCorticosteroid injection

Physical therapyHome exerciseOccupational therapySurgery

Work AccommodationsEngineering control

Ergonomic design modificationUse tools with proper ergonomic design

Administrative Reduce working hoursAppropriate work-rest period

Job rotationSafe work practiceTemporary job transfer to low-risk jobRe-training

Lateral Epicondylitis

Lateral Epicondylitis ( Tennis Elbow)Inflammation, or

enthesitis, at the muscular origin of the extensor carpi radialis brevis (ECRB).

the most common overuse injury of the elbow

up to 10 times more frequently than medial epicondylitis

most often occurs between the third and fifth decades of life.

Ergonomic StressorsFrequent liftingRepetitive contraction

of the wrist extensors (repetitive wrist dorsiflexion with force)

Sustained power gripping.

Repetitive forearm supination

Sudden elbow extension

Tool use, shaking hand, twisting movement

Common Jobs Involved

Clinical Presentationslateral elbow pain of

gradual onset. pain generally

increases with activityPicking up a cup of

coffee or a gallon of milkHeavy liftingGripping

Pain may be present at night.

Symptoms are typically unilateral.

Area of Pain

Physical Examination

localized tenderness to palpation just distal and anterior to the lateral epicondyle.

The combination of lateral epicondylar pain on palpation plus pain on resisted wrist extension is highly suggestive of the diagnosis of lateral epicondylitis. As this maneuver is performed, the

Presumptive Diagnosis Requires:Local tenderness directly over the lateral

epicondylePain aggravated by resisted wrist extension

and radial deviationPain aggravated by strong gripping Normal elbow range of motion

Paraclinical TestingNo specific test is required

Differential DiagnosisCervical radiculopathy ( C6-C7)Radial tunnel syndromeSynovitis of the radiohumeral jointPosterior interosseous nerve palsyNeuralgic amyotrophy Cervical myofacial pain

Splints for Tennis Elbow

Carpal Tunnel Syndrome (CTS)• Most common entrapment neuropathy• Cause: median nerve injury in carpal tunnel• RF: repetition, force, awkward postures (wrist flexion,

extension, ulnar deviation)• Jobs: seamstresses, packinghouse workers, electronic

assemblers, furniture assemblers, clerical workers, VDT users, typists, …

CTS (cont.)• Non-occupational risk factors: female sex, obesity, small

carpal tunnel• Non-occupational causes: diabetes, RA, Thyroid

dysfunction, amyloidosis, wrist OA, edema, acute trauma, …

CTS (cont.)Carpal tunnel:

Limits: wrist bones, transverse carpal ligament Traversing elements:

Digital flexor tendons Flexor policis longus Median nerve

a

MEDIANNERVE

CARPALLIGAMENT

TENDONSBONES

CTS (cont.)Signs and symptoms

Early: paresthesia, hypersthesia, hyposthesia (intermittent and in dominant hand)

Then: pain, numbness, clumsiness Late: progressive pain and numbness, weakness and

atrophy, loss of sweatingDD: TOS, C7 radiculaopathy, general neuropathy

CTS (cont.)Diagnostic methods:

Provocative tests Tinel Phalen

Electrophysiologic tests (gold standard) Screening for diabetes, Thyroid dysfunction, and RA

CTS (cont.)Therapy:

Non-surgical: Indications: intermittent or mild symptoms, no atrophy,

contraindication for surgery Methods: night splint, NSAIDs, work limitations Causes of inappropriate response: age>50, symptoms>10m.,

persistent paresthesia, positive phalen test in less than 30s.

CTS (cont.)Surgical therapy:

Indications: inappropriate response to non-surgical therapy, severe and prolonged symptoms, muscular weakness or atrophy, positive electrophysilogic tests

Post-surgery problems: persistent symptoms, recurrence, median nerve injury, neuroma formation, adhesions, …

Ergonomic ModificationsDepends on ergonomic stressor:

VDT User: adjust workstation, ergonomic mouse, wrist pad, modify contact stress, work-rest period, ergonomic keyboard, work exercises

Hand tool user: electrical hand tools, work-rest period, work exercises, ergonomic hand tools

Electrical Screwdriver

Wrist Awkward Posture

Ergonomic Mouse pad

Compression = soft tissue is compressed between the bone and a hard or sharp object

Before: Worker rests his wrists on the sharp tray edges. His wrist is extended into a non-neutral posture.

Ergonomic Improvement: Worker rests her wrists and forearms on a padded surface. Wrist and forearms are in a neutral position.