Work-related Upper Extremity Musculoskeletal Diseases

1. Work-related Upper Extremity Musculoskeletal Diseases Kayvan Karamifar, M.D Occupational Medicine Specialist

2. The Most Important Disorders • Shoulder: • Rotator cuff tendinitis • Bicipital tendinitis • Elbow: • Lateral Epicondylitis • Medial Epicondylitis • Olecranon Bursitis • Cubital Tunnel Syndrome • Forearm: • PronatorTeres 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

4. Occupational Physical Stressors (Job Risk Factors) • Repetition • Force • Awkward posture • Contact stress • Vibration

5. High-risk Jobs • Some examples: • Auto assemblers • Butchers • VDT users • Drivers • Packinghouse workers • Seamstresses • Musicians • Clerical workers • Textile workers • Miners • Dentists

7. Diagnosis Requirements • Definite clinical diagnosis • History • Specific physical examination • Motor, sensation, reflexes, …. • Ergonomic stressors • Taking occupational history • Job visit and ergonomic analysis • Video recording • Off-the-job exposure • Previous trauma

8. Treatment Methods • Conservative therapy • Specific splint use • Medical therapy • Drug therapy • Corticosteroid injection • Physical therapy • Home exercise • Occupational therapy • Surgery

9. Work Accommodations • Engineering control • Ergonomic design modification • Use tools with proper ergonomic design • Administrative • Reduce working hours • Appropriate work-rest period • Job rotation • Safe work practice • Temporary job transfer to low-risk job • Re-training

11. Lateral Epicondylitis

12. 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. Lateral Epicondylitis ( Tennis Elbow)

14. Frequent lifting Repetitive 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 Ergonomic Stressors

15. Common Jobs Involved

16. Clinical Presentations • lateral elbow pain of gradual onset. • pain generally increases with activity • Picking up a cup of coffee or a gallon of milk • Heavy lifting • Gripping • Pain may be present at night. • Symptoms are typically unilateral.

17. Area of Pain

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

20. Presumptive Diagnosis Requires: • Local tenderness directly over the lateral epicondyle • Pain aggravated by resisted wrist extension and radial deviation • Pain aggravated by strong gripping • Normal elbow range of motion

21. Paraclinical Testing • No specific test is required

22. Differential Diagnosis • Cervical radiculopathy ( C6-C7) • Radial tunnel syndrome • Synovitis of the radiohumeral joint • Posterior interosseous nerve palsy • Neuralgic amyotrophy • Cervical myofacial pain

25. Lateral Epicondylitis Injection

26. Splints for Tennis Elbow

28. 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, …

29. 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, …

30. CTS (cont.) • Carpal tunnel: • Limits: wrist bones, transverse carpal ligament • Traversing elements: • Digital flexor tendons • Flexor policis longus • Median nerve

31. 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 sweating • DD: TOS, C7 radiculaopathy, general neuropathy

32. CTS (cont.) • Diagnostic methods: • Provocative tests • Tinel • Phalen • Electrophysiologic tests (gold standard) • Screening for diabetes, Thyroid dysfunction, and RA

34. 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.

38. 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, …

39. Ergonomic Modifications • Depends 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

46. Electrical Screwdriver

49. Wrist Awkward Posture

50. Ergonomic Mouse pad