Musculoskeletal disorders


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Musculoskeletal disorders

  1. 1. ErgonomicsWRULD and musculoskeletal disorders Loisa Sessman, Halmstad University
  2. 2. Health and safety Accidents  Unsafe behavior  Unsafe systems Everyday accidents  Slipping, tripping & falling  Machinery – safety distance Ergonomic injuries  Lifting and handling injuries  Work-related upper limb disorders  Musculoskeletal pain resulting from unsatisfactory working posture Loisa Sessman, Halmstad University
  3. 3. Ergonomic injuries Mismatch  Over-use injury  “Creep” effect (fatigue)  Mechanical strength  Co-ordination  Range of motion Foreseeable, injuries can be predicted! Back pain  Occupational  Personal risk factors Loisa Sessman, Halmstad University
  4. 4. Lifting and handling Lift close to the body  Reduce the lever arm  Control Symmetric  Avoid asymmetric lifting  Foot placement Weight limits  Different limits for different countries  Sweden, 7 kg = ok, 7-25 kg = risky 25 kg = very high risk Loisa Sessman, Halmstad University
  5. 5. Work-related upper limb disorders WRULD  Umbrella term for CTD and RSI Repetitive strain injury (RSI) Cumulative trauma disorders CTD Mainly affects:  Industrial assembly workers  Workers at supermarket checkouts  Musicians  Keyboard users Loisa Sessman, Halmstad University
  6. 6. RSI & CTD Often occurs in the upper limb Injuries in nerves, muscles, ligaments, tendons and joints etc Causes pain Related to work intensity and duration Weeks, months or years Diffuse symptoms Often unreported Several reasons (work and/or leisure time) Loisa Sessman, Halmstad University
  7. 7. RSI & CTD CTD & RSI increases  Increased awareness and reporting  Increased specialization  Computer work  Mental stress Posture Force Repetition Loisa Sessman, Halmstad University
  8. 8. Postures Extreme flexion and extension, ulnar and radial deviation of the hand  Carpal Tunnel Syndrome  Tenosynovitis Extreme flexion of the elbow  Cubital Tunnel Syndrome Extreme rotation of the forearm  Epicondylitis Work above shoulder level  Thoracic Outlet Syndrome Loisa Sessman, Halmstad University
  9. 9. Carpal Tunnel Syndrome Results from high repetitive work in extreme positions, often in combinations with force Median nerve get squeezed Numbness, tingling pain and clumsiness Loisa Sessman, Halmstad University
  10. 10. Tenosynovitis Tendon sheath swells Occurs at wrists and ankles where tendons cross ligaments Pain, burning sensation and swelling Loisa Sessman, Halmstad University
  11. 11. Cubital Tunnel Syndrome Compression of the ulnar nerve in the elbow Tingling and numbness occurs at the little finger and the ulnar side of the ring finger Causes when resting the elbow on a hard surface or sharp edge Loisa Sessman, Halmstad University
  12. 12. Epicondylitis Lateral epicondylitis – De Quervains disease (tennis elbow) Lateral epicondylitis  Injuries and pain resulting from work with computer mouse  Causes of high repetitive finger Medial movements in combination with epicondylitis static work Tendon  The symptoms: pain in the forearm Muscle and weakness in the hand and wrist Medial epicondylitis – golfer’s arm  Similar to tennis elbow  Affects the medial epicondyle of the humerus Loisa Sessman, Halmstad University
  13. 13. Tendonitis or tendinitis Inflammation of a tendon  Pain, swelling, burning sensation Tendonitis or bursitis at the rotator cuff  Unnatural static positions  Heavy work  External load  Repetitive arm movements  Work above shoulder height Loisa Sessman, Halmstad University
  14. 14. Thoracic outlet syndrome Compression of three nerves of the arm and blood vessels  Numbness  Difficult to move the arm Loisa Sessman, Halmstad University
  15. 15. Contact stress Mechanical stress (contact stress) on nerves and tendons  Handhold objects with sharp edges and hard objects  Vibrating tools - Raynauds syndrom (white fingers) Reducing contact stress  Change posture  Use gloves  Use design-friendly tools  Use grip surfaces that are smooth, non conductive of cold or heat and anti-slip Loisa Sessman, Halmstad University
  16. 16. Repetition High repetitive work require more muscle effort  The muscles need more time to recover Vary postures can reduce repetitive movements Loisa Sessman, Halmstad University
  17. 17. Other causes Temperature  Cold • Blood circulation • Time for recovery  Heat • Sweat – slip Vibration  Blood circulation  Require greater grip force  Try to isolate the vibrations! Loisa Sessman, Halmstad University
  18. 18. ConclusionThere are several musculoskeletal disorders caused by extreme postures, forces, high repetitive work. Also hand-tools and environmenment can cause injuries. Loisa Sessman, Halmstad University