MSDs are the single largest category of work-related illness,

1. Work Related Musculoskeletal DisordersPhysical Factors in Work Place and ErgonomicsProf. Dr. Selma KARABEY

2. Work-relatedmusculoskeletaldisorders (WMSDs) are a group of painfuldisorders of muscles, tendons, andnerves. lowbackpain, neckpain carpaltunnelsyndrome, tendonitis, thoracicoutletsyndrome, tensionnecksyndrome,

3. WMSDsareverydifficultto define withintraditionaldiseaseclassifications. Thesedisordershavereceivedmanynames, such as: Repetitivemotioninjuries. Repetitivestraininjuries. Cumulativetraumadisorders. Occupationalcervicobrachialdisorders. Overusesyndrome. Regionalmusculoskeletaldisorders. Softtissuedisorders.

4. MSDs are the single largestcategory of work-related illness, • representing athird or more of all registeredoccupational diseases inthe United States, the Nordic countries, and Japan. • MSDs occur in certain industries and occupationswith rates up to three or four times higher than theoverall frequency.

5. What are the risk factors for WMSDs? • WMSDs arise from arm and hand movements such as bending, straightening, gripping, holding, twisting, clenching and reaching. • These common movements are not particularly harmful in the ordinary activities of daily life. • WMSDs are associated with work patterns that include: Fixed or constrained body positions. Continual repetition of movements. Force concentrated on small parts of the body, such as the hand or wrist. A pace of work that does not allow sufficient recovery between movements.

6. High-risk sectors include • nursingfacilities; • air transportation; • mining; • food processing; • leather tanning; and • heavy and light manufacturing(vehicles, furniture, appliances, electrical and electronicproducts, textiles, apparel and shoes)

7. Upperextremity musculoskeletal disorders are also highlyprevalent in manual-intensive occupations, such as • clerical work, • postal service, • cleaning, • industrial inspection • and packaging.

8. Back and lower limb disorders occur disproportionately among • truck drivers, • Warehouseworkers, • airplane baggage handlers, • Constructiontrades, • nurses, nursing aides and other patient-careworkers, • operators of cranes and other large vehicles

12. Lowbackpain

13. Thebestpredictor of lowbackpain is a history of lowbackpain. • First episodesoccuramongpersons in theagerange20-39 years. • But theproportion of thepopulation is relativelyuniformacrosstheworkingyears. • It is seenmorefrequentlyamongmalesthanfemales in Western countries • But in surveys in the general population, malesandfemalesareaffectedwithequalfrequency.

14. Persons in lower social classes are more likely to report low back pain than those in higher classes, • Probably because of their tendency to have jobs requiring heavy physical labour. • Worldwide at least 37 percent of low back pain has been attributed to occupational factors(Punnett et al.2005) • The prevalence of low back pain is also high in low income areas of the world.

15. In a communitybasedstudyin ruralChina, thepercentagehavinglowbackpainduringthecourse of a yearwas65 percent (Barrero et al. 2006) • Itwas61 percentfortanneryworkersin India (Öry et al. 1997) • 56 percentin steelindustryin South Africa (Van Vuuren et al. 2005) • 36 percentin an urban populationin Turkey (Gilgil et al. 2005)

16. Lifting objects of 25 Ibormore • Lifting of heavyobjectswhilebendingandtwistingthe body • Holding heavyobjectsfromthe body while lifting • Failingtobendthekneeswhile lifting. • Drivingmotor vehicleseither on or of thejob • Exposuretowhole-body vibrationincreasethe risk forthelowbackpain

17. Sitting in combinationwithotherexposuressuch as whole body vibrationandawkwardpostureincreasesthe risk forlowbackpain • Cigarettesmokinghas beenfound in manystudiesto be associatedwithlowbackpain • Psychologicalattributessuch as lowsocialsupport in theworkplaceandlowjobsatisfactionmayincrease risk.

18. Many risk factors in middleandlowincomecountriesaresimilartothosehighincomecountries. • InruralChina, havingbeen a farmer, reportingmoderateorheavyphysicalstressand • Beingexposedtovibrationwereassociatedwithlowbackpain (Barrero et al.2006) • In urban Turkey, cigarettesmokingwasrelatedtotheoccurrence of lowbackpain. (Gilgil et al. 2005)

19. Estimatingthe global burden of lowbackpainattributabletocombinedoccupationalexposures. Punnett L., Prüss-Üstün A., Nelson D.I., et al. AmericanJournal of IndustrialMedicine,2005;48:459-69 Relative risk for low back pain by selected occupational category

20. Neckpain

21. Inhigh-incomecountries, about60-70 percentof adultsreporthavingexperiencedneckpain at same time • Somestudiesreportthatmalesandfemalesareaffectedwithequalfrequencywhereas • Othersshow a femaleexcess. • Chronicneckpainanddisabilityfromneckpainoccurmoreoften in femalesthanmales.

22. Neckpainoccursmostfrequently in youngadulthood, andsomeevidencesuggeststhatitsprevelencedecreaseswithage

23. Risk factorsforeither general neckpainorherniatedcervicaldiscare • Heavy lifting, • Cigarettesmoking, • Driving motor vehicles, • Exposuretowhole body vibration • Psychologicaldistress • Psychosomaticproblems • Headaches

24. WorkRelatedInjuries • WMSDs include three types of injuries: Muscle injury. Tendon injury. Nerve injury.

25. Muscle Injury • When muscles contract, they use chemical energy from sugars and produce by-products such as lactic acid which are removed by the blood. • A muscle contraction that lasts a long time reduces the blood flow. • Consequently, the substances produced by the muscles are not removed fast enough, and they accumulate in the muscles.

26. Muscle Injury-2 • The accumulation of these substances irritates muscles and causes pain. • The severity of the pain depends on the duration of the muscle contractions and the amount of time between activities for the muscles to get rid of those irritating substances

27. Tendon Injury • Tendons consist of numerous bundles of fibres that attach muscles to bones. • Tendon disorders related to repetitive or frequent work activities and awkward postures • Occur in two major categories --tendons with sheaths found mainly in the hand and wrist; and tendons without sheaths, generally found around the shoulder, elbow, and forearm.

28. Tendon Injury-2 • The inner walls of the sheaths contain cells that produce a slippery fluid to lubricate the tendon. • With repetitive or excessive movement of the hand, the lubrication system may malfunction. • It may not produce enough fluid, or it may produce a fluid with poor lubricating qualities. • Failure of the lubricating system creates friction between the tendon and its sheath, causing inflammation and swelling of the tendon area.

29. Tendon Injury-3 • Repeated episodes of inflammation cause fibrous tissue to form. • The fibrous tissue thickens the tendon sheath, and hinders tendon movement. • Inflammation of the tendon sheath is known as tenosynovitis. • When inflamed, a tendon sheath may swell up with lubricating fluid and cause a bump under the skin. • This is referred to as a ganglion cyst.

30. Nerve Injury • Nerves carry signals from the brain to control activities of muscles. • They also carry information about temperature, pain and touch from the body to the brain, and control bodily functions such as sweating and salivation. • Nerves are surrounded by muscles, tendons, and ligaments. • With repetitive motions and awkward postures, the tissues surrounding nerves become swollen, and squeeze or compress nerves .

31. Nerve Injury-2

35. When parts of the body are near the extremes of their range of movements, stretching and compression of tendons and nerves occur. • The longer a fixed or awkward body position is used, the more likely we are to develop WMSDs. • For example, working with the torso bent forward, backward or twisted can place too much stress on the low back.

36. reaching above shoulder level reaching behind the body

37. Rotating the arms Bending the wrist

38. Reaching forward too far out in front of the body

40. How are WMSDs treated? • The treatment of WMSDs involves several approaches including the following: Restriction of movement. Application of heat or cold. Exercise. Medication and surgery.

41. How can we prevent WMSDs? • Hazards are best eliminated at the source; this is a fundamental principle of occupational health and safety. • In the case of WMSDs, the prime source of hazard is the repetitiveness of work. • Other components of work such as the applied force, fixed body positions, and the pace of work are also contributing factors.

42. Human factors and ergonomics (HF&E) • a multidisciplinary field incorporating contributions from psychology, engineering, biomechanics, mechanobiology, industrial design, physiology and anthropometry. • it is the study of designing equipment and devices that fit the human body and its cognitive abilities.

43. Definition of the International Ergonomics Association • Ergonomics (or human factors) is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data and methods to design in order to optimize human well-being and overall system performance. • .

44. Proper ergonomic design is necessary to prevent repetitive strain injuries and other musculoskeletal disorders, which can develop over time and can lead to long-term disability. • Human factors and ergonomics is concerned with the "fit" between the user, equipment and their environments.

45. HF&E is employed to fulfill the goals of occupational health and safety and productivity. • It is relevant in the design of such things as safe furniture and easy-to-use interfaces to machines and equipment.

46. It takes account of the user's capabilities and limitations in seeking to ensure that tasks, functions, information and the environment suit each user. • To assess the fit between a person and the used technology, human factors specialists or ergonomists consider the job (activity) being done and the demands on the user; the equipment used (its size, shape, and how appropriate it is for the task), and the information used (how it is presented, accessed, and changed).

47. Mechanization • One way to eliminate repetitive tasks is to mechanize the job. • Where mechanization is not feasible or appropriate, other alternatives are available. • Job Enlargement and Enrichment • This increases the variety of tasks built into the job. • It breaks the monotony of the job and avoids overloading one part of the body. • Job enrichment involves more autonomy and control for the worker.

48. Job Rotation • It requires workers to move between different tasks, at fixed or irregular periods of time. • But it must be a rotation where workers do something completely different. • Different tasks must engage different muscle groups in order to allow recovery for those already strained.

49. Team Work • Team work can provide greater variety and more evenly distributed muscular work. • The whole team is involved in the planning and allocation of the work. • Each team member carries out a set of operations to complete the whole product, • allowing the worker to alternate between tasks, hence, reducing the risk of WMSDs.

50. Workplace Design • The guiding principle in workplace design is to fit the workplace to the worker. • Evaluation of the workplace can identify the source or sources of WMSD. • Proper design of the workstation decreases the effort required of the worker to maintain a working position. • Ideally, the workstation should be fully adjustable, providing a worker with the options to work in standing, sitting or sitting-standing positions, as well as fitting the worker's body size and shape.