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1. CUMULATIVE TRAUMATIC DISORDER’S MRUNAL KULKARNI PG-2

2. OBJECTIVES: Definition Risk factors Occupational Personal

3. Definition: A cumulative trauma disorder, excessive wear and tear on tendons ,muscles and sensitive nerve tissue caused by continuous use over an extended period of time.

4. Cumulative Trauma Disorders mostly observed in the industrial environment include :- Carpal Tunnel Syndrome:-Continuous repetitive motions and fluid retention causing median nerve compression . Tendinitis:-Inflammation of the tendon e.g.:- bicipital tendinitis, supraspinatus tendinitis . Bursitis:-Inflammation of the bursa(small fluid filled sacs) eg.knee bursitis, hip bursitis Raynaud's syndrome-A condition in which some areas of the body feel numb and cool due to reduced blood supply to the particular areas.

5. Risk factors of CTD Work does not have to be harmful if the limits of the human body are understood and not exceeded Example : You will not take your family car and roar down a country road banging through pot holes and screeching around corners. The mechanical stress would cause fatigue in parts of your car that would eventually cause serious damage

6. Just like cars, people have certain limits • If we work outside those limits we will cause fatigue in body parts , shortening their functional life • If we exceed the capacity of the body, the components will fatigue, become unreliable and eventually fail

7. Risk factors usually have their harmful effects on the operator in some combination Example: when we talk about a stressful posture, we imply that this posture is potentially harmful when it is used repeatedly (Risk factor = REPETTITIVENESS), normally in association with muscular exertion (risk factor = FORCEFULNESS

8. Risk factors of concerned usually have their harmful effects through prolonged exposure . The injuries are mainly cumulative. • That means that they develop over a period of time , usually months or even years ‘ chronic vs acute ’

9. Six general occupational risk factors: • Repetitiveness - Repeated or sustained exertions • Forceful Exertions - Also called forcefulness • Stressful Postures - Also called awkward postures • Mechanical Stress - Also called mechanical stress concentration • Temperature Extremes - The effect of heat and cold • Vibration - Both high and low frequencies Gender Previous Injuries Disease Physical stature

10. REPETITIVENESS If you think of what is involved in many jobs you will realize that they often require the worker to constantly repeat certain sequences of movements or to maintain certain stressful postures for prolonged period of time .

11. Such movements or postures, which are normally harmless when used once in a while or briefly, may cause injury when they are used repeatedly on daily basis • Example: if we lightly squeeze a soft drink can with our hands. Initially the sides of the can crinkle, but it regain shape. – The force we applied was not strong enough to immediately destroy the can. However, if we repeatedly apply this same pressure say 15 to 20 times , the can will develop fatigue and tear apart

12. The result of repetitive force Hassle – Pain – INJURY • It is the same with the human body, but instead of 15 or 20 times , the frequency is measured in hundred and thousands of repetitions . • The repeated application of force that is not strong enough to cause immediate damage, but over time it will fatigue in the tissues . • This usually means that this job soon become a hassle.

13. • After a period of time, there will be pain as the tissues involved (the skin, muscles, tendons, joint, ligaments, nerves, and blood vessels ) are repeatedly rubbed, compressed and stretched from movement and exertion. • If these tissues are not allowed to recover, the cumulative damage will result in serious injury .

14. • Unfortunately there are no precise guidelines for the rate of repeated or sustained exertions that would cause injury • The degree of stress and the resulting risk of injury depends on the kind of muscular movements involved and on the presence of other risk factors such as forcefulness and postures used.

15. FORCEFUL EXERTIONS (FORCEFULNESS) • When you contract your muscles, you exert force in order to move your limbs, lift of hold an object, operate a tool, or maintain a posture. • As your muscles contract and relax, the tendons are stretched . They may rub or press on adjacent tissues. The degree of musculoskeletal strain depends on how much force you exert.

16. FORCE = amount of work which the muscles, tendons, joints and adjacent tissues must do in order to perform the particular action . • The force exerted depends on a variety of factors, including posture , weight, friction and recovery time.

17. Importance of force and posture You can perform work more efficiently with some postures than others • In certain posture you have to exert more force to perform the same job. • Example; pinch grip requires more force than a hook grip. • To demonstrate yourself, compare what it feels like to pick up and hold a heavy book by the binding in two ways

18. Between your thumb and the pads of your fingers, with your hand above the book Hooking your fingers under the book and holding it against your forearm Which is easier?

19. Other factors to consider • The weight of load that has to be moved or manipulated is very important. • All things being equal, a heavier load requires a greater exertion , that is, more force to manipulate it • The friction of an object moved if it is also slippery, will require more force to keep it in your hand • Similarly, you will have to work harder to push a cart if your feet tend to slip on the floor than if your footing is secure

20. • Although force, can be estimated by measuring the number of muscular exertions, there are no fixed guidelines for what degree of force is harmful .

21. • As with repetitiveness, the hazard from force, depends on: – What part of the body is exerting the force – What kind of movement is involved – The presence of other risk factors, such as repeated exertions

22. STRESSFUL POSTURES • Certain postures, when used repeatedly or when sustained , can be stressful to the structures of the body, especially when force is exerted. • posture is so critical to ergonomics and affects various parts of the body

23. Hand postures Power grip Pinch grip in which the hand is wrapped around and object with continuous contact between the tip of the thumb and the Fingers In which only the pads of thumb and fingers touch the object, is best for precision task

24. • Using a pinch grip when you have to exert a lot of force can result in pain and injury • Unless the work being performed is very precise, the pinch should be replace with power grip. • Also important to provide for a good grip of objects being handled. • Avoid slippery handles • Increase friction by providing tool handles with textures or coated handle coverings or by providing gloves with non-slip palms

25. Wrist posture • The least stressful posture for the wrist is called the neutral posture . • The wrist normally assumes this posture when your hand is hanging comfortably at your side.

26. • Non-neutral wrist postures are potentially stressful Hyper- ExtensioN Flexion Ulnar Deviation Radial Deviation

27. Important of hand and wrist posture: • Cumulative Trauma Disorders (CTD) of the upper extremities are “wear-and-tear” injuries that affect many people who do hand-sensitive work.

28. Posture of hand and wrist that must be avoided Posture of hand and wrist that must be avoided

29. SHOULDER POSTURES • Stressful postures of the shoulder can cause a significant reduction in endurance Awkward postures of the shoulder

30. • All stressful postures result in strength reduction EXTREME POSTURE % STRENGTH REDUCTION UD 25 RD 20 WE 25 WF 55 Arm Fully Extended 81 Floor Level Lift 40 High Vertical Lift 60 45° Twist During Lift 15 90° Twist During Lift 30

31. NECK POSTURES • Any improper neck postures may lead to muscles fatigue and/or headaches . •The neck is stresses by holding the tilted forward of backward more than 20 ° for extended period of time

32. • Care must also be taken to prevent moving the head repeatedly from side to side and excessive twisting. • Stressful neck postures should not be repeated more than 2 times/min

33. MECHANICAL STRESS • Mechanical stress is produced by the contact between some parts of the body and the sharp edges of tools, parts, work surfaces or work pieces

34. • Hand tools are common cause of mechanical stress. The figure gives a good example of how a hand tool can compress finger tendons . (a) A sharp-edged tool (b) is more likely to produce injury than a rounded tool (c).

35. TEMPERATURE EXTREMES • Extremes of both cold and heat can be stressful • Skin temperature should not be allowed to fall below 68°F (20°C) due to contact with air, tool exhaust or cold materials • This conditions may impair the sense of touch and reduce dexterity in the hands. • When the hands are cold and numb, you tend to misjudge the amount of force necessary to perform a task. • Additional stress is created by a tendency to over-exert under these conditions.

36. Extreme heat are harmful in two ways First • Handling hot tools, surfaces or work pieces without protective gloves can result in burns Second • Environmental heat, especially if accompanied by high humidity, can increase the physiological strain during whole-body exertions. • This is because muscular activity produces heat .

37. • The body can release most of this heat through perspiration under normal circumstances. • As the temperature in the air and humidity rise, the body must work harder to give off this heat. Various heat related disorders can result , among them are heat stress and heat stroke

38. VIBRATION EXPOSURE TO: MEDIUM EFFECT DESCRIPTION Vibration Low-frequency vibration Hands • Back • Buttock Damage to the nerves, blood vessels and bones of the hands and arms Increase an individual risk for back injuries Can occur with the use of powered hand tools and impact tools Normally associated with people who drive vehicles, eg : fork trucks, platform trucks

39. PERSONAL RISK FACTORS • Also recognized as other factors. • Factors may affect an individuals overall risk for overexertion injuries : – Age – Fitness level – History of injury – Medical conditions – Smoking – Obesity – Gender – Physical structure

40. The “HIT LIST” A method of helping us become more aware and experienced in ergonomics is to summarize the most common risk factors seen in the plant . The Ergonomic “ Hit List”

41. the Washrag . • It is a summary of the stressful hand and wrist postures making it very easy to spot Continuous movement of the wrist and hands, increase like likelihood of repetitive motion disorders

42. There are three postures that commonly observes in the plant have a direct effect on the low-back • “Butts Up” position • It is the most common in the plant • A good indicator of risk for possible low-back problems Can be seen offloading conveyors, pushing and positioning component carts lifting and loading material, etc

43. • “ Horizontal Distance” • Usually seen when loads are being handled away from the body • This can put great forces on the spine Anytime there is a lack of clearance which prevents the worker from getting close to the load there will be trouble. Look for this around conveyors and tables

44. • “Twist and Shout” • Usually seen when loads are being moved from one location to another. • The twisting motion puts extremely high forces on the lower back Look Look for transferring components or finished product from one surface to another such as off-loading conveyors, repetitive splicing type operations or transferring product from a conveyor to a pallet.

45. There are two postures that are the result of failure to locate the work to be done in the proper place “Shoulder Too High/Shoulder Too Low” position This usually the result of controls or tools located at the wrong height. Look for this at work stations, especially product assemble

46. • “ Comfort Zone” position • Usually seen when loads are being lifted from floor level or t work stations Observe work stations to make sure that the work is located well within reach. This can also greatly effect product quality and productivity

47. There are two positions s commonly observed when tools are being used “Tool/Target” position This can also result from working too high or to low. Look for this posture whenever tools are used

48. “ Elbow Out” This is most common where screwdrivers and pliers are used. It can also be observed when the product is being worked on or manipulated

49. There are two postures that are not seen as often but also can cause ergonomic injury/illness problems Hungry Head” position This usually the result of inspection and/or handling material. Look for this at work stations in final finish, maintenance and inspection areas

50. • “Sit-Stand” position • Usually seen when around conveyors and tables Observe work stations to make sure that there is adequate space for the feet and that there are no knee obstruction s

51. Bad Vibes” • This is a problem that can occur with powered hand tools This can result from using pneumatic tools that are worn out. It can also occur when the work is performed on or around vibrating bins or feeders .

52. “Don’t Give Me Static” position • This position occur when stationary positions are maintained . Look for instances of prolonged standing or holding. Static problems can also occur when carrying boxes or other objects .