Addressing the Root Cause of Preventable Injuries

Transcription

1 Addressing the Root Cause of Preventable Injuries Presented by: Misty J. Chapman Ergonomic Consultants of Indiana N. Meridian Street Suite 140 Carmel, IN (317) in.com 1

2 Musculoskeletal Disorders in the Workplace 2

3 Musculoskeletal disorders, or MSDs, are injuries or illnesses to soft body tissue such as: Muscles Nerves Tendons Ligaments Joints Cartilage Spinal Discs 3

4 Sprains/Strains Injuries 1. Sprains: stretching or tearing ligaments 2. Strains: stretching or tearing tendons or muscles Chart B. Distribution of sprain, strain, and tear cases requiring days away from work by selected event or exposure and part of body, all ownerships,

5 Common Musculoskeletal Disorders (MSD S) Carpal Tunnel Syndrome Muscle Strains Shoulder Pain & Soreness Elbow Tendonitis Plantar Fasciitis 5

6 Who is at Risk? Repeat the same motion throughout their workday Must do their work in an awkward position Use a high force to perform their job Repeatedly lift heavy objects Combination of risk factors Ergonomics Primary focus of an ergonomics program is the reduction of WMSD This is accomplished through the management of employee exposure to workplace hazards» Awkward postures» Forceful exertions» High rates of repetition 6

7 What is Ergonomics? Ergonomics (er'gõ nom'iks): The study of work and the relationship of work to the physical and cognitive capabilities of people Fitting the job (tools, tasks, and environment) to the employee, instead of forcing the worker to fit the job Ergonomic principles derived from many areas, including: Biomechanics Physiology Anthropometry Industrial engineering Safety Fitting the Workplace to the Person 7

8 Ergonomics OSHA defines ergonomics as: the science of designing the job to fit the worker, instead of forcing the worker to fit the job. Lathe Operator 8

9 Perfect Lathe Operator Normal guy Occupational Ergonomics Risk Factors inherent to the Task Risk Factors inherent to the Worker Risk Factors inherent to the Environment 9

10 Why do Injuries Occur at Work? Job Design & set-up Job demands exceed employee capabilities Failure to account for human physiological limitation Work stress (psychosocial factors) Failure to account for body size differences One of many factors that contributes or creates an undesired outcome (MSD) and if eliminated would have prevented the undesired outcome! Have to start with analyzing Workplace Risk Factors! 10

11 Risk Factors inherent to the Task In the picture, the worker is moving a box from the pallet to a dolly. Using the dolly eliminates forceful exertions needed to carry the box, but when he moves the box to the dolly, he is exposed to two risk factors: forceful exertions and awkward postures 11

12 Ergonomic Risk Factors & Hazards for WMSD s Repetitive Motions Awkward Postures & sustained Forceful exertions Pressure points (contact stress) Vibration Repetitive Motion Duration of task Frequency of task Speed of work or cycle time to do each cycle Productivity requirements 12

13 Repetition Repeating the same motions every few seconds or repeating a cycle of motions involving the affected body part more than twice per minute for more than 2 consecutive hours in a workday. Using an input device, such as a keyboard and/or mouse, in a steady manner for more than 4 hours total in a workday. Source: OSHA Repetitive Motion Is often a concern in: assembly tasks sorting tasks loading or off-loading materials inventorying products product stocking software programming telemarketing customer service 13

14 Ergonomic Tips to Minimize Repetition Repetition: Use power tools when available Use shortcuts on keyboard Use ergonomic products (trackball) Change tasks, stretch, or take a break from repetitive tasks Follow job rotation policies where applicable effective job rotations work alternate muscle groups between successive job functions 14

15 Awkward Postures Positions that require more effort than others or that result in compression or stretching of the tissues in or around joints Non-Neutral Examples: Overhead Reaching Twisting Forward Bending ECI s Guidelines Awkward Postures Hands/Wrists Flexed 45 Extended 45 Ulnar Deviation 30 Radial Deviation 30 Elbows Elbow Extension 135 Fully Rotated wings Shoulders Arm Raised 45 Arm behind body Shoulders Shrugged Neck Flexed 30 Extended Twisted 20 Sideways 30 15

16 Awkward Postures cont d BACK LEGS Flexed 20 Twisted 20 Extension Sideways Unsupported (chair) Kneel Unsupported Partial Squat (45 ) 31 Awkward Postures are caused by: Location of parts, equipment or tools Position of parts, equipment or tools Design of parts, equipment or tools Employee work habits (choice vs. design) 16

17 BACK Flexed 20 Twisted 20 Extension Sideways Unsupported (chair) 17

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19 37 19

20 Proper Sitting Position 2010 IAOHN Conference PARTIAL Forward Bending 40 20

21 Risk Factors for the Hands and Wrists Flexed 45 Extended 45 Ulnar Deviation Radial Deviation Wrist Use straight wrist positions Working with bent wrists decreases grip strength Use tools that let you keep your wrist straight 42 21

22 Neutral vs. Non Neutral 43 Common Keyboard Position 2010 IAOHN Conference 44 22

23 ELBOWS Elbow Extension 135 Fully Rotated wings Arms Away from Body 23

24 Excessive Reaching Keyboard Position Arms by your side Are elbows relaxed and resting by the torso during keying or mousing? Elbows out and wrists bent ELBOWS IN Move keyboard and mouse closer to you, adjusted to approximately elbow height. 24

25 SHOULDERS Arm Raised 45 Arm behind body Shoulders Shrugged Raised Shoulders Source: 40 horizontal repetitive reach for sander located on the side wall. In addition, the employee will reach for tools and parts resulting in elbow extension. 25

26 SHOULDER SHRUGGED & RAISED NECK Flexed 30 Extended Twisted 20 Sideways 26

27 Forward Head Your head weighs?? Forward head posture puts up to three times more force on the base of your neck Headaches are associated with this posture 27

28 Neck: Twist >20 Forceful Exertions Lifting bag weighing 50 lbs. Lifting manhole cover weighing 75lbs. 28

29 Ergonomic Tips to Minimize Force Use mechanical lift assists and carts when available Avoid manually handling heavy objects (more than 35 pounds) Avoid carrying objects more than 100 feet Practice Proper Cart Handling Push instead of pulling Use both hands when pushing Stand directly behind the cart when pushing (avoid twisting your body) Maintain good control and limit speed Ensure cart is not overloaded Pushing versus Pulling Force exerted by the body Type of wheels Types of bearings Type of surface Slope of surface Handle height 29

30 Pushing versus Pulling Force exerted by the body Pulling force Flex spine Back muscles contracting > compressive forces Force exerted by the body Pushing force Abdominal muscles are more active Less compressive force Pushing versus Pulling 30

31 Control options Pushing versus Pulling Keep forces low Initial and peak Handle height between hip and shoulder Large wheels To friction Slip resistant shoes Good housekeeping Good steering mechanism Incline surfaces < 2 Ergonomic Tips to Minimize Force Use proper lifting techniques when lifting Examine the load and the surrounding area Bend knees when lifting a load Look forward to keep back straight Position the load close to the body Maintain a firm grip on the load Use smooth, controlled movements Keep arms in front of body Turn feet in direction of movement to avoid twisting Get help before performing tasks requiring excessive force 31

32 Ergonomic Tips to Minimize Force A Two Person Lift Is Appropriate When... A lift, hoist or other mechanical assistance is unavailable The object is heavier than you are capable of lifting alone (typically more than 35 pounds) The object is not heavier than what two people are capable of lifting (typically less than 60 pounds) The object is awkward or oversized. Any object that does not have its weight equally distributed within the load. Remember some objects are too heavy or awkward to be handled with two people Ergonomic Tips to Minimize Force Use the correct tools / powered tools for the task Powered tools tend to require less exertion to perform a task Ensure that the weight of a powered tool (and cording) does not create additional force issues Use only the amount of force necessary to complete the task 32

33 Minimize Pressure Points Minimize Pressure Points Contact: Forearm Before 33

34 Contact: Hard Floor Contact: Fatigue Mat 34

35 Treatment for Plantar Fasciitis ErgoMates: Anti-fatigue mat on the shoe. Protects the feet where you walk. Do calf stretches Stretch calves before getting out of bed. Ice with water bottle! Use golf ball to massage heel. Roll heel over ball. Ergonomic Tips to Minimize Contact Stress Select hand tools that conforms to the geometry of the hands Pistol grip & in line tools: Recommended handle length: 5.0 inches Recommended handle diameter: 1.0 to 1.5 inches Pliers & crimping action tools: Recommended handle length: 4.0 inches (minimum) Recommended handle span: 2.5 inches 4.0 inches Avoid handles that end in the palm of the hand 35

36 Ergonomic Tips to Minimize Contact Stress Avoid pressure on knees: Avoid kneeling on hard surfaces for prolonged periods Use knee pads when kneeling tasks are unavoidable Avoid pressure on palms, wrists, and elbows: Use padding on hard or sharp surfaces Change your position to eliminate the stress Vibration Using tools or equipment that typically have high vibration levels (such as chainsaws, jack hammers, percussive tools) for more than 30 minutes per day. Using tools with moderate vibration levels (such as jig saws, grinders, etc.) for more than two hours per day. Source: OSHA 36

37 Hand arm vibration measurements and analyses should be performed according to ANSI S3.34, ACGIH TLV, and NIOSH recommendations. Any and all vibration is hazardous. 37

38 Vibration Values Die Grinders Dotco 12L psi/23000rpm 3M ,000rpm Dynabrade Straight-Line Die Grinder Dotco Straight-Line Extension Vibration Value (m/s2) 3.5 < Ergonomic Tips to Minimize Vibration & Torque To lessen vibration: Pad tool handles with a soft compressible surface Use vibration damping (gel filled) gloves Select tools (hammers and chippers) with built in damping systems (springs/hydraulics) To lessen torque reaction: Use electric tools as opposed to air driven tools Use pulse tools or auto shutoff tools 38

39 Human Factors People are Different People have Limitations People have Predictable Reactions Risk Factors inherent to the Worker Age 26% in the age category Gender Physical Activity Strength Athropometry 39

40 Risk Factors inherent to the Worker Age 26% in the age category Gender Physical Activity Strength Athropometry 40

41 Incorporate Movement: Treadmill Walkstation Energy Expenditure Aerobic activities Produce whole body fatigue Fast paced: lifting, lowering, walking, climbing Repetitive lifting > overexertion injury Factors affecting aerobic capacity Gender Age Physical fitness Nature of work Whole body 41

42 Energy Expenditure: Control Options Effect of the workload Lifts versus trips Fatigue versus spinal compression Lifting technique Efficiency Amount of work Endurance Work pace Heavier object Heavier body weight Lift versus lower Lower less energy Carrying location Center of gravity Risk Factors inherent to the Worker Age 26% in the age category Gender Physical Activity Strength Athropometrics 42

43 Different Shapes & Sizes 43

44 Behavioral & Cognitive Daily time at workstations (personal vs. work) Design vs. User s behavior Lack of "ownership" in personal safety on the part of the employee. IT WON T HAPPEN TO ME!!!! Lack of adjustable furniture at some worksites Risk Factors inherent to the Environment Lighting Temperature Vibration & Shock Noise, etc. 44

45 Ergonomics Improvement Process 1. Analyze Issues 2. Identify root causes or source of problem 3. Identify Improvements 4. Justification of cost or improvements 5. Follow Up to verify improvements Ergonomic Consultants of Indiana N. Meridian St., Ste 140 Carmel, IN (317) Services: in.com Ergo Products: 45