Ergonomics: Why do workers get injured? Presented by: Steve Bilan Ergonomic Specialist

Transcription

1 Ergonomics: Why do workers get injured? Presented by: Steve Bilan Ergonomic Specialist

2 What do you know about Ergonomics? Ergonomics is the study of designing equipment and devices that fit the human body, its movements, and its cognitive abilities.

3 What do you know about Ergonomics? Equipment: Anything that requires any sort of human input to make it work Movements: Any body movement required for the task Cognitive Abilities: Intelligence and behavior, especially focusing on how information is represented, processed, and transformed (in faculties such as perception, language, memory, reasoning, and emotion) within nervous systems

4 Cognitive Ability Factors that will impact Cognitive perception: Sleep Deprivation Noise Medications Work Scheduling Stress Research is also finding diseases such as Hypertension have a major role in cognitive ability. What does this means in regards to ergonomics?

5 Riddle What goes up but does not come down?

6 Answer AGE

7 How does this contribute to a Musculoskeletal injury/disorder?

8 Safe Workload IF WE CAN CONTROL FATIGUE, WE CAN TAKE AWAY MSD S Under regular good working conditions with sufficient rest breaks injury is not as likely occur Miniature rest breaks are essential throughout the day to prevent injury

9 Safe Workload Force Rest Periods Time Workload Tissue Tolerance

10 Chronic Injury Force Time Workload Tissue Tolerance

11 Rest and Recovery During the rest phase, physiologically your body is seizing the opportunity to repair itself to become stronger in preparation for the next stresses placed upon it Not surprisingly, as you get older, the more your body relies on rest and recovery time.

12 Rest and Recovery The recovery rate closely relates to how fast the body can grow new cells to repair itself. Studies show that injured athletes 45 and older recover between 15 to 18 percent more slowly than a similarly injured 30-year-old.

13 Rest and Recovery of individuals later in life

14 Fool Proof Prevention To ensure that your design will not cause injury the most important factor of your design is to ensure that REST and RECOVERY periods are sufficient to recover from the demands of the tasks workers perform The body is self repairing and can repair itself throughout the day This does not mean coffee breaks. This is the application of work at the right times for employee

15 TRUE or FALSE If all your muscles could pull in one direction you could create a force of 1000 lbs!

16 FALSE If all your muscles could pull in one direction you could create a force of 25 tons!

17 How to identify risk factors for MSI/MSDs (poor ergonomics)

18 Ergonomics 5 W s and a H (A Task analysis) Who What Where When Why How

19 Who Workers Age (as mentioned earlier) Height Capabilities Previous Injuries/General Health Anthropometrics Training History Job Experience

20 What Tasks are being performed, workstation, environment, work structure Necessary and unnecessary movements, motions, lifts, etc

21 (What) Work System Task Environment Employee Workstation Work Structure

22 Task What is the job description What are the essential steps Physical Demand Description (PDD) Safety Skill requirement

23 Workstation Equipment and Tools Machinery Workstation layout Measurements such as height, width, depth Weights of objects

24 Environment Light levels Noise levels Vibration levels Temperature Air Quality

25 Work Structure Production Rate Training Supervisor Management Style Policies and Procedures Workload

26 Where Areas that are at the greatest risk How do you determine where?

27 Tools that can be used to identify tasks for potential injury MSI survey Risk Analysis Checklist Injury History WCB information Talking with employees Reviewing OHC committee minutes and first aid kit logs

28 MSI Survey MSI SURVEY FORM 1. What department do you work in? What is your job title? 2. In the last year, have you had any pains, aches, soreness, numbness, tingling, swelling, burning feelings, muscle weakness, muscle tightness, changes in skin colour or difficulty in grasping or holding objects, that have lasted for more than a week, that you believe are mainly caused by your work? YES NO. If YES, please complete the remainder of this survey. If NO, you do not have to complete the rest of the survey. 3. How long have you worked in your present job? Less than 1 year 1 5 years More than 5 years 4. How many hours do you work at your job each week, not including lunch and coffee breaks? 5. How long are your daily breaks at work? 6. List the 2 most physically demanding (forceful, awkward or repetitive, etc.) tasks that you do at work? 7. How often do you perform these tasks? 8. Please put an X in the boxes in the table below that apply to you. In the last 2 months I have had symptoms (such as aches, pains, discomfort, or numbness) in my: Neck No Yes Shoulders No Yes in the right shoulder in the left shoulder Elbows No Yes in the right elbow in the left elbow Wrist / Hands No Yes in the right Wrist / Hand in the left Wrist / Hand Upper Back No Yes Lower Back (Small of Back) No Yes One or both hips/thighs/buttocks No Yes One or both Knees No Yes One or both Ankles / Feet No Yes In the last 7 days I have had symptoms (such as aches, pains, discomfort, or numbness) in my: Neck No Yes Shoulders No Yes in the right shoulder in the left shoulder Elbows No Yes in the right elbow in the left elbow Wrist / Hands No Yes in the right Wrist / Hand in the left Wrist / Hand Upper Back No Yes Lower Back (Small of Back) No Yes One or both hips/thighs/buttocks No Yes One or both Knees No Yes One or both Ankles / Feet No Yes

29 Risk Analysis Checklist Risk Analysis Checklist Department: Position: Workplace Characteristics: Awkward Postures (bending, twisting, above shoulder, etc.) Static / Sustained muscle work No sitting while performing the job Controls / parts require reaching Poor working heights (bending required to perform) Crowding Components beyond normal reaches Poor chairs (not adjustable, no back support, no foot rest) No adjustability in workstation Environment: High noise levels Poor task lighting Poor ambient lighting Cold temperatures (require PPE) Hot temperatures Fumes and vapors Poor air circulation Humid Glare (direct of reflected) Hot surfaces Slippery floor surfaces Physical Demands: Frequent heavy lifting Lifting from overhead or below the waist Obstructed pathway Twisting while lifting Load above 40 lb. Sudden or jerky movements Endurance requirements Poor grips Awkward objects to lift (bulky, large) Static holding or carrying Frequent stair or ladder climbing Lack of handling aids Comments: Comments: Comments: Controls and Displays: Poor compatability No display lighting Frequent used controls not centrally located Controls are confusing or not easily identified Controls are too small Frequent operation of controls appears rushed Controls labeled and marked Hand Tool Use: Heavy hand tools (>10 lb.) Bent wrist postures with tool usage Vibration Poor handles / grips (pressure points, sharp edges, etc.) Mental Load: High skill requirement Multiple tasks done simultaneously Tactile requirements Training time high High concentration requirements Monotony Information handling demands Complex decision making Deadline pressures Othat Factors: Shift work Travelling Breaks extending past normal durations No rotation schedule Risk Level = 0.00 Comments: Comments: Comments: Comments:

30 Injury History- Injury Log Log of Work-Related Injuries & Illnesses Resulting in Lost Time or Medical Treatment Department: Year: Date Example 1 May 1/11 Example 2 June 6/11 Example 3 Aug 7/11 Body Part Injured *Type of Injury *Direct Cause of Injury **Systemic Cause of Injury Back Strain Lifting No mechanical lifting devices Eye Scratch Metal chip in eye Wrist Carpal Tunnel Repetitive Motions Eye protection not worn; did not fit. Work Area Bin assembly Bracket making area. Occupation Labourer Welder No job rotation Data Entry Data Entry Clerk Shift/Time of Day Days/No specific time Evening Shift/ 7:00 PM Daytime/ Cumulative Steps Taken to Prevent Similar Injuries Purchased gantry crane. Managers and supervisors must ensure that all safety policies are enforced. Purchased various sizes & types of eye protection. Eye protection program established. Supervisors annual pay increments tied to enforcement of health & safety policies and injury statistics for their area of responsibility. Data entry clerks and file clerks rotate jobs every 2 hours. * For type of injury and cause of injury use only 1 or 2 words whenever possible such as fall, trip, knife cut, lifting, repetition, fracture, hit thumb, pushing, pulling, etc. ** Example: Direct Cause of Injury - Employee didn t have guard on saw Systemic Cause of Injury Inadequate training provided to employee or safety policies not being enforced by manager/supervisor. *** Modified work is also called light duty work etc., (All modified/light duty work needs to be purposeful, productive work.)

31 Committee Minutes

32 Talking with Employees Early warning signs of MSIs Numbness Pain Tingling Swelling and Inflammation Burning sensations Weakness Red skin

33 When Proactive is the best, prevent injuries from happening before they happen Immediately after incident

34 Why Reduced risk of PAIN or INJURY Positive feelings about work Ability to work at full potential. Higher quality of life when at work and when away from work

35 How How do you know what to look for? 1. Amount of FORCE needed to perform all or part of job task 2. AWKWARD POSTURE (arm, wrist, neck, leg, back, etc.) required by the job or job task 3. Amount of REPETITION in the job

36 EMG Electromyography (EMG) is an electro diagnostic medicine technique for evaluating and recording the electrical activity produced by skeletal muscles

37 FORCE Force is not weight. Force is defined as a push, pull, or lift acting upon an object. Force required to do a certain task depends on several factors. Force can be measured using a force gauge dynamometer.

38 Force

39 AWKWARD POSTURES Awkward postures can be defined as any posture where any joint deviates from its natural neutral position. This could be a bent wrist, back, neck, raised shoulders, etc. When any joint is in an awkward posture the muscles are stretched and the joint becomes weak and susceptible to injury. Ideally joint deviation should be 0, this will minimize the torque about a joint

40 How Examples of Awkward Postures

41 Examples of Awkward Postures

42

43 REPETITION Definitions: 1) Cycle time of less than 30secs; where the cycle time is the time to do one operation (Silverstein et al, 1986). This is a definition from the automotive industry 2) Cycle time less than 1 minute is monotonous (Kivi, 1984) 3) Over 120 cycles/hour (Sjogaard et al, 1987)

44 Repetition We can look at repetition several ways, for example: Parts/hour Movements/hour Pauses in a cycle Periodization of rest breaks

45 Repetitive Motions

46 Examples of Repetition

47 Combining Risk Factors

48 Force and Posture Height of object being lifted: 36 Distance of object from body 15 Back compression force lbs Weight of object 25 lbs The NIOSH Action limit is 770lbs of back compressive force (at L5/S1)

49 Force and Posture Height of object being lifted: 36 Distance of object from body 33 Back compression force lbs Weight of object 25 lbs The NIOSH Action limit is 770lbs of back compressive force (at L5/S1) Lifting a relatively light object can cause large compressive forces in the spine.

50 Force and Posture Height of object being lifted: 6 Distance of object from body 17 Back compression force lbs Weight of object 25 lbs The NIOSH Action limit is 770lbs of back compressive force (at L5/S1) This means that even this task of lifting 25lbs once is potentially unsafe

51 To Summarize Reducing or eliminating unnecessary movements (Repetition) and/or awkward postures and/or excessive force will greatly reduce musculoskeletal injuries, because it will decrease the workers fatigue. When workers are fatigued they are at greater risk to become injured both chronically and Acute.

52 Questions?