Safety Manual: Ergonomics. February 8, 2017

Transcription

1 Safety Manual: Ergonomics February 8, 2017

2 Overview 2.0 Ergonomics Introduction This Chapter provides a general overview of issues in the workplace and recommendations for reducing ergonomic injuries. This Chapter contains the following information: 2.0 Ergonomics General Information Definitions Cumulative Trauma Disorders Office Requirements Office Equipment Standards Guidelines for Tools Care and Protection of the Back Preventing Ergonomic Injuries Updated June 20, 2017 (Rev 2) Page 1

3 2.1 General Information Program Requirement As per WorkSafeBC and the Workers Compensation Act, the TNRD is required to have an ergonomic program in place. This chapter provides guidance to reduce the risk of ergonomic injury to workers at work and to help each person work safely and efficiently. The objective of ergonomics is to match the job, the workplace, and worker behaviours to prevent work-related injuries or cumulative traumas. Ergonomics focuses on making the workplace suitable for the worker and encouraging the worker to use job practices which reduce the likelihood of injury. Human Factors Model An ergonomic program addresses the three areas of the Human Factor Model: Facilities: Properly designed or adjusted work stations, tools, equipment, and processes that meet the ergonomic principles Management Systems: Written procedures, training plans, risk assessments, and incident investigations and follow-up People: Individual characteristics and capabilities Updated June 20, 2017 (Rev 2) Page 2

4 General Information, Continued Reporting Employees must report symptoms of ergonomic injury or illness as soon as possible after noticing them and comply with the requirements of the TNRD reporting protocol. Early intervention is important to prevent or reduce physical impacts from potential ergonomic injuries. If you experience any of the following symptoms, report them immediately: Symptoms: Pain or discomfort aggravated by active or passive movements Pain in response to light tough Numbness Tingling, a pins and needles feeling Burning sensation Pain or numbness that worsens or wakes you at night Inability to grasp objects Lack of normal dexterity Lack of normal strength Swelling of muscles or connecting tissues Finger curled in flexed position, usually after awakening Hands become cold and blue, fingers become chalky in colour Decreased range of motion of any join Responsibilities Supervisors are expected to: Follow up immediately with worker who reports any ergonomic concerns Ensure worker completes Workstation ergonomic assessment tool on an annual basis, or if they change location. Workers are expected to: Use tools and equipment as instructed Use proper work practices Report any symptoms of ergonomic injury or illness Updated June 20, 2017 (Rev 2) Page 3

5 2.2 Definitions Cumulative Trauma Disorder (CTD) Disorders of the musculoskeletal and nervous systems that develop over a period of time as a result of longer-term repetitive motion, forceful exertions, vibration, mechanical compression, and sustained or awkward postures. Ergonomics The study of the relationship between the worker, the work environment, and the work being performed. Ergonomic Injury Results from Cumulative Trauma Disorders (CTDs) as a result of a workrelated activity. Musculoskeletal Anything that relates to muscles and bones. Musculoskeletal Disorder (MSD) Injuries and illnesses that affect muscles, nerves, tendons, ligaments, joints or spinal discs. MSDs are caused by exposure to the following risk factors: repetition, forceful exertions, awkward postures, contact stress, or vibration (or a combination of these factors). MSDs may also be referred to as CTDs and repetitive stress injuries (RSIs). Repetitive Motion and Strain Pain or discomfort involving muscles, nerves, or joints (or all three) that results in reduced mobility and ability to function. This may be caused by strain from repetitive work tasks, such as the same action repeated frequently. Examples: Computer keyboarding, vibrating tools, assembly, or loading tasks RSI Repetitive stress injury (RSI) is another term applied to CTDs and MSDs. Updated June 20, 2017 (Rev 2) Page 4

6 2.3 Cumulative Trauma Disorders Ergonomic Considerations The following task, worker, and environmental factors may contribute to traumas to the musculoskeletal system: Load: size, stability, grip, sharp edges, slipperiness Force: weight of load pushed, pulled, or lifted Lifting: techniques used Distance: horizontal distance of load from worker, vertical distance being lifted, total distance load is moved Repetition of movement Posture or position: degree the body part is bent or twisted Work environment: heat, cold, working/walking surface, obstacles, vibration Personal: size, strength, flexibility, physical condition Risk Factors The four major mechanical risk factors associated with Cumulative Trauma Disorders (CTDs) are as follows: Force Repetition Awkward posture Insufficient recovery time CTD Examples The following are examples of scenarios that can contribute to CTDs: Bent or flexed wrists: keyboarding, bicycling, and musical instruments Repetitive motions of the fingers, hand, arm, or shoulder: keyboarding, painting, and knitting Long periods of sitting or standing in a fixed or awkward posture Overextended and repetitive reaching for materials Neck bent forward (tucked chin) Looking downward at hard copy documents or at books lying flat on surface tops Neck bent too far back or forward while looking at computer monitor or other objects (frequently occurs with use of bifocal lenses) Inadequate light or glare Updated June 20, 2017 (Rev 2) Page 5

7 Extensive use of pens, pencils, or hand tools in a "pinch grip" fashion Leaning on an elbow on a hard or sharp surface Repetitive hand work Lessrecognized Contributors to CTDs Not all causes of CTDs are easily identified. Some less-recognized contributors may include: Lack of control over work Perceived stress Inability to communicate with the supervisor Lack of general wellbeing Perception of being undervalued by the organization Job content (workload) Good Work Practices To reduce the potential for the occurrence of CTDs: Change activity at least every hour for a minute or two. Stretch the muscles being used. Schedule the work to avoid repetition. Relax periodically when you work ( micro breaks ). Try to maintain a neutral posture at your workstation. Neutral Posture Each part of the body, from the legs, to the back, to the eyes, has a neutral posture. The neutral posture is the most comfortable or least tiring to maintain over time. For example, if you work with your arms overhead, they may become tired and sore very quickly. If you do exactly the same work with your arms comfortably at your sides, you can work longer without experiencing fatigue or discomfort. Updated June 20, 2017 (Rev 2) Page 6

8 2.4 Office Requirements Workstation Assessment The workstation assessment checklist (WorkStation Assessment) guides individuals through the assessment and highlights the appropriate adjustment to be made. Upon completing the assessment, review the findings with the respective supervisor. If there is no issue, the supervisor signs off and sends the completed form to the Safety and Wellness Advisor for record keeping. If issues need to be resolved: Supervisor, Safety and Wellness Advisor and employee will review the Ergonomic Assessment to see if additional accommodations are required. If employee requires a medical accommodation, they may be requested to have their physician complete a medical certificate stating any required accommodations. Training Annual Training program includes: A presentation on ergonomics awareness. Completion of the Work Station Assessment Checklist. Resolution of issues resulting from the assessment. Joint Health and Safety Committee activities that promote ergonomic awareness. Updated June 20, 2017 (Rev 2) Page 7

9 2.5 Office Equipment Standards Objective Provide the minimum parameters needed to accommodate most users when seated and performing tasks at a workstation. The recommendations in the American National Standards Institute (ANSI) standards specify minimum parameters that accommodate 90 percent of the work population typically the 5th percentile female dimensions through the 95th percentile male dimensions. Reference: ANSI/HFS 100 Note: The guidelines are intended for workstation setup prior to assignment of the individual to a specific workstation. Desks The work-surface height should be 26 to 30 inches (66 to 75 centimeters) if adjustable, or 28 inches (70 cm) if not adjustable. Minimum leg clearance under the work surface: From knee to back of work surface: 15 inches (38 centimeters) Width: 20 inches (51 centimeters) Chairs The chair should have the following features: Ability to swivel At least five (5) legs with casters for mobility and stability. Casters suitable for the flooring type An adjustable seat height of 14 to 20 inches (35 to 50 centimeters) A seat pan with rounded or scrolled front edge, seat depth between 15 to 17 inches (38 to 43 centimeters), a seat width of at least 18 inches (45 centimeters), and the seat is inclined between 0 and 10 A seat back with adjustable height and lower back support that is convex in the vertical and concave in the horizontal direction Armrests, if installed, should be padded and not interfere with the user's movement, especially in keyboard work. Updated June 20, 2017 (Rev 2) Page 8

10 Office Equipment Standards, Continued Keyboard and Mouse Support The keyboard should be at elbow height, allowing the seated user to maintain an elbow angle of 70 to 135. The keyboard support should be: Height adjustable and tiltable (negative tilt desirable). Large enough to have the mouse next to the keyboard. Otherwise provide a mouse extension tray. Without a hard or sharp front edge. Back Rests The purpose of a backrest is to provide support to the lumbar region of the spine and relieve pressure in the spinal disks. Backrests can be used by employees who do not have chairs with adequate lumbar support. An adjustable backrest can also be used to shorten the seat pan of a chair for individuals who find the seat pan of the chair too long. The backrest should provide a lumbar support area of 6 to 9 inches (15 to 23 centimeters) high and at least 12 inches (30 centimeters) wide with a slight protrusion to fit the lumbar concavity of the body. It should be adjustable at angles from a nearly upright position to 20 to 30 behind vertical. Footrests After adjusting the chair to suit the height of the work surface, some people may not be able to place their feet flat on the floor. Footrests serve as a support surface to provide stability for the seated posture and to reduce pressure on the underside of the thigh. Footrests should be stable and adjustable. Wrist Rests A wrist rest is not necessary if the keyboard tray is properly placed. If needed, a wrist rest should be: Soft, so pressure is not placed on the underside of the wrist. It should be made of a material that discourages perspiration and moisture build-up. A gel-filled type is preferred. Thick enough to be at the same height as the top of the space bar on the keyboard. Updated June 20, 2017 (Rev 2) Page 9

11 Office Equipment Standards, Continued Document Holders Telephone Headsets Position the document holder next to the display screen in the viewing zone as shown on the figure presented under "Workstation positioning". Document holders help to improve efficiency and reduce fatigue of the shoulder and neck muscles. Telephone headsets free the hands for other work and eliminate the need to squeeze the handset between the neck and shoulder. Cradling the telephone against the shoulder causes stress to the neck joints. Headsets are recommended for jobs requiring frequent or extensive telephone use. General Lighting Lighting in general office areas should be a minimum of 30 footcandles (325 Lux); lighting at desks should be 50 to 70 footcandles (540 to 755 Lux) for reading and paperwork activities. Lighting levels below 30 footcandles (325 Lux) may be acceptable for areas where work involves only monitor use. Monitor Placement The monitor should be located just below eye level (the top of the screen at eye level) to minimize neck muscle strain. Monitors are designed to be operated at a distance of approximately 20 inches (50 centimeters) from the operator's eyes. This distance can be adjusted (depending on the individual) from 12 inches (30 centimeters) to the length of the operator's arm reach about 31 inches (80 centimeters). The monitor should be positioned to minimize or eliminate bright reflections (glare) on the screen. The following steps can aid in reducing glare on the monitor: Place the screen between rows of overhead light fixtures rather than directly under them, to minimize the reflection on the screen. Place the monitor at a right angle to the window to minimize the reflection of light from the window onto the screen. Use blinds or curtains help to reduce excess illumination and reflected glare. Horizontal blinds are more suitable for the optimum utilization of natural light. Adjust the screen tilt as needed to minimize reflections. Add a screen hood if needed to completely or partially shield the screen from reflection. Note: A glare shield may reduce glare but it also decreases screen illumination and contrast. It is usually not as effective as the measures mentioned above. Updated June 20, 2017 (Rev 2) Page 10

12 Office Equipment Standards, Continued Keyboard and Mouse The keyboard should be at seated elbow height so that the arms and hands can be positioned in a neutral posture while typing. The mouse should be positioned at the same level and next to the keyboard. Workstation Positioning Maintaining a neutral posture at workstations minimizes stress on the body during the workday. The following figure displays the neutral posture for the seated worker. While the neutral posture is a design objective, movement throughout the day is also important in reducing body stress. Updated June 20, 2017 (Rev 2) Page 11

13 2.6 Guidelines for Tools Selecting Work Tools Risk assessments that consider ergonomic principles are conducted when new or modified work tools or process equipment is selected. The following are guidelines for selecting work tools, Tools Select work tools that best fit the job. Look for these qualities: Tools that require a "power grip" (closed fist around the tool handle) rather than a "pinch grip" (pinched fingertips around the tool) Note: Avoid tools that require a bent-wrist position. Tools with non-slip grips Lightest-weight tool possible to do the job Tools that have their weight balanced with the center of gravity at mid-point Vibration-dampening grip points on pneumatic tools Store heavy tools, greater than 25 pounds, (11.3 kilograms), between knee and shoulder height to avoid lifting the tool from the ground or above the shoulders. Selecting Work Tools Risk assessments that consider ergonomic principles are conducted when new or modified work tools or process equipment is selected. Updated June 20, 2017 (Rev 2) Page 12

14 2.7 Care and Protection of the Back Preventing Back Problems The back is one of the most injury-prone part of the human body. On average, two out of every three people will experience back pain sometime in their lives. Back problems result in pain, lost time, expense, inconvenience, and disability. Preventing back injuries is preferred to simply treating them after they occur. Supervisors are responsible for ensuring that employees are aware of the proper techniques for lifting, bending, and carrying objects when performing their jobs. Common Problems Some common back problems include the following: Strain Fatigue Injury Disease Ruptured ("slipped") disk Fracture These problems are often a result of: Improper lifting techniques. Poor posture (slouching, rounded shoulders, and one hip higher than the other). Lack of exercise (a factor in up to 80 % of reported back pain). Excess weight (a constant forward pull from excessive stomach weight on the back muscles stretches and weakens the abdominal muscles). Check-ups Any job that requires an employee to sit or stand partially bent over for long periods of time can cause chronic conditions of strain and fatigue. These can be relieved by changing positions, stretching, adjusting work height, and relaxing the muscles of the neck and shoulders. Updated June 20, 2017 (Rev 2) Page 13

15 Care and Protection of the Back, Continued Relax Muscles Employees can learn to relax muscles while they: Stand: Stand tall, head held high, chin tucked in, abdomen flat, and chest slightly up and forward. Sit: Keep knees higher than hips and use a low stool to slightly raise feet. Cross the knees for temporary relief (alternate often). Keep lower back pressed firmly against firm backrest. Relax Muscles Lifting, pushing, or pulling objects manually is a major cause of strains and sprains. Follow these guidelines to prevent injury when lifting and carrying objects: Eliminate manual lifting whenever possible. When heavy items are to be moved, arrange for necessary help or lifting equipment. Examine the object and decide where and how to hold it. Check for grease, oil, moisture, and sharp edges. Get help if there is any doubt about lifting the object alone. Ensure that you have firm footing. Avoid carrying loads that extend above eye level or obstruct vision. Prior to lifting the object, clear the path of obstructions and possible tripping hazards. Know where and how to set the object down. Keep objects close to the body to reduce forces on the lower back. Avoid twisting and awkward body positions. Do not lift objects beyond your strength limitations. Split heavy items into lighter loads. When lifting, let the legs do the work - not the back. Bend at the knees. Materials should be lifted and moved in a slow, controlled, smooth motion. Wear gloves to protect the hands if an object to be handled could cause cuts or splinters. Store heavy materials between knee and shoulder height. Do not climb ladders while carrying heavy or bulky items. Updated June 20, 2017 (Rev 2) Page 14

16 Care and Protection of the Back, Continued Lifting Techniques Improper lifting techniques account for up to 50 percent of back injuries. Supervisors must ensure that employees are instructed in proper lifting techniques. Use the following procedure when lifting. Note: The figures on the following pages show lifting techniques. Updated June 20, 2017 (Rev 2) Page 15

17 Care and Protection of the Back, Continued Updated June 20, 2017 (Rev 2) Page 16

18 Care and Protection of the Back, Continued Care and Protection of the Back, Continued Lifting from Overhead Use extra care when lifting objects from or to high positions. One cannot lift as much weight in this case because the legs cannot be used. Spread the feet with one foot slightly forward. Use a firm platform or sturdy ladder for extra-high lifts; do not stand on a chair or box. When in doubt, get help. If an object is too heavy, too large, or hard to handle, either get others to help or use a mechanical aid such as a forklift, winch, or jack. Updated June 20, 2017 (Rev 2) Page 17

19 2.8 Preventing Ergonomic Injuries Good Practices Ergonomic injuries can be reduced and in many cases prevented by following good practices: Work environment Evaluate workstation and tasks Adjust work environment Monitor work technique Work Habits Avoid stress to the musculoskeletal system by stretching and warming up before working Move during the day. Do not sit at the workstation for more than one hour Avoid repetitious activity without appropriate rest Decrease the amount of force used Use correct body posture. Note: Sitting with your legs crossed or even sitting with a bulging wallet in your back pocket can throw your spine out of its ideal alignment. Work at a reasonable pace. Lifestyle Maintain a healthy lifestyle Exercise regularly Check-ups References Any job that requires an employee to sit or stand partially bent over for long periods of time can cause chronic conditions of strain and fatigue. These can be relieved by changing positions, stretching, adjusting work height, and relaxing the muscles of the neck and shoulders. Document ID Document Title F Computer Workstation Self-Assessment Tool Human Resources WorkSafeBC Ergonomic Medical Certificate How to Make Your Computer Workstation Fit You Updated June 20, 2017 (Rev 2) Page 18