17.9.1 Overview of Ergonomics
17.9.2 Ergonomics Principles
22.214.171.124 Avoiding Awkward Postures
17.9.3 The Work Envelope
17.9.4 Work-Related Musculoskeletal Disorders
17.9.5 Risk Factors
17.9.6 Examples of Work-Related Musculoskeletal Disorders
17.9.7 Prevention of Work-Related Musculoskeletal Disorders
17.9.8 Office Ergonomics
17.9.9 Ergonomics Product Catalog
17.9.10 Industrial Ergonomics
17.9.11 Manual Material Handling
126.96.36.199 American Conference of Governmental Industrial Hygienists (ACGIH) Lifting Guidelines
188.8.131.52 Best Practices for Lifting
17.9.12 Standing Workstation
17.9.13 Hand Tools
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Lawrence Berkeley National Laboratory (LBNL) maintains and implements an Ergonomics Program that identifies, prevents, and controls ergonomics-related hazards. The Ergonomics Program consists of health and risk factor surveillance, worksite evaluations and improvement, coordination with medical management, ergonomics training, and program review and evaluation. The goal of the Ergonomics Program is to minimize employee exposure to risk factors for work-related musculoskeletal disorders (WRMSDs), and to help improve work practices, software, furniture, tools, and equipment. Strategies for reducing risk factors focus on engineering controls, when feasible, and/or administrative controls.
This policy applies to all Laboratory employees, guests, and LBNL-supervised subcontractors. The ergonomics program has an impact on LBNL employees who use computers, work in laboratories, handle heavy objects or materials, use tools, and operate vehicles. This chapter describes resources and approaches to help maximize comfort and safety. An ergonomics program is most effective when it helps to optimize tools, equipment, software, and work practices as a system.
All LBNL division directors, department heads, group leaders, supervisors, work leads and staff have responsibilities to help ensure a safe and healthful work environment. Commitment and cooperation from all employees, students, and subcontractors at all levels are required to successfully implement this policy. The individuals, groups, and organizations listed in the following sections are responsible for implementing the Laboratory’s ergonomics policy.
Division Directors are responsible for ensuring that the work performed by their division is planned and executed to minimize employees’ exposure to hazards, including those related to ergonomics. In order to meet these responsibilities, the following actions are required of division directors:
Managers, supervisors and work leads, as delegated by supervisors, are responsible for providing an ergonomically safe workplace. This will be accomplished by participating in the LBNL Ergonomics Program. Supervisors’ responsibilities include:
Based on the negotiated Agreement between the University of California and the Coalition of University Employees (CUE), LBNL supervisors have specific obligations (Article 8 – Health and Safety) with regard to workplace ergonomics. For example, supervisors should be aware that any CUE-represented employee who have reported musculoskeletal discomfort to the employee's supervisor or to EH&S, or whose computer-related work activities involve:
must have an ergonomics review within 90 calendar days of reporting a musculoskeletal
discomfort to the employee's supervisor or EH&S. Supervisors have
60 days following the ergonomics review to advise the employee of the results
of the review, what actions, if any, the department will implement, and their
expected completion date.
If additional time is needed to review a computer workstation, supervisors are able to extend the process another 60 days, provided that the affected employee is notified (documented with a follow-up email) of the:
Employees identified as being at elevated risk for developing work-related
musculoskeletal disorders (WRMSDs) based on their work tasks (e.g., an average
of 4 or more hours per day at computer or 4 or more hours per day performing
repetitive or static office work) must complete appropriate training: the classroom-based
Ergonomics Awareness for Computer Users (EHS 0060), or Remedy Interactive Web-based
self-assessment and training (EHS 0059). The JHQ will trigger a brief
annual re-evaluation for all employees using a computer for an average of 4
or more hours per day.
Employees have the responsibility to:
The Ergonomics Program Manager is responsible for building effective collaborations and partnerships throughout the Laboratory to help managers, supervisors, work leads, safety coordinators, ergo advocates, and employees reduce risk factors for ergonomics problems. Specific duties include:
The program manager and the professional ergonomists are responsible for:
The Facilities Division is responsible for integrating ergonomics considerations into workspace planning, workstation design, and building modifications, with the goal of accommodating employees of various sizes and job functions while facilitating changes in technology and work processes over time.
The Procurement and Property Management Department is responsible for preparing purchase requisitions to acquire furniture, equipment, and accessories. The buyers in this unit monitor the types of products being ordered to assure they meet ergonomics criteria specified by EH&S.
The EH&S Health Services Group maintains a medical management program that includes evaluation of employees at risk for work-related musculoskeletal disorders and the medical surveillance of such employees through pre-placement, periodic, and return-to-work examinations. Trained and qualified health care professionals in the EH&S Health Services Group evaluate all employees, and their workplaces, who are referred to them with work-related symptoms and provide related injury and illness reports to the Ergonomics Program Manager. Employees who meet the eligibility requirements (e.g., computer use more than 4 hours/day) may contact LBNL Health Services (ext. 6266) to schedule an appointment with an optometrist for refractions and/or to obtain appropriate eyewear (PUB-3000, Chapter 3.18).
The responsibilities of the divisional Ergo Advocates include:
There is a three-tier program for conducting ergonomics evaluations of computer
workstation use. Ergo Advocates’ in each division are trained to
carry out basic, preventive workstation evaluations and follow-up for employees
within their division. Before conducting evaluations, Ergo Advocates
must successfully complete EHS 61 - Ergonomics Evaluator Training
The situations that trigger a preventive evaluation by an Ergo Advocate or via a web-based self-assessment (e.g., Remedy Interactive) include:
The responsibilities of the Division ES&H Coordinators are outlined in
PUB-3000 Sec 184.108.40.206., and include:
* Administering the division’s ES&H program.
* Supporting division line managers or work leads in the execution of their safety responsibilities.
* Serving as a point of contact for all division staff regarding the implementation and interpretation of ES&H policies, procedures, and programs.
Ergonomics is one of the areas included in these duties, and as such, the Division ES&H Coordinators are responsible for monitoring and coordinating the results of ergonomics training, walk-throughs, ergonomics evaluations (including those by ergonomists, ergo advocates, and web-based self-evaluations), and interventions. Specifically, the Safety Coordinator should oversee the work of the Ergo Advocates. Familiarity with relevent policies, documents, and databases is essential, including the Ergo Database, the Ergo Product Catalog, Remedy Interactive web-based self-assessment and training, and RSIGuard Break Reminder software.
Current information about ergonomics and applying the principles at LBNL are provided in the appendix to this chapter, Section 17.9, and on the EHS website in 1 Minute for Safety slides and the Ergonomic Product Catalog. Ergonomics information can also be obtained through the contacts below:
There is a three-tier program for conducting ergonomics evaluations of computer workstations:
For employees who use a computer more than 4 hours/day, the first step in
this process is to complete a Web-based ergonomics assessment and training
through Remedy Interactive. On the basis of the information provided
through this self-assessment, participants are ‘sorted’ into 3
risk categories: High (red zone), Moderate (yellow), or Low (green zone). All ‘red
zone’ employees should be seen by a professional ergonomist. These
evaluations should be requested online by going to the EH&S Ergonomics
Web site, then
selecting “Work Station Eval” in the left-hand column. Employees
in the yellow zone should be evaluated by the ‘Ergo Advocate’ responsible
for that division, based on the employee’s responses to the Remedy Interactive
self-evaluation. Those in the green zone may be monitored by other means,
such as safety walkarounds and comfort surveys to determine if problems may
be developing. Completion of the Remedy Interactive Web-based ergonomics
assessment and training (EHS 0059) is equivalent to completion of the EHS 0060
(Ergonomics Awareness for Computer Users) requirement.
Any employee experiencing work-related discomfort should have an evaluation by a professional ergonomist. All employees who report Work-Related Musculoskeletal Disorder (WRMSD) symptoms should be referred to the Health Services Group.
The Ergonomics Display Room is located in Building 75B, Room 110B. Employees can try out various furniture and accessories, and obtain information on the features and adjustment of each product. A computer is available so that visitors can spend sufficient time in the room evaluating the comfort and suitability of furniture and equipment they are considering for purchase. Smaller items are available to borrow and use at the employee’s workplace for one-week trials. The purchase of ergonomic furniture and accessories is the responsibility of each employee’s supervisor, and the cost is the responsibility of the employee’s division. Appointments for technical assistance and consultation are encouraged, although walk-ins can often be accommodated between 10 a.m. to noon, and between 2 p.m. to 4 p.m. daily.
Requests for ergonomics evaluations are completed through an online system (see Fig. 17.1). The request can be made by an employee, ergonomics evaluator, supervisor, or Division Safety Coordinator, Ergo Advocate, or EH&S Division Liaison. To find out who your EH&S Division Liaison is, go to "Who to Call" from the EH&S Division home page. This Ergo Database is also used as a means of entering observations and recommendations, and tracking the actions by employees, supervisors, and ergonomists stemming from the evaluation.
Upon entry of the ergonomics evaluation results, the online system will send a summary of the recommendations to the employee, supervisor, Division Safety Coordinator, LBNL Health Services, and the EH&S Division Liaison. There will also be an automatic 30-day email reminder sent to the supervisor if there are some outstanding (unresolved) action items that need to be addressed. Up to three email reminders will be sent at 30-day intervals. When the third reminder is sent, a copy of the email will also be electronically forwarded to the Division Director.
The steps to an online ergonomics evaluation are:
Fig. 17.1. Ergonomics Evaluation Request login page.
EH&S facilitates telecommuting and remote location work by offering support services for LBNL employees using computers off site. Employees using a computer either at a remote location or telecommuting 20 or more hours per week should take Web-based Remedy Interactive self-evaluation & training (EHS0059). Those telecommuting less than 20 hours per week should take equivalent self-evaluation and training on the EH&S Web site, and will be tracked through the Ergo database.
After employees have completed EHS0059 or its equivalent, employees working off site should contact EHS ergonomists to:
The flowchart below sets out the proposed procedure, and notes two related issues:
Administrative controls are procedural risk-control measures that include, but are not limited to, redesigning work duties, adjusting work pace, using rest periods/breaks, training, or assisting the supervisor in issuing work instructions to control risk factors for work-related musculoskeletal disorder (WRMSDs).
Computer user is an employee who routinely works at a computer for a total of four or more hours, inclusive of breaks, during any 12-hour period.
Engineering controls are physical risk-control measures that include, but are not limited to, adjustments in furniture, equipment, and tools; and physical modifications to workstations, equipment, tools, production processes, or any other aspect of the work environment.
Ergonomics is the study of human interaction with tools, equipment, software, the work process, and the environment in which people function. The goal is to fit the job to the person. Ergonomics recognizes the capabilities, differences, and limitations of individuals, and adjusts the tools, work process, or work environment accordingly.
Ergonomics evaluation. The term used to describe observations of a workers’ workstation, workplace and/or behaviors (e.g. body mechanics) to identify risk factors. Commonly termed an Ergo eval.
A healthcare professional is a licensed physician, a registered nurse, or other health care professional who has received appropriate medical training.
Manual material handling (MMH) refers to materials being moved directly by people.
Risk factors are conditions that contribute to the risk of developing a disorder. In the case of work-related musculoskeletal disorders, these include awkward postures, highly repetitive activities, the application of high forces, static positions (maintained over long periods of time), exposure to hand-arm or whole-body vibration, and exposure of hands or feet to temperatures cold enough to cause discomfort.
Surveillance is the ongoing systematic collection, analysis, and interpretation of health and risk factor exposure data. Surveillance data are used to determine the need for actions in support of occupational safety and health, and to plan, implement, and evaluate ergonomic interventions and programs.
Work-related musculoskeletal disorder (WRMSD) is the term used for health disorders arising from biomechanical stresses on the body, including those of a cumulative nature. WRMSDs are disorders of the muscles, tendons, and/or nerves that develop from or are aggravated by repeated or sustained exertions on the body. WRMSDs are also referred to as cumulative trauma disorders, repetitive motion injuries, repetitive strain injuries, repetitive trauma disorders, and overuse injuries.
"Ergonomics is the scientific discipline concerned with the understanding
of the interactions among humans and other elements of a system . . . that
applies principles, data and methods to design in order to optimize human well-being
. . . ergonomists contribute to design and evaluation of tasks, jobs, products,
environments and systems in order to make them compatible with the needs, abilities,
and limitations of people."— International Ergonomics Association
“Ergonomics” means fitting the work to the worker by modifying or redesigning the job, workstation, tool, or environment. It draws from the fields of engineering, information technology, and medical and cognitive sciences to optimize the work environment. By identifying risk factors that can result in an injury or illness, and correcting these hazards, employees can have a healthier workplace. Some of the factors evaluated in an ergonomic analysis are the:
The potential benefits of ergonomics are:
Ergonomics is an ongoing process, not a “quick fix.” Over time, changes in equipment, software, and work procedures can either enhance or undermine the ergonomics of the work environment. Continued awareness and cooperation among responsible groups are essential to an effective ergonomics program. It is a continuous process that must anticipate and adapt to changes in work processes and technology.
It is important to avoid repetitive or sustained awkward postures (Fig. 17.2) to minimize the potential for developing a WRMSD.
Fig. 17.2. Examples of awkward postures that may increase an employee’s potential for developing a WRMSD.
The work envelope is the zone in which an employee performs the most common
tasks and movements. Frequently used materials and controls (including computer
input devices) should be located within (16-18 inches) of the operator (see
Fig. 17.3). Such an arrangement reduces potential stress to the back, shoulders,
and arms by avoiding awkward postures and positions.
|Fig. 17.3a. The work envelope should be within easy reach.||Fig. 17.3b. Reaching behind the shoulder should not be done on a repetitive basis or with high force.|
Musculoskeletal disorders include a group of conditions that involve the nerves,
tendons, muscles, and supporting structures such as intervertebral discs. They
represent a wide range of disorders, which can differ in severity from mild
periodic symptoms to severe chronic and debilitating conditions. WRMSDs
are musculoskeletal disorders caused or made worse by the work environment,
and are also referred to as cumulative trauma disorders, repetitive motion
injuries, repetitive strain injuries, and overuse injuries.
WRMSDs can cause severe and debilitating symptoms such as pain, numbness, and tingling; reduced worker productivity; lost time from work; temporary or permanent disability; inability to perform job tasks; and an increase in workers’ compensation costs.
Musculoskeletal disorders are often confused with ergonomics. Ergonomics is the practice of fitting workplace conditions and job demands to the capabilities of workers. In other words, musculoskeletal disorders are the problem, and ergonomics is a solution.
Repetitive, forceful, or prolonged exertion of the hands; frequent or heavy lifting; pushing, pulling, or carrying heavy objects; prolonged awkward postures; cold temperatures; and vibrations contribute to the risk of WRMSDs.
The level of risk depends on how long a worker is exposed to these conditions, how often a worker is exposed to them, and the level of exposure.
An inflammation of the tendon, usually in the hand, wrist, elbow, or shoulder, due to repetitive use without sufficient recovery time. Symptoms include pain, swelling, and tenderness. Types of tendinitis include:
This is an inflammation of the tendons at the back of the thumb.
Also known as tennis elbow, lateral epicondylitis is an inflammation of the tendons on the outside of the elbow.
This condition results when the tendon of a finger is sufficiently swollen so that the tendon becomes “locked” in the sheath. This can cause a snapping and jerking movement when attempting to move the finger.
This condition involves compression of the median nerve that runs through the wrist. Symptoms include pain, numbness, or tingling in the first three fingers and the base of the thumb. An aching sensation and wrist pain (mostly at night) is also typical of many cases.
This is also referred to as “White Finger” or Raynaud's Phenomenon. This disorder occurs when blood vessels and/or nerves in the fingers are damaged, especially from using vibrating tools in cold weather. Symptoms include paleness, pain, and tingling in the fingers.
This is a muscle and joint-related disorder associated with static, awkward neck postures, such as when viewing a computer monitor for extended periods. It is very common when the neck is held in a bent position, as in highly precise work in laboratories.
Back pain can be caused by static, awkward postures; heavy materials handling; or long periods of sitting, especially in a motor vehicle.
Risk reduction includes the use of good work practices and procedures, good workstation and tool design (engineering controls), and the use of administrative controls. Early intervention makes a big difference for employees who experience discomfort. It is important for employees to report early signs and symptoms of WRMSDs to their supervisor, to ask their supervisor for an ergonomics evaluation, and/or to contact the Health Services Group for an ergonomics evaluation.
Reducing the length of time spent in awkward postures is important for minimizing the risk of developing a WRMSD (see Fig. 17.4). Equipment, tools, furniture, and the visual demands of a job have a direct effect on posture.
Fig. 17.4. Awkward postures improved by ergonomics interventions
Engineering control measures (physical changes to the tools or workplace) should be addressed as the first line of defense to eliminate or reduce ergonomics risk factors. It is important to implement engineering controls that can eliminate the problem when this approach is feasible.
Figure 17.5. The most effective forms of relief from strain due to static work (e.g., working at a computer or a lab bench) include walking and stretching.
A computer workstation should be designed to accommodate each user. Furniture adjustability is the key: it allows each employee to fit individual needs. General guidelines for setting up a computer workstation are illustrated below (see Figure 17.6). The best choice for working patterns and postures will differ from one person to another, based on the type of work performed.
|Pivot forearms on armrests
and float arms/hands to
the keyboard and mouse
Pivot forearms on desk
|Work at elbow height
with arms at sides and
Fig. 17.6. Three good approaches to computer workstation set-up.
Figure 17.7. (left) A Microsoft Natural 4000 keyboard, and (right) a Goldtouch keyboard (a numeric keypad is available).
|Shift + Arrow Keys||Selects one letter at a time|
|Shift + Ctrl + Arrow keys||Selects one word at a time|
|Shift + End or Home||Selects lines of text to the R or L|
|Shift + Page Up or Down||Selects text to top or bottom|
Figure 17.8. In the Control Panel, the mouse driver can be used to assign additional functions to extra button
Alternative pointing devices can be borrowed from the Ergonomics Display Room for a 1-week trial period
A footrest may be necessary if the operator cannot rest his/her feet comfortably on the floor.
Computer users should have eye checkups on a regular basis. Some computer users who wear corrective lenses/contacts should wear lenses designed specifically for computer use. Contact Health Services, ext. 6266, regarding eligibility requirements for computer glasses.
Locate the paper supply and output where the operator can avoid awkward postures to reach it.
To minimize eye fatigue and eyestrain:
After an ergonomics evaluation, additional equipment or accessories may not be needed or appropriate in all cases. However, if such items will reduce risk factors or discomfort, they should be selected and used with sound ergonomics principles in mind. The Ergonomics Product Catalog is intended to help identify and obtain appropriate products. Employees are encouraged to discuss these options with their division’s Ergonomics Advocate or another ergonomics evaluator.
The following items are recommended products described in the Ergonomics Product Catalog:
When ergonomics is applied at an industrial work area (e.g., workshops, labs, process areas), it is known as "Industrial Ergonomics." The same WRMSD risk factors are relevant and good work practices and body posture should be employed to minimize muscle tension and strain.
Manual material handling involves lifting, lowering, and carrying objects. If ergonomics principles are ignored, stresses on the muscles, joints, and disks in the back can eventually lead to or aggravate a WRMSD. For objects that are too heavy or bulky for safe manual handling by employees, mechanical lifting devices must be used for lifting and moving. (See Chapter 27 (Cranes, Hoisting and Rigging) and Chapter 28 (Forklifts and Other PITs))
LBNL POLICY STATES THAT THOSE INDIVIDUALS WITHOUT A PRIOR MEDICAL CLEARANCE SHOULD NOT LIFT LOADS THAT WEIGH MORE THAN 50 POUNDS.
Lifting limits should also take into account the location of the load and the frequency of lifting. The following tables indicate situations in which loads should be less than 50 pounds.
There are three tables, one for Low, Medium, or High-Frequency Lifting, that consider the horizontal (from the spine) and vertical (from the floor) location of the load. Their intersection yields the recommended limit for that type of lift. The three tables represent different frequencies and duration of exposure to lifting during the shift.
To choose a table, determine the duration of the task (<2hrs or >2 hrs/day) and the frequency of lifts per hour.
Table A: Low-frequency lifting: <2 hrs/day or >2 hrs/day with <12 lifts/hr.
Table B: Moderate-frequency lifting: >2 hours/day and <30 lifts/hour.
Table C: High-frequency lifting: >2 hours/day and <360 lifts/hour.
Further information is available in Physical Agents, 7th Edition, by the American Conference of Governmental Industrial Hygienists (ACGIH) (Publication #7DOC-734, 2005).
Shown in Figures 17.9a–i: Improved work practices and work layouts that can help reduce risk for WRMSDs.
|Fig. 17.9a. Bend the knees and hips instead of the low back.|
|Fig. 17.9b. Keep the natural inward curve in the low back.|
|Fig. 17.9c. Support your upper body weight.||
Fig. 17.9d. Pivot instead of twisting.
|Fig. 17.9e. Support your upper body weight.||
Fig. 17.9f. Pivot instead of twisting.
|Fig. 17.9g. Store heavier loads between knee and shoulder height. Very heavy loads (50 lbs. or more) should be stored where they won't have to be manually lifted. Lighter and less frequently moved items should be placed on higher shelves.||Fig. 17.9h. Create openings in containers to reduce reaching & bending.|
Fig. 17.9i. Try to reduce the number of times objects need to be handled, and substitute sliding for lifting.
Standing for extended periods of time places static load on the back muscles, which can contribute to a back injury. To minimize the risk of developing a WRMSD in the back due to standing, follow these guidelines:
Fig. 17.10. Raised and tilted work surfaces should be selected according to the task being performed.
Fig. 17.11. A saddle seat can help for work surfaces between sitting and standing height.
The height and position of the work and the worker can help avoid awkward postures:
A tool that is poorly designed, maintained, or inappropriately used can cause WRMSDs. Hand tools should fit the employee's hand; employees with small hands or who are left-handed may need tools designed specifically for these situations. A tool that works well in one situation may expose the user to awkward postures, harmful pressures on the hand, or excessive vibration in another. When selecting and purchasing hand tools, follow these guidelines:
Fig. 17.12. A manual screwdriver (left) vs. a powered screwdriver (right). >
Fig. 17.13. Pinch grip vs. power grip.
Fig. 17.14. Pliers exerting pressure on the palm.
Fig. 17.15. Vibration dampening built into pneumatic tool.
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