Physical ergonomics is about the human body's responses to physical and physiological work demands [tifaq.com< ]. Repetitive strain injuries from repetition, vibration, force, and posture are the most common types of issues, and thus have design implications.
Physical ergonomics is concerned with the impact of anatomy, anthropometry, biomechanics, physiology, and the physical environment on physical activity. Areas of focus in physical ergonomics include the consequences of repetitive motion, materials handling, workplace safety, comfort in the use of portable devices, keyboard design, working postures, and the work environment.
Physical ergonomics is one of three aspects of ergonomics: physical, cognitive and organizational [IEA< ]. Ergonomics more generally is the science of designing the job, equipment, and workplace to fit the worker [Wikipedia< ]. The terms ergonomics and human factors
The process of ergonomics involves studying the user and studying the job or task
Study of the user involves understanding physical characteristics, capabilities, limitations, and motivations. Study of jobs or tasks includes assessing the technical systems, work processes, workstations/equipment, and tools [National Safety Council< ].
A formal task and/or worksite analysis can be done as part of the ergonomic approach to design.
Related Links
Organizations
Formal Publications
Here are some general ergonomics books that provide comprehensive coverage of physical ergonomics topics:
Helander, Martin (2005). A Guide to Human Factors and Ergonomics, Second Edition. CRC Press.
Karwowski, Waldemar (ed) (2005). Handbook of Standards and Guidelines in Ergonomics and Human Factors. Lawrence Erlbaum Associates.
Salvendy, Gavriel (1997). Handbook of Human Factors and Ergonomics. John Wiley & Sons, Inc.
Woodson, Welsey, E. (1981) Human Factors Design Handbook: Information and Guidelines for the Design of Systems, Facilities, Equipment, and Products for Human Use. New York McGraw-Hill.
There are many books on general ergonomics, posture and movement, environmental factors, workplace safety and health, and the ergonomic approach. There are also scientific journals and many ISO standards on ergonomics.
The study of ergonomics involves many disciplines including engineering, medicine, orthopedics, psychology, and sociology. Formal study on physical ergonomics can be found in many educational programs including computer science, human factors, industrial design
Here are three general ergonomics books:
Dul, Jan, Weerdmeester, B. (2008) Ergonomics for Beginners: A Quick Reference Guide. CRC Press.
This book provides details on how to design for posture and movement, information and operation, environmental factors, work organization jobs and tasks, and the ergonomic approach. Included are comprehensive checklists to aid design of work systems, workplaces, and workstations.
Kroemer, Karl (1997). Fitting the Task to the Human: A Textbook of Occupational Ergonomics. Taylor & Francis.
This book deals with the workplace and how ergonomic solutions can impact safety, health and overall well-being.
Pheasant, Stephen & Haslegrave, C. (2006) Bodyspace, Anthropometry, Ergonomics and the Design of Work, Third Edition. CRC Press.
This book outlines principles and practice of anthropometrics, workspace design, sitting and seating, hands and handles, ergonomics in the office, ergonomics in the home, and health and safety work.
Detailed description
How To
Developing comprehensive ergonomic design solutions requires a task and/or worksite analysis. There are many solutions that do not require extensive analysis and can implemented easily and with minimal costs.
Ergonomic checklists and anthropometric data is used to facilitate collecting of data. There are numerous checklists and anthropometric (body measurements) data provided within all of the references listed.
The section below provides just a general overview of some risk factors and common interventions associated with:
Posture and Movement (Repetitive Motion)
Materials, Equipment Handling
Workplace Safety
Work Environment
Keyboard Design
Comfort Using Portable Devices
Posture and Movement (Repetitive Motion)
Common postures include sitting, standing, changes in postures and head/arm postures. Movement, and thus risk factors occur with changes in posture including:
Lifting and carrying
Twisting and turning
Pushing and pulling
Consequences of repetitive motion can result in musculoskeletal disorders (MSD's) such as carpal tunnel syndrome and tendinitis.
Common low-cost interventions include:
Changing work processes to minimize repetition, twisting, bending, and stretching
Providing carrying handles
Putting tools, controls and handle within easy reach
Automating some tasks to reduce physical (and mental) workload
Using adjustable chairs and work surfaces
Using wristpads and footrests
Materials, Equipment Handling
Risk factors associated with handling machinery, equipment and tools include:
Amount of force required
Movements and repetitions (cumulative injuries such as carpal tunnel syndrome)
Use of handles (gripping, squeezing)
Torque (twisting of hand or wrist)
Tool or equipment design
Pace required to keep up with equipment
Use of chemicals and hazardous materials
Common interventions include:
Making controls and handles easy to access and grip
Using clamps or vices to hold tools and provide stability
Using visual affordances to reduce physical and mental workloads
Using personal protective clothing and protection
Using protective equipment (gloves, goggles, dust masks, etc.)
Workplace Environment
Environmental factors include:
Noise
Vibration
Lighting (illumination, glare)
Climate (air quality, temperature, humidity)
Chemical Substances
Common interventions include:
Using of anti-glare computer monitor screens
Using adequate light sources
Fixing heating and air conditioning
Providing proper ventilation
Workplace Safety
Basic safety relates not only to a user's clearance, reach, muscular strength and posture, but also to job hazards associated with materials, processes and equipment.
Some preventive measures to eliminate job hazards and protect include:
Redesign of equipment (to prevent accidental operation)
Modifications of a material, equipment or process (use of hands-free controls)
Change in a process to minimize MSDs
Procedures to limit user's exposures to risks
Use of protective equipment and clothing
Some safety aspects of workplace ergonomic plans can include:
Establishing of safety procedures and training programs
Conducting a job/task or worksite analysis
Positioning equipment and work surfaces so improper movements are eliminated
Keyboard Design
Keyboard design is an important area in office ergonomics which includes the physical setup of the computer. Common design issues include:
Position of the screen relative to the keyboard
Layout and familiarity of the keyboard
Size and spacing of the keys
Size and position of attached input device (mouse)
Some low-cost interventions include:
Centering the mouse to accommodate both right and left-handed users
Grouping function keys together
Color-coding function keys
Comfort Using Portable Devices
Portable devices include laptop computers as well as hand-held devices.
Risk factors associated with laptop computers include:
Carrying (size and weight)
Screen height and distance with keyboard height and distance
Position and type of pointing device
Glare
Some common design solutions include:
Centering or making pointing device adjustable
Making screen adjustable to reduce glare and optimize viewing
Some interventions for hand-held devices include:
Providing a strap to prevent device from slipping from user's hands
Making a non-slip surface and shape conform to the hand to prevent slipping
Color-coding frequently used function keys
Data Analysis and Reporting
To identify and assess risk factors, and then to design ergonomic solutions, a task and/or worksite analysis may be conducted.
According to the National Safety Council, common items reviewed during a worksite analysis are:
Overall environment
Workstation Design
Task/job design
Machinery and equipment design
Materials handling
Accessibility
Guarding and warnings
Types of documents that are typically reviewed include:
Injury reports
Accident reports
Insurance claims
Worker's compensation reports
Absenteeism and turnover reports
Ergonomic checklists used to make evaluations can include such questions as:
Are office chairs and worktables adjustable?
Are employees using proper lifting techniques?
Are machines and equipment maintained on schedule?
Is adequate light provided?
Are protective clothing and equipment used?
Are controls and handles properly labeled?
Are safety warnings posted?
Next Steps
Changes and/or considerations that can affect design include:
New technology
Government regulations (ìgreenî technology, new equipment, hazardous materials, etc.)
Accessible technology and regulations (Section 508)
Legacy equipment
Refurbishing or building of new facilities
Security issues
Special Considerations
Facts
Also called:
Human Factors Engineering, Workspace Design, Workplace Design
Sources and contributors:
Karen Shor, Chauncey Wilson
