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 are often used interchangeably.
The process of ergonomics involves studying the user and studying the job or task, and then designing the work environment (or processes and products) to optimize the userís safety, health, comfort, and performance.
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.
Sources and contributors:Karen Shor, Chauncey Wilson