Ergonomics
Biomechanics
Learning Objectives:
- Understand the basic principles and concepts of biomechanics, including the application of mechanical principles to biological systems.
- Biomechanics is the application of mechanical principles in the study of living organisms
- Involves the principles of anatomy and physics in the descriptions and analysis of movement.
- The study of biological structures, processes and functions by applying the methods and principles of mechanics.
- To understand the forces acting on the human body
- To manipulate these forces in treatment procedures so that human performance may be improved and further injury may be prevented.
Brina Schenk with Douglas College, CC BY 4.0, via Wikimedia Commons
Solved Example: 9386-01
Which of the following statement(s) is/are correct with respect to biomechanics?
I. It is the study of the airflow in the athlete's lungs and the strength of the athlete's tissues.
II. It is the study of forces and their effects on living systems.
A. Only I
B. Both I and II
C. Neither I nor II
D. Only II
Correct Answer: D
Cumulative Trauma Disorders
Learning Objectives:
- Define and explain the concept of Cumulative Trauma Disorders.
- Explain the role of ergonomics in preventing and mitigating cumulative trauma disorders.
- Differentiate between various types of CTDs (e.g., carpal tunnel syndrome, tendonitis, etc.).
- Evaluate and propose prevention strategies, including ergonomic interventions.
Risk factors concerned usually have their harmful effects due to prolonged exposure. The injuries are mainly cumulative.
Cumulative Truma Disorders can occur due to following reasons- Repetitiveness: Repeated or sustained exertions
- Forceful exertions: Exceeding the safe limits of force and mobility
- Stressful postures: Awkward sitting/standing/lifting or walking positions for long time
- Mechanical stress: Stress concentration of certain muscles or joints
- Temperature extremes: May be either hot or cold
- Vibrations: Maybe both high or low frequencies
Anthropometry
Learning Objectives:
- Learn the fundamental anthropometric measurements, including height, weight, length, circumference, and skinfold thickness.
- Learn how anthropometric data is used to design ergonomic workspaces, furniture, and equipment to fit the human body.
Anthropometry is a branch of anthropology that involves quantitative measurement of human body.
It deals with techniques for assessing and applying size, proportions and composition of human body
Parameters of Anthropometry
Age dependent factors- Weight
- Height
- Head circumference
- Chest circumference
- Id-arm circumference (1-5 years)
- Weight for height
- Skinfold thickness
- Mid upper arm/height ratio
- Gender: Males have less fat and more muscle. Also, fat accumulation region are different for men and women.
- Aging: body weaight decreases after 50 years in males and after 60 years in females.
- Ethnicity: Lower body weights for people living in tropical countries. Differences diminish due to migration. Body proportions are different for different ethnicity and should be considered in machine design and operating conditions.
- Occupation
See page for author, Public domain, via Wikimedia Commons
Solved Example: 9045-01
Following are the parameters of anthropometry, Which of the following is age independent anthropometry factor:
A. Mid-arm Circumference
B. Weight
C. Height
D. Head Circumference
Correct Answer: A
Solved Example: 9045-02
What activity is done in an anthropometry survey?
A. Take the physical measurement
B. Take the intelligence quotient
C. Take the economic survey
D. Measure the social status
Correct Answer: A
Workplace Design
- Work-space envelopes consist of the three-dimensional spaces that are reasonably optimum for seated or standing persons who perform some type of manual activity.
- Thus (for example) control devices and other objects to be used usually should be located within such space. The reasonable limits of such space are determined by functional arm reach, which is influenced by such variables as direction of arm reach, the nature of the manual activity, the use of restraints, apparel worn, the angle of the backrest, and personal variables such as age, sex, ethnic group, and handicaps.
- Whenever feasible, such spaces should be designed with consideration for the personal characteristics of the population to use the facility.
- It is fairly standard practice to design such space for the 5th percentile of the using population, thus making it suitable for 95 percent of the population.
- Thus, with such special populations the design of the work space requires particular (and sometimes individual) attention.
- The limits of the work-space envelope for seated personnel are determined by functional arm reach, which in turn is influenced especially by the direction of arm reach and the nature of the manual activity (i.e., the task or function) to be performed.
- Functional arm reach is also influenced by such factors as the presence of any restraints and by the apparel worn.
Solved Example: 9387-01
Four commonly recognized computer workstation postures are:
A. Sitting, Standing on both feet, standing on one foot resting and reclined
B. Standing, sitting tilted forward, sitting upright, sitting tilted back
C. Standing forward, laying down, sitting up, sitting on knees
D. Sitting with arms supported, standing with no arm support, seated with foot support, seated with no foot support
Correct Answer: B
Macroergonomics
Learning Objectives:
- Understand the definition and significance of macroergonomics in the context of systems and industrial engineering.
Macroergonomics:
- The analysis, design and evaluation of work systems.
- Concerned with the 'human-organization' interface.
- Personal Subsystems
- Technology Subsystems
- Organizational Structure
- External Environment
- How do organizational constrains affect how people work with machines?
- What factors come into when people work together in groups?
Solved Example: 9388-01
Macroergonomics:
A. Allows user to maintain a neutral body position
B. Combines jobs, technological systems to harmonize with organizational goals and structure
C. Accommodates variations in hand and grip size
D. Eliminates unnecessary complexity
Correct Answer: B