CPE Anthropometry & Physical Dimensions in Ergonomics 2 — Questions and Answers
Question 1: For designing hand tool handles, which anthropometric measurement is most relevant for determining optimal grip diameter?
- Hand length from wrist crease to middle fingertip
- Hand breadth at the metacarpal heads
- Hand grip circumference (maximum circumference of the closed hand) (Correct answer)
- Index finger length
Correct answer: Hand grip circumference (maximum circumference of the closed hand)
Grip circumference describes the hand's wrapping capacity and is the primary determinant of the tool handle diameter that allows adequate force generation and control.
Question 2: In ergonomic design, 'accommodation percentage' refers to:
- The adjustment range built into a workstation
- The proportion of the target population whose dimensions fall within the design limits (Correct answer)
- The comfort rating assigned to a product by test users
- The number of distinct postures a workstation can support
Correct answer: The proportion of the target population whose dimensions fall within the design limits
Accommodation is the fraction of the target population physically served by a design; designing for the 5th–95th percentile achieves 90% accommodation of the population.
Question 3: Knee clearance height beneath a work surface should be designed based on which anthropometric reference?
- 5th percentile female sitting knee height
- 50th percentile combined sitting knee height
- 95th percentile male sitting knee height (Correct answer)
- Average of male and female 75th percentile values
Correct answer: 95th percentile male sitting knee height
Clearance dimensions must accommodate the largest user — the 95th percentile male — so that if the tallest-kneed user fits, all smaller users will also be accommodated.
Question 4: When applying US anthropometric data to design workstations for a predominantly Asian workforce, the primary concern is:
- Measurement error rates in the source database
- Systematic differences in body proportions and absolute dimensions between populations (Correct answer)
- Seasonal variation in body dimensions that affects the data
- Age-related measurement drift in the source survey participants
Correct answer: Systematic differences in body proportions and absolute dimensions between populations
Different national and ethnic populations exhibit distinct anthropometric profiles and body proportion ratios; applying US data directly to Asian populations can result in systematic design mismatches.
Question 5: Popliteal height is defined as the distance from:
- The top of the head to the floor in a seated posture
- The floor to the underside of the thigh just behind the knee (Correct answer)
- The floor to the top of the thigh while seated
- The seat surface to the top of the shoulder while seated
Correct answer: The floor to the underside of the thigh just behind the knee
Popliteal height is measured from the floor to the underside of the thigh just posterior to the knee, and is the primary anthropometric basis for seat height design.
Question 6: The impact of clothing and personal protective equipment (PPE) on workstation anthropometric design is typically addressed by:
- Using clothed subject measurements exclusively for all design calculations
- Adding functional allowances to nude anthropometric measurements to account for added bulk (Correct answer)
- Reducing accommodation percentile targets to compensate for PPE movement restriction
- Ignoring clothing effects since PPE thickness is below measurement resolution
Correct answer: Adding functional allowances to nude anthropometric measurements to account for added bulk
Most anthropometric databases collect nude measurements; ergonomists add functional allowances (additional millimeters) to account for clothing thickness, PPE bulk, and restricted movement before applying data to design.
Question 7: Which statement correctly distinguishes static anthropometry from dynamic anthropometry?
- Static anthropometry measures body dimensions in standardized rest postures; dynamic anthropometry captures dimensions during movement and task performance (Correct answer)
- Static anthropometry is inherently less accurate than dynamic measurements due to postural variability
- Dynamic anthropometry is used exclusively for military equipment design applications
- Static measurements are always numerically larger than equivalent dynamic measurements
Correct answer: Static anthropometry measures body dimensions in standardized rest postures; dynamic anthropometry captures dimensions during movement and task performance
Static (structural) anthropometry records fixed body dimensions in standardized postures, while dynamic (functional) anthropometry captures dimensions during actual movement, yielding more task-relevant design data.
CPE Anthropometry & Physical Dimensions in Ergonomics 2
For designing hand tool handles, which anthropometric measurement is most relevant for determining optimal grip diameter?