Exercise - Drawing Chairs

Objective

  • Make anthropometry tangible: see how measurements vary even in a small group.
  • Apply the “5th–95th percentile” design rule to a real dataset.
  • Visualize how chairs/tables must be adjusted for comfort across body sizes.

Step 1: Measure (10 min)

Each student pairs up with another and takes 3 body measurements with a tape measure or phone ruler app:

  1. Popliteal height (floor to back of knee, sitting) → for seat height.
  2. Buttock–popliteal length (back of buttock to back of knee, sitting) → for seat depth.
  3. Elbow height (sitting) (seat to underside of elbow, arm bent at 90°) → for table height.

Record values in a shared Google sheet.

Step 2: Build the “Class Anthropometry Dataset” (10 min)

  • Plot all measurements in a quick table.
  • Calculate min, max, median.
  • Identify approx. 5th percentile and 95th percentile (with only 7 students, use the lowest and highest as proxies).

Step 3: Design Specs (20 min)

As a class, answer:

  • What seat height would fit most people? (Usually between 5th–95th popliteal height).
  • What seat depth would avoid cutting off circulation behind knees? (shouldn’t exceed shortest buttock–popliteal).
  • What table height matches median elbow height?

Write down one chair + one table spec that fits your class population.

E.g., “Seat height 44cm, depth 42cm, table height 70cm.”

Step 4: Sketch (10 min)

  • Individually: each student draws a few chairs on paper that match the chosen class dimensions. It can be a standard classroom chair, ergonomic adjustable chair, a stool, a bench, anything.

  • Share sketches around. Notice variety in solutions. Discuss:

Step 5: Reflection (10 min)

Group discussion:

  • What compromises did you have to make?
  • Who would this chair be a good chair for?
  • Did designing for the “average” leave anyone uncomfortable?
  • What does this teach us about universal design vs. personalization?

Submission format

  • Submit 3 drawings of chairs in the Google Drive. Try and get the submitted photos as clean as possible.