Canadian Centre for Occupational Health and Safety
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Health and Safety: Teaching Tools
A C T I V I T I E S
ACTIVITY 1

Force, Duration, Repetition
and Posture


Purpose: To demonstrate an ergonomic problem.

Materials required: None.

Instructions: Have students stand in a doorway and place their hands on the door frame at shoulder level. Ask them to push against each side of the doorframe with their hands using maximal effort and hold for 30 seconds. Then, have the students rest for 30 seconds and try again. This time however, they place their hands on the doorframe just above head level.

Have the student observe:

  • how long they lasted,
  • how they felt - first vs. second time around?

Expected Results: The intent is to get them to experience high force demand without sufficient recovery time and differences in force generation based on different hand locations. Placing hands above the head usually causes more discomfort.



Source: This activity comes from the Repetitive Strain Injuries for Young Workers developed by the Industrial Accident Prevention Association and is reproduced with permission.