Canadian Centre for Occupational Health and Safety
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Health and Safety: Teaching Tools
A C T I V I T I É S
ACTIVITY 3

Repetition


Purpose: To demonstrate an ergonomic problem.

Materials required: Grip exercisers and a stopwatch.

Grip exerciser and stopwatch

Instructions: Learners are required to grip the exerciser and perform as many grips as possible with their dominant hand in the span of 30 seconds. They are asked to record the feeling in their hand on a scale of 1 to 10 and then take a 2-minute break. Using the same hand, students are asked to perform one grip every two seconds by counting slowly and gripping on every second number. They stop after 90 seconds this time and record the feeling in their hand again.

Expected Results: The intent is to get the learners to experience fatigue and discomfort from repetitive hand exertions and to be introduced to the concepts of speed and duration in regard to muscle contraction. Both exercises result in discomfort. The exercise with one grip every two seconds often results in less discomfort.


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