Which principle ensures the design can be used with minimal fatigue?

• A. Simple and Intuitive
• B. Size and Space for Approach and Use
• C. Low Physical Effort
• D. Perceptible Information

Answer: (C)

The concept being tested is reducing the effort needed to use something. Low Physical Effort focuses on designing interfaces and environments so actions require as little body strength, stamina, or repetitive motion as possible. This means features like easy-to-operate controls, light-touch mechanisms, comfortable grips, and layouts that minimize bending, reaching, or twisting. When a design requires less physical exertion, people can use it longer without getting fatigued, which is especially important for users with limited strength or endurance.

Other principles address different aspects of usability—how easy something is to understand (Simple and Intuitive), ensuring there’s enough space and proper reach (Size and Space for Approach and Use), or making information easy to notice and understand (Perceptible Information). None of these directly target the amount of physical effort required, so Low Physical Effort is the best fit for minimizing fatigue.