Ergonomic design and evaluation of pliers

Area of Science:

• Ergonomics and Human Factors
• Occupational Health
• Biomechanical Engineering

Background:

• Conventional pliers can cause discomfort due to unnatural wrist postures.
• Ergonomic redesign aims to improve user comfort and reduce strain.

Purpose of the Study:

• To investigate the effectiveness of bent-handle needle-nose pliers designed for improved ergonomics.
• To determine optimal handle angles for reducing wrist discomfort and physiological strain.

Main Methods:

• Six redesigned pliers with varying angles (0°, 10°, 20° for ulnar deviation; 0°, 5° for wrist extension) were tested.
• Fourteen male university students (20-24 years) participated.
• Discomfort (Visual Analogue Scale) and blood pressure changes were measured.

Main Results:

• Angles to prevent ulnar deviation and wrist extension significantly impacted discomfort (p<0.001).
• Ulnar deviation angle significantly affected systolic blood pressure.
• Pliers with 10° for ulnar deviation and 5° for wrist extension yielded minimal discomfort.

Conclusions:

• Bent-handle pliers, within specific angles, can effectively reduce user discomfort.
• Optimal angles are crucial for comfortable plier use, offering significant design implications.
• This study highlights the importance of considering wrist extension angles in ergonomic plier design.