Related Experiment Videos
Handle displacement and operator responses to pneumatic nutrunner torque buildup
Jia-Hua Lin1, Raymond W McGorry, Patrick G Dempsey
1Liberty Mutual Research Institute for Safety, Hopkinton, MA, USA.
Applied Ergonomics
|October 6, 2005
Summary
Workstation and tool design significantly impact operator responses to powered hand tool forces, potentially reducing upper extremity musculoskeletal disorder risks. Optimizing tool selection and workstation ergonomics is key for operator safety.
Area of Science:
- Ergonomics
- Occupational Health
- Biomechanics
Background:
- Powered hand tools generate impulsive reaction forces.
- These forces can contribute to upper extremity musculoskeletal disorders.
- Direct measurement of tool-operator forces is crucial for understanding operator responses.
Purpose of the Study:
- To investigate workstation and tool effects on operator responses to impulsive reaction forces.
- To quantify handle displacement and grip forces during tool operation.
- To provide data for improved workstation design and tool selection.
Main Methods:
- Direct measurement of forces at the tool-operator interface.
- Experiment involving 15 experienced male operators in 3 work configurations (pistol grip/horizontal, right angle/horizontal, pistol grip/vertical).
- Full factorial design with 36 conditions examining working height, distance, tool type, and fastener joint hardness.
Main Results:
- Operator responses varied based on work configuration.
- For pistol grip tools on vertical surfaces, handle displacement decreased with increased working height.
- Maximum handle displacement and grip force for right angle tools occurred at specific working distances and heights.
Conclusions:
- Workstation and tool design factors significantly influence operator responses to reaction forces.
- Quantitative data supports optimizing workstation ergonomics and tool selection.
- Findings can help reduce torque reaction and mitigate musculoskeletal disorder risks for powered nutrunner operators.