Hand tools can enhance human performance and productivity by extending physical capabilities to reach, apply force, and make precise movements. However, they can also cause injuries if improper forces are generated or poor postures are adopted due to poor tool design or use. When designing hand tools, factors like handle shape and size, required gripping and operating forces, weight, noise and vibration levels should be considered to minimize risks of musculoskeletal injuries. Maintenance of tools and workstations as well as worker training are also important to ensure safe hand tool use.

1. ADVANCED ERGONOMICS
(#MOS 6701)
HAND TOOLS

2. HAND TOOLS
Tools are devices designed to extend human physical capabilities
■ To reach
■ Force application
■ Precision movement
Thereby hand tools can enhancing the human performance,
productivity and quality of work.

3. HAND TOOLS
Unfortunately hand tools can also be a source of injury
 Forces are generated from the human musculoskeletal system
through the tool to the work piece and vice versa.
 Stresses arising from excessive forces.
 Poor postures are frequently the result of poor tool design.
 Inappropriate use.
In some cases if a tool slips, breaks or looses purchase acute
injuries can occur.

4. HAND TOOLS
The status of the equipment can be transmitted to the operator
through a display of some kind.
Handles
• Gripping characteristics
• proper shape
• Thickness
• length

5. HAND TOOLS
Forces
• The forces required to grip tools during use should be minimal
• prevent slippage
• The grip surface should be compressible,
• Used of Flanges
• Non-conductive to vibration, heat, cold and electricity.

6. HAND TOOLS
Design
• All edges of tool should be rounded off and sharp.
• To be held and used with wrist/hand in neutral position.
• Align tool's centre of gravity with the grasping hand
• Ensure that the transmission of noise and vibration is
minimised
• Guard all moving parts.

7. HAND TOOLS
Type of Operation
• Power operated instead of muscle power
• Using a single finger to operate a power tool
• repetitive and/or is required for extended periods.
• use the right hand tools should be designed
• Guard all moving parts.

8. HAND TOOLS
Weight
• Tool weight should be minimal
• Using a single finger to operate a power tool
• repetitive and/or is required for extended periods.
• use the right hand tools should be designed
• Guard all moving parts.

9. HAND TOOLS
While the majority of the population prefers to use the right hand
tools should be designed so that they can be used with either
hand.

10. HAND TOOLS
key factors in making hand tool use safe and minimizing the risk
of developing musculoskeletal injuries
 A maintenance program, to avoid unnecessary vibration and
to keep equipment in good order

11. HAND TOOLS
 Avoiding tools with handle shapes that result in high pressures
on the skin in the area of contact
 Selecting tools that require small contact forces (ie grip and
feed forces)

12. HAND TOOLS
 Keeping the mass of the tool to a minimum provided other
parameters (such as vibration magnitude or contact forces) are
not increased
 Purchasing policy for replacing old equipment and tools

13. HAND TOOLS
 Improving workstation design, such as using jigs and
counterbalancing tools
 Clothing to keep workers warm and dry
 Avoiding use of tools that expel cold gases or fluids over the
operator's hand

14. HAND TOOLS
■ Burgess-Limerick, R., Straker, L., et al. (2004) Manual Tasks Risk Assessment Tool
(ManTRA) V 2.0. Human Factors and Ergonomics Society of Australia, Cairns, Qld,
Australia
■ Geller, E.S. (2001) The psychology of safety handbook (2nd Ed.) Boca Raton, Fla.;
London: Lewis Publishers
■ HSE (2005) Control the risks from hand-arm vibration
http://www.hse.gov.uk/pubns/indg175.pdf
■ Stanton, N. and Young, M. (1999) A guide to methodology in ergonomics: designing
for human use London: Taylor & Francis

15. THANK YOU