Information on this page is drawn from "Installation and Repair: Using Tools" published by OSHA

Potential Hazards

• Poorly designed or improperly used hand tools may require excessive force and cause awkward postures resulting in tendonitis in hands, wrists and elbows.

• Short handles may press or rub against the palm and fingers (Figure 1) causing contact stress. Small handle diameter may increase force requirements of tool leading to fatigue, discomfort and pain.

Figure 1
Wire clipper rubbing the palm.

• Tools with wide handle spans require extended thumb and finger positions (Figure 2) to activate the tool. These postures require increased finger force to provide adequate activation force increasing fatigue, discomfort and pain.

Figure 2
Wide handle spans and finger positions require additional force exertion to perform a task.

• Improper orientation of the tool handle may result in awkward position of the hand, wrist, or arm and increase force requirements of the task.

Possible Solutions

• Use power tools (Figure 3) to do the job when repetitive or prolonged force exertion is required.

Figure 3
Power drill.

• Use a properly designed tool to promote neutral posture of the wrist and hand. (Figure 4). Generally, an inline tool is best on horizontal surfaces at about waist height, and a pistol grip is preferable for vertical surfaces at about waist height. Bent-handled tools can be designed to accommodate differing work positions and angles.

Figure 4
Bent-handled tool.

• Use tools with padded grips and handles that extend across the whole palm of the hand to minimize contact pressure.

• Ensure that tools such as screwdrivers have appropriately sized and shaped handles. Generally, handles should be about 1 1/2 inches to 3 inches in diameter. Triangular handles with rounded edges provide a better grip.

• Use tools that do not require an extended grip. The hand should be in the shape of a "C" while gripping the tool. A span of 2 1/2 to 3 1/2 inches is best.
  o Ergonomic Design for People at Work, Volume 2. Eastman Kodak Company, (1986).
• Replace tools if handles are damaged.

• Take regular breaks and rotate tasks when using a hand tool for an extended period of time.

• Use fitted gloves which protect the hands from contact stress.

• Keep tools well maintained and in good repair.

Additional Resources

A Guide to Selecting Non-Powered Hand Tools. US Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) and California Occupational Safety and Health Administration (Cal/OSHA), (2004, August), 20 page PDF.

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Installation and Repair: Using Tools