Investing in ergonomic hand tools may seem like an unnecessary expense. However, over time, maintaining awkward postures or harmful contact pressures can contribute to costly injuries. Reduce the risk of injury by selecting hand tools that fit your hand and the job you are doing. Use the guidelines below to assist in evaluating hand tools.
• Precision tasks: Single-handle tools used for precision tasks, such as screwdrivers, should have a handle diameter between ¼ inch and ½ inch. Other ergonomic options would be to use a rachet-style screwdriver that reduces the time and force needed to complete a job.
• Power tasks: Select a tool that feels comfortable and has a handle diameter between 1 1/4 inches and 2 inches. An example of a single-handle tool used for power tasks would be a hammer or a large screwdriver.
• Power tasks: Double-handle tools used for power tasks, such as pliers, should have a grip span of at least 2 inches when closed and no more than 3 ½ inches when open. When continuous force is required, consider using a clamp, drip or locking pliers.
• Precision tasks: Select a tool with a grip span no less than 1 inch when closed and no more than 3 inches when open. Also, try to select tools that have angled or contoured handles to make the job easier. Double-handle tools used for precisions tasks are usually plier-like such as snips.
• Double-handle tools that are used for pinching, dripping or cutting, should have spring-loaded handles.
• Select a tool coated with soft material, without sharp edges or finger grooves in the handle.
• Make sure the tool can be used at an angle that allows work to be done with a straight wrist. Tools with bent handles are typically better than those with straight handles when force is applied horizontally in the same direction as the straightened forearm and wrist.
• The tool should be able to be used with either hand.
For high-force tasks
• The tools should have a handle length longer than the widest part of the hand, usually 4 to 6 inches. Prevent contact pressure by making sure the end of the handle does not press on the nerves and blood vessels in the palm of the hand. If the handle is too short, the end will press against the palm of the hand and may cause injury.
• Select a tool that has a non-slip surface to ensure the best possible grip. Adding a sleeve to the tool improves the surface texture of the handle. To prevent tool slippage within the sleeve, make sure the tool fits snugly within the sleeve.
These guidelines are adapted from "Easy Ergonomics: A Guide to Selecting Non-Powered Hand Tools," published by the National Institute for Occupational Safety and Health (NIOSH).