Ergonomic Control Measures - Hand Tool Operation

angled wrench for ergonomic work

Each year, hand tools are a significant source of compensable injuries in the workplace. Many of these injuries can be prevented through the use of proper technique and equipment.

Powered and non-powered hand tool operation is found in many occupations, including:

  • assembly;
  • construction;
  • equipment/vehicle maintenance and repair;
  • metalworking; and
  • woodworking.

Each year, hand tools are a significant source of compensable injuries in the workplace. To eliminate, reduce or control the frequency and severity of these injuries, the following ergonomic control measures should be implemented:

Reduce Vibration

  • Only properly balanced tools should be utilized.
  • Tool speed should be reduced.
  • Duration of use should be reduced.
  • Tool cushioning, suspension, exhaust ports and vents should be improved.
  • Workers should wear gloves to dampen vibration.
  • Tool grips and handles should be wrapped with cushioning material.
  • Replace one-finger activated tools with lever arm, air-operated push start methods or thumb-switch tools.
  • Personnel should be rotated to reduce their exposure time.

Reduce Torque

  • Slip-clutches or torque limiters should be installed on the tools.
  • Tools can be mounted on an articulated arm to keep torque from reaching the worker's hand(s).
  • Extra handles can be provided to allow worker to use both hands to counter the torque.
  • Torque settings should be kept as low as possible.
  • Personnel should be rotated to reduce their exposure time.

Grips and Handles

  • Grips and handles should be designed to keep wrists as straight as possible.
  • Positive stop or flanged end grips should be provided to increase hand stability.
  • Sharp corners should be eliminated.
  • The use of form-fitting handles should be avoided.
  • Textured surfaces should be provided.
  • Neutral-torque tool balances should be utilized.
  • Clutch and tool extensions should be kept as short as possible to minimize balancing problems.
  • If gloves must be worn, they should cover only the areas of the hands needing protection, not the entire hand.

Force Requirements

  • Tool handle should be altered to make it more efficient.
  • Tool weight should be reduced.
  • Tools should be held at their center of gravity.
  • Use power tools rather than non-powered tools.
  • Tools should be counterbalanced and suspended to eliminate the need for the worker to support the tool.

Hand Positions

  • Ergonomically designed tools, which allow straight-wrist positions and minimize bent-wrist positions, should be utilized.
  • Alter or modify the work task to the current tools to allow straight-wrist positions and to minimize bent-wrist positions.
  • Angle the work object/surface to improve accessibility.
  • Switch to power tools and reduce the force necessary to operate hand tools.

Non-Powered Hand Tools

  • Utilize ergonomically designed tools, which allow straight-wrist positions and minimize bent-wrist positions.
  • Awkward hand positions (primarily bent-wrist positions) should be avoided.
  • Force required to use the tool should be minimized.
  • Adequate hand grips should be provided.
  • Tool handles should extend past the palm of the worker's hand. Surfaces should be broad to distribute pressures evenly. Surfaces should also be padded and slip resistant.
  • Sharp corners and edges should be eliminated.
  • To maximize grip strength while using tools, such as pliers, wire strippers or scissors, distance between tool handles should be kept between 2.5 to 3.5 inches.