Construction Solutions - Ergonomic Hand Tools



Solution: Ergonomic Hand Tools
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	Description:	There is an association between use of hand tools that require awkward and forceful hand exertions and work-related musculoskeletal disorders (carpal tunnel syndrome, tendinitis, muscle strain, etc.). The foremost consideration in selecting a hand tool is to select the correct tool for the job. For example, don't use a tool that was designed for crimping wire to twist wire. Ergonomic hand tools are designed to accomplish the task with reduced hand force, awkward postures, and contact stresses. An ergonomic hand tool may address one or more of the following problems: forceful gripping bending the wrist rapid wrist movements repeating the same wrist movement many times The description below provides more information, examples and images of Ergonomic Hand Tools: More Detail The American Industrial Hygiene Association recommends that hand tool selection maximize performance and work quality, while minimizing physical demands placed on the worker. Desirable hand tool features that make the tool more ergonomic: Handle Material non-slip, soft material a sleeve can be used to cover hard handles, but be cautious because a sleeve adds to diameter and/or grip span of the tool (see below for diameter/grip span recommendations) make sure the sleeve fits snugly so that the tool doesn't slip out of the sleeve while someone is working. Operating mechanism Select spring-loaded handles that automatically return t an open position for pinching, gripping or cutting tools. Clamps, grips, or locking pliers can be used for tasks that require continuous application of force Handle diameter for single-handed tools, such as a screwdriver Between 1.25 and 2 inches for power tasks (high force) Between 0.25 and .5 inches for precision tasks (low force) Grip span for double-handled tools, such as pliers For power tasks (high force) Closed grip span at least 2.0 Open grip span less than 3.5 Spring loaded handles are preferred For precision tasks (low force) Closed grip span at least 1.0 Open grip span less than 3.0 spring-loaded handles are preferred Handle length - longer than the worker's hand width Handle shape – Avoid finger grooves and sharp edges Select a handle that helps to keep the wrist straight For horizontal forearm motions a bend handle works well For vertical movements a straight handle is usually the best choice. Example of a straight vs. bent handled tools: The California Division of Occupational Safety and Health website and NIOSH's Simple Solutions report both have some useful guidelines for hand tool selection that include many pictorial examples. Less Detail
	Risks Addressed:	Musculoskeletal disorders associated with stressful hand and wrist work activities. Injuries associated with using the wrong hand tool for the job.
	How Risks are Reduced:	Forceful hand and wrist activities, awkward postures of the wrist and other joints, and contact stress (e.g. from sharp edges) have all been associated with increased risk for musculoskeletal disorders. Ergonomic hand tools can reduce the risk of injury by: Reducing the amount of grip force required to operate a tool and perform a particular task Making it possible to perform a task while maintaining neutral, comfortable postures of the wrist, elbow, or other joints Reducing contact stress from tools that may 'dig' into hands by eliminating sharp edges, finger grooves, or excessively short handles. Quality of Evidence Independent published studies have found a risk reduction. Manufacturers, vendors, or worksites have reported a risk reduction. Safety and health experts believe there is a risk reduction. Independent studies have shown an association between musculoskeletal disorders and risk factors such as forceful exertions, awkward postures, and contact stresses (e.g contact pressures are concentrated in a small area). Measures of forceful exertions, awkward postures, or contact stresses for ergonomics hand tools tend to be lower compared to the same measures for the equivalent standard versions of the same tool, according to some studies. Companies such as Bahco North America, Klein TOOLS, Marshalltown Company, Snap-on Inc., Stanley^TM, and Swanstrom Tools USA claim that their ergonomic hand tools are able minimize exposure to forceful exertions, awkward postures, and contact stresses compared to standard versions of the tools. There have not been independent published studies measuring the effect of using ergonomic hand tools on the incidence of musculoskeletal disorders. Regardless, health and safety experts are convinced that workers will be less likely to develop musculoskeletal disorders if they use ergonomic hand tools due to reduced exposure to known risk factors.
	Effects on Productivity:	Using the appropriate tool with ergonomic features can improve productivity because workers may be able to complete tasks more quickly and with less mistakes. This increased productivity may be due to reduced muscle fatigue, fewer mistakes, the ability to use more powerful gripping positions, and less lost time due to worker musculoskeletal illnesses. Quality of Evidence Independent published studies have found an increase in productivity. Manufacturers or vendors have reported an increase in productivity. Safety and health experts believe there is an increase in productivity. Independent studies of hand tools have found that the interaction of the hand tool, its operators, the workplace, the work organization, and the work task also influence work efficiency and high product quality. Operator fatigue starts sooner when more strength is required for each hand tool exertion. Manufacturers of ergonomic hand tools claim that 'workers who are more comfortable are more productive.' The manufacturers believe that their ergonomically designed hand tools will reduce discomfort in the operator. Health and safety experts believe reducing the risk of developing musculoskeletal disorders may lead to increased productivity because: 1) workers can use tools for longer periods with fewer breaks and less fatigue, and 2) there may be a reduction in lost time injuries.
	Return on Investment:	No specific calculation ROI information exists for this particular solution, however, there are some general approaches that might be useful for a “Return On Investment” analysis. For a general discussion of these approaches, visit our “Return on Investment Calculation” page.
	Availability:	Where to Get It Ergonomic hand tools can be purchased from local or online retail stores that sell hardware or construction supplies. Several manufacturers have developed ergonomic versions of hand tools. Bahco North America Inc. www.bahco.com/us/ Klein Tools www.kleintools.com Marshalltown Company www.marshalltown.com Snap-On Inc. www.snapon.com Stanley^TMwww.stanleyworks.com Swanstrom tools USA www.swanstromtools.com Approximate Cost Many tool manufacturers now produce ergonomically improved hand tools. Often these are no more expensive than non-ergonomic tools.
	Additional Considerations:	Although it is generally a good idea to have soft handles because it reduces grip force requirements and prevents slipping, in some situations a soft handle may increase risk. In particular, if small shards of glass or metal are present in the work environment then it is possible for those shards to become lodged in the soft handle material and cut workers. Make sure that if you add a soft sleeve to a handle that the handle diameter is still no more than 2 inches. Also make sure that the sleeve does not slip on the handle.
	Sources:	Albers, James T., and Estill, Cheryl F. Simple Solutions: Ergonomics for Construction Workers. DHHS (NIOSH) Publications. March 2007. http://www.cdc.gov/niosh. To view the Table of Contents for the Simple Solutions Document, please visit: http://www.cpwr.com/simple.html. Please send requests for copies of this publication to cdcinfo@cdc.gov, referencing document number 2007-122.