To ensure a good grip on a handle, sufficient friction must exist between the hand and the handle. This is particularly important where a considerable force must be applied with a sweaty hand. Hand tools should be made of non-slip, non-conductive and compressible materials.
For example, textured rubber handles provide a good grip, reduce the effort needed to use the tool effectively, and prevent the tool from slipping out of the hand. Glossy coatings and highly polished handles should be avoided. The electrical and heat insulation properties of the handles are important for power hand tools.
Handles made of plastics or compound rubber are recommended. Sharp edges and contours can be covered with cushioned tape to minimize lacerations. When manual hand tools are used for tasks that require the frequent and repetitive use of force to perform a task or job, the risk of contracting an WMSD increases.
One of the most effective ways in reducing injury risk associated with the use of manual hand tools is to replace them with power tools. Always conduct a risk assessment before making any change. Make sure that all aspects of the new tool have been considered weight, size, etc. A longer trigger which allows the use of two or three fingers to activate them reduces discomfort and minimizes the risk for injury.
The only effective way to reduce vibration in power tools is at the design stage. This fact makes tool selection most critical. The condition of tools is an important factor. Blunt or dull tools such as scissors, cutters, saws, screwdriver tips, in fact any tools in a poor state of repair, not only compromise safety but also increase sometimes by a factor of ten the effort needed to use them. Tools in poor condition should be discarded with the exception of those few that can be restored to optimum condition, for example, a wood chisel or wood saw and replaced with new ones.
Add a badge to your website or intranet so your workers can quickly find answers to their health and safety questions. If the arm is uncomfortable, the rest of the body is likely to be so as well, because it is natural to compensate for discomfort by trying to re-align the body by bending the back, rounding the shoulders, tilting the neck, and so on.
Awkward positions of the upper body considerably increase the effort needed to complete the task. The resulting fatigue, discomfort, and pain add further to the risk for developing injury.
As a rule, using a hand tool requires a firm grip. The resulting compression of soft tissue in the palm and fingers may obstruct blood circulation, resulting in numbness and tingling. Blisters are also common due to friction between the palm of the hand and the handle of the tool.
Certain heavy tools such as a chipping hammer can produce significant vibration which is responsible for handarm vibration syndrome HAVS , more commonly known as white finger or Raynaud's syndrome. Tool selection is of critical importance for user safety, comfort and health.
However even the best tool on the market will not transform a poorly designed workstation into a safe and comfortable one for the operator. Many work space components such as work surfaces, seats, flooring, tools, equipment, environmental conditions, etc. If the workplace design does not meet your physical needs, it can create risk factors for discomfort, aches and pains, fatigue, and eventually, WMSDs.
On the other hand, in a well-designed workplace, where you have the opportunity to choose from a variety of well-balanced working positions and to change between them frequently, work can be carried out safely and injury-free. Avoid bending over your work; instead keep your back straight and, if possible, elevate the work area or task to a comfortable level.
Keep your elbows close to the body, and reduce the need to stretch your arms overhead or out in front of you. Tool extensions can help where it is difficult to reach the object of work. Using a stepladder or step-stool can improve the working body position where the task requires elevating your arms above the shoulder.
At the same time, frequent stretching breaks will relieve any built-up muscle tension. If standing, distribute your weight evenly between the feet. Even better, use a foot stool or rail to rest your legs, and shift from one to the other periodically.
How should one design the workstation for precision work? Provide the worker with a height-adjustable workstation Figure 1a. For a fixed-height workbench: provide work platforms to accommodate shorter workers; raise the work surface for taller workers. Provide sufficient leg clearance to allow the worker to get close to the work object, thereby reducing the need to bend the torso. Provide a foot rest as foot support that will improve body balance and minimize the static load on the workers back.
Anti-fatigue matting reduces lower back and leg discomfort and minimizes fatigue. Consider using chairs or stools to allow work in a sitting or standing position.
Where feasible provide the worker with a tilted workstation. This reduces static load on the back and upper body Figure 1b. Use jigs or vices to hold the work object steady and secure at the proper height and position for optimum comfort Figure 1c. Use vices to minimize pinching and gripping forces. In assembly work, static load, awkward postures and forceful movements are major risk factors for WMSDs.
Prolonged standing and the fatigue resulting from it additionally contribute to WMSDs. Use jigs and vices to hold the work object steady at the right height and position for optimum comfort Figure 2a. Use tool balancers to reduce the effort of holding and operating the tool Figure 2b. If possible use the lightest tool that can get the job done properly, preferably one weighing less than 1 kg 2 lbs. People working at a correctly designed workstation and using the best available tools can still get injured.
It happens where their work is poorly designed. Work organization involves:. Jobs that involve using only one kind of tool for one or a few tasks that do not vary in the movements and muscles used can cause an overload of those muscles, ligaments, tendons or tissues. The resulting overload on the same part of the body can cause pain and injury.
A greater variety of tasks allow for changing body position to distribute the workload over different parts of the body, and to give overtaxed muscles some relief and recovery time.
Rotate tasks among workers; have workers move from one task. Ensure tasks are different in the type of movement and body parts used. Add more tasks to the job. Assign a larger part of work to a team: workers form a team and each member of the team shares several different tasks. A fast pace of work is a strong risk factor for WMSDs. If the pace is too fast, the muscles involved do not have enough time to recover from the effort and to restore sufficient energy to continue the work.
If the pace of work is imposed externally -- assembly. Incentive systems that reward for the quality of work naturally determine the "right" pace of work. Incentive systems that reward for the amount or quantity of work increase the risk for WMSDs and, in the long run, will compromise quality as well.
The work break is a time period between tasks. Even short periods of time, literally seconds, that allow one to relax muscles involved in operating tools are important in preventing injuries. The rest break is the period after work stops.
Besides allowing for refreshment, rest breaks can be used to stretch and relax. An adjustment or acclimatization period is the time needed to get "in shape" when returning to work after a long absence, or when starting a new job. It should allow one to refresh old work habits or get used to a new routine. An adjustment period is a very important element of injury prevention.
Having a supply of industrial ergonomic hand tools available for your employees can help to reduce the risk of work-related musculoskeletal disorders. For a hand tool to be considered ergonomic , it should be safe to operate with one hand. Ergonomic handles for hand tools should be cushioned and non-slip.
Managers and administrators involved in the purchase of work tools review ergonomic guidelines. Before beginning your search into ergonomic hand tool design, start by asking yourself these questions:. When choosing ergonomic tools , consider grip diameter on the single-handle tools such as hammers, nut drivers, wrenches, and screwdrivers. Larger diameters allow workers to grip these tools more comfortably and reduces stress on the hands, wrists, and fingers.
Single-handle tool diameters should range from one and a quarter inch to two inches to help prevent tool slippage. Of course, there are times where the work requires more delicacy.
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