Safety should always be a top priority. Musculoskeletal Disorders* (MSDs), caused by improper ergonomics, account for 34% of all lost-workday injuries and illnesses and account for $15-20 billion annually in workers’ compensation costs, while total direct costs can add up to $50 billion annually. Not incorporating ergonomics into your business plan incurs significant costs to you and your company. Even smaller businesses are not immune, with the average expenditure for a single upper extremity MSD case being $8,070. Start reducing time spent away from work and employee turnover rate by investing in ergonomic equipment, as well as improve the safety, productivity, and morale of your employees. Can you really afford not to invest in ergonomics?
One common tool that increases the risk for an MSD are manually-driven clamps, such as those shown below in Figure 1. Manual clamps force workers to repeatedly apply torque by twisting their wrist and arm with high force. The types of MSDs that can be caused by manual clamp usage include overexertion, soreness, Carpel Tunnel Syndrome, De Quervain’s disease, and Tenosynovitis. Depending upon the severity and type of injury, individuals can require an average of 12 to 28 days away from work. According to the Canadian Centre for Occupational Health and Safety (CCOHS), “One of the most effective ways to reducing injury risk associated with the use of manual hand tools is to replace them with power tools.” However, prior to the Dimide Clamp, shown in Figure 2, there was no alternative to manual clamps that could also be considered both powerful and portable. The Dimide Clamp changes this by offering compatibility with power tools, such as impact wrenches and pulse tools, which makes it the first clamp capable of combining ergonomics with portability, speed, and power.
Dimide has been working with several large manufacturers to help improve worker safety, comfort, and morale through programs tasked with advancing ergonomics within their workplace. The result of these programs has been increased productivity and product quality, and a reduction in costs associated with injuries.
Preventing Accidents Due to Part-Slippage
Another risk when dealing with manual clamps is part-slippage. This occurs when a clamp is delivering inadequate clamping force to hold a part, creating a significant risk toward worker safety. When relying on manually tightened clamps, several factors can lead to a preventable accident or injury. Employees who have become sore from repeatedly tightening clamps, or must tighten clamps in awkward positions, can overestimate the force that is being applied. With a Dimide Clamp, this is prevented by using power tools which will reliably deliver the same load every time. A 400-foot-pounds impact wrench has been found to reliably tighten the Dimide Clamp to over 4,000-pounds of clamp load, as shown in Video 1.
Note: If you use battery-powered power tools, keep note of your batteries charge as this will affect the clamp load applied by the Dimide Clamp.
The Ergonomics of Power Tools
While power tools prevent twisting of the hand and wrist, reduce your risk for particular MSDs such as Carpel Tunnel Syndrome, Tenosynovitis, and De Quervain’s disease, it is also important to keep ergonomics in mind when selecting these tools. Power tools can lead to other types of MSDs, including Raynaud’s Syndrome and Trigger Finger. It is therefore important to carefully select the most suitable power tool for the task at hand, and to adhere to the following power tool ergonomic guidelines:
- Prevent Raynaud’s Syndrome by:
- Limiting exposure to harmful vibrations of between 5 and 150 hertz to less than 4.5 hours per day
- Wearing full fingered work gloves and tool wraps that have viscoelastic material to absorb excess vibration
- Switch tasks to provide a recovery period and protect your hands
- Prevent trigger finger by:
- Selecting power tools with longer triggers that allow for the use more than one finger to activate them
Impact wrenches vibrate with an average acceleration of 6.6 meters per second squared and can reach noise levels ranging between 94 to 110 decibels. To protect both your hands and your ears, be aware that there are two alternatives to an impact wrench: a pneumatic nut runner with an automatic shut-off clutch, or a pulse tool. A pneumatic nut runner produces a noise level of just 77 decibels, similar to a garbage disposal, while vibrating at 2.5 meters per second squared. A pulse tool generates a noise level around 80 decibels and vibrates the least at 2.1 meters per second squared.
Providing Ergonomics Without the Need for Purchasing Expensive Power Tools
While power tools offer the greatest ergonomic improvement, the Dimide Clamp also allows you to use a wrench or breaker bar with a ½-inch hex socket in combination with a reaction bar inserted into the provided ½-inch diameter hole next to the screw, shown in Figure 3. Use of a wrench improves ergonomics by applying load horizontally through a lever arm, as opposed to a T-handle or knob which requires users to apply torque through harmful twisting of their wrists. While the wrench delivers torque to the clamp, the reaction bar acts to stabilize the clamp, preventing undesired rotation. Not only does the combined use of a wrench and reaction bar improve ergonomics, it also allows users to deliver increased clamp load - helping to further reduce the risk of part-slippage.
When selecting a hand tool, make sure to follow ergonomic guidelines:
- Look for handle diameters between 1.25-inches and 2-inches which allow for a more powerful grip
- Ensure the handle length extends across the entire breadth of your palm, including your work gloves, which is roughly between 5-inches and 6-inches
- Avoid high contact forces and static loading
- Reduce excessive gripping force or pressure
How an Ergonomics Program Benefits Your Company
Practicing ergonomics helps reduce your costs and employee turnover while also improving productivity and product quality. By reducing MSD cases, which account for 34% of all lost-workday injuries and illnesses, employees will need fewer days away from work. Not only do ergonomic practices help reduce time away from work, they also increase productivity by making jobs easier and more comfortable for workers, thus reducing fatigue and soreness. When workers become tired they are much more prone to costly mistakes.
According to Occupational Safety and Health Administration (OSHA), MSDs account for $1 out of every $3 spent on workers’ compensation. Therefore, by reducing MSDs you can lower the cost incurred through workers compensation and other payments for illnesses or replacement of workers.
Implementing an ergonomics program also does more than just save you and your company money. You also help prevent potentially permanent disabilities that prevent workers from returning to their jobs or handling simple, everyday tasks.
Common Symptoms of MSDs
You may have an MSD if you experience one or more of the following:
- Numbness in your finger[s]
- Numbness in your thighs
- Difficulty moving your finger[s]
- Stiff joints
- Back pain
Helpful links on Ergonomics