Over the last three or four years, more utilities have been adding ergonomic experts to their tool committees. So far, it has primarily been the larger Investor Owned Utilities (IOUs), but the trend is clear and mid-sized companies and municipalities are now doing the same.
The primary goal of these safety committees are to maintain worker quality of life over the long term. Ergonomic experts do this by evaluating the tools their workers use and find ways to make the work more ergonomic, either by choosing other tools or by changing work practices.
“In response, we began testing our utility tools, which include Sherman + Reilly, Greenlee Utility and HD Electric Company products, and when necessary, redesigning tools to make them safer and easier to use. Now, ergonomic testing is a part of everything we do, from concept design to product updates, we aim to ensure our tools are safe for the end user over the entire product lifespan,” said Denis Hanna, Director of Sales and Marketing, Textron Utility - Sherman + Reilly, HD Electric Company and Greenlee Utility.
Figure 1: Linemen come to the lab and a variety of sensors are placed on their skin. They then use the tool in a variety of positions, while the electrical activity in their muscles is monitored.
Prevent Soft Tissue Damage
An effective tool is designed to get the job done but it must also protect a lineman’s physical well-being. One of the dangers of poorly designed tools is soft tissue damage, which is a common injury found in lineman and has been a priority for the industry to prevent.
Soft tissue damage is not immediately apparent; the effects are cumulative and can be debilitating over the course of a career. Ergonomic design reduces the risk of small tears in a number of ways, primarily by reducing muscle fatigue. Fatigue is the precursor to injury.
“The first step toward ergonomic design is to reduce the amount of force needed to do a particular task. For example, linemen commonly use tools to cut conductors. If a manual tool such as a bolt cutter is used to cut a conductor, a significant amount of force is required to bring both arms together. If a lineman repeatedly performs this action, his chest and arm muscles are at risk of fatigue and injury. By transitioning to a battery powered cutting tool, the muscle use is greatly reduced,” said Ryan Berg, Director of Product Development, Textron Utility.
The next thing to consider is ergonomic posture. Actual line work is not performed in a lab. Workers typically reach and bend, so the ergonomics of a tool’s performance needs to be tested in variety of different positions. An effective tool is designed to work well in any posture.
The length of cycle time is also important. Cycle time is how long it takes to perform a specific, small activity. The less time, the better. While one cut may not have any implications, the repetitive motion can.
Figure 2: The electromyograph reveals which muscles are being used and how hard they are contracting. This information can be used to improve tool design.
Muscle Tests
Data from a number of sophisticated tests is used to design an ergonomic tool. Textron’s utility businesses perform in-house testing and also commissions third party testing for objectivity.
Once the muscles using the highest amount of energy are identified, tools and work practices can be designed to minimize the amount of energy required. In short, ergonomically designed tools are easier to use, require less energy, and are less likely to cause muscle fatigue. The test results are quantitative and can be used to compare tools from various vendors and different work practices to find the best position and most effective tool.
Better ergonomics lead to healthier workers, which is the main goal. It is also positive for the utility’s bottom line: jobs are completed faster; fewer workers need time off to heal; workman's compensation costs decrease; and experienced workers can continue on the job for longer, minimizing training costs. It is an overall win.
At the end of the day, the common goal is to keep linemen healthy.
