Issue link: https://read.dmtmag.com/i/764523
musculoskeletal disorders/sprains and strains are the single biggest component of a truck- ing company's workers' compensation claims." They say that these types of prob- lems account for 33 percent of all workers' comp claims and that the lower back is the area most affected (30 percent). As vibration is transmitted to the body, its effects can be amplified, according to a safe- ty-training program by the Texas Department of Insurance, Division of Workers' Compensation. "Vibrations can agitate the body to the point of causing micro fractures in the vertebrae, disc protrusion, nerve dam- age and acute lower back pain. Vibration also causes increased muscle tension as the mus- cles work to dampen the vibration. Plus, low-frequency vibrations of moderate inten- sity can induce sleep." Researchers are studying vibration and how it causes physical and mechanical changes to the body. "The key to reducing fatigue and improving alertness is trying to make a calm environ- ment," Bowman says. Vibration is commonly linked to driver fatigue so "what we want in the cab is materials that help dampen the vibration and alleviate some of the harshness of the driving experience," he says. This includes material used for seats and flooring. Russoli says a last item that may some- times be forgotten is noise. "To someone spending their whole day and even their whole week in a truck, noise — or perhaps better said, quiet — is important and plays a part in fatigue. The Mack cab is not only roomy and smooth riding but also quiet." He adds, "The quietness of the cab is often mentioned by drivers and with the upcoming 2017 engines with common rail fuel injection the engine runs quieter so the in-cab noise will be even less, which improves driver comfort." Take a seat It is no surprise that ergonomists and design engineers focus a great deal of attention on seats since truckers spend so much time in them. They analyze the shape and contour of the seat to understand how it impacts the pressure points and blood flow of the occupant looking at how that translates into comfort. They are trying to achieve evenly-distributed pressure from the seat. The other thing that ergonomists try to understand is the adjustability of the seat — to provide not only more adjustability but optimal adjustability because of the height range among drivers. "The key is not just giv- ing more adjustability but providing it in its optimum locations to give drivers the greatest ability to achieve a comfortable position," Bowman says. An air suspended driver's seat along with an air suspended cab, fully adjustable tilt and telescopic steering column (all found on Mack cabs) contribute to driver comfort. "Air seats with various lumbar, leg and other adjustments are common in the industry, so the customer can choose different levels of comfort in this area," Russoli says. Beyond the seat itself, part of the comfort of the seat is the seat back angle and Mack has designed the seat to be able to tilt to a comfortable position even in the rearmost position. "The roomy cab allows plenty of for- ward to aft seat adjustment and the infinitely adjustable tilt and telescopic steering column allows drivers of all sizes to find that 'just right' position," he adds. 2 0 1 6 V 3 | BULLDOG | 9 One major area where ergonomics is playing an increasing role is in the dashboard and instrument cluster. There is now so much informa- tion coming to the driver via telematics and other devices that manag- ing the real estate in the dash has become a challenge. "You are starting to see more wraparound dashboards that match the biomechanics or the reach of the driver, so the more important con- trols are within the driver's cone of vision. They are easy to read while driving without increasing the 'eyes off the road' time or having the driver reach down into the vehicle to get to certain important con- trols," Bowman explains. Russoli adds, "If the driver can see, not only out of the cab, but all the gauges and switches without having to lean forward or out of his or her driving position they will be more comfortable and less fatigued at the end of the day." The Mack dash panel is designed to wrap around the driver and the "wrap" is designed so the driver can reach all the controls while seated and without leaning out of the seat. Mack has designed the accelerator pedal and brake pedal to be parallel to each other for a smooth comfortable transition when moving the foot from one pedal to the other. The pedals are also suspended rather than pivoting up from the floor and are designed for comfort. Another development is the migration of controls to the steering wheel and stalk so the driver's hands can maintain control of the vehi- cle and reduce the amount of time the driver has to take his or her hands off the wheel. Larger multiple graphic displays replacing traditional analog gauges are also making their way into truck cabs. These new displays provide drivers with more in-depth information. "You will start to see more of this in trucks. It will move to be more like what you are already seeing in automobiles where there is a display in front of the driver and one to the side," Bowman says. He explains that the display on the side might be a touch screen that will reduce the number of switches and "help the drivers quickly get to what they need to see." Ergonomists evaluate those screens to determine which ones should be locked out while the vehicle is moving to help mitigate driver distraction. They study how the driver will use the various screens and then determine which are safe to use while driving and which are not. Dashboard and instrument cluster