New Equipment vs Ergonomic Posture on Old Equipment in Manual Material Handling
Most manual material handling (MMH) requires some cognitive and physical multitasking. The ability to multitask is such a given these days that managers gloss over it on resumes. Still, multitasking is a skill in which many people pride themselves. However, according to Stanford University researchers, with the exception of about three percent of the population, “…gifted multitaskers actually perform worse than those who prefer to complete one task at a time” (http://www.ergoweb.com/news/detail.cfm?id=2712). How do these studies relate to MMH and ergonomics?
MMH is one of the highest-risk industries for work-related musculoskeletal disorders (MSDs) and other injuries. Ergonomic specialists look at factors like repetition, force, posture, and duration of activities when recommending changes to job tasks. Therefore, equipment and workstations are often redesigned to eliminate repetitive movements and place the employee in a neutral posture that is right for his or her specific height.
When redesign and equipment is too costly, however, management may be tasked with training employees on proper body mechanics. Here employees are asked to do the same work but focus on maintaining the appropriate posture so as not to hurt him or herself. Is this really an efficient and productive solution?
Research on Multitasking
When a person is focused on one task, both sides of the brain are engaged in the task. When a second task is introduced, the brain dedicates one side to each separate task. Generally speaking, a person can accurately complete two tasks at a time. Add more tasks, however, and performance suffers. In MMH, employees are simultaneously engaged in at least one physical activity and one mental activity. The more experience a person has with a task, the more second-nature it becomes. Similarly, managers would expect productivity to be slowed initially when employees have to think about new body mechanics. After a while, it should become second nature and not slow a person down. However, the brain still has to focus on a physical activity even when a person no longer has to think about it. We can compare this to a well-researched combination of tasks that are second-nature to most adults: driving while talking on the phone.
The majority of drivers feel they’re the exception to the rule that talking on the phone negatively affects our driving. Researchers at the University of Utah attribute our self-bias to inattention blindness. When we talk on our cell phones, we don’t notice our own driving impairments. What we do know, according to various studies, is that “driving performance is significantly degraded by cell phone conversations. For example, when drivers talk on either a handheld or hands-free cell phone, brake reaction times are delayed, object detection is impaired, traffic-related brain potentials are suppressed, and accident rates increase” (http://www.psych.utah.edu/lab/appliedcognition/publications/supertaskers.pdf). Additionally, this article states, “Elsewhere, it has been demonstrated that cell-phone conversations lead to a form of inattention blindness, causing drivers to fail to see up to half of the information in the driving environment that they would have noticed had they not been conversing on the phone.”
So we see that driving, multitasking we can mostly do without thinking about it unless we need to react, is negatively impacted by simply talking on the phone – even a hands-free set. Worse, we generally have no idea that our performance is suffering when we talk on the phone.
We can therefore assert that this also happens when we have to teach our bodies proper mechanics in addition to the tasks we are already attempting. Even when we don’t have to think about the body mechanics anymore, our brains have to prioritize activities. Either body mechanics will take priority and productivity will suffer, the task will be successfully accomplished but safety will be compromised, or none of the tasks will be performed at a successful level.
Ergonomic equipment is designed so that proper posture is natural when using it. For example, Load Mover power tuggers have adjustable handles to accommodate any range of adult height. With proper posture taken care of, using ergonomic equipment limits the number of tasks a person has to focus on. Additionally, this equipment is known for boosting productivity, even if the change isn’t automating a process. Increased productivity is consistently noted in case studies of companies who use tuggers. In both cases on tuggers and dramatic ergonomic overhauls, businesses report that the increased productivity and safety yields enough profit that equipment is fully paid for within five years.
When choosing between a financial investment in ergonomics or training employees to use their bodies differently, the latter is actually more costly in the end.