The Bottom Line: Mechanical Lifting Devices – Why Aren’t They Used?
Posted on July 12, 2022 | in Ergonomics
VelocityEHS ergonomist Blake McGowan explains why lifting devices sometimes gather dust and how companies can avoid this problem.
Hi, I’m Blake McGowan, and I’m a certified professional ergonomist with Humantech (now VelocityEHS Ergonomics). One of the questions I get a lot from management is, “Why don’t my employees use the material handling devices provided?” Management really feels frustrated. They’ve invested a lot of resources and money in these devices in the name of safety, and then the employees don’t use them. Why is this?
Well, in 1999 and 2000, Maureen Nussbaum and Don Chaffin conducted a few studies to help answer this question. Basically, they wanted to compare lifting an object manually with using a material handling device. They measured the forces, the postures, as well as the motion times. Basically, they were trying to determine the effectiveness as well as the efficiency of each device. So, what did they find?
Well, first, using a material handling device significantly reduces the forces on the hands, the shoulders, as well as the low back. Second, they found that using a material handling device really didn’t change any of the shoulder and back postures. So, these postures weren’t really reduced, and the risk associated with them aren’t reduced, and it may even increase the motion time of the task. Lastly, they found that using these material handling tasks actually increases the motion time during retrieval of the object as well as the placement.
So, what does this all mean? What’s the bottom line? Well, the bottom line is employees abandon the use of material handling devices because they are too slow. So, what can we do to improve this? How can we help management? Well, there are two recommendations.
First, we need to quantify as well as address the awkward postures in the workplace. If we address those and reduce them, we’re also going to save some time and reduce those wasted motions. Second, we need to identify and quantify the additional time needed to use this device and then account for that time in the cycle. So, overall, using these two recommendations, we can improve the effectiveness as well as the efficiency of these devices and improve use.