What happens when powerful handheld tightening tools are used repeatedly at high torque? Ava Mazaheri is investigating the force exposures and how to turn the learnings into great product design.
Ava Mazaheri first joined Atlas Copco as a summer intern in the Industrial Technique business area in Sickla, Sweden. She then pursued her master's thesis project in biomedical engineering with the company, focusing on new ways of evaluating tools from an ergonomics perspective. This developed into a larger research project with the Industrial Design and Human Factors team, in collaboration with the Royal Institute of Technology in Sweden, with Ava as a PhD student.
These tools are used to fasten screws, nuts and bolts to certain torque levels, and the tool handle then undergoes a forceful displacement which we refer to as reaction force. The user must counteract the reaction through muscular force. As assembly work by nature is highly repetitive, this can lead to disorders or injuries that take a very long time to heal. My mission is to find ways to avoid that, or at least minimize the risks.
We develop and evaluate all our handheld tools from various ergonomics perspectives, such as handle design, noise, vibrations and temperature. Customers have for a long time asked for recommendations from tool manufacturers regarding reaction force exposure. Neither the scientific community nor our competitors have had well-grounded answers to provide, so we’ll be the first ones to do this. Ergonomics is key to us and makes us stand out from the crowd.
The hypothesis is that our highly dynamic tightening program, which runs with very high tool speed, is more ergonomic than traditional programs. Due to its ballistic fashion, a great deal of the reaction force is absorbed by the tool itself, instead of by the operator. However, although force is reduced, the tool motion is still jerky. The challenge lies in understanding which levels of these exposures could increase the risk of musculoskeletal disorders. It’s about finding the right balance.
Apart from providing facilities and resources, I have continuous access to expertise and input from the company, as well as from our broad network of customers. This means that I can ground my approach in real industry needs.
Yes! A gray Thursday afternoon in November 2020, with probably enough caffeine in my blood to power a small car, I discovered a way to quantitatively explain what we had previously only been able to observe and describe subjectively. I would claim this to be a, in this context, new way of measuring discomfort.