Sitting for prolonged periods of time makes us ill, and a lack of exercise can lead to physical as well as mental illnesses. Office staff have a particularly high risk of back pain and chronic musculoskeletal disorders since they work seated for many hours a day. As part of the Own Personal Care (OPC) project, TU Dresden researchers have analyzed the mechanics of office chairs and developed a sensor that, in combination with a dedicated software, can in the future help employees move more and more consciously during office work.

To prevent illness, people who spend a lot of time sitting are often advised to move more often. They could walk around, or alternate between different postures and strains. Depending on the mechanism, dynamic and 3D office chairs have a different pivot point and thus create a certain type of hip movement for the person sitting on the chair. The Own Personal Care project investigated, which mechanics best replicate the natural movement of the hips and spine, how much seat tilt is conducive, and what moving frequency would be best while sitting.

“We looked at the above features in a variety of 3D office chairs and found that office chairs with a center of rotation above the seat (similar to a pendulum or rocking chair) are the most beneficial from a biomechanical standpoint. Of all the models considered, the type of motion that is created for the user can be best compared to a walking motion for the pelvis and spine. This way, the intervertebral discs can be supplied with nutrients and the back muscles are tensed and relaxed,” explains Mark Bührer, project manager at OPC. “As a next step in the project, we used the results to develop a sensor that records movement behavior while sitting and that can be used in conjunction with an application software as a preventive measure to stimulate more movement in everyday office life,” adds Bührer.

© TU Dresden

The sensor is attached under the seat of the office chair. Based on various parameters, the sensor counts the number of changes in movement, calculates the energy consumption in kilo calories and provides the user with a virtual distance traveled. This results from the combination of the number of movement changes and an average step length, which is determined on the basis of the movements performed while sitting. The sensor provides both staff and managers with a preventive tool. It is coupled with a software that helps the seated person keep track of their own movement. The sensor and software are currently patent pending. In future, this innovation could play a key role in preventive care.

In our new video of the TUD series “Kurze Frage” (“Quick question”), project manager Mark Bührer shares insights into the Own Personal Care project research and explains what the optimal office chair looks like:

The OPC project has been funded by the Karl Schlecht Foundation.

Contact:

Mark Bührer, M.Eng.
TU Dresden
Institute of Material Handling and Industrial Engineering
Chair of Labour Engineering
Tel.: +49 351 463-38130
Email: