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Pilot study by ETH Zurich with Simplex 3D

The three-dimensional movement it allows is the core concept behind the Simplex 3D. To investigate the influence on sitting behaviour of the three-dimensionally mobile seat shell, the Institute for Biomechanics at ETH Zurich was commissioned to carry out a pilot study.

The pilot study was undertaken with participants in the coworking environment at the Startup Academy in Basel and in a more traditional office environment at the company JOP Josef Ottiger + Partner AG in Rothenburg.



Fabric pressure sensor | Figure 2.1Figures 2.2

Measurement method

A total of 6 chairs were fitted with sensors: 3 Simplex chairs with a 3D mechanism and, as a reference, 3 Simplex chairs without a 3D mechanism. To quantify sitting behaviour, the Sensomativescience fabric pressure sensor (Figure 2.1) was used.

A fabric pressure mat with a 14 x 14 grid of sensors (= 196 sensors) and a size of 450 mm x 520 mm was attached to the seat of the chairs, using fabric bands and belt loops. Using Bluetooth Low Energy (BLE) at a measuring frequency of 1.5 Hz, the pressure readings were transmitted to and stored on a mobile phone (Figures 2.2).

In addition, a triaxial acceleration sensor was attached to the backrests of the chairs. The acceleration data were recorded at 10 Hz and stored locally on an SD card, to enable analysis of the chair's tilt (sideways and forwards/backwards).


The pilot study successfully demonstrated that, compared with the reference Simplex chair without 3D mechanism, the Simplex with 3D mechanism can promote dynamic sitting. All the averages of the three sitting parameters ascertained ("Number of movements", "Percentage moved" and "Static sitting") point to slightly more dynamic sitting.

Simplex 3D tends to increase the dynamics of the person sitting on it by, on average, around 10 to 15%. 2/3 participants moved more when sitting on the Simplex 3D. As regards the displacement of the seat, for both the sideways movement and the forwards/backwards movement a significant increase in the useful range was observed.

The sideways tilt of the seat increased significantly by around 50%. The increase in forward and backward tilt was around 70%. All participants made use of the potential for the Simplex to tilt further sideways and exhibited an increased range of movement.