Table 2 Characteristics of the six chairs used: special attributes, sitting area and height of sitting position
| Chair | Abbreviation |
Special attributes/ backrest | Sitting area | Height of sitting position (knee ankle) | Company, chair name |
|---|---|---|---|---|---|
| Chair 1 | Sib | no backrest | disc-shaped, horizontal | height adjustable | Sirona, CARL |
| Chair 2 | Sal | no backrest | saddle-shaped, two parts mutually adjustable, adjustable inclination |
height adjustable manufacturer information: 135° knee angle | Salli, Saddle chair |
| Chair 3 | Sio | backrest removed | ventrally inclined, flexible in the front part | height adjustable | Sirona, Hugo Freehand |
| Chair 4 | Sw | no backrest | hemispherical, resilient, flexible | height adjustable weight adjustable, spring tension adjustable, lateral deflection adjustable | Aeris, Swopper |
| Chair 5 | Kg | backrest removed | ventrally inclined, central elevation | height adjustable | KaVo, Physioform 5005 |
| Chair 6 | Kb | backrest removed | ventral inclination to max. 15°, central elevation | height adjustable | KaVo, Evo |