Comparison of office chairs with fixed forwards or backwards inclining, or tiltable seats

  • Tom Bendix
  • JØrgen Winkel
  • Flemming Jessen


Three adjustments of an office chair seat: — one inclining +10‡ (forwards), one inclining − 5‡ (backwards), and one being freely tiltable from −8‡ to +19.5‡ — were investigated using two groups of healthy female workers in a field (n=12), and a laboratory study (n=10), respectively. The seat adjustments were examined with regard to effects on foot swelling, lumbar muscular load, backrest pressure and subjective acceptability. Desk-work and typing were compared according to lumbar muscular activity, seat movements (tiltable seat), and backrest pressure. Foot swelling tended to increase with increasing seat height but was not influenced by the ability to tilt the seat or not. With the different seat adjustments lumbar muscular activity did not change systematically in spite of greater backrest pressure when the seat inclined backwards. The tiltable seat was preferred to the others. Typing was associated with a more constrained and tens posture than desk work, because movements, transferred to the tiltable seat, decreased and the muscular load increased. Backrest pressure was highest during typing. A tendency towards gradually increasing restlessness (i. e. seat movements) and increasing forward inclination of the tiltable seat with time was observed.

Key words

Back Electromyography Muscular load Sitting posture Tiltable seat 


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Copyright information

© Springer-Verlag 1985

Authors and Affiliations

  • Tom Bendix
    • 1
  • JØrgen Winkel
    • 2
    • 3
  • Flemming Jessen
    • 1
  1. 1.Laboratory for Back Research, Department of Reumatology, RigshospitaletState University HospitalCopenhagenDenmark
  2. 2.Work Physiology Division, Department of Human Work SciencesUniversity of LuleåSweden
  3. 3.Unit of Work PhysiologyNational Board of Occupational Safety and HealthSolnaSweden

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