Theories of ergonomic
von Lisa Stolz·
Why furniture should allow our bodies to move?
Theories of ergonomics
The relationship between body and furniture is a widely studied topic and can be understood as part of the larger term of ‘ergonomics’. The term was defined 1949 as deriving from the Greek ‘ergon’, meaning ‘work’, and ‘nomos’ meaning ‘natural law’ (ergonomics origin and overview, no date), describing “the study of the relationship between man and his working environment” (Galley, no date).
“Throughout the last two centuries, industrialization resulted in physical inactivity and increased use of the sitting position for more and more people”, states Norwegian furniture designer Peter Opsvik, who plays a key role in modern ergonomic chair design. (2008, p.7) Consequently the impact, a seated working life can have on the body, gained a lot of attention and was focus of various studies and research projects.
As an outcome different approaches to ergonomics and how to ensure best a healthy seat have emerged since the 1980’s. A widely accepted opinion today is that there is one ideal seating posture ‘the right angle’ or ‘physiologic neutral position', which, according to physiotherapist Alexandra Gauster, is known for “causing the least mechanic charge on our bones and structure, like muscles, ligaments, tendons and joints.” (2017, p.37)
In contrary to that, the second theory is based on the idea that the body is not designed for standstill and therefore a constant change of posture is more beneficial to our health.
Galen Cranz, Professor of Architecture at the University of California, Berkeley, explains it as follows: “Another thing we can say about the structure of our bodies is that mechanical stability is not built in. The human body is a dynamic system, which cannot find stasis, so we can’t find any point of complete rest. Because we have no flat places in our joints that can be lined up against each other to lock into place, which might free muscles from having to do any work. For chair design, this means rejecting the ergonomic search for a position of ‘no work’ ”. (1998, p.130)
Peter Opsvik summarises the human need for variety in sitting in the phrase “the best posture is always the next one” and draws the comparison to sleeping behaviour, where we change position regularly. (2008, p.37)
Also big players in the furniture industry like Herman Miller support the same view. Their research revealed that people move around an average of 53 times per hour when seated. And if their chairs are inflexible, people tend to become less engaged in their work over time. (Bernard, 2016, p.38)
Negative impacts of postural fixity
Galen Cranz in her book The chair points out “If people are ‘unstable’ because they move frequently, chairs should accommodate that movement“. And, she even goes further in saying ”chairs that fail to offer that flexibility can harm our bodies”. (1998, p.95)
She underlines the possible negative effect of concentrating on only one posture, by quoting A. Grieco, director of the Institute of Occupational Health in Milan, who concludes that ergonomic furniture itself contributes to a new problem, postural fixity. According to him, ergonomic furniture has created back problems because it succeeds too well in supporting the body in one position. (Cranz, 1998, p.105)
Alexandra Gauster explains the physiologic effects of postural fixity as follows: “even if sitting in a neutral position, there is still a considerable charge on your system, which can harm your body when keeping it the whole day. Without movement our muscles become tired and tense. While moving, blood supply is enabled and circulation is stimulated”. (2017, p.37)
Dieter Breithecker, a founder of the German federal working committee for the promotion of posture and movement tells the story from a pupil’s perspective and emphasises the important relation between physical and mental activity. “Combined with the static design of most academic furniture, students are deprived of critical physical and sensory experiences that are essential for physical and mental growth. Inactive sitting places greater stress on the tissues and systems of developing bodies. Students forced to remain still in a physically static environment become more uncomfortable, more tired, and less productive“. (2015)