Many studies have demonstrated that discomfort lowers office productivity. For example, Liao and Druy (2000) demonstrated that the discomfort, fatigue and overuse syndromes of long periods of repeated office work reduce overall performance and productivity. However, studies also demonstrate that ergonomic changes in office equipment, especially in office seating, can greatly increase productivity and efficiency. Sullivan (1990) found that a large scale design in office space, furniture, and chairs resulted in a 64% increase in worker productivity. Dainoff (1984, 1990) reported that that the ideal ergonomic configurations of office furniture resulted in increases from 17-25% in keyboard typing input.          

 

Several studies show that traditional (and faulty) wisdom that there is one ideal posture—namely rigid and upright—shapes the design of many office chairs (Pustinger et al. 1985, Oborne 1987: 216). Coleman et. al. (1998) suggested that office chairs with traditional padded fixed height lumbar supports cannot deliver pain-free or comfortable seating for a variety of unique users. Callaghan and McGill (2001) found that static chairs do not provide enough movement to achieve muscular activation levels or relieve the weight loads put on the lower back.

 

As opposed to nonadjustable static office chairs, experts agree that that office chairs that provide a variety of possible positions are desirable for comfort and health reasons. Ergonomically equipped office chairs that allow for changes in posture minimize skeletal stress and lessen discomfort (Corlett 1989). Van Dieen et al. (2001) suggested that multi-position chairs may reduce spinal shrinkages. One study (Legg et. al. 2000) found, in a study of office workers, that the use of a multi-position chair lowered discomfort in the neck, shoulders and upper back. Simply put, “studies imply that dynamic chairs, which promote changes in posture in the user, should reduce perceived discomfort” (S.J. Legg et. al. 2002). Multi-position, or dynamic, office chairs are the true measure of ergonomic design for comfort in office chairs. 

 

Multi-position ergonomic chairs have been found to offer health benefits to their users. Stranden (2000) reports that multi-position chairs that allow for variations in the seat angle promoted leg movements in the seated position; this leads to the activation of leg veins that stoppeswelling in the lower legs and the occurrence of local oedema. S.J. Legg et. al. found that users of multi-position chairs changed their seating position more often (2002). These movements could encourage more circulation throughout the body.

 

  

 

CALLAGHAN, J. P. and MCGILL, S. M. 2001, Low back joint loading and kinematics during standing and unsupported sitting, Ergonomics, 44, 280-294.

 

COLEMAN, N., HULL, B. P. and ELLITT, G. 1998, An empirical study of preferred settings for lumbar support on adjustable office chairs, Ergonomics, 41, 401-419.

 

CORLETT, E. N. 1989, Aspects of the evaluation of industrial seating, Ergonomics, 32,  257-     269.

 

DAINOFF, M. 1984, A model of human efficiency: relating health, comfort and performance in the automated office, in G. Salvendy (ed.), Human-Computer Interaction (Amsterdam:     Elsevier), 355-360.

 

LEGG, S.J. et. al. 2002, Evaluation of a prototype multi-posture office chair, Ergonomics, 45      153-163

LIAO, M.-H. and DRURY, C. G. 2000, Posture, discomfort and performance in a VDT task, Ergonomics, 43, 345-359.

 

PUSTINGER, C., DAINOFF, M. J. and SMITH, M. 1985, VDT workstation adjustability: Effects on worker posture, productivity, and health complaints, in R. E. Eberts and C. G. Eberts (eds), Trends in Ergonomics/Human Factors II (Amsterdam: Elsevier), 445-451.

 

STRANDEN, E. 2000, Dynamic leg volume changes when sitting in a locked and free floating  tilt office chair, Ergonomics, 43, 421-433.

 

SULLIVAN, C. 1990, Employee comfort, satisfaction, and productivity; recent efforts at Aetna, in S. Sauter, M. Dainoff and M. J. Smith (eds), Promoting Health and Productivity in the Computerized Office (London: Taylor & Francis), 28-48.

 

VAN DIEEN, J. H., DE LOOZE, M. P. and HERMANS, V. 2001, Effects of dynamic office chairs on trunk kinematics, trunk extensor EMG and spinal shrinkage, Ergonomics, 44, 739-750.