Ergonomic chair intervention: Effect on chronic upper quadrant dysfunction, disability and productivity in female computer workers

C Hoeben,Q Louw

doi:10.4102/sajp.v70i2.32

Abstract

AIM: To compare the effect of two ergonomic chairs on upper quadrant musculoskeletal pain and tension, disability and productivity among female computer workers in the office workplace.METHODS: A series of two N=1 studies were conducted using the A-B-A-C-A design whereby an intervention ergonomic chair was compared to a less adjustable control ergonomic chair using visual analogue scales (VAS) for pain and muscle spasm, the Neck Disability Index and the Work Productivity and Activity Impairment questionnaire. The female participants were assessed over the four week phases as they performed high intensity visual display unit work. The results were compiled and tabulated.RESULTS: Both the control and intervention ergonomic chairs showed a reduction in both the mean and variance of pain and muscle spasm. The second participant also showed an increase in productivity with both chairs.CONCLUSION: The introduction of an ergonomic chair shows a reduction in VAS intensity and frequency for pain and muscle spasm, as well as a reduction in variance of the symptoms. Both chairs showed a similar reduction in symptoms, thus indicating almost equivalent benefit from the use of both ergonomic chairs.

Highlights

Physiotherapists are often consulted for advice regarding computer workstations and the use of ergonomic office chairs to improve posture and musculoskeletal pain (Nakazawa et al 2002)
There was no history of upper quadrant
Ergonomic adaptations are a common workplace intervention to reduce upper quadrant musculoskeletal symptoms (Anderson 2006). This is the first study to report whether an ergonomic office chair, irrespective of arm rest adjustability, could have an effect on pain, muscle tension, productivity and disability. The findings of this single subject design study illustrated an immediate reduction in the intensity and variance of the symptoms following the introduction of the ergonomic chair, irrespective of which chair was allocated for the first intervention phase

Summary

Introduction

Physiotherapists are often consulted for advice regarding computer workstations and the use of ergonomic office chairs to improve posture and musculoskeletal pain (Nakazawa et al 2002). Upper quadrant musculoskeletal symptoms in the working population who use visual display units (VDU) are increasing and may be as high as 74 cases per 100 persons (Lindegard et al 2012). An ergonomic chair is one which has been designed in order to improve the performance of its user. Various ergonomic chair features are suggested to aid the user: adjustable height, adjustable back support, castors with a wide base of support, curved seat pan, arm rests (adjustable or fixed), cushioning and the comfort of the chair (European Agency for Safety and Health at Work 2005). Research to affirm these features is inconclusive (Van Niekerk, Louw & Hillier 2012)

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