Critical Ergonomic Examination of the Impact of Personal, Postural and Design Factors upon Seat Pan Interface Pressure

The observation that most human activities are carried out seated has been verified and proven with emergence of muscolosketal disorder emanating from man machine interface in office chairs evaluation. During sitting operation ischial tuberosities becomes the main weight bearing structure in close contact with the seating surface while the lumbar spine may flatten and the pelvis rotates backward. The ergonomic office chairs selected in the study were sourced from various international manufacturers. All chairs were available to public offices (ie) they were in wide spread distribution and use at the time of this study. The six postural treatments were created using a contribution of three different trunk-high angles (100o, 1100,100o). These specific angles and the use of armrest were of particular interest due to their use in prior studies which reported significant findings for other physiological variables associated with increased (reclined) postural angle. Results indicated mean and peak pressure could indeed be represented as one “pressure factor” with factor loadings of 0.87 for every of the 2 variables, an eigen value of 1.52, and explanation of 76.2% of the total variance. Chair design qualities associated with the greatest pressure factor reduction were not expertly quantified by this study, and further investigation of chair based differences in suggested with focus upon specific engineering aspect of chair and seat pan construction