Search Results

A need to develop methodologies to obtain objective measurements of the effects of different seat contours on people is evident. In an effort to monitor muscle activity during static seated postures, electromyography (EMG) was employed. In an experimental setting, fatigue was induced in back extensor muscles for different seated postures. The resultant EMG signals were then sampled bilaterally for three different vertebral levels and the effects of the different seating systems on posture were evaluated. In preliminary tests involving 4 subjects of similar size and build, utilizing three differently contoured seats, findings support the use of EMG to quantify muscular fatigue as a viable means of objectively measuring the effects of different seat contours.

Driver and passenger comfort, as related to automotive seats, is a growing issue in the automotive industry. As this trend continues, automotive seat designers and developers are generating a greater need for more anthropometrically accurate tools to aid them in their work. One tool being developed is the JOHN software program that utilizes three-dimensional solid objects to represent humans in seated postures. Contours have been developed to represent the outside skin surfaces of three different body types in a variety of postures in the sagittal plane. These body types include: the small female, the average male, and the large male.

Human accommodation, has undergone rapid changes in the past few years which are outdistancing current concepts, data and design tools. This paper examines the basis of current problems in the application of these tools to the design of safe and comfortable seats. Examples of the types of new data needed are given and the discussion proposes new paths to solve current problems.