Analysis of partial-body and whole-body static sitting comfort

Abstract

The whole-body comfort sensation was moderately to highly correlated with local body part comfort sensation in both sitting and driving, in order to understand what exact relationship exists between them, the seating comfort evaluations under the stimulus of four body parts (i.e. backs, waist, hips and thighs) were carried out for 15 subjects separately, subjective ratings on both partial-body and whole-body comfort are derived under different conditions. Impact factor (IF) of the partial-body comfort to whole-body comfort is calculated by the linear regression method, and the main variables are obtained by the stepwise regression algorithm. The most significant local body part in influencing whole body comfort is found at the region of hips, followed by backs, waist and hips. With impact factor analysis on partial body comfort, the results show that the local comfort feeling of waist is most potential to be influenced by other body parts, while the comfort sensitivity of thighs is the lowest.

Railways Passengers Comfort Evaluation through Motion Parameters: A Systematic Review

“…The increased contact area also supports this fact [67]. Xu et al [60] discussed the association between local comfort and whole-body comfort. Four body parts were defined: the back, waist, hips, and thighs.…”

“…Moreover, pressure distribution directly correlates with seat comfort and subjective comfort evaluation once it is obtained with a person sitting. This way, pressure measurements evaluate the biomechanics factor of sitting discomfort by evaluating and correlating objective measurements with subjective rankings [3,9,60,61].…”

“…When a passenger sits down, more than 70% of their body weight is supported by the seat cushion, resulting in a significant concentration of pressure, particularly in the ischial tuberosity area, leading to pressure peaks. This interface pressure causes low oxygen content in cells, inducing fatigue, pain, and discomfort [10,60,62,63]. However, the literature has no consensus about the maximum pressure threshold.…”

“…Multiple authors defend the fact that 32 mmHg should not be exceeded. That pressure corresponds to the capillary pressure value, and an above-normal pressure can be considered harmful once it can obstruct the capillaries, restricting blood circulation and, consequently, resulting in a deprivation of oxygen in the tissues, causing discomfort [59,60,[64][65][66]. In contrast, other authors state that a seat is considered comfortable if it presents a maximum of 43.50 mmHg pressure under the ischial tuberosities and 21.75 mmHg elsewhere.…”

“…Pressure measurements and a subjective ranking assessed discomfort. Results highlighted the hips as the most significant body part affecting whole-body discomfort, followed by the back, waist, and thighs (Figure 6a; [60]). A similar study by Peng et al [63] revealed the passengers' local and overall comfort degradation mechanisms on high-speed railways.…”