An investigation on inter-individual variation in perceived discomfort of static posture holding.

Abstract

Realizing population-level discomfort evaluation and control of common static posture holding tasks requires an understanding of the inter-individual variation in discomfort perception. However, little research is available. This study aimed to determine the types of mathematical probability distribution suitable for modeling population discomfort distributions of various static posture holding tasks and characterize how the magnitude of inter-individual variation in perceived discomfort varies across static posture holding tasks. Ten male and ten female subjects participated. The participants conducted static posture holding for a set of 180 short-duration (20-second-long) static posture holding tasks and subjectively rated the overall perceived discomfort for each task using the Borg CR-10 discomfort scale. Statistical analyses were conducted according to the study objectives. The static posture holding tasks exhibited multifarious discomfort distribution patterns. Probability distribution identification analyses indicated that no single distribution type could represent population discomfort distributions universally across different static posture holding tasks. Sample standard deviation of discomfort ratings data quantifying the magnitude of inter-individual variation in discomfort perception varied considerably across static posture holding tasks. It seemed to have a positive relationship with sample mean within the range of the experimental conditions. Population-level evaluation of discomforts associated with static posture holding tasks must be based on careful examinations of empirical discomfort distributions.