A unified fuzzy system for evaluating work related postural risk score of discomfort prone body parts of workers through rapid upper limb assessment

A unified fuzzy system has been developed in this paper for assessing weighted postural risk score (PRS) of body parts by reducing errors relating to human perception in measuring exact body joint angles corresponding to different working postures used as inputs of rapid upper limb assessment (RULA) process. In the proposed method a Mamdani fuzzy inference system is generated using two input parameters based on modified Nordic questionnaire and RULA. Fuzzy analytic hierarchy process is incorporated to calculate the weight of postural risk associated with each body part using the body part discomfort scale. Finally, weighted PRS of each body part is evaluated to identify the discomfort prone body parts for taking preventive strategies well in advance. To establish application potentiality of the proposed methodology a case study is performed for assessing weighted PRS of different discomfort prone body parts of female brick moulders engaged in several brick fields.