Design and fabrication of a personal digital assistant (PDA) prototype for postural assessment using RULA, REBA and QEC techniques

The analysis posture methods are counted as a source of investigating the risk of musculoskeletal disorders related to work. Personal digital assistant is a small mobile system with an operative system that can install on various programs such as posture analysis methods. Firstly, three ways for posture analysis such as QEC, RULA and REBA determined. Afterward, the program of posture analysis methods written by BASCOM software with Basic language in IC MICRO CONTROLLER belong to AVR family, and interned in IC by programmer for making PDA. PDA Usability evaluated by Persian version of system usability scale questionnaire after specifying the validity and reliability of questionnaire. Finally, postural analysis was compared using a PDA with paper method. The system usability scale of PDA method is 84.2±6.2 which that got B rank and placed in very well situation. Cronbach's Alpha and Pierson correlation coefficient belongs to System usability Scale are 0.716 and 0.888, sequentially (p˂0.001). The comparison between PDA and paper methods show us that time’s operation for analysis posture in PDA method is less than half of the time in papers method. Also, the probability of calculation errors in PDA is zero, but in paper method has tolerance between 2.33 to 8.66. Use of personal digital assistant for analysis posture solved the problems related to delay achieving to final results and removed the error probability in final results.