Ergonomic evaluation of non-powered hand tools: introduction and validation in dentistry

Non-powered hand tools are frequently used in many trades and industries. The importance of paying attention to ergonomic design، evaluation and selection of hand tools، justify the necessity of creating an appropriate evaluating tool. The aim of the present study was to desing such a questionnaire as well as to validate it. Based on the literature، previous studies and diverse usability models، a primary questionnaire was written with 34 items to which the validation process was applied. In order to determine the reliability of the questionnaire، four commonly used non-owered dental hand tools was evaluated by 30 dental students. After confirming face and content validity،the instrument yields good internal reliability by Cronbach''s alpha coefficient equal to 0. 85، 0. 92 0. 94 and 0. 94 for aspiration syringe، usual syringe، usual forceps and notched forceps،respectively. Finally، the «ergonomic evaluation of non-powered hand tools questionnaire» consists 20 items in a 3-factor structure including usability، safety and physical interaction. The proposed questionnaire is quite brief and written in a clear and common language. Our results confirmed its applicability for dental non-powered hand tools. However، it is preferable to conduct furthere researches in order to evaluate its validity in other occupations and other non-powered hand tools.