IntroductionBack Pain and Body Posture Evaluation Instrument for Adults (BackPEI-A) lags the most recent literature, as it does not assess issues related to activity increasingly present in the daily lives of people of all ages. Purpose(1) to update the BackPEI-A by including four new questions regarding the use of mobile devices; (2) to present a new graphic design of the issues related to back and neck pain to facilitate understanding of the location of these pains; (3) to test the content validity and the reliability of the new questions; and (4) to identify whether the BackPEI-A version in online form has adequate reliability. MethodsThe content validation by evaluation of eight experts, and the reliability of the new questions and of the online version were assessed. The new questions were translated to English. Content validation was assessed by the content validity index (CVI). Reliability was assessed using the agreement percentage (%C), the kappa statistic (k), and the intraclass correlation coefficient (ICC). k > 0.4 and %C > 0.5 were assumed to include new questions. ResultsThe new questions showed good agreement among the experts, k > 0.4 and %C > 0.5. Both forms applied presented an average kappa of total sample ranging from moderate to good, and moderate ICC values, showing an adequate reliability. ConclusionThe updated BackPEI-A is valid and reliable and allows the identification of aspects related to back and neck pain, as well as possible risk factors.