Back Pain and Body Posture Evaluation Instrument for Adults: Expansion and Reproducibility.

Background: The BackPEI questionnaire was developed and validated just exclusively to evaluate children.

Aims: To propose, validate, and test the reproducibility of an expanded version of the Back Pain and Body Posture Evaluation Instrument (BackPEI), originally designed to assess back pain in school-aged children, for use with adults.

Design: Validation Study.