Purpose:
To be used across different cultures, a physical activity questionnaire must be translated and cross-culturally adapted into target languages with a structured method. To date, there is no evidence supporting the use of the Physical Activity Questionnaire for Children (PAQ-C) in Brazil. Therefore, the purposes of this study were to translate and crossculturally adapt PAQ-C into the Brazilian Portuguese language and to determine its measurement properties.

Methods:
Overall, 82 participants were initially recruited and the final PAQ-C version was applied in 52 children (28 boys, 24 girls). The translation and cross-cultural adaptation process was performed, and the measurement properties of the Brazilian Portuguese version of PAQ-C were determined in order to assess the internal consistency (Cronbach’s alpha), test-retest reliability (ICC , intra-class correlation coefficient) and the level of agreement between test-retest measurements (Bland-Altman method). Paired t-test was used to compare PAQ-C means (test-retest).

Results:
The meaning of the items was considered easily understood by the children. Cronbach’s alpha reached acceptable values, ranging from 0.85 (test) to 0.87 (retest). ICC equalled 0.90, indicating excellent test-retest reliability. Paired t-test showed no significant difference between means. Bland-Altman plot proved a good level of agreement between two measurements.

Conclusions:
The translation and cross-cultural adaptation process was successful in reaching semantic equivalence between the original PAQ-C and the Brazilian Portuguese version; the measurement properties of the new PAQ-C version achieved a good level. Therefore, this study provided evidence supporting PAQ-C use among Brazilian children.