Translation, transcultural adaptation into Brazilian Portuguese and concurrent validity of the rheumatoid arthritis assessment scale (RAKAS-13/Brazil)

Abstract Background Knowledge of patients about Rheumatoid Arthritis (RA) is a necessary aspect to better approach self-management support in a patient-centered manner. The research instrument known as the Rheumatoid Arthritis Knowledge Assessment Scale (RAKAS), consisting of 13 items, is simple, reliable and reproducible, and can be applied in both clinical practice and research protocols. Objectives This study aimed to translate and culturally adapt the RAKAS vocabulary into Brazilian Portuguese and to evaluate its concurrent validity. Methods The RAKAS was translated into Brazilian Portuguese and administered to 52 elderly women with RA recruited between May 2021 and May 2022. Concurrent validity was assessed using the Spearman's correlation coefficient between RAKAS and Patient Knowledge Questionnaire (PKQ). Results The participants considered RAKAS-13/BRAZIL easy to understand and did not report any doubts in answering the final version. Concurrent validity of the RAKAS-13/BRAZIL was low compared to the PKQ (ρ = 0.283, p = 0.038). Conclusion The Brazilian Portuguese version of the RAKAS (RAKAS-13/BRASIL) proved to be a questionnaire that was easy and quick to administer to assess patient knowledge about Rheumatoid Arthritis, despite its low correlation with the PKQ in the present study.

Influence of subcutaneous fat on mechanomyographic signals at three levels of voluntary effort

Abstract Introduction This study aims to assess the influence of different skinfold thicknesses (ST) and their relation to the attenuation of the mechanomyographic (MMG) signal at different force levels (maximal voluntary contraction – MVC, 40% of MVC and 70% of MVC) of the rectus femoris muscle. Methods Fifteen volunteers were divided in two groups: ST lower than 10mm (G<10) (8 participants) and ST higher than 35mm (G>35) (7 participants). Student t tests were employed to investigate differences between G<10 and G>35 regarding MMG analysis parameters (acceleration root mean square – aRMS, zero crossing – ZC, and median frequency – MDF), for the X, Y and Z axes, as well as for the modulus of these three axes. Results We found that thicker layers of body fat act as attenuator filters for the MMG signal [MDFMVC: X (p = 0.005), Z (p = 0.003); MDF70%MVC: X (p = 0.034); ZCMVC: Z (p = 0.037), modulus (p = 0.005); ZC70%MVC: Z (p = 0.047)]. We found significant correlation between ST values and aRMS in three levels, in the Yaxis (p = 0.591), for the group G<10. For the modulus, the aRMS value showed correlation with ST values for group G>35 in 40%MVC (R2 = 0.610), and 70%MVC (R2 = 0.592). The MDF parameter showed correlation with ST values only in the Yaxis in 70%MVC (R2 = 0.700) for G>35. Conclusions We observed MMG signal attenuation in at least one of the parameters analyzed for each level of the rectus femoris muscle force, indicating that MMG signals are significantly attenuated with increasing thickness of the subcutaneous fat layer.