Nijholt, WillemkeBakker, AstridBennett, Alicia C.Borgen, Morten H.Ellermann, AnneHogg, PeterGamboa, Patrícia T.Thorskog, MartineVorster, LieslAandahl, Ingrid J.2016-12-222016-12-222016Nijholt W, Bakker A, Bennett AC, Borgen MH, Ellermann A, Gamboa PT, et al. An analysis of the validity and reliability of a handheld ultrasound device for measuring rectus femoris muscle size. In: Hogg P, Blakeley C, Buissink C, editors. OPTIMAX 2015 – Multicultural team-based research in radiography: a holistic educational approach. Groningen: Hanze University of Applied Sciences; 2016. p. 75-85.9781907842771http://hdl.handle.net/10400.21/6667Background: Previous studies show that ultrasound is valid and reliable when measuring muscle size. A Philips handheld ultrasound device was released in April 2015. The aim of this study was to investigate the validity and reliability of the handheld ultrasound device compared to a conventional ultrasound device, when measuring the size of the rectus femoris (RF). Methods: Two sonographers scanned 39 volunteers (mean age=29.3y, 26 female), once with the Toshiba SSA-660A (regular) ultrasound device and twice with the Philips hand held VISIQ device. The size of the RF (expressed in cross sectional area (CSA) was measured two ways; using the trackball on the Toshiba device and an automatic region of interest on the VISIQ device (method 1), and an ellipse on both devices using the formula π*half width*half length (method 2). Results: Method 1 resulted in an intraclass correlation coefficient (ICC) of .811 with a 95% (confidence interval) CI of .773-.837 (inter-rater reliability) and .907 with a 95% CI of .822-.951 (validity). The ICCs of method 2 were .787 with a 95% CI of .593-.888 (inter-rater reliability) and .867 with a 95 % CI of .746-.930 (validity). Conclusion: VISIQ is a valid and reliable device for measuring RF-CSA. In clinical practice VISIQ could be used for measuring RF-CSA, consequently it could be an economical and easily portable technology for use in both clinical and residential settings.engRectus femorisReliabilityUltrasoundValidityHandheldbook part