title: Ultrasound Assessment of the Rectus Femoris Cross-Sectional Area: Subject Position Implications.
abstract: Ultrasonic measurement of the rectus femoris (RF) is a novel, proxy measure for muscle strength. The impact of hip flexion/head of bed positioning on RF cross-sectional area (CSA) has not been fully explored. This study describes and compares differences in RF CSA across four degrees of hip flexion. This repeated-measures, comparative study enrolled healthy, pre-menopausal women (n = 20). RF CSA of the dominant leg was measured using the SonoSite M-Turbo ultrasound system with the head of bed at 0°, 20°, 30°, and 60°. One-way repeated measures indicated significant differences in RF CSA, F(3, 17) = 14.18, p < .001, with variation in hip flexion/head of bed elevation and significant RF CSA differences between: (a) 0° and 20°, (b) 0° and 30°, (c) 0° and 60°, and (d) 20° and 60°. Standardizing patient positioning when conducting ultrasonic measurement of RF CSA is vital for researchers who assess muscle mass.
authors.affiliation: The University of Illinois at Chicago, USA ehacker@uic.edu.
authors.forename: Eileen Danaher
authors.initials: ED
authors.lastname: Hacker
authors.affiliation: The University of Illinois at Chicago, USA.
authors.forename: Tara
authors.initials: T
authors.lastname: Peters
authors.affiliation: The University of Illinois at Chicago, USA.
authors.forename: Miglena
authors.initials: M
authors.lastname: Garkova
mesh_terms: D000328:Adult; D019412:Anatomy, Cross-Sectional; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000502:physiology; D010865:Pilot Projects; D011187:Posture / Q000502:physiology*; D052097:Quadriceps Muscle / Q000502:physiology*; D013848:Thigh / Q000033:anatomy & histology / Q000502:physiology; D014463:Ultrasonography / Q000379:methods*
keywords: methodological inquiry; mobility; muscle strength testing; musculoskeletal; ultrasound