title: Local architecture of the vastus intermedius is a better predictor of knee extension force than that of the other quadriceps femoris muscle heads.
abstract: The purpose of this study was to determine whether the muscle architecture of each head of the quadriceps femoris (QF) at multiple regions can be used to predict knee extension force. Muscle thickness and pennation angle were measured using sonographic images from multiple regions on each muscle of the QF with the knee flexed to 90°. The fascicle lengths of the rectus femoris (RF), vastus lateralis (VL) and vastus intermedius (VI) muscles were estimated based on sonographic images taken along the length of the thigh. The muscle architecture of the vastus intermedius was determined in two separate locations using sonographic images of the anterior (ant-VI) and lateral portions (lat-VI). The maximal voluntary contraction (MVC) was measured during isometric knee extension at a knee joint angle of 90°. The relationship between MVC force and muscle architecture was examined using a stepwise linear regression analysis with MVC force as the dependent variable. The muscle thickness of the ant-VI was selected as an independent variable in the first step of the linear regression analysis (R(2) = 0.66, P<0.01). In the second step, pennation angle of the lat-VI was added to the model (R(2) = 0.91, P<0.01). These results suggest that among the four muscles that make up the QF, the muscle architecture of the VI is the best predictor of knee extension force.
authors.affiliation: Graduate School of Education and Human Development, Nagoya University, Nagoya, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Ando
authors.affiliation: Graduate School of Education and Human Development, Nagoya University, Nagoya, Japan.|Japan Society for the Promotion of Science, Tokyo, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Saito
authors.affiliation: School of Health and Sport Sciences, Chukyo University, Nagoya, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Umemura
authors.affiliation: Graduate School of Education and Human Development, Nagoya University, Nagoya, Japan.|Research Center of Health, Physical Fitness & Sports, Nagoya University, Nagoya, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Akima
mesh_terms: D000328:Adult; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology* / Q000648:ultrastructure*; D016059:Range of Motion, Articular / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D014463:Ultrasonography
keywords: fascicle length; knee extensor strength; muscle thickness; pennation angle; quadriceps femoris; ultrasonography