title: Mechanical environment of the supraspinatus tendon: a two-dimensional finite element model analysis.
abstract: We performed 2-dimensional finite element model analysis to estimate the mechanical environment of the supraspinatus tendon. The geometric shape of the finite element model was determined by magnetic resonance imaging of a normal human shoulder obtained at 0 degrees, 30 degrees, and 60 degrees of abduction, whereas the histologic location of noncalcified and calcified fibrocartilage was determined from a cadaveric specimen. The supraspinatus tendon was pulled proximally with the force of 10 N at 0 degrees, 53 N at 30 degrees, and 115 N at 60 degrees of abduction. The area of high principal stress maximum was observed on the articular side of the supraspinatus tendon, which shifted toward the insertion as the arm was abducted. High stress concentration on the articular side of the supraspinatus tendon near its insertion during arm elevation may explain the frequent occurrence of rotator cuff tears at this site.
authors.affiliation: Department of Orthopedic Surgery, Akita University School of Medicine, Hondo, Japan.
authors.forename: Ikuko
authors.initials: I
authors.lastname: Wakabayashi
authors.forename: Eiji
authors.initials: E
authors.lastname: Itoi
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Sano
authors.forename: Yotsugi
authors.initials: Y
authors.lastname: Shibuya
authors.forename: Ryuji
authors.initials: R
authors.lastname: Sashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Minagawa
authors.forename: Moto
authors.initials: M
authors.lastname: Kobayashi
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013314:Stress, Mechanical; D013710:Tendons / Q000503:physiopathology*; D013718:Tensile Strength