title: The effects of isometric contraction of shoulder muscles on cervical multifidus muscle dimensions in healthy office workers.
abstract: It is argued that cervical multifidus muscles (CMM) are responsible for providing neck stability. However, whether they are actually activated during the tasks performed by the upper extremities to the neck is still unknown. Therefore, the aim of this study was to examine the effects of isometric contraction of shoulder muscles on the dimensions of CMM. Twenty three healthy males voluntarily participated in this study. Ultrasonography imaging of CMM was conducted at rest and at 25%, 50%, 75%, and 100% of maximal voluntary contraction of shoulder muscles in 6 directions of shoulder movements. Anterior-posterior dimension (APD), lateral dimension (LD), shape ratio and multiplied linear dimension (MLD) of cervical multifidus were measured. The APD of CMM was increased while LD and shape ratio were decreased by shoulder muscles contraction (P < 0.01).
authors.affiliation: Shahid Beheshti University of Medical Sciences, Faculty of Rehabilitation Sciences, Department of Physiotherapy, Tehran, Iran.
authors.forename: Leila
authors.initials: L
authors.lastname: Rahnama
authors.affiliation: Shahid Beheshti University of Medical Sciences, Faculty of Rehabilitation Sciences and, Physiotherapy Research Center, Tehran, Iran. Electronic address: a_rezasoltani@sbmu.ac.ir.
authors.forename: Asghar
authors.initials: A
authors.lastname: Rezasoltani
authors.affiliation: Shahid Beheshti University of Medical Sciences, Faculty of Rehabilitation Sciences, Department of Physiotherapy, Tehran, Iran.
authors.forename: Minoo
authors.initials: M
authors.lastname: Khalkhali Zavieh
authors.affiliation: Shiraz University of Medical Sciences, Department of Radiology, Medical Imaging Research Center, Shiraz, Iran.
authors.forename: Farhang
authors.initials: F
authors.lastname: Noori Kochi
authors.affiliation: Shahid Beheshti University of Medical Sciences, Faculty of Rehabilitation Sciences, Department of Basic Sciences, Tehran, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Akbarzadeh Baghban
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D004576:Electromyography; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000502:physiology*; D009333:Neck / Q000000981:diagnostic imaging / Q000502:physiology*; D016272:Occupational Health; D064170:Paraspinal Muscles / Q000000981:diagnostic imaging / Q000502:physiology; D012782:Shoulder / Q000000981:diagnostic imaging / Q000502:physiology*; D014463:Ultrasonography
keywords: Cervical multifidus muscle; Isometric contraction; Muscle dimension; Muscle size; Neck; Shoulder; Ultrasonography; Ultrasound imaging