title: Modifying a shrug exercise can facilitate the upward rotator muscles of the scapula.
abstract: BACKGROUND
  Scapular dyskinesis, characterised by drooping scapulae and reduced upward rotation, has been implicated in the presentation of a number of shoulder disorders. Traditionally, in shoulder rehabilitation programmes, the shrug exercise has been prescribed to facilitate upward rotation of the scapula by strengthening the upper trapezius muscle. The aim of this research was to compare muscle activation levels during the standard shrug and the upward rotation shrug in a normal and pathological population.
  
  
  METHODS
  Surface electrodes recorded electromyographical activity from upper trapezius, middle trapezius, lower trapezius and serratus anterior muscles in 23 normal participants and 14 participants with multi-directional shoulder instability. Participants completed 10 trials of the standard shrug exercise at 0° of shoulder abduction and the upward rotation shrug exercise at 30° of shoulder abduction in the coronal plane. Muscle activity was expressed as a percentage of maximum voluntary isometric contraction.
  
  
  RESULTS
  The four muscles tested performed at a higher intensity during the modified shrug than the standard shrug. Upper trapezius and lower trapezius activity was significantly greater (P < 0.05) in both populations. Though for middle trapezius and serratus anterior muscles, the modified shrug was statistically significant only in the normal population, P = 0.031 and P = <0.001 respectively.
  
  
  CONCLUSIONS
  The upward rotation shrug is a more effective exercise for eliciting muscle activity of the upper and lower trapezius than the standard shrug in a normal and multi-directional instability population. Clinically, the upward rotation shrug might be useful to address scapular dyskinesis involving drooping shoulders and reduced scapula upward rotation.
authors.affiliation: Lower Extremity & Gait Studies Research Group, Australia; Department of Physiotherapy, La Trobe University, Victoria, Australia. Electronic address: t.pizzari@latrobe.edu.au.
authors.forename: Tania
authors.initials: T
authors.lastname: Pizzari
authors.affiliation: School of Biomedical Science, Charles Sturt University, NSW, Australia.
authors.forename: James
authors.initials: J
authors.lastname: Wickham
authors.affiliation: LifeCare Prahran Sports Medicine, Victoria, Australia.
authors.forename: Simon
authors.initials: S
authors.lastname: Balster
authors.affiliation: Department of Physiotherapy, La Trobe University, Victoria, Australia.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Ganderton
authors.affiliation: Department of Physiotherapy, La Trobe University, Victoria, Australia; LifeCare Prahran Sports Medicine, Victoria, Australia.
authors.forename: Lyn
authors.initials: L
authors.lastname: Watson
mesh_terms: D000293:Adolescent; D000328:Adult; D004576:Electromyography; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D007593:Joint Instability / Q000503:physiopathology* / Q000534:rehabilitation; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology* / Q000503:physiopathology; D012399:Rotation; D012540:Scapula / Q000502:physiology*; D019534:Shoulder Impingement Syndrome / Q000534:rehabilitation; D012785:Shoulder Joint / Q000502:physiology* / Q000503:physiopathology; D064171:Superficial Back Muscles / Q000502:physiology* / Q000503:physiopathology; D055815:Young Adult
keywords: Electromyography; Rehabilitation; Shoulder; Trapezius