title: Neck and shoulder muscle strength in patients with tension-type headache: A case-control study.
abstract: BACKGROUND
  Tension-type headache (TTH) is highly prevalent in the general population, and it is characterized by increased muscle tenderness with increasing headache frequency and intensity.
  
  
  OBJECTIVE
  The aim of this case-control study was to compare muscle strength in neck and shoulder muscles in TTH patients and healthy controls by examining maximal voluntary isometric contraction (MVC) during shoulder abduction, neck flexion and extension as well as the extension/flexion strength ratio of the neck.
  
  
  METHODS
  Sixty TTH patients and 30 sex- and age-matched healthy controls were included. Patients were included if they had TTH ≥8 days per month. The MVC neck extensor and flexor muscles were tested with the participant seated upright. MVC shoulder abduction was tested with the individual lying supine.
  
  
  RESULTS
  Compared to controls TTH patients had significantly weaker muscle strength in neck extension (p = 0.02), resulting in a significantly lower extension/flexion moment ratio (p = 0.03). TTH patients also showed a tendency toward significantly lower muscle strength in shoulder abduction (p = 0.05). Among the 60 TTH patients, 25 had frequent episodic TTH (FETTH), and 35 had chronic TTH (CTTH).
  
  
  CONCLUSIONS
  Patients with TTH exhibited decreased muscle strength in the neck extensor muscles, inducing a reduced cervical extension/flexion ratio compared to healthy people.
authors.affiliation: Danish Headache Centre, Department of Neurology, University of Copenhagen, Glostrup Hospital, Denmark bjarne.kjeldgaard.madsen@regionh.dk.
authors.forename: Bjarne K
authors.initials: BK
authors.lastname: Madsen
authors.affiliation: Institute of Sports Science and Clinical Biomechanics, Physical Activity and Health in Work Life, University of Southern Denmark, Denmark.
authors.forename: Karen
authors.initials: K
authors.lastname: Søgaard
authors.affiliation: National Research Centre for the Working Environment, Copenhagen, Denmark.
authors.forename: Lars L
authors.initials: LL
authors.lastname: Andersen
authors.affiliation: National Research Centre for the Working Environment, Copenhagen, Denmark.
authors.forename: Jørgen H
authors.initials: JH
authors.lastname: Skotte
authors.affiliation: Danish Headache Centre, Department of Neurology, University of Copenhagen, Glostrup Hospital, Denmark.
authors.forename: Rigmor H
authors.initials: RH
authors.lastname: Jensen
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D009334:Neck Muscles / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology; D012782:Shoulder / Q000502:physiology*; D018781:Tension-Type Headache / Q000175:diagnosis* / Q000503:physiopathology*; D055815:Young Adult
keywords: Tension-type headache; extension; extension/flexion ratio; flexion; maximal voluntary contraction (MVC); neck and shoulder muscles