title: Reduced neck-shoulder muscle strength and aerobic power together with increased pericranial tenderness are associated with tension-type headache in girls: A case-control study.
abstract: BACKGROUND
  Tension-type headaches (TTH) are common among children worldwide and mean a potential risk of disability and medication overuse headache. The associated mechanisms, however, remain unsolved. Our study investigated muscle strength in the neck-shoulder region, aerobic power and pericranial tenderness in girls with TTH compared with healthy controls.
  
  
  METHODS
  A blinded case-control study comprising 41 girls with TTH and 41 age-matched healthy controls. Standardised testing of isometric maximal voluntary contraction (MVC) and force steadiness of neck flexion and extension, as well as MVC and rate-of-force development of dominant shoulder, was conducted. VO2 max was recorded by a submaximal ergometer test and pericranial tenderness by standardised manual palpation. Logistic regression analyses were applied.
  
  
  RESULTS
  Girls with TTH demonstrated significantly higher pericranial tenderness than controls, in correlation with headache frequency (r = 0.66, p < 0.001). Results indicated that the odds ratio of girls having headache are 7.6 (95% CI 1.4-40.9) for weak to strong shoulder muscles; weak to average neck-shoulder strength OR 3.1 (95% CI 1.2-8.1); neck flexion strength OR 1.3 (95% CI 1.0-1.6) and 5.2 (95% CI: 1.4-19.6) for each unit of decrease in VO2 max.
  
  
  CONCLUSIONS
  Reduced neck-shoulder strength and aerobic power together with increased pericranial tenderness are associated with TTH in girls. Future interventions should be directed towards health promoting patient educational programmes on enhanced physical exercising. Much more exact and detailed research in young girls and boys are needed.
authors.affiliation: Department of Health Sciences, Lund University, Sweden Children's Headache Clinic, Department of Paediatrics E, University of Copenhagen, Herlev Hospital, Denmark Department of Physiotherapy and Occupational Therapy, University of Copenhagen, Glostrup Hospital, Denmark Department of Physiotherapy, Medical Department O, University of Copenhagen, Herlev Hospital, Denmark Birte.tornoee@regionh.dk.
authors.forename: Birte
authors.initials: B
authors.lastname: Tornoe
authors.affiliation: National Research Centre for the Working Environment, Ministry of Employment, Denmark.
authors.forename: Lars L
authors.initials: LL
authors.lastname: Andersen
authors.affiliation: National Research Centre for the Working Environment, Ministry of Employment, 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
authors.initials: R
authors.lastname: Jensen
authors.affiliation: Department of Health Sciences, Lund University, Sweden.
authors.forename: Gunvor
authors.initials: G
authors.lastname: Gard
authors.affiliation: Children's Headache Clinic, Department of Paediatrics E, University of Copenhagen, Herlev Hospital, Denmark.
authors.forename: Liselotte
authors.initials: L
authors.lastname: Skov
authors.affiliation: Department of Health Sciences, Lund University, Sweden.
authors.forename: Inger
authors.initials: I
authors.lastname: Hallström
mesh_terms: D016022:Case-Control Studies; D002648:Child; D015444:Exercise / Q000502:physiology*; D005260:Female; D019416:Head Movements / Q000502:physiology; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D009334:Neck Muscles / Q000503:physiopathology*; D019547:Neck Pain / Q000503:physiopathology*; D010100:Oxygen / Q000097:blood; D010809:Physical Fitness / Q000502:physiology; D012016:Reference Values; D012782:Shoulder / Q000503:physiopathology*; D018781:Tension-Type Headache / Q000503:physiopathology*
chemical_list: D010100:Oxygen
keywords: Neck and shoulder muscles; cardiovascular fitness; children; hypersensibility; strength capacity; tension-type headache