title: Knee function in 10-year-old children and adults with Generalised Joint Hypermobility.
abstract: OBJECTIVE
  Knee function is reduced in patients with Benign Joint Hypermobility Syndrome. The aim was to study knee function in children and adults with Generalised Joint Hypermobility (GJH) and Non-GJH (NGJH)).
  
  
  METHODS
  In a matched comparative study, 39 children and 36 adults (mean age children 10.2 years; adults 40.3 years) were included, comprising 19 children and 18 adults with GJH (Beighton ≥ 5/9; Beighton ≥ 4/9), minimum one hypermobile knee, no knee pain (children), and 20 children and 18 adults with NGJH (Beighton <5; Beighton <4). Totally, 85% of the adults were parents to these children. Knee function was determined by self-reported physical fitness (100mm VAS), Knee injury and Osteoarthritis Outcome Score (KOOS) (only adults), measured maximum isokinetic knee strength (60°/s) and peak vertical jump displacement (PVJD), with calculated knee strength balance, Hamstring/Quadriceps (H/Q) ratio and peak rate of force development (PRFD).
  
  
  RESULTS
  Adults with GJH had lower knee function (KOOS: pain, p=0.001; symptoms, p=0.001; Activities of Daily Living, p=0.001; Sport/Recreation, p=0.003; knee-related quality of life, p<0.001), and H/Q ratio (0.46 vs. 0.54, p=0.046) than adults with NGJH, regardless of age and knee pain. Both GJH groups had normal physical fitness, isokinetic knee strength, and (only children) H/Q ratio.
  
  
  CONCLUSIONS
  Children at 10 years with GJH have normal, but adults with GJH have impaired knee function. To track the risk of developing impaired knee function, children with GJH must be followed longitudinally. Meanwhile, attention to knee function may be given to children with GJH who have parents presenting GJH.
authors.affiliation: University of Southern Denmark, Institute of Sports Science and Clinical Biomechanics, Research Unit for Musculoskeletal Function and Physiotherapy, Odense M, Denmark. bjuul-kristensen@health.sdu.dk
authors.forename: Birgit
authors.initials: B
authors.lastname: Juul-Kristensen
authors.forename: Henrik
authors.initials: H
authors.lastname: Hansen
authors.forename: Erik B
authors.initials: EB
authors.lastname: Simonsen
authors.forename: Tine
authors.initials: T
authors.lastname: Alkjær
authors.forename: Jens Halkjær
authors.initials: JH
authors.lastname: Kristensen
authors.forename: Bente Rona
authors.initials: BR
authors.lastname: Jensen
authors.forename: Lars
authors.initials: L
authors.lastname: Remvig
mesh_terms: D000328:Adult; D000367:Age Factors; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000150:complications* / Q000503:physiopathology*; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D052097:Quadriceps Muscle / Q000503:physiopathology; D016059:Range of Motion, Articular / Q000502:physiology; D012737:Sex Factors; D016474:Weight-Bearing / Q000502:physiology