title: Cardiopulmonary exercise capacity, muscle strength, and physical activity in children and adolescents with achondroplasia.
abstract: OBJECTIVE
  To study in children with achondroplasia the response to exercise and muscle strength compared with healthy peers and to describe the relation between exercise capacity, anthropometric factors, and physical activity.
  
  
  METHODS
  Patients (7 boys and 10 girls; mean age, 11.8 +/- 3.3 years) with achondroplasia performed a maximal treadmill exercise test. Anthropometric variables and muscle strength were measured and compared with the general population. The level of everyday physical activity was measured by using a diary. Functional ability was measured by using the Activity Scale for Kids.
  
  
  RESULTS
  The exercise capacity of the children with achondroplasia was significantly reduced compared with reference values. All anthropometrical measurements differed significantly from reference values. There was a decrease in muscle strength in almost all muscle groups. We found a reduced physical activity level and impairments in functional ability.
  
  
  CONCLUSIONS
  Cardiopulmonary exercise capacity and muscle strength in children with achondroplasia was reduced compared with reference values. Children with achondroplasia have a unique response to exercise. Clinicians should take these characteristic differences into account when the exercise capacity of subjects with achondroplasia is being tested.
authors.affiliation: Department of Pediatric Physical Therapy and Exercise Physiology and the Department of Pediatric Orthopedics, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands. t.takken@umcutrecht.nl <t.takken@umcutrecht.nl>
authors.forename: Tim
authors.initials: T
authors.lastname: Takken
authors.forename: Monique W M
authors.initials: MW
authors.lastname: van Bergen
authors.forename: Ralph J B
authors.initials: RJ
authors.lastname: Sakkers
authors.forename: Paul J M
authors.initials: PJ
authors.lastname: Helders
authors.forename: Raoul H H
authors.initials: RH
authors.lastname: Engelbert
mesh_terms: D000130:Achondroplasia / Q000503:physiopathology*; D000293:Adolescent; D000328:Adult; D049628:Body Size; D002648:Child; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D012307:Risk Factors; D012720:Severity of Illness Index