title: Repeatability and validity of a standardised maximal step-up test for leg function--a diagnostic accuracy study.
abstract: BACKGROUND
  Objectively assessed physical performance is a strong predictor for morbidity and premature death and there is an increasing interest in the role of sarcopenia in many chronic diseases. There is a need for robust and valid functional tests in clinical practice. Therefore, the repeatability and validity of a newly developed maximal step up test (MST) was assessed.
  
  
  METHODS
  The MST, assessing maximal step-up height (MSH) in 3-cm increments, was evaluated in 60 healthy middle-aged subjects, 30 women and 30 men. The repeatability of MSH and the correlation between MSH and isokinetic knee extension peak torque (IKEPT), self-reported physical function (SF-36, PF), patient demographics and self-reported physical activity were investigated.
  
  
  RESULTS
  The repeatability between occasions and between testers was 6 cm. MSH (range 12-45 cm) was significantly correlated to IKEPT, (r = 0.68, P < 0.001), SF-36 PF score, (r = 0.29, P = 0.03), sex, age, weight and BMI. The results also show that MSH above 32 cm discriminates subjects in our study with no limitation in self-reported physical function.
  
  
  CONCLUSIONS
  The standardised MST is considered a reliable leg function test for clinical practice. The MSH was related to knee extension strength and self-reported physical function. The precision of the MST for identification of limitations in physical function needs further investigation.
authors.affiliation: Center for Family and Community Medicine, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden. lillemor.nyberg@orebroll.se
authors.forename: Lillemor A
authors.initials: LA
authors.lastname: Nyberg
authors.forename: Mai-Lis
authors.initials: ML
authors.lastname: Hellénius
authors.forename: Jan
authors.initials: J
authors.lastname: Kowalski
authors.forename: Per
authors.initials: P
authors.lastname: Wändell
authors.forename: Peter
authors.initials: P
authors.lastname: Andersson
authors.forename: Carl Johan
authors.initials: CJ
authors.lastname: Sundberg
mesh_terms: D000328:Adult; D005080:Exercise Test / Q000379:methods* / Q000592:standards*; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005684:Gait / Q000502:physiology; D006801:Humans; D007866:Leg / Q000502:physiology; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D018908:Muscle Weakness / Q000175:diagnosis* / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000502:physiology*; D009135:Muscular Diseases / Q000175:diagnosis; D011237:Predictive Value of Tests; D052097:Quadriceps Muscle / Q000502:physiology; D016059:Range of Motion, Articular / Q000502:physiology; D016138:Walking / Q000502:physiology