title: Measuring shoulder external and internal rotation strength and range of motion: comprehensive intra-rater and inter-rater reliability study of several testing protocols.
abstract: BACKGROUND
  Shoulder range of motion (ROM) and strength measurements are imperative in the clinical assessment of the patient's status and progression over time. The method and type of assessment varies among clinicians and institutions. No comprehensive study to date has examined the reliability of a variety of procedures based on different testing equipment and specific patient or shoulder position. The purpose of this study was to establish absolute and relative reliability for several procedures measuring the rotational shoulder ROM and strength into internal (IR) and external (ER) rotation strength.
  
  
  METHODS
  Thirty healthy individuals (15 male, 15 female), with a mean age of 22.1 ± 1.4 years, were examined by 2 examiners who measured ROM with a goniometer and inclinometer and isometric strength with a hand-held dynamometer (HHD) in different patient and shoulder positions. Relative reliability was determined by intraclass correlation coefficients (ICC). Absolute reliability was quantified by standard error of measurement (SEM) and minimal detectable change (MDC). Systematic differences across trials or between testers, as well as differences among similar measurements under different testing circumstances, were analyzed with dependent t tests or repeated-measures analysis of variance in case of 2 or more than 2 conditions, respectively.
  
  
  RESULTS
  Reliability was good to excellent for IR and ER ROM and isometric strength measurements, regardless of patient or shoulder position or equipment used (ICC, 0.85-0.99). For some of the measurements, systematic differences were found across trials or between testers. The patient's position and the equipment used resulted in different outcome measures.
  
  
  CONCLUSIONS
  All procedures examined showed acceptable reliability for clinical use. However, patient position and equipment might influence the results.
authors.affiliation: Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University Hospital, Ghent, Belgium. Electronic address: ann.cools@ugent.be.
authors.forename: Ann M
authors.initials: AM
authors.lastname: Cools
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Faculty of Medicine and Health Sciences, University Hospital, Ghent, Belgium.
authors.forename: Lieven
authors.initials: L
authors.lastname: De Wilde
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Faculty of Medicine and Health Sciences, University Hospital, Ghent, Belgium.
authors.forename: Alexander
authors.initials: A
authors.lastname: Van Tongel
authors.affiliation: Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University Hospital, Ghent, Belgium.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Ceyssens
authors.affiliation: Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University Hospital, Ghent, Belgium.
authors.forename: Robin
authors.initials: R
authors.lastname: Ryckewaert
authors.affiliation: Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University Hospital, Ghent, Belgium.
authors.forename: Dirk C
authors.initials: DC
authors.lastname: Cambier
mesh_terms: D053587:Arthrometry, Articular; D005260:Female; D006801:Humans; D008297:Male; D053581:Muscle Strength Dynamometer; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012399:Rotation; D012785:Shoulder Joint / Q000502:physiology*; D055815:Young Adult
keywords: Shoulder rotation; goniometer; hand-held dynamometer; inclinometer; range of motion measurement; reliability; strength measurement