title: Reliability and criterion validity of two applications of the iPhone™ to measure cervical range of motion in healthy participants.
abstract: BACKGROUND
  Recent smartphones, such as the iPhone, are often equipped with an accelerometer and magnetometer, which, through software applications, can perform various inclinometric functions. Although these applications are intended for recreational use, they have the potential to measure and quantify range of motion. The purpose of this study was to estimate the intra and inter-rater reliability as well as the criterion validity of the clinometer and compass applications of the iPhone in the assessment cervical range of motion in healthy participants.
  
  
  METHODS
  The sample consisted of 28 healthy participants. Two examiners measured cervical range of motion of each participant twice using the iPhone (for the estimation of intra and inter-reliability) and once with the CROM (for the estimation of criterion validity). Estimates of reliability and validity were then established using the intraclass correlation coefficient (ICC).
  
  
  RESULTS
  We observed a moderate intra-rater reliability for each movement (ICC = 0.65-0.85) but a poor inter-rater reliability (ICC < 0.60). For the criterion validity, the ICCs are moderate (>0.50) to good (>0.65) for movements of flexion, extension, lateral flexions and right rotation, but poor (<0.50) for the movement left rotation.
  
  
  CONCLUSIONS
  We found good intra-rater reliability and lower inter-rater reliability. When compared to the gold standard, these applications showed moderate to good validity. However, before using the iPhone as an outcome measure in clinical settings, studies should be done on patients presenting with cervical problems.
authors.affiliation: Université de Sherbrooke, School of Rehabilitation, 12e Avenue Nord, Sherbrooke, QC 3001, Canada. yannick.tousignant-laflamme@usherbrooke.ca
authors.forename: Yannick
authors.initials: Y
authors.lastname: Tousignant-Laflamme
authors.forename: Nicolas
authors.initials: N
authors.lastname: Boutin
authors.forename: Alexandre M
authors.initials: AM
authors.lastname: Dion
authors.forename: Carol-Anne
authors.initials: CA
authors.lastname: Vallée
mesh_terms: D000328:Adult; D040421:Cell Phone; D002574:Cervical Vertebrae / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D016059:Range of Motion, Articular / Q000502:physiology*; D015203:Reproducibility of Results; D012984:Software; D055815:Young Adult