title: The reliability and concurrent validity of measurements used to quantify lumbar spine mobility: an analysis of an iphone® application and gravity based inclinometry.
abstract: PURPOSEAIM: This purpose of this study was to investigate the reliability, minimal detectable change (MDC), and concurrent validity of active spinal mobility measurements using a gravity-based bubble inclinometer and iPhone® application. MATERIALSMETHODS: Two investigators each used a bubble inclinometer and an iPhone® with inclinometer application to measure total thoracolumbo-pelvic flexion, isolated lumbar flexion, total thoracolumbo-pelvic extension, and thoracolumbar lateral flexion in 30 asymptomatic participants using a blinded repeated measures design.
  
  
  RESULTS
  The procedures used in this investigation for measuring spinal mobility yielded good intrarater and interrater reliability with Intraclass Correlation Coefficients (ICC) for bubble inclinometry ≥ 0.81 and the iPhone® ≥ 0.80. The MDC90 for the interrater analysis ranged from 4° to 9°. The concurrent validity between bubble inclinometry and the iPhone® application was good with ICC values of ≥ 0.86. The 95% level of agreement indicates that although these measuring instruments are equivalent individual differences of up to 18° may exist when using these devices interchangeably.
  
  
  CONCLUSIONS
  The bubble inclinometer and iPhone® possess good intrarater and interrater reliability as well as concurrent validity when strict measurement procedures are adhered to. This study provides preliminary evidence to suggest that smart phone applications may offer clinical utility comparable to inclinometry for quantifying spinal mobility. Clinicians should be aware of the potential disagreement when using these devices interchangeably.
  
  
  METHODS
  2b (Observational study of reliability).
authors.affiliation: Nova Southeastern University, Fort Lauderdale, FL, USA.
authors.forename: Morey J
authors.initials: MJ
authors.lastname: Kolber
authors.forename: Matias
authors.initials: M
authors.lastname: Pizzini
authors.forename: Ashley
authors.initials: A
authors.lastname: Robinson
authors.forename: Dania
authors.initials: D
authors.lastname: Yanez
authors.forename: William J
authors.initials: WJ
authors.lastname: Hanney
keywords: Inclinometer; range of motion; smart phone; spine