title: Trueness and Minimal Detectable Change of Smartphone Inclinometer Measurements of Shoulder Range of Motion.
abstract: Digital inclinometer applications using data from embedded sensors on smartphone/multi-purpose pocket computers or "smart digital inclinometers" (SDIs) are now used to clinically assess range of motion (ROM).
  
  
  
  The objectives of this study were to assess, compared with a biomechanical gold standard (GS), the trueness and minimal detectable change (MDC) of shoulder range of motion (SROM) measurements obtained from an SDI.
  
  
  
  Twenty-five (n = 25) asymptomatic healthy participants performed three trials of shoulder flexion (SF), shoulder abduction (SA), and shoulder external rotation (SER) at full-range and mid-range.
  
  
  
  SROM was measured concurrently from sensor data (pitch, yaw, roll angles) from an iPod Touch installed on the posterior aspect of the humerus and 3D orientation of the upper arm obtained from an optical motion tracking system GS.
  
  
  
  The mean level of bias between SDI and the GS across all SROM measurements was 3.4°, with a 95% confidence interval varying between -8.9° and 15.8°. The mean and standard deviation absolute difference of SDI measurements with the GS were 5.8° ± 3.7° for SF, 8.7° ± 5.2° for SA, and 1.7° ± 1.4° for SER. The trueness of these values varied according to the movement. MDC was 1.9° for SF, 2° for SA, and 0.3° for SER.
  
  
  
  SROM measures in SER with an SDI seem to be accurate and robust for clinical use. However, SROM measures in other planes of motion should be interpreted with caution depending on the evaluation objective, the plane of motion assessed, and the range of ROM measured.
authors.affiliation: 1 Department of Surgery, Orthopedics Division, Faculty of Medicine and Health Sciences, Université de Sherbrooke , Sherbrooke, Quebec, Canada .|2 Research Center on Aging , CIUSSS de l'Estrie CHUS, Sherbrooke, Quebec, Canada .
authors.forename: Patrick
authors.initials: P
authors.lastname: Boissy
authors.affiliation: 1 Department of Surgery, Orthopedics Division, Faculty of Medicine and Health Sciences, Université de Sherbrooke , Sherbrooke, Quebec, Canada .|2 Research Center on Aging , CIUSSS de l'Estrie CHUS, Sherbrooke, Quebec, Canada .
authors.forename: Serigne
authors.initials: S
authors.lastname: Diop-Fallou
authors.affiliation: 1 Department of Surgery, Orthopedics Division, Faculty of Medicine and Health Sciences, Université de Sherbrooke , Sherbrooke, Quebec, Canada .|2 Research Center on Aging , CIUSSS de l'Estrie CHUS, Sherbrooke, Quebec, Canada .
authors.forename: Karina
authors.initials: K
authors.lastname: Lebel
authors.affiliation: 1 Department of Surgery, Orthopedics Division, Faculty of Medicine and Health Sciences, Université de Sherbrooke , Sherbrooke, Quebec, Canada .|2 Research Center on Aging , CIUSSS de l'Estrie CHUS, Sherbrooke, Quebec, Canada .
authors.forename: Mikael
authors.initials: M
authors.lastname: Bernier
authors.affiliation: 1 Department of Surgery, Orthopedics Division, Faculty of Medicine and Health Sciences, Université de Sherbrooke , Sherbrooke, Quebec, Canada .|4 Research Center of the Centre Hospitalier Universitaire de Sherbrooke (CRCHUS), CIUSSS de l'Estrie CHUS , Sherbrooke, Quebec, Canada .
authors.forename: Frederic
authors.initials: F
authors.lastname: Balg
authors.affiliation: 3 School of Rehabilitation, Faculty of Medicine and Health Sciences, Université de Sherbrooke , Sherbrooke, Quebec, Canada .|4 Research Center of the Centre Hospitalier Universitaire de Sherbrooke (CRCHUS), CIUSSS de l'Estrie CHUS , Sherbrooke, Quebec, Canada .
authors.forename: Yanick
authors.initials: Y
authors.lastname: Tousignant-Laflamme
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D008297:Male; D016059:Range of Motion, Articular / Q000502:physiology*; D012680:Sensitivity and Specificity; D012785:Shoulder Joint / Q000502:physiology*; D000068997:Smartphone; D055815:Young Adult
keywords: digital inclinometer application; evaluation; gyroscope sensor; optical motion tracking system