title: Reliability of Using a Handheld Tablet and Application to Measure Lower-Extremity Alignment Angles.
abstract: Landing kinematics have been identified as a risk factor for knee injury. Detecting atypical kinematics in clinical settings is important for identifying individuals at risk for these injuries.
  
  
  
  To determine the reliability of a handheld tablet and application (app) for measuring lower-extremity kinematics during drop vertical-jump landings.
  
  
  
  Measurement reliability.
  
  
  
  Laboratory.
  
  
  
  23 healthy young adults with no lower-extremity injuries and no contraindications for jumping and landing.
  
  
  
  Subjects performed 6 drop vertical jumps that were captured with an iPad2 and analyzed with a KinesioCapture app by 2 novice and 2 experienced raters. Three trials each were captured in the frontal and sagittal planes.
  
  
  
  Frontal-plane projection angles, knee flexion, and hip flexion at initial contact and maximum knee flexion were measured. ICC and SEM were calculated to determine intertrial and interrater reliability. One-way ANOVAs were used to examine differences between the measured angles of the raters.
  
  
  
  Average intertrial reliability ranged from .71 to .98 for novice raters and .77 to .99 for experienced raters. SEMs were 2.3-4.3° for novice raters and 1.6-3.9° for experienced raters. Interrater ICC2,1 was.39-.98 for the novice raters and .69-.93 for the experienced raters. SEMs were smallest with the experiences raters, all less than 1.5°.
  
  
  
  A handheld tablet and app is promising for evaluating landing kinematics and identifying individuals at risk for knee injury in a clinical setting. Intertrial reliability is good to excellent when using average trial measures. Interrater reliability is fair to excellent depending on experience level. Multiple trials should be assessed by a single rater when assessing lower-extremity mechanics with a handheld tablet and app, and results may vary with experience level or training.
authors.affiliation: Dept. of Physical Therapy, Ithaca College, Ithaca, NY.
authors.forename: Deborah L
authors.initials: DL
authors.lastname: King
authors.forename: Barbara C
authors.initials: BC
authors.lastname: Belyea
mesh_terms: D000704:Analysis of Variance; D001265:Athletic Injuries / Q000503:physiopathology* / Q000517:prevention & control; D015982:Bias; D001696:Biomechanical Phenomena / Q000502:physiology*; D034201:Computers, Handheld; D005260:Female; D006621:Hip Joint / Q000502:physiology / Q000503:physiopathology; D006801:Humans; D007718:Knee Injuries / Q000503:physiopathology* / Q000517:prevention & control; D007719:Knee Joint / Q000502:physiology / Q000503:physiopathology; D035002:Lower Extremity / Q000293:injuries* / Q000502:physiology / Q000503:physiopathology; D008297:Male; D063731:Mobile Applications; D015588:Observer Variation; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D055815:Young Adult
keywords: kinematics; landing; injury prevention