title: Analysis of gait and balance through a single triaxial accelerometer in presymptomatic and symptomatic Huntington's disease.
abstract: OBJECTIVE
  To investigate the capacity of a single triaxial accelerometer sensor in detecting gait and balance impairments in pre-manifest and manifest Huntington's disease (HD) subjects.
  
  
  METHODS
  Fourteen manifest HD (MHD) (age: 51.83±14.8), ten pre-manifest HD (PHD) (age: 44.8±11.7) and ten healthy subjects (HLY) (age: 56.4±10.9) were recruited. The sensor was attached to the upper sternum as subjects completed gait and Romberg balance tests. An inverted pendulum model of the body's centre of mass and an unbiased autocorrelation procedure were employed to derive gait parameters from the triaxial accelerometer signal. The accuracy of the gait measurements was compared to those recorded by a computerized walkway.
  
  
  RESULTS
  Strong agreement was seen between the sensor and the walkway; cadence (ICC=0.95, CI=[0.75, 0.97]), velocity (ICC=0.94, CI=[0.75, 0.97]) and step length (ICC=0.89, CI=[0.77, 0.95]). Sensor derived velocity was significantly higher in HLY (p<0.001) and PHD (p<0.005) when compared to MHD. Step and stride length was significantly longer in HLY (p<0.05) and PHD (p<0.001) when compared to MHD. Significant differences between subject groups across all four balance tasks (p<0.001) were found.
  
  
  CONCLUSIONS
  An accelerometer based sensor may be an effective means of differentiating between pre-manifest and manifest Huntington's disease subjects.
authors: School of Engineering and Informatics, National University of Ireland Galway, University Road, Galway, Ireland. anthony.f.dalton@gmail.com
authors: Anthony
authors: A
authors: Dalton
authors: Hanan
authors: H
authors: Khalil
authors: Monica
authors: M
authors: Busse
authors: Anne
authors: A
authors: Rosser
authors: Robert
authors: R
authors: van Deursen
authors: Gearóid
authors: G
authors: Ólaighin
mesh_terms: D061725:Accelerometry / Q000379:methods*; D000328:Adult; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D005684:Gait; D020233:Gait Disorders, Neurologic / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D006816:Huntington Disease / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D004856:Postural Balance; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted