title: Kinect-based choice reaching and stepping reaction time tests for clinical and in-home assessment of fall risk in older people: a prospective study.
abstract: BACKGROUND
  Quick protective reactions such as reaching or stepping are important to avoid a fall or minimize injuries. We developed Kinect-based choice reaching and stepping reaction time tests (Kinect-based CRTs) and evaluated their ability to differentiate between older fallers and non-fallers and the feasibility of administering them at home.
  
  
  METHODS
  A total of 94 community-dwelling older people were assessed on the Kinect-based CRTs in the laboratory and were followed-up for falls for 6 months. Additionally, a subgroup (n = 20) conducted the Kinect-based CRTs at home. Signal processing algorithms were developed to extract features for reaction, movement and the total time from the Kinect skeleton data.
  
  
  RESULTS
  Nineteen participants (20.2 %) reported a fall in the 6 months following the assessment. The reaction time (fallers: 797 ± 136 ms, non-fallers: 714 ± 89 ms), movement time (fallers: 392 ± 50 ms, non-fallers: 358 ± 51 ms) and total time (fallers: 1189 ± 170 ms, non-fallers: 1072 ± 109 ms) of the reaching reaction time test differentiated well between the fallers and non-fallers. The stepping reaction time test did not significantly discriminate between the two groups in the prospective study. The correlations between the laboratory and in-home assessments were 0.689 for the reaching reaction time and 0.860 for stepping reaction time.
  
  
  CONCLUSIONS
  The study findings indicate that the Kinect-based CRT tests are feasible to administer in clinical and in-home settings, and thus represents an important step towards the development of sensor-based fall risk self-assessments. With further validation, the assessments may prove useful as a fall risk screen and home-based assessment measures for monitoring changes over time and effects of fall prevention interventions.
authors: Assistive Healthcare Information Technology Group, Austrian Institute of Technology, Vienna, Austria ; Vienna University of Technology, Vienna, Austria ; Neuroscience Research Australia, University of New South Wales, Sydney, Australia.
authors: Andreas
authors: A
authors: Ejupi
authors: Neuroscience Research Australia, University of New South Wales, Sydney, Australia.
authors: Yves J
authors: YJ
authors: Gschwind
authors: Neuroscience Research Australia, University of New South Wales, Sydney, Australia.
authors: Matthew
authors: M
authors: Brodie
authors: Vienna University of Technology, Vienna, Austria.
authors: Wolfgang L
authors: WL
authors: Zagler
authors: Neuroscience Research Australia, University of New South Wales, Sydney, Australia.
authors: Stephen R
authors: SR
authors: Lord
authors: Neuroscience Research Australia, University of New South Wales, Sydney, Australia.
authors: Kim
authors: K
authors: Delbaere
keywords: Accidental falls; Fall risk assessments; Microsoft kinect; Older adults; Reaching; Reaction time; Sensors; Stepping