title: Parameterization and reliability of single-leg balance test assessed with inertial sensors in stroke survivors: a cross-sectional study.
abstract: OBJECTIVE
  There are no published studies on the parameterisation and reliability of the single-leg stance (SLS) test with inertial sensors in stroke patients. Purpose: to analyse the reliability (intra-observer/inter-observer) and sensitivity of inertial sensors used for the SLS test in stroke patients. Secondary objective: to compare the records of the two inertial sensors (trunk and lumbar) to detect any significant differences in the kinematic data obtained in the SLS test.
  
  
  METHODS
  Design: cross-sectional study. While performing the SLS test, two inertial sensors were placed at lumbar (L5-S1) and trunk regions (T7-T8). Setting: Laboratory of Biomechanics (Health Science Faculty - University of Málaga). Participants: Four chronic stroke survivors (over 65 yrs old). Measurement: displacement and velocity, Rotation (X-axis), Flexion/Extension (Y-axis), Inclination (Z-axis); Resultant displacement and velocity (V): RV = √Vx2+Vy2+Vz2. Along with SLS kinematic variables, descriptive analyses, differences between sensors locations and intra-observer and inter-observer reliability were also calculated.
  
  
  RESULTS
  Differences between the sensors were significant only for left inclination velocity (p = 0.036) and extension displacement in the non-affected leg with eyes open (p = 0.038). Intra-observer reliability of the trunk sensor ranged from 0.889-0.921 for the displacement and 0.849-0.892 for velocity. Intra-observer reliability of the lumbar sensor was between 0.896-0.949 for the displacement and 0.873-0.894 for velocity. Inter-observer reliability of the trunk sensor was between 0.878-0.917 for the displacement and 0.847-0.884 for velocity. Inter-observer reliability of the lumbar sensor ranged from 0.870-0.940 for the displacement and 0.863-0.884 for velocity.
  
  
  CONCLUSIONS
  There were no significant differences between the kinematic records made by an inertial sensor during the development of the SLS testing between two inertial sensors placed in the lumbar and thoracic regions. In addition, inertial sensors. Have the potential to be reliable, valid and sensitive instruments for kinematic measurements during SLS testing but further research is needed.
authors.forename: David
authors.initials: D
authors.lastname: Perez-Cruzado
authors.forename: Manuel
authors.initials: M
authors.lastname: González-Sánchez
authors.affiliation: Departamento de Psiquiatria y Fisioterapia, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, 29071 Málaga, Spain. acuesta.var@gmail.com.
authors.forename: Antonio Ignacio
authors.initials: AI
authors.lastname: Cuesta-Vargas
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D020811:Biomedical Technology / Q000295:instrumentation; D003430:Cross-Sectional Studies; D004582:Electronics, Medical / Q000295:instrumentation*; D006801:Humans; D007866:Leg / Q000033:anatomy & histology; D008161:Lumbosacral Region / Q000000981:diagnostic imaging; D008962:Models, Theoretical; D009068:Movement; D004856:Postural Balance; D015203:Reproducibility of Results; D020521:Stroke / Q000503:physiopathology*; D014463:Ultrasonography