title: The feasibility of measuring joint angular velocity with a gyro-sensor.
abstract: OBJECTIVE
  To determine the reliability of an assessment of joint angular velocity using a gyro-sensor and to examine the relationship between ankle angular velocity and physical functions.
  
  
  METHODS
  Cross-sectional.
  
  
  METHODS
  Kinesiology laboratory.
  
  
  METHODS
  Twenty healthy young adults (mean age, 22.5 y) and 113 community-dwelling older adults (mean age, 75.1 y).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Maximal ankle joint velocity was measured using a gyro-sensor during heel-rising and jumping with knee extended. The intraclass correlation coefficient (ICC) was used to determine the intertester and intratester reliability. The Pearson correlation coefficient was used to examine the relationships between maximal ankle joint velocity and isometric muscle strength and isokinetic muscle power in young adults and also to examine the relationships between maximal ankle joint velocity and functional performance measurements such as walking time in older adults.
  
  
  RESULTS
  High reliability was found for intertester (ICC=.96) and intratester reliability (ICC=.96). The data from the gyro-sensor highly correlated with muscle strength (r range, .62-.68; P<.01) and muscle power (r range, .45-.79; P range, .01-.05). In older subjects, mobility functions significantly correlated with the angular velocity of ankle plantarflexion.
  
  
  CONCLUSIONS
  Measurement of ankle angular velocity using a gyro-sensor is both reliable and feasible, with the results representing a significant correlation to muscle power and performance measurements.
authors.affiliation: Department for Prevention of Dependence on Long-term Care, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo Met, Japan. arait@tmig.or.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Arai
authors.forename: Shuichi
authors.initials: S
authors.lastname: Obuchi
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Shiba
authors.forename: Kazuya
authors.initials: K
authors.lastname: Omuro
authors.forename: Chika
authors.initials: C
authors.lastname: Nakano
authors.forename: Takuya
authors.initials: T
authors.lastname: Higashi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000843:Ankle Joint / Q000502:physiology*; D003430:Cross-Sectional Studies; D005240:Feasibility Studies; D006801:Humans; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology; D015203:Reproducibility of Results; D016138:Walking / Q000502:physiology