title: Repeatability of knee impulsive loading measurements with skin-mounted accelerometers and lower limb surface electromyographic recordings during gait in knee osteoarthritic and asymptomatic individuals.
abstract: OBJECTIVE
  To determine the repeatability of knee joint impulsive loading measurements with skin-mounted accelerometers (SMAs) and lower limb surface electromyography (EMG) recordings during gait.
  
  
  METHODS
  Triaxial SMA and EMG from 4 muscles during level and stair walking in nine healthy and nine knee osteoarthritis (OA) subjects were used. The initial peak acceleration (IPA), root mean square (RMS), maximal acceleration transient rate (ATRmax) and mean EMG activity (EMGact) were calculated. The coefficient of variation (CV) and the intraclass correlation coefficient (ICC) were calculated to measure repeatability.
  
  
  RESULTS
  The CV and ICC of RMS accelerations ranged from 4.9% to 10.9% and from 0.69 to 0.96 in both study groups during level walking. The CV and ICC of IPA and ATRmax varied from 7.7% to 14.2% and from 0.85 to 0.99 during level and stairs up walking in healthy subjects. The CV and ICC of EMGact ranged from 8.3% to 31.7% and from 0.16 to 0.97 in both study groups.
  
  
  CONCLUSIONS
  RMS accelerations exhibited good repeatability during walking in healthy and knee OA subjects. The repeatability of EMG measurements was acceptable in healthy subjects depending on the measured muscles.
authors.affiliation: Department of Physical and Rehabilitation Medicine, Kuopio University Hospital, Kuopio, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Lyytinen
authors.forename: T
authors.initials: T
authors.lastname: Bragge
authors.forename: M
authors.initials: M
authors.lastname: Hakkarainen
authors.forename: T
authors.initials: T
authors.lastname: Liikavainio
authors.forename: P A
authors.initials: PA
authors.lastname: Karjalainen
authors.forename: J P
authors.initials: JP
authors.lastname: Arokoski
mesh_terms: D061725:Accelerometry / Q000379:methods*; D000328:Adult; D000368:Aged; D004576:Electromyography / Q000379:methods*; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology*; D010808:Physical Examination / Q000379:methods*; D015203:Reproducibility of Results