title: Intra-rater Reliability of Arm and Hand Muscle Strength Measurements in Persons With Late Effects of Polio.
abstract: BACKGROUND
  Muscle weakness in the upper limb is common in persons with late effects of polio. To be able to measure muscle strength and follow changes over time, reliable measurements are needed.
  
  
  OBJECTIVE
  To evaluate the intra-rater reliability of isometric and isokinetic arm and hand muscle strength measurements in persons with late effects of polio.
  
  
  METHODS
  A test-retest design.
  
  
  METHODS
  A university hospital outpatient clinic.
  
  
  METHODS
  Twenty-eight persons (mean age 68 years, SD 11 years) with late effects of polio in their upper limbs.
  
  
  METHODS
  Isometric shoulder abduction, isokinetic concentric elbow flexion and extension, isometric elbow flexion, and isometric grip strength were measured twice, 14 days apart. Reliability was evaluated with the intra-class correlation coefficient, the mean difference between the test sessions (d¯), together with the 95% confidence intervals for d¯ , the standard error of measurement (SEM and SEM%), the smallest real difference (SRD and SRD%), and Bland-Altman graphs.
  
  
  METHODS
  A fixed dynamometer (Biodex) was used to measure arm strength and an electronic dynamometer (GRIP-it) was used to measure grip strength.
  
  
  RESULTS
  Intra-rater reliability was high, with intra-class correlation coefficients between 0.87 and 0.98. The SEM%, representing the smallest change for a group of persons, ranged from 7%-24% for all strength measurements, and the SRD%, representing the smallest change for an individual person, ranged from 20%-67%.
  
  
  CONCLUSIONS
  Muscle strength in the upper limbs can be reliably measured in persons with late effects of polio. However, the measurement errors indicate that the method is more suitable to detect changes in muscle strength for a group of persons than for an individual person.
authors.affiliation: Department of Health Sciences, Box 157, Lund University, SE-221 00 Lund, Sweden.|Department of Neurology and Rehabilitation Medicine, Skåne University Hospital, Lund, Sweden.
authors.forename: Christina
authors.initials: C
authors.lastname: Brogårdh
authors.affiliation: Department of Health Sciences, Box 157, Lund University, SE-221 00 Lund, Sweden.
authors.forename: Ulla-Britt
authors.initials: UB
authors.lastname: Flansbjer
authors.affiliation: Department of Neurology and Rehabilitation Medicine, Skåne University Hospital, Lund, Sweden.
authors.forename: Håkan
authors.initials: H
authors.lastname: Carlsson
authors.affiliation: Department of Health Sciences, Box 157, Lund University, SE-221 00 Lund, Sweden.|Department of Neurology and Rehabilitation Medicine, Skåne University Hospital, Lund, Sweden.
authors.forename: Jan
authors.initials: J
authors.lastname: Lexell
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D053581:Muscle Strength Dynamometer; D018908:Muscle Weakness / Q000175:diagnosis* / Q000209:etiology; D015588:Observer Variation; D016262:Postpoliomyelitis Syndrome / Q000150:complications* / Q000503:physiopathology*; D016059:Range of Motion, Articular / Q000502:physiology; D015203:Reproducibility of Results; D034941:Upper Extremity