title: Validation of a new strength measurement device for amyotrophic lateral sclerosis clinical trials.
abstract: BACKGROUND
  Strength measures with reduced variability and higher sensitivity could improve efficiency in clinical trials of amyotrophic lateral sclerosis (ALS). The Accurate Test of Limb Isometric Strength (ATLIS) was developed to precisely and conveniently measure force in 12 muscle groups. In this study we evaluate the reliability and validity of the ATLIS testing protocol.
  
  
  METHODS
  Twenty healthy adults and 10 patients with ALS were tested twice by the same or by different evaluators to determine test-retest and interrater reliability. Twenty healthy adults were examined using ATLIS and a well-validated strength testing protocol (TQNE) to assess criterion-based validity.
  
  
  RESULTS
  Mean absolute variation between tests was 8.6%, and intraclass correlation coefficients for each muscle group were high (range 0.82-0.99). The Pearson correlation coefficient of mean ATLIS and TQNE scores was 0.90. A subject survey demonstrated high user acceptance of ATLIS.
  
  
  CONCLUSIONS
  ATLIS is convenient for patients and evaluators, produces precise strength measurements, and is easily moved between examining rooms.
authors.affiliation: Neurology Clinical Trials Unit, Massachusetts General Hospital, 149 13th Street, Room 2274, Charlestown, Massachusetts 02129, USA. pandres1@partners.org
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Andres
authors.forename: Linda M
authors.initials: LM
authors.lastname: Skerry
authors.forename: Theodore L
authors.initials: TL
authors.lastname: Munsat
authors.forename: Brenda J
authors.initials: BJ
authors.lastname: Thornell
authors.forename: Jackie
authors.initials: J
authors.lastname: Szymonifka
authors.forename: David A
authors.initials: DA
authors.lastname: Schoenfeld
authors.forename: Merit E
authors.initials: ME
authors.lastname: Cudkowicz
mesh_terms: D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D007839:Functional Laterality; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000503:physiopathology; D010807:Physical Endurance; D015203:Reproducibility of Results; D055815:Young Adult