title: New assessment of forearm strength: reliability and validity.
abstract: OBJECTIVE
  The objective was to determine the reliability of a portable forearm strength hydraulic dynamometer with a doorknob handle and assess its validity compared with a Cybex 6000 (Cybex International, Inc., Medway, MA) isometric torque assessment.
  
  
  METHODS
  Eighteen volunteers (with a total of 30 forearms) participated in this one-session methodological study to determine the intra- and interrater reliability and criterion validity of a forearm dynamometer.
  
  
  RESULTS
  Intrarater reliability for both assessors for pronation was (intraclass correlation coefficient [ICC](3,1) = .937-.961) and for supination was (ICC(3,1) = .923-.968). Interrater reliability for pronation was ICC(3,2) = .927 and for supination was ICC(3,2) = .847. Criterion validity of the Baseline hydraulic dynamometer (Fabrication Enterprises Inc., White Plains, NY) compared with the Cybex 6000 was .574-.664 for pronation and .749-.750 for supination.
  
  
  CONCLUSIONS
  The Baseline hydraulic dynamometer with a more functional doorknob handle had good intra- and interrater reliability and demonstrated moderate validity compared with Cybex 6000 strength testing.
authors.affiliation: Program in Physical Therapy, Columbia University, 710 West 168th Street, New York, NY 10032, USA. ckw7@columbia.edu
authors.forename: Christopher Kevin
authors.initials: CK
authors.lastname: Wong
authors.forename: Neil
authors.initials: N
authors.lastname: Moskovitz
mesh_terms: D000328:Adult; D004867:Equipment Design; D005260:Female; D005542:Forearm / Q000502:physiology*; D006801:Humans; D008297:Male; D053580:Muscle Strength; D053581:Muscle Strength Dynamometer; D015203:Reproducibility of Results; D055815:Young Adult