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.
METHOD. 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 (ICC3,1 = .923–.968). Interrater reliability for pronation was ICC3,2 = .927 and for supination was ICC3,2 = .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.
CONCLUSION. 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.