Assessment of hand grip strength: validity and reliability of the saehan dynamometer

Abstract

There is a great variety of instruments available for evaluating hand grip strength. There is, however, a lack of studies showing the validity and reliability of most of these instruments. The purpose of this study was to examine the concurrent validity and test-retest reliability of the hydraulic Saehan dynamometer using the hydraulic Jamar dynamometer. One hundred healthy subjects (50 men and 50 women), between the ages of 20 and 50 years old, without cognitive impairment, physical disability, neuromuscular or orthopedic dysfunction, and history of upper extremity injuries were tested with the Jamar and Saehan dynamometers. The concurrent validity between the Jamar and the Saehan dynamometers was excellent for both the right hand (r=0.976) and the left hand (r=0.986). Test-retest reliability was excellent for both the Jamar (r=0.985 right and left hands) and the Saehan (r=0.981 right hand and r=0.985 left hand). The Saehan dynamometer is valid, reliable and comparable to the Jamar dynamometer. Therefore, the Jamar and Saehan dynamometers measure handgrip strength equivalently. As a result, strength values obtained with the Saehan dynamometer can be compared with reference values which were collected with the Jamar dynamometer.