Reliability of Grip Strength Assessment with the Computerized Jamar Dynamometer

Abstract

The purpose of our study was to determine the reliability of the model PC5030PT computerized Jamar dynamometer (J. A. Preston, Jackson, MI). A test-retest reliability study was conducted in which 33 normal subjects were tested three times over a 6-week period. Standard procedures for assessing grip strength were followed. Both left and right hands were tested. We quantified three characteristics of the force curve: (a) the slope of the rise in force, (b) the maximal or peak force, and (c) the mean sustained force over the last 3 sec of a 5-sec contraction. Reliability was good with intraclass reliability coefficients ranging from .84 to .93. We conclude that the computerized Jamar will yield reliable measurement of grip strength if the instrument is calibrated properly and if standardized procedures for grip strength testing are followed.

Test-Retest Intra-Rater Reliability of Grip Force in Patients With Stroke

“…Hamilton et al (10) showed a fatigue effect between trials in a study of healthy men and women but they had no rest interval between the trials. Another study of healthy subjects showed a significant drop in peak force between occasions four weeks apart and stated that variation although standardised procedures can be expected (19).…”

“…Often the highest peak value is used clinically since this intuitively makes sense as a maximum for the patient and the clinician. Both the highest peak value (6,17) and the mean of three trials (19) has been used in research. This study showed slightly lower coefficients of reproducibility between occasions (C R ) when calculated with the mean of all three values.…”

Weak Grip Strength Does not Predict Upper Extremity Musculoskeletal Symptoms or Injuries Among New Workers

“…Prior studies have shown the Jamar dynamometer was a reliable instrument for inter-rater reliability and test-retest reliability. [22, 24-27]…”

Handgrip strength testing: A review of the literature

“…The Jamar dynamometer is reported as a reliable instrument, both for inter‐rater reliability (Mathiowetz et al , 1984; MacDermid et al , 1994) and test‐retest reliability (Mathiowetz et al , 1984; Hamilton et al , 1994; Niebuhr et al , 1994). Both forms of reliability were at levels considered necessary for clinical applications to ensure the valid interpretation of findings (i.e.…”

“…The force produced is plotted over time and the curve examined. Equipment such as the computerized Jamar is used to record peak force, as well as continuous force measurements over the duration of a 5‐second contraction (Niebuhr et al , 1994). A maximal effort has a rapid initial rise that is sustained over 5 seconds, while a submaximal effort also has a rapid initial rise but is followed by a gradual decline over the last few seconds (Lechner et al , 1998).…”