Reliability and validity of the BTE-Primus grip tool

Area of Science:

• Rehabilitation Engineering
• Biomechanics
• Clinical Measurement

Background:

• Grip strength assessment is crucial in clinical practice.
• Evaluating new tools for accuracy and reliability is essential.
• The Baltimore Therapeutic Equipment (BTE)-Primus offers a new grip tool for evaluation.

Purpose of the Study:

• To determine the reliability and validity of the BTE-Primus grip tool.
• To investigate factors influencing grip strength measurements: body position, handedness, and fatigue.
• To compare the BTE-Primus with the established Jamar dynamometer.

Main Methods:

• Maximal grip strength tests were performed using both Jamar dynamometer and BTE-Primus.
• Intraclass correlation coefficients assessed test-retest reliability and criterion-related validity.
• Repeated measures ANCOVA analyzed differences across instruments, positions, hands, and sessions.

Main Results:

• The BTE-Primus grip tool demonstrated high reliability (r = 0.97–0.98) and validity (r = 0.95–0.96).
• No significant differences in grip strength were found between the BTE-Primus and Jamar, or between sitting and standing positions.
• The right hand showed significantly greater grip strength than the left, and the first session yielded higher scores than the second.

Conclusions:

• The BTE-Primus grip tool is a reliable and valid instrument for grip strength measurement.
• Clinicians can utilize the BTE-Primus at the second handle setting, as it is comparable to the Jamar dynamometer.
• Findings support the use of the BTE-Primus in clinical settings for accurate grip strength assessment.