Reliability and validity of grip and pinch strength evaluations

Area of Science:

• Occupational therapy
• Rehabilitation medicine
• Biomechanics

Background:

• Accurate measurement of hand strength is crucial for diagnosing impairments and monitoring recovery.
• Existing hand strength tests vary in their reliability and validity, necessitating evaluation of different methods.

Purpose of the Study:

• To assess the reliability and validity of four common hand strength tests: grip, palmar pinch, key pinch, and tip pinch.
• To compare the accuracy of different measurement protocols and instruments.

Main Methods:

• Twenty-seven college women performed standardized grip, palmar pinch, key pinch, and tip pinch tests.
• Inter-rater reliability and test-retest reliability were evaluated using one trial, the highest of three trials, and the mean of three trials.
• The Jamar dynamometer and B&L pinch gauge were assessed for accuracy.

Main Results:

• All tested hand strength assessments demonstrated very high inter-rater reliability.
• Test-retest reliability was maximized when the mean of three trials was used for all tests.
• Using a single trial or the highest score of three trials resulted in lower reliability.
• The Jamar dynamometer and B&L pinch gauge exhibited the highest accuracy among the tested instruments.

Conclusions:

• The mean of three trials provides the most reliable measurement for grip and pinch strength tests.
• The Jamar dynamometer and B&L pinch gauge are recommended for accurate hand strength evaluations.
• Standardized procedures are essential for consistent and valid hand strength assessments in clinical and research settings.