Comparative Study of the Test-Re-Test Reliability of Four Instruments to Measure Grip Strength in a Healthy Population

Outcome measures need to have an acceptable level of reliability for sound use in clinical and research practice. This study compared the test-re-test reliability of four hand dynamometers measuring grip strength. Using a counterbalanced, repeated measures design, 30 healthy individuals performed three consecutive grip measurements on the MIE digital grip analyser, Baseline Bulb, Jamar® and Lafayette hand dynamometers in a random order on two separate days at the same time. Results indicated that all tools showed a similar and acceptable level of reliability, with a minimum of 90% of the repeat grip data falling within 95% of agreed levels of agreement. The dominant hand showed less variation in grip strength than the non-dominant. Hand pressure was seen to be no less reliable than hand force in a healthy population. Clinicians and researchers can be reassured that the test-re-test reliability of four commonly available dynamometers is acceptable for clinical and research work.