Evaluating the reliability of a novel neck-strength assessment protocol for healthy adults using self-generated resistance with a hand-held dynamometer.

Purpose: To evaluate the intra- and inter-session test-retest agreement of a novel neck-strength assessment protocol using a hand-held dynamometer.

Background: A literature review found a lack of neck-strength assessment protocols that are both portable and reliable. Hand-held dynamometry is a portable and inexpensive method of assessing muscle strength, but it is not commonly used for neck-strength assessment.

Methods: A hand-held dynamometer was used to evaluate neck strength in 30 healthy participants. The device measured maximum force in cervical flexion, extension, side flexion, side flexion with rotation, and pure rotation, using the ipsilateral hand to apply isometric resistance over 3 seconds. Three measurements were taken over 6-8 days.

Results: Test-retest intra-class correlation coefficients (ICCs) showed high reliability, ranging from 0.94 to 0.97 for all tested directions from Trial 1 to Trial 2 (intra-session reliability, ICC [2,1], absolute). ICC values demonstrated good to high inter-session reliability, ranging from 0.87 to 0.95 for all tested directions from Trial 1 to Trial 3 (ICC [2,1], absolute).

Conclusion: The results suggest that the five test positions of the neck and upper-quadrant strength assessment protocol can be performed using hand-held dynamometry with good to high reliability.