Intratester and intertester reliability of neck isometric dynamometry

Strimpakos N, Sakellari V, Gioftsos G, Oldham J. Intratester and intertester reliability of neck isometric dynamometry. Arch Phys Med Rehabil 2004;85:1309-16. Objective To evaluate the reproducibility of measurement for maximum voluntary isometric contractions of the cervical musculature in different movements. Design Repeated test-retest measurements. Setting A department of physiotherapy. Participants Thirty-three healthy subjects (17 men, 16 women; age range, 19-63y) for the intraexaminer study and 10 healthy subjects (4 men, 6 women; age range, 20-37y) for the interexaminer study. Interventions Maximum isometric strength in sitting and standing for flexion, extension, lateral flexion, and rotation using a custom isomyometer device. Three tests, performed 5 to 8 days apart, to assess intraexaminer reliability. Two examiners, each performing 1 trial, measuring on the same day to assess interexaminer reliability. Main outcome measures Intraexaminer and interexaminer reliability of neck muscle strength. Results The standing position showed better reproducibility than the sitting position. The intraclass correlation coefficient (ICC1,3) was above .84 for all tests in any movement and position and above .93 when the first test was excluded. The standard error (SE) of measurement (