Abstract
BACKGROUND: Cervical muscle strength, proposed as a modifiable risk factor in concussions, can be assessed using various methods. The purpose of this study was to compare the reliability and force outputs of 3 methods that use handheld dynamometry (HHD) for assessing cervical muscle strength. HYPOTHESIS: All 3 testing methods are reliable, and force outputs are significantly different between methods. STUDY DESIGN: Repeated-measures reliability. LEVEL OF EVIDENCE: Level 5. METHODS: The study used a convenience sample of 30 participants. HHD "make tests" for cervical extension, flexion, and right and left side bending were performed using lying push tests, sitting push tests, and sitting pull tests. A sole examiner performed all tests. Two testing sessions were conducted 1 week apart. Analysis included intraclass correlation coefficients (ICCs), repeated-measures analyses of variance (α = 0.05) with post hoc Bonferroni tests, and minimal detectable change (MDC) calculations. RESULTS: All testing methods were reliable; the lying push test had the greatest point estimate values (ICC, 0.89-0.95). Significant differences in force were found between the 3 testing methods. The MDC was most sensitive for the lying push method. CONCLUSION: Of the 3 cervical muscle testing methods investigated, the lying position with a push test had the largest ICC according to the point estimate and the most sensitive MDC. Force values between the 3 methods were significantly different, which suggests that consistent testing methods should be used. CLINICAL RELEVANCE: Results from this study support the clinical use of an HHD "make test" in a lying position for assessing cervical muscle strength. The test is reliable and more sensitive to change compared with tests in a seated position.