Association of manual muscle tests and mechanical neck pain: Results from a prospective pilot study

Abstract

To determine whether there was a statistical difference for manual muscle test (MMT) findings for cervical muscles in subjects with and without mechanical neck pain (MNP), and to use confidence intervals to evaluate the sensitivity and specificity of the MMT in this group of subjects. Manual muscle strength tests were conducted on two groups of patients who reported to two outpatient chiropractic clinics. In group 1, 148 patients were evaluated for MMT data (50 males and 98 females, average age 37), 127 with "whiplash"-type injuries (average duration 16 weeks) and 21 with non-traumatic chronic neck pain (average duration 36 weeks). In group 2, 100 patients were evaluated for comparative MMT data (39 males and 61 females, average age 38) with no current MNP or remarkable history of MNP. Standardized MMT assessments of the strength of the sternocleidomastoid, anterior scalene, upper trapezius, and cervical extensor muscles bilaterally were performed on all subjects in groups 1 and 2. In group 1, 139 of 148 patients reporting neck pain also showed positive results in at least one of four MMT tests (sternocleidomastoid, anterior scalene, upper trapezius, and cervical extensors). In group 2, 30 of the 100 patients without MNP showed positive results in one or more of the four MMT tests. Confidence intervals were calculated and showed that, in terms of MMT findings, there was a significant difference between the two groups of patients. A symptomatic group of patients with MNP demonstrated significantly increased MMT findings in the form of reduced strength levels compared to a control group. This evidence suggests that the MMT is potentially a sensitive and specific test for evaluating cervical spine muscular impairments in patients with MNP.