Influence of pain, sequential movement or short-term rest performance on the evaluation results of neck muscle...

Individuals with neck pain (NP) often experience altered muscle mechanical properties (MMPs), such as increased tone and stiffness. Myotonometry has become a reliable, noninvasive tool for measuring MMPs. However, the effect of movement and rest on MMPs in acute neck pain (ANP) individuals remains insufficiently explored.

This study aimed to evaluate how sequential movement and short-term rest influence the MMPs of neck muscles in subjects with ANP.

A case-control study was conducted with 37 subjects with APN and 37 matched healthy controls. Muscle mechanical properties were assessed by myotonometry at baseline, post-movement (after a motion assessment sequence), and post-rest. The outcome measures of MMPs were frequency or tone, stiffness, decrement, which is the inverse of elasticity, relaxation, and creep.

Subjects with ANP showed higher muscle tone, stiffness and decrement, and lower relaxation than controls, all with p < .05. In the ANP group, decrement was the only property that showed a significant change after movement and rest, both with p < .05. Reduced means values (m) with its standard deviation (SD) were observed post-movement (m = 1.35 Ø, SD = 0.03) and post-rest (m = 1.33 Ø, SD = 0.03) compared to baseline values (m = 1.43 Ø, SD = 0.04). The other MMPs remained stable across evaluation times (p > .05).

The evaluation of MMPs should be conducted prior to any mobility protocol to ensure that the results reflect the basal tissue characteristics in individuals with ANP, highlighting decrement as a sensitive marker of these changes.