Real time ultrasound imaging shows changes in deep neck flexor activation during exercise in individuals with mechanical neck pain

Abstract

BACKGROUND: Deep neck flexor muscle atrophy and increased superficial neck muscle activation are associated with disability and pain intensity in individuals with neck pain. There is a lack of evidence to support direct assessment of deep neck flexor muscles in a non-invasive way during exercise performance to help determine the effectiveness of different neck strengthening exercises. OBJECTIVE: Compare longus colli (LC) and sternocleidomastoid (SCM) activation between individuals with and without neck pain using real time ultrasound (RTUS) during a series of craniocervical exercises. METHODS: This cross-sectional cohort study recruited 10 control and 10 neck pain participants to complete four deep neck flexor activation activities involving varying levels of craniocervical flexion. Dimensions of the LC and SCM were measured using RTUS at rest and during exercise. Independent t-tests assessed baseline differences and analysis of variance examined activation changes. RESULTS: At rest, the neck pain group had significantly smaller cross-sectional area and thickness of the LC compared to the control group (p< 0.05). During exercise, the neck pain group showed significantly larger increases in LC thickness and cross-sectional area across exercise compared to the control group, with no differences in SCM activation between groups. CONCLUSIONS: Despite atrophy, individuals with neck pain can activate their deep neck flexor muscles appropriately without activating their superficial neck flexor muscles in a supine series of craniocervical flexion exercise as measured by non-invasive ultrasound imaging.

Cervical Multifidus and Longus Colli Ultrasound Differences among Patients with Cervical Disc Bulging, Protrusion and Extrusion and Asymptomatic Controls: A Cross-Sectional Study

“…For instance, Javanshir et al [19] found that patients with mechanical bilateral chronic neck pain exhibited smaller bilateral CSA and anteroposterior (AP) distance of the LC compared with controls. These findings seem to be more present on the symptomatic side and correlated with clinical features such as neck pain intensity and duration or related disability [19,20], but not associated with the ability of the patient to perform deep neck flexor contraction (without the activation of superficial muscles) during a low-load task such as cranio-cervical flexion tests [21]. Although findings concerning other pain cohorts, such as cervical radicular pain [22,23], were comparable, neck pain etiology seems to play a relevant role in ultrasound (US) findings as specific populations, such as patients with cervicogenic headache, showed no differences with the healthy controls [24].…”