Longus colli has a postural function on cervical curvature

Abstract

To determine the postural role of longus colli (LC) and dorsal neck muscles, we have studied the relationship between their cross-sectional areas related to their force of contraction and the lordosis and the length of the cervical spine. This study was carried out in 36 healthy subjects. Muscle cross-sectional areas were measured by computerized tomography. The index of lordosis and the length of the cervical spine were measured on an X-ray profile. The cross-sectional area of LC was correlated to the lordosis index (R = -0.432, p < 0.02) whereas all the other parameters were not correlated. The authors conclude that LC counteracts the lordosis increment related to the weight of the head and to the contraction of the dorsal neck muscles. Postural functions of LC and postcervical muscles are complementary. They form a sleeve which encloses and stabilizes the cervical spine in all positions of the head.

The Effect of Cervical Spine Manipulation on Postural Sway in Patients With Nonspecific Neck Pain

“…The cervical musculature, in particular the longus colli and longus capitus, have an essential role in providing structure and support to the highly mobile cervical joint and lordotic structure Mayoux-Benhamou et al, 1994;Winters & Peles, 1990). …”

Correlations between Cervical Lordosis, Forward Head Posture, Cervical ROM and the Strength and Endurance of the Deep Neck Flexor Muscles in College Students

“…Since only the neck, and not the head, is bent, this test method is said to be adequate for assessing the anatomical activities of deep muscles such as the longus colli and the longus capitis rather than the activities of the sternocleidomastoid (SCM) and the anterior scalenus, which are surface muscles 8) . In this study, the CCFT was modified in order to examine the functions of the DNF 9) .…”

Tissue motion pattern of ventral neck muscles investigated by tissue velocity ultrasonography imaging

“…One possible explanation for these results is that even if the exercise was isometric, the PT applied and stopped the manual resistance gently, causing a small movement in the start and end phases that elicited an Lco reaction. Such a conclusion could be interpreted as confirmation of, in particular, Lco as a sensitive stabilizer in the cervical spine (Boyd-Clark et al 2002;Falla et al 2007;Mayoux-Benhamou et al 1994). Another explanation for the results could be different biomechanical parameters, such as the length of each muscle, the locations of origins and insertions, and/or the location where the force was applied relative to the muscles; however, these parameters could not be measured with the methodology used here.…”

“…In the present study of tissue dynamics, a higher deformation in the later phases was found in Lca and SCM. The deformation of Lco was mostly constant during the phases, possibly because of its postural function (Falla et al 2007b;Mayoux-Benhamou et al 1994) in an upright position. An explanation for the differences among the studies could be the different experimental set-ups with the different US methods used and the different study purposes.…”

“…Functional (T2-weighted) magnetic resonance imaging (MRI) (Cagnie et al 2008;Conley et al 1995), computerized tomography (CT) (Mayoux-Benhamou et al 1994), and ultrasonography (US) (Cagnie et al 2009;Jesus et al 2008) have been used to study differences in signal activity or tissue deformations. With EMG, deep ventral neck muscles have been investigated invasively by surface electrodes inserted via the nose and fixed to the posterior mucosa of the oropharynx, which "indirectly" captures signals of interest from Lco and Lca, with some risk of cross-talk from other muscles.…”