Performance of Longus Colli Muscle in Women with and without Forward Head Posture

Abstract

Background. Forward head posture (FHP) is the most common poor postures in patients with shoulder and neck pain. Longus colli (LCo) muscle has important role in maintaining normal posture of the cervical spine and dysfunction of this muscle may lead to abnormal posture of the cervical spine. Ultrasonography is one of the most common methods used to evaluate muscle performance. The aim of this study was to compare performance of LCo muscle between women with and without FHP. Methods. This cross-sectional study included 70 women with and without FHP (35 in each group). Thickness of LCo muscle in resting state, contraction state (50% of maximal isometric contraction of craniocervical flexion) and thickness change of this muscle between resting and contraction state were measured by ultrasonography and compared between two groups using Independent-Samples T test. Results. The results indicated that there was no significant difference between two groups regarding thickness of LCo muscle in resting and contraction state but, thickness change of this muscle between resting and contraction state was significantly smaller in women with FHP compared with control group. Conclusions. The results of this study indicated that measurement of thickness change of LCo muscle between resting and contraction state seems to be a better parameter than thickness of this muscle in resting or contraction state for assessment of performance of this muscle.

Comparison of Muscle Thickness and Changing Ratio for Cervical Flexor Muscles During the Craniocervical Flexion Test Between Subjects With and Without Forward Head Posture

“…The results of a previous study showed greater muscle thickness change of LCo during craniocervical flexion in subjects without FHP compared subjects with FHP [19]. This can be explained by the fact that the FHP translated forward in relation to a vertical reference line [2,22,27], as well as the disuse of the DCF muscles in daily living and overuse of the SCM muscle in neck flexion movements [19]. For SCM, there was no significant difference in the SCM muscle thickness and muscle thickness changing ratio between subjects with and without FHP.…”

“…In a previous study, the DCF thickness was shown to be reduced in subjects with FHP compared to those without FHP [27]. In a previous study, the muscle thickness of the LCo in the resting state, contraction state (50% of maximal isometric contraction of craniocervical flexion), and thickness change between subjects with and without FHP were measured using ultrasonography [19]. Participants performed craniocervical flexion movements while push on the inferior load cell placed on their chin in a sitting position [19].…”

“…In a previous study, the muscle thickness of the LCo in the resting state, contraction state (50% of maximal isometric contraction of craniocervical flexion), and thickness change between subjects with and without FHP were measured using ultrasonography [19]. Participants performed craniocervical flexion movements while push on the inferior load cell placed on their chin in a sitting position [19]. The results of a previous study showed greater muscle thickness change of LCo during craniocervical flexion in subjects without FHP compared subjects with FHP [19].…”

“…Participants performed craniocervical flexion movements while push on the inferior load cell placed on their chin in a sitting position [19]. The results of a previous study showed greater muscle thickness change of LCo during craniocervical flexion in subjects without FHP compared subjects with FHP [19]. This can be explained by the fact that the FHP translated forward in relation to a vertical reference line [2,22,27], as well as the disuse of the DCF muscles in daily living and overuse of the SCM muscle in neck flexion movements [19].…”

“…The changes in muscle thickness are correlated with amplitude of the EMG signal [18]. This means that more change in muscle thickness express more muscle EMG activity, and quantifying muscle thickness changes may indirectly represent muscle function [18,19]. However, no studies have compared the muscle thickness and muscle thickness changing ratio for the SCM and DCF muscles when performing the CCFT between subjects with and without FHP.…”