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.