Phrenic nerve and cervical functional interdependence and its sensorimotor anomalies: A musculoskeletal pain consideration review

Background: Optimal breathing occurs when using the diaphragm muscle, which is known as diaphragmatic breathing. Any disruption or faulty habit of this breathing pattern would result in breathing pattern disorders (BPDs). Objectives: The aim of this review is to shed light on the importance of detecting the presence and extent of asymptomatic functional anomalies of cervical segments among individuals with breathing pattern disorders. Materials and methods: This narrative review was performed by searching in MEDLINE using terms related to phrenic nerve and cervical functional, interdependence, and sensorimotor anomalies. Additionally, articles regarding this topic were extracted in full for a comprehensive and critical analysis. Any study design, such as observational studies, systematic reviews, or narrative reviews, was included. The results were narratively synthesized and described. Results: Breathing is a physiological process that occurs without any conscious effort. Optimal breathing utilizes the deep diaphragmatic muscles, which lead to filling the lungs with air more efficiently. However, breathing pattern disorders may result from inadequate diaphragm use. BPDs can lead to structural musculoskeletal pathologies, including neck, low back, temporomandibular joint pain, and/or scapular dyskinesis. BPDs cause motor reflexive changes in the cervical spine, which may contribute to pain, restriction, and functional impairments. Conclusion: Early identification of this faulty habitual suboptimal breathing is required to minimize its adverse effect, which can be disruptive to the motor control mechanism.