Abstract
Until now, non-specific chronic neck pain has mainly been considered as a musculoskeletal system dysfunction, with associated psychological involvement due to its prolonged or recurrent nature. However, patients with non-specific chronic neck pain frequently additionally exhibit respiratory dysfunction. Emerging evidence suggests that addressing the respiratory dysfunction in these patients will provide additional therapeutic benefits in musculoskeletal and respiratory-related outcomes for several reasons (biomechanical, biochemical, and psychological). Motor control dysfunction of the muscles surrounding the spine (diaphragm included) negatively affects the mechanics and biochemistry of breathing (pH-homeostasis). An impaired and ineffective breathing pattern has been recognized as the primary source of many unexplained symptoms (anxiety, depression, confusion, chest pain, hypocapnia, and breathlessness) in patients with non-specific chronic neck pain. The proposed protocol's purpose is dual: to assess the relative effectiveness of manual therapy in the cervical spine and the diaphragm, in combination with breathing reeducation exercises, along with cervical spine manual therapy or usual physical therapy care on the underlying dysfunctions in patients with non-specific chronic neck pain via a randomized controlled clinical trial, and to validate part of the outcome measures. Several musculoskeletal and respiratory dysfunction outcomes will be employed to delimit the initial extent and level of dysfunction and its resolution with the treatments under study.