How does modern science explain the stagnation and binding of qi and blood described in Donguibogam? Sitting slouched all day does more than create poor posture. It gradually disrupts our body's delicate systems, ultimately leading to persistent chest tightness.
First, consider the neurological perspective. Rounded shoulders and forward head posture can compress nerve fascicles around the neck and shoulders, particularly nerves and blood vessels in the thoracic outlet. This leads to arm numbness or paresthesia at the fingertips, as well as excessive tension in muscles running behind the shoulders and back, such as the trapezius muscle, rhomboid muscle, and levator scapulae. These chronically tensed muscles hinder blood circulation and accumulate fatigue substances such as lactic acid, becoming the main culprits behind severe shoulder stiffness and back pain. Hardened muscles constrict our body much like overly tight clothing.
Circulatory issues are just as significant. A slouched posture can compress major blood vessels such as the subclavian artery and vein, reducing blood flow volume to the arms and head. When blood does not circulate smoothly, the supply of oxygen and nutrients decreases, and waste removal slows down, manifesting as chronic fatigue, numbness, or coldness in the hands and feet. In particular, when venous flow is impeded, limbs may feel swollen or heavy, and inflammatory responses can readily develop.
Respiratory issues, a prime cause of chest tightness, also play a key role. A slouched posture restricts the movement of the thoracic cage, preventing the lungs from expanding sufficiently. As the movement of the diaphragm is suppressed, one shifts toward shallow, rapid thoracic breathing instead of deep abdominal breathing. When this happens, our body does not receive enough oxygen, and carbon dioxide elimination is impaired. Oxygen deficiency causes systemic fatigue and can affect brain function, leading to impaired concentration or decreased cognitive ability. This is also why the chest feels tight and sighing occurs frequently.
Posture also affects the endocrine system and autonomic nervous system. Chronic pain and discomfort place our body in a continuous state of stress. This causes hyperactivation of the sympathetic nerve and raises levels of the stress hormone cortisol. A chronic increase in cortisol worsens inflammatory responses, leads to decreased immunity, and can even induce insulin resistance. Furthermore, an autonomic nervous system imbalance manifests as psychological symptoms such as anxiety, restlessness, and insomnia, compounding chest tightness into a cycle where physical discomfort leads to mental distress.
Finally, musculoskeletal system imbalances complete the picture. Rounded shoulders and a curved back weaken certain muscles while placing excessive tension on others. Muscles important for maintaining posture—such as deep neck flexors, rhomboid muscles, and the serratus anterior—weaken, while chest muscles (pectoralis major, pectoralis minor muscle), the upper trapezius muscle, and the sternocleidomastoid become shortened and tight. This upper crossed syndrome entrenches improper posture, making it difficult to break free from chronic pain.
Through these mechanisms, a routine issue of posture influences our nerves, blood vessels, respiration, hormones, and mental state. The stagnation and binding of qi and blood described in Donguibogam is understood in modern medicine through these interrelated physiological factors.
