Diaphragm

Clinical Notes

• The diaphragm forms the "roof" of the intra-abdominal pressure cylinder (TrA is the walls, multifidus is the posterior wall, and the pelvic floor is the floor). During normal function, the diaphragm descends on inspiration, increasing intra-abdominal pressure, which stabilizes the lumbar spine. Dysfunctional breathing patterns (apical breathing, breath-holding) disrupt this mechanism and contribute to spinal instability.

• Dysfunctional breathing patterns — chronic stress, anxiety, and pain produce apical breathing (chest breathing), which underutilizes the diaphragm and overloads the accessory respiratory muscles (scalenes, SCM, upper trapezius, pectoralis minor). This is directly linked to conditions/upper-crossed-syndrome — the accessory muscles become hypertonic from overuse as respiratory muscles.
• Hiccups — involuntary spasmodic contractions of the diaphragm, usually self-limiting but persistent hiccups can indicate phrenic nerve irritation.
• Rib dysfunction — the diaphragm attaches to ribs 7–12. Restricted diaphragmatic motion can limit rib cage mobility and contribute to thoracic stiffness.
• Relevant to chronic conditions/low-back-pain through the stabilization cylinder mechanism — diaphragmatic dysfunction reduces intra-abdominal pressure generation.

• In clients with chronic stress, anxiety, or pain, the breathing pattern is almost always altered. Observation of breathing at rest reveals chest-dominant (apical) breathing instead of diaphragmatic breathing. The lower ribs do not expand laterally, and the upper chest and shoulders elevate with each breath.
• The costal attachments are often tender and restricted — palpation under the costal arch meets resistance and the client reports sensitivity. This is especially common on the right side.

• Release of the costal diaphragm attachments (gentle sustained pressure under the costal arch) can produce immediate improvement in breathing depth and pattern. Clients often report a sense of "opening" or "being able to breathe fully" for the first time.
• Diaphragmatic breathing retraining (cueing lateral rib expansion with hands on the lower ribs) complements manual release and is the most important self-care prescription for these clients.
• Post-treatment, accessory muscle tone (scalenes, upper trapezius, SCM) often decreases spontaneously because the respiratory load shifts back to the diaphragm.

• The liver (right side) and spleen (left side) lie immediately deep to the diaphragm under the costal margin. Use gentle progressive pressure when working under the ribs. Sharp pain, rigidity, or rebound tenderness suggests visceral pathology — refer for medical evaluation.
• The aortic hiatus, esophageal hiatus, and inferior vena cava foramen pass through the diaphragm. These are not palpable but are important for understanding that the diaphragm is a structure surrounding major vessels and the esophagus.
• Shoulder tip pain (Kehr's sign) in the absence of shoulder pathology is a red flag for subdiaphragmatic irritation — consider hepatic, splenic, gallbladder, or ectopic pregnancy pathology. Refer immediately.

• The diaphragm is the missing link between breathing disorders and musculoskeletal pain. When a client presents with chronic upper trapezius, scalene, and SCM hypertonicity that does not respond to direct treatment, assess their breathing pattern. If they are apical breathers, the accessory muscles are overworking as respiratory muscles — no amount of direct treatment will resolve their hypertonicity until the diaphragm takes back the primary respiratory workload. Teach diaphragmatic breathing before treating the neck.