THORACIC OUTLET SYNDROME ⠀ COSTOCLAVICULAR SYNDROME ⠀ [ANATOMY AND TREATMENT] ⠀ The costoclavicular passage is formed by the clavicle, the first rib and the scapula. The brachial nerve plexus, subclavian artery and subclavian vein run within the costoclavicular space. The neurovascular bundle is vulnerable to compression in this space. ⠀ This can occur in different ways: 1️⃣The clavicle depresses toward/against the first rib. This can be observed in the common postural condition of rounding and slumping of the shoulders. This narrows the costoclavicular passage by pushing the scapula forwards. A tight subclavius can also cause this to occur! 2️⃣A similar mechanism operates in usually obese, middle aged or elderly women. Tight, narrow brassiere straps supporting heavy breasts cut into the soft tissues around the shoulders and exert direct downward pressure on the clavicles, usually around the junction of the mid and lateral thirds. A scissoring action of the clavicle against the first rib narrows the costoclavicular passage and shears the neurovascular bundle. 3️⃣The first rib elevates toward/against the clavicle. This often occurs in clients who have laboured breathing. Tight anterior and middle scalenes and subclavius can also cause this to occur. The clavicle depresses and the first rib elevates. ⠀ Symptoms: ▪️Pain or ache sometimes accompanied by stiffness in the neck and shoulders, pain, paraesthesiae, and fatigueability of the upper limbs are the main presenting complaints.�▪️Symptoms are usually bi-lateral, though more pronounced on the dominant side. ▪️They are aggravated by work and exercise, particularly carrying heavy shopping bags. ▪️Symptoms are relieved by rest and sleep, are minimal or absent in the morning, and become pronounced as the day progresses. ▪️Patients occasionally complain of puffy blue hands. ⠀ Active trigger points in the Subclavius muscle can mimic a TOS and initiate similar symptoms, often characterized by numbness or tingling in the thumb or index finger .