Massage therapy · Kitchener–WaterlooCostoclavicular Syndrome

Costoclavicular syndrome happens when the nerves or blood vessels that pass between the first rib and the collarbone (clavicle) become squashed. It is one form of thoracic outlet syndrome, a group of conditions in which nerves or blood vessels near the top of the ribs are compressed (Cleveland Clinic, 2026; Jones et al., 2019). It usually affects one arm and hand, causing pain, pins and needles or numbness in the fingers, an arm that tires easily, and sometimes swelling, coldness or a change in skin colour in the hand (NHS, 2023). Sometimes the cause is unknown, but it has been linked to injuries such as a car accident, repetitive arm movements at work or in sport, poor posture, and being born with an extra rib (NHS, 2023; Jones et al., 2019).

Costoclavicular Syndrome Anatomy

The costoclavicular space is the narrow gap between the collarbone (clavicle) and the first rib, with a small muscle called the subclavius at the front. The main bundle of nerves to the arm (the brachial plexus), the main artery to the arm (subclavian artery) and the main vein from the arm (subclavian vein) all pass through this space. Costoclavicular syndrome happens when this space narrows and puts pressure on these structures (Jones et al., 2019). If the muscles around the shoulder aren't strong enough to hold the collarbone in place, it can drop down and forward, adding to the pressure (American Academy of Orthopaedic Surgeons, n.d.).

How to Treat Costoclavicular Syndrome

Treatments you may want to discuss with your family doctor or nurse practitioner

Tips

1. Avoid letting your shoulders droop and holding your head forward for long periods, to help ease pressure in the neck (cervical) and upper back (thoracic) area.
2. Avoid carrying heavy bags over your shoulder, as this pushes the collarbone down and increases pressure on the nerves and blood vessels (American Academy of Orthopaedic Surgeons, n.d.).
3. Injuries to the chest, neck or ribs, such as a car accident, can lead to compression of the nerves and blood vessels (NHS, 2023).
4. Jobs or activities with lots of repetitive arm movements, such as building work or swimming, can contribute, so try to vary your movements and take breaks (NHS, 2023).
5. Being born with an extra rib (a cervical rib) can cause the condition (NHS, 2023).
6. See your family doctor or nurse practitioner if you think you have this condition (NHS, 2023).

Costoclavicular syndrome squeezes the nerves and blood vessels to your arm between your collarbone and first rib. My aim is to give them more room: ease tight muscles, get the collarbone and upper ribs moving, change the postures that close the space, and build the strength to keep it open.

Which path applies depends on your symptoms

• If your symptoms are mild (aching, or pins and needles or numbness that comes and goes, with no weakness or changes in your hand's colour, temperature or swelling), I can treat this directly.
• If your symptoms are more severe (weakness in your hand or arm, numbness or other nerve symptoms that are getting worse, or a hand that is swollen, cold or changing colour), see your family doctor or nurse practitioner first. Once you've been assessed, and cleared by your surgeon if you've had surgery, I can support your medical team's plan with gentler care.

I start by assessing your posture, how your neck and shoulder move, and your shoulder strength, with a neuro screen of sensation, reflexes and strength in your arm.

Hands-On Treatment

• Myofascial and trigger point work and gentle stretching for the side of the neck, chest, upper back and shoulder blade muscles
• Gentle pressure under the collarbone; symptoms may come on briefly and should ease when I let go
• Gentle mobilisation of the collarbone, neck, upper back and upper ribs
• Nerve glides to help the nerves move freely

Breathing, Posture and Strength

1. NHS (2023) Thoracic outlet syndrome. Available at: https://www.nhs.uk/conditions/thoracic-outlet-syndrome/ (Accessed: 7 October 2026).
2. Cleveland Clinic (2026) Thoracic outlet syndrome (TOS). Available at: https://my.clevelandclinic.org/health/diseases/17553-thoracic-outlet-syndrome-tos (Accessed: 7 October 2026).
3. American Academy of Orthopaedic Surgeons (n.d.) Thoracic outlet syndrome. OrthoInfo. Available at: https://www.orthoinfo.org/diseases--conditions/thoracic-outlet-syndrome/ (Accessed: 7 October 2026).
4. Jones, M.R., Prabhakar, A., Viswanath, O. et al. (2019) 'Thoracic outlet syndrome: a comprehensive review of pathophysiology, diagnosis, and treatment', Pain and Therapy, 8(1), pp. 5–18. doi: 10.1007/s40122-019-0124-2