What Is Thoracic Outlet Syndrome?
Thoracic outlet syndrome (TOS) happens when nerves or blood vessels get compressed between the collarbone and first rib. This can lead to pain, weakness, tingling, or circulation problems in the arms, shoulders, and hands. The symptoms can range from mild discomfort to severe limitations in movement and daily activities.
TOS can develop due to injury, repetitive strain, or structural differences in the body. Many people with TOS experience symptoms when performing overhead movements, carrying heavy objects, or maintaining poor posture for long periods. The condition can affect one or both arms and can worsen over time if left untreated.
Common Causes of TOS
Several factors can contribute to thoracic outlet syndrome:
- Trauma – Car accidents, fractures, or tumors can cause swelling or structural changes that put pressure on nerves or blood vessels.
- Repetitive Movements – Activities like throwing, swimming, or lifting can lead to muscle tightness or swelling, reducing space in the thoracic outlet. Jobs or sports that require repetitive arm motions often increase the risk.
- Anatomy – Some people are born with an extra rib (cervical rib) or have muscle variations that create less room for nerves and blood vessels, making them more susceptible to compression.
Types of Thoracic Outlet Syndrome
TOS can affect different structures, leading to varying symptoms. The type of compression determines how the condition presents.
- Neurogenic TOS (90% of cases) – Caused by nerve compression in the thoracic outlet. Symptoms include pain in the neck, shoulders, and arms, as well as numbness or tingling in the hands. Some people also experience headaches, a weak grip, or a feeling of heaviness in the affected arm. This type can impact one or both arms.
- Venous TOS (3-5% of cases) – Caused by compression of the subclavian vein. More common in men, it typically affects the dominant arm and is linked to repetitive upper body movements. Symptoms include swelling, a bluish tint to the skin, and discomfort in the affected arm.
- Arterial TOS (1-2% of cases) – The least common but most serious type, caused by compression of the subclavian artery. It can lead to circulation problems, numbness, cold hands, and a weak pulse in the affected arm.
How Physical Therapy Can Help
Most cases of TOS respond well to physical therapy. A structured treatment plan can relieve pain, improve mobility, and strengthen weak muscles to reduce compression in the thoracic outlet.
A physical therapist will assess:
- Posture and alignment – Poor posture, especially forward head positioning and rounded shoulders, can contribute to compression.
- Muscle imbalances – Overactive or tight muscles may need stretching, while weaker muscles need strengthening for better support.
- Range of motion – Limited mobility in the shoulders, neck, and upper back can increase strain on nerves and blood vessels.
Treatment Approach
Physical therapy focuses on relieving symptoms and restoring function. Most people see improvement without needing surgery. Treatment may include:
- Stretching – Helps lengthen tight muscles like the pectorals, lower trapezius, and scalenes to create more space in the thoracic outlet.
- Strengthening – Targets muscles around the shoulder blade and neck to improve posture, stability, and overhead motion.
- Mobility Exercises – Restores movement in the neck and upper back to reduce stiffness and nerve irritation.
- Nerve Glides – Encourages proper nerve movement to reduce compression and improve sensation in the arms and hands.
Get Back to Pain-Free Movement
About 90% of people with TOS see improvement with physical therapy. If pain, weakness, or numbness is affecting your daily life or your ability to participate in activities, a movement expert can help. Schedule an assessment to find the best approach for relieving your symptoms and improving mobility.
