The thoracic outlet is home to a bundle of nerves, a vein, and an artery travelling from the neck toward the shoulder. The borders of the thoracic outlet include the anterior and middle scalene muscles, the first rib, and the collar bone. When the neurovascular structures become compromised within this outlet, the umbrella term is thoracic outlet syndrome (or TOS).
Thoracic outlet syndrome may have a number of contributing factors:
- Anatomical variation, some people are born with an extra rib that further closes down the thoracic outlet
- Repetitive overuse from work, sports, or recreational activities
- Poor posture
There are two main types of thoracic outlet syndrome, affecting primarily the nerves or venous system. Each presents with its own characteristic symptoms.
- Neurogenic thoracic outlet syndrome is a result of compression of the nerve network called the brachial plexus, as it passes through the thoracic outlet. Common symptoms include:
- Numbness or tingling in your arm, hand, or fingers
- Pain in your neck, shoulder, arm, or hand
- Possible weakening grip
- Possible muscle wasting in the fleshy base of your thumb
- Vascular thoracic outlet syndrome is due to compression of subclavian artery and/or vein as it passes through the thoracic outlet. Common symptoms include:
- Weakness of the arm, especially in overhead positions
- Discoloration of your hand (bluish coloration or pallor)
- Cold fingers, hand, or arm
- Arm fatigue with activity (especially overhead activity)
There are multiple possible contributing factors to thoracic outlet syndrome. Some things you can do on your own to manage symptoms include:
- Postural modification can reduce compression to the structures running through the thoracic outlet
- Stretching the pectoral muscles will help to reduce the forward shoulder posture often associated with thoracic outlet syndrome (although use caution to avoid causing tingling or pain when stretching)
- Avoid activities that produce tingling or pain in your arm, overhead activities often contribute
A physical therapist can assess how changes in muscle function, muscle length, joint mobility, and posture may be contributing to your symptoms. Physical therapy for thoracic outlet syndrome may include:
- Soft tissue treatment: Hands on treatment of muscles and tendons surrounding the region of your symptoms will improve the ability of your joints to move optimally, and reduce compression at the thoracic outlet. Muscle pain contributing to your symptoms may be due to:
- Muscle guarding: Injury or pathology at the shoulder often causes the body to subconsciously guard the area by tightening up muscles in the region; this phenomenon is known as muscle guarding.
- Muscle stiffness: Changes in alignment and movement related to ergonomics, postural habits, and repetitive overuse can cause a muscle to become chronically tight.
- Joint mobilization: Hands on treatment focused at the level of the joint surfaces to reduce pain, improve joint specific mobility, and re-educate proper joint movement. This may be targeted at the shoulder, neck, mid back, and ribs to address contributions to your specific problem.
- Targeted stretching: Specific stretching associated with joint mobilizations may be more effective to reduce compression at the thoracic outlet than independent stretching
- Neuromuscular re-education: Training targeted at re-educating faulty movement patterns, improving muscle coordination, or facilitating muscle firing in muscles that are weak or inhibited. These movements are often small in nature and not targeted at making muscles bigger.
- Stabilization: Exercises targeting strength and endurance of the muscles closest to your joints (and therefore better at stabilizing joints than moving them).
- Activity training: Exercises targeted to your specific goals, fitness activities, recreational activities, or job requirements that will facilitate return to your lifestyle prior to pain.