The thoracic outlet is basically a small area, the space between your collarbone and your first rib & vertebrae. Thoracic outlet syndrome is a group of disorders that occur when blood vessels or nerves compressed in thoracic outlet are entrapped or compressed.

Figure: Thoracic Outlet Syndrome

Anatomy of the Thoracic Outlet

Figure: Thoracic Outlet

The structures most commonly compromised in Thoracic Outlet Syndrome are:

• subclavian artery
• subclavian vein
• lower roots of the brachial plexus (bundle of nerves supplying the upper body and arms)

 Causes Injuries:

• Whiplash, physical trauma from a car accident, a broken collarbone, or other injury can leave scar tissue and inflammation.

• Poor posture: When your shoulders slump, your collarbones can move out of place and press on your nerves. Weak shoulder muscles can cause bad posture.
• Repetitive stress: It can affect people who move their arms in a certain way over and over again.
• Congenital Physical defects: Some people are born with an extra rib or a thoracic outlet that’s smaller than normal.
• Pressure on the joints— Obesity or carrying a heavy backpack can create pressure and compression.
• Weight gain: As with extra muscle mass, extra fat in the neck may compress nerves or subclavian vessels.
• Repeated overhead motions: People who take up swimming, baseball or painting, or who work as hairstylists, auto mechanics or other jobs that require raised arms may develop thoracic outlet syndrome.

• Pregnancy: TOS can happen as your joints begin to get looser.
• Sleep disorders
• Tumors, especially in your upper chest or under your arm
• Stress or depression

Risk Factors

There are several factors that seem to increase the risk of thoracic outlet syndrome, including:

• Sex: Females are far more likely to be diagnosed with thoracic outlet syndrome than are males.
• Age: Thoracic outlet syndrome is more common in young adults, between 20 and 40 years old.

Types of Thoracic Outlet Syndrome (TOS)

TOS can be subdivided into three separate conditions caused by compression of a group of nerves or artery:

• Arterial TOS  (compression of the axillary-subclavian artery)
• Neurogenic TOS (compression of the brachial plexus nerves)
• Venous TOS  (compression of the axillary-subclavian vein)

All three of these conditions are related to neurovascular compression within the thoracic outlet, but each type of TOS gives rise to a distinct clinical presentation.

Thoracic Outlet Syndrome Symptoms

You’re most likely to feel them in your arms and hands. They include:

• Pain in the neck, shoulder &/ or arm
• Numbness and tingling
• Swelling
• Weakness
• Discoloration — blue, red or pale
• Cold hands
• Atrophy (when the tissue or muscle in your arm starts to waste away) 
• Weak pulse in your affected arm
• Painful lump near your collarbone
• Shrinking of the muscle in the fleshy base of your thumb (also called Gilliatt-Sumner hand)

Diagnosis

• Physical examination. Your doctor will perform a physical examination to look for external signs of thoracic outlet syndrome, such as a depression in your shoulder, swelling or pale discoloration in your arm, abnormal pulses, or limited range of motion.
• Medical history. Your doctor will likely ask about your medical history and symptoms, as well as your occupation and physical activities.

Imaging and nerve study tests

• X-ray
• Computerized tomography (CT) scan
• Magnetic resonance imaging (MRI)
• Angiography
• Electromyography (EMG)
• Nerve conduction study

 Special Tests:

• Arson’s sign or Arson’s maneuver 
• Elevated Arm Stress/ Roos test

Treatment:

Conservative management should be the first strategy to treat TOS since this seems to be effective at decreasing symptoms, facilitating return to work and improving function. Conservative management includes physical therapy, which focuses mainly on patient education, pain control, range of motion, nerve gliding techniques, strengthening and stretching.

^{Physiotherapy}

• Electrotherapy:
• Ultrasound: UST is therapeutic modalities that generate ultrasound causes deep heat, provide micro-massage to soft tissue, increase flexibility, promotes healing of tissue as well improve localized blood supply to area. And ultimately pain relief.
• Low -level laser therapy: laser therapy is found to be an effective method for treating heel spurs.
• Electrical Stimulation: Transcutaneous electrical nerve stimulation (TENS) is a method of pain relief involving the use of a mild electrical current.
• IRR (Infrared Ray): Infrared ray is delivered to the site of injury or inflammation at certain wavelengths, promoting cell repair.

• Manual
• MFR (Myofascial Release): It is done mildly with hands with combination of lotion and any kind of diclofenac Sodium.
• Neurodynamic Solution (NDS) : Median nerve, Radial nerve, ulnar nerve stretching & flossing

We can do various types of stretching and strengthening exercises for the treatment of Thoracic outlet syndrome and for it’s rehabilitation also. Such as:

• Scalene stretch: Sit or stand and clasp both hands behind your back. Lower your left shoulder and tilt your head toward the right until you feel a stretch. Hold this position for 15 to 30 seconds and then come back to the starting position. Then lower your right shoulder and tilt your head toward the left. Hold for 15 to 30 seconds. Repeat 3 times on each side.

• Pectoralis stretch: Stand in an open doorway or corner with both hands slightly above your head on the door frame or wall. Slowly lean forward until you feel a stretch in the front of your shoulders. Hold 15 to 30 seconds. Repeat 3 times.

• Scapular squeeze: While sitting or standing with your arms by your sides, squeeze your shoulder blades together and hold for 5 seconds. Do 2 sets of 15.

• Arm slide on wall: Sit or stand with your back against a wall and your elbows and wrists against the wall. Slowly slide your arms upward as high as you can while keeping your elbows and wrists against the wall. Do 2 sets of 8 to 12.

• Thoracic extension: Sit in a chair and clasp both arms behind your head. Gently arch backward and look up toward the ceiling. Repeat 10 times. Do this several times each day. Or we can do it with a foam roll like the figure.

• Rowing exercise: Close middle of elastic tubing in a door or wrap tubing around an immovable object. Hold 1 end in each hand. Sit in a chair, bend your arms 90 degrees, and hold one end of the tubing in each hand. Keep your forearms vertical and your elbows at shoulder level and bent 90 degrees. Pull backward on the band and squeeze your shoulder blades together. Do 2 sets of 15.

• Mid-trap exercise: Lie on your stomach on a firm surface and place a folded pillow underneath your chest. Place your arms out straight to your sides with your elbows straight and thumbs toward the ceiling. Slowly raise your arms toward the ceiling as you squeeze your shoulder blades together. Lower slowly. Do 3 sets of 15. As the exercise gets easier to do, hold soup cans or small weights in your hands.

• Lifestyle changes
  • Maintain good posture
  • Avoid strenuous activities
  • Avoid repetitious activities, such as sitting at a computer for too long
  • Weight loss, if you are overweight