Most  medical research, medical documents and treatment protocols regarding the correction of  Thoracic Outlet Syndrome state that conservative treatment utilizing

1. Postural and behavioral modification

combined with

2. Proper exercise

was a must for treatment.

You will see that most experts agree that a conservative approach is the first-line treatment in the management of patients with (TOS)...

Here are some examples of what the experts says:

The Official Patient's Source Book on Thoracic Outlet Syndrome

James N. Parker, M.D. and Philip M. Parker, Ph.D., Editors

"The goals of treatment are two-fold: to correct postural abnormalities that might contribute to the compression, and establish an exercise program to strengthen the shoulder muscles. Most often a conservative course of treatment is followed. If vascular or neurological impairment is present, surgical decompression may be considered. However, only a small number of patients require surgery."

Medifocus Guidebook:

Thoracic Outlet Syndrome

• Decreasing compression on the brachial plexus (nerve bundle in the upper arm and shoulder)
• Correcting muscle imbalance in the cervico scapular region through:
  • patient education
  • behavior modification
  • appropriate exercises
• Stretching muscles
• Increasing mobility and range of motion of cervical and scapular muscles and strengthening these muscles"

The American Academy of Orthopedic Surgeons state in their Website :

• Physical therapy can help strengthen the muscles surrounding the shoulder so that they are better able to support the collarbone.
• Postural exercises can help you stand and sit straighter, which lessens the pressure on the nerves and blood vessels.
• Nonsteroidal anti-inflammatory drugs, like aspirin or ibuprofen, can ease the pain.
• If you are overweight, your physician may recommend that you go on a diet.
• You may need to change your workstation and avoid strenuous activities.
• In rare cases, surgery may be recommended if conservative treatment fails."

Cleveland Clinic (Ranked one of the Top 3 Hospitals in the nation by U.S. News and World Report 2006)

Department of Vascular Surgery says...

"Thoracic Outlet Syndrome is a condition where nerves and/or vascular structures are compressed in the shoulder region by the first rib, accessory (cervical rib) when present, muscles or abnormal fibrous bands resulting in various symptoms such as pain, numbness, weakness and swelling of the arm and hand. The most common variety is produced by compression of nerves (brachial plexus) as they cross over the first rib to enter the arm. The majority of patients with this variety of Thoracic Outlet Syndrome are treated successfully with exercises and physical therapy alone."

CNN.COM Health Library

• Physical therapy. You'll learn how to do exercises that strengthen your shoulder muscles to open the thoracic outlet, improve your range of motion and improve your posture. These exercises, done over time, will take the pressure off your blood vessels and nerves in the thoracic outlet.
• Relaxation. Techniques that help you relax, such as deep breathing, can keep you from tensing your shoulders and remind you to maintain good posture.
• Medications. Your doctor may prescribe pain medications, muscle relaxants and anti-inflammatory drugs - aspirin or ibuprofen (Advil, Motrin IB, others) - to decrease inflammation and encourage muscle relaxation."