The deep fascia of the thorax invests the pectoralis major muscle.

• Laterally it becomes the axillary fascia forming the floor of the axilla.
• Inferiorly it is continuous with the abdominal fascia.
• It also merges with the brachial fascia of the upper extremity.

ACT scan through the chest shows muscles that cross between the upper extremity and the torso. These lie in a common fascial sheath that runs from the arm to surround the upper portion of the torso, reaching all the way to the sacrum. Inside the fascial sheath are muscle compartments housing abdominal and thoracic muscles — hypaxial / front of body, and epaxial / back of body — each surrounded by its own fascial sheath.

The fasciae of the body are both contiguous in one plane, and continuous through deeper planes. Hence pectoral traction affects not only the chest and its contents, but also the neck, upper extremities, and abdomen.
— Zink & Lawson

A classical soft tissue approach, based on osteopathic methodology — that encourages release and relaxation of these structures, while simultaneously improving lymphatic drainage  —  involves gentle "axillary traction." This myofascial release method also produces an increased range of movement for the upper ribs, and a consequent increase in thoracic volume. Kuchera and Kuchera note that, "a one centimetre[less than half-an inch] increase in the diameter of the chest, increases air intake by 200 to 400cc."

The effect on lymphatic drainage is also profound, because the pumping action involved in the breathing process impacts directly on lymph motion. Kuchera and Kuchera also observe, "This is [a] technique that can be used with relative ease [even] with patients with brittle bones … and with post-surgical patients." In other words, it is a safe procedure. Direct myofascial stretch involving the anterior axillary fold.

Steps for Anterior Axillary Release

The patient should be supine with the arms comfortably at the sides.

• The therapist should stand or sit at the head of the table, and place the palms of the hands into the axilla. Palms should be touching the medial humerus and the index fingers touching the axilla.
• The therapist should then slowly externally rotate his / her arms, while using gentle pressure to insinuate fingertips further under the border of the muscle. In this way, the dorsum of the fingers would be located between the pectoralis minor muscles and the ribcage.
• The hands should be drawn lightly toward each other until all the slack in the pectoralis minor has been removed.
• The therapist should then slowly and painlessly lift the tissues anteriorly — towards the ceiling, to their easy elastic barrier — to ease the muscle away from its attachments, while sensing the relative tension between left and right hands, until all slack has been removed (i.e. no actual stretching should be taking place, merely a removal of all slack).
• The therapist should then lean backwards to traction the tissues slightly, in a superior direction (toward the head).
• The fascial and muscle fibres will now have been eased medially, an-teriorly and superiorly towards
  the middle, towards the ceiling, and towards yourself.
• The tissues should be held at these combined barriers, as they slowly release, over the next few minutes, while the patient breathes deeply and slowly.
• If applied correctly, this procedure should be painless.

The combination of traction and respiratory motion releases the upper thoracic muscle tension.
— E. Wallace

What About Posterior Axillary Release?

With the patient prone, a similar procedure can be used to modify excessive tone in related myofascial soft tissues of latissimus dorsi, teres major and minor, and anterior serratus.

The Key to Painless Success

It is essential that the process should be painless, and to achieve this the degree of ‘load' (stretch) needs to be minimal. The barrier of easy resistance needs to be engaged (in three directions — as described above) — with no force, and no increase in the degree of load over time, allowing a gradual, creeping, release of myofascial structures, as slack is taken up, and the load on the barriers is maintained.

A variety of additional methods can be incorporated — including gentle muscle-energy techniques (MET) — but these are not essential.

Resources

• Chaitow L, DeLany J. Clinical application of neuromuscular techniques: the upper body, First Edition. London: Elsevier Health Sciences, 2008.
• Ferguson LW. "Adult Idiopathic scoliosis: The tethered spine." Journal Bodywork & Movement Therapies, 2014, 18(1):99 -111.
• Ferguson L, Gerwin R. Clinical Mastery in the Treatment of Myofascial Pain. Baltimore: LWW, 2005.
• Kuchera W, Kuchera M. Osteopathic principles in practice, Second Edition. Columbus: Greyden Press, 1994.
• Stecco C, et al. "The expansions of the pectoral girdle muscles onto the brachial fascia: morphological aspects and spatial disposition." Cells Tissues Organs, 2008; 188(3):320-329.
• Wallace E, et al. Lymphatic Systems: Foundations for Osteopathic Medicine. Baltimore: LWW, 1997; pp. 941-967.