d. Gravitational Propulsion-
Because gravity exerts such a substantial force and because lymph has so far to climb to get to the thoracic duct's entry into the sub-clavian vein any inversion of the limbs or even the prone body position allows for a free flow of lymph unencumbered by the effects of gravity. Elevation of the lower limbs is often prescribed for health problems characterized by a pooling of interstitial fluids.

In Qi Gong and Yoga the thousands of different postures and forms, including lying prone and motionless, often create this mechanical dynamic where the lymph is actually propelled centrally by gravity. In many methods of Qigong there are postures and movements that invert the limbs. In certain walking forms the practitioner is constantly but slowly moving all of the limbs in beautiful circular motions that recurrently activate this mechanism. In Yoga many of the assanas (postures) invert the limbs. In the head and shoulder stands the whole body is inverted.

e. Breath Apparatus: Mechanical Propulsion-
The most powerful of the multiplicity of mechanisms that work together to form the "lymph heart" is the mechanical action of the breathing apparatus itself(43). The concentration of lympoid tissue just above and just below the diaphragm is many times more dense, and contains greater fluid volume, than any of the lymphoid tissue at the periphery, or even in the moderately prolific lymphoid areas of the axilla or groin.(40) Lymph that has been carried from all over the body accumulates centrally and is then propelled by the breath/diaphragm in a final rush through the thoracic lymph duct into the blood at the sub-clavian vein where it leaves behind its identity as lymph and is transformed into blood serum.(49)

Above the diaphragm the thoracic duct of the lymphatic system is a central collecting vessel. Its size is many times that of a peripheral lymph vessel. Below the diaphragm a substantial dilation of the thoracic duct forms a collecting capsule for lymph, called the "cisterna chyli" (cisterna=cavity, receptical or reservior) Chyle is a milky fluid infused with nutritional factors absorbed from the small intestine by the lacteals, which is passed into the circulating blood through the thoracic duct. The fluid that fills the cisterna chyli is a mixture of the nutrient rich chyle from the lacteals and the lymph that carries the metabolic by-products from the tissue of the organs, muscles and glands.

When full inspiration of the breath occurs, the diapragm drops downward and a tremendous negative pressure is generated in the thoracic cavity. As air rushes into fill this negative pressure the lungs are fully expanded. This compresses the thoracic duct. Due to the one way nature of the valvular system lymph is forced upward into the sub-clavian vein.