Unlike the Luo or Divergent Channels, we are born with our Sinew Channels. A healthy body has defensive Qi roaming around its exterior, just under the skin, ready to respond to a multitude of potential pathogenic factors. This is the realm of goosebumps, shivering, sneezing and sweating, as well as bumps, bruises, and burns.
The Sinew Channel response is automatic, and as such is in realm of the instincts. I describe it sometimes in terms of an air hockey table (pictured to the left), upon which a puck floats seamlessly across the surface. Air is blowing up through the tiny holes, making the puck hover.
A healthy body similarly has a constant air pressure coming from the inside out through the skin. This Guarding Qi keeps external factors from pushing into the millions of pores of our skin.
Or if an acute injury occurs, this same Guarding Qi brings blood and fluid to promote healing.
Acupuncture can help the body release this superficial pathology from the skin, relieving pain and enabling the body to restore its shield.