Modern location: An acupoint located on the anterior aspect of the lower leg, 8 cùn inferior to ST-35 (dú bí), slightly lateral to the crest of the tibia.
Classical location: Two cùn below Upper Great Hollow (ST-37), located with the foot raised. From The Golden Mirror of Medicine (医宗金鑑 yī zōng jīn jiàn)
Action: Soothes the sinews and quickens the network vessels; warms the channels and disperses cold.
Modern indications:Stomach pain; wilting-impediment (wěi bì) of the lower limbs; shoulder pain; leg cramps; swelling of the dorsum of the foot; leg qì (jiǎo qì, beriberi).
Classical indications: Pain in the lower leg; pain in the stomach duct; dysentery; painful pharynx; swelling of the knee and thigh; cold pain and swelling.
Needle stimulus: Needling: 0.5‒1.0 cùn perpendicular insertion. Moxa: 3‒5 cones; pole 5‒20 min.
One way to interpret the meaning of the point name is to visualize the qì flowing from the Upper Great Hollow (ST-37) to the Lower Great Hollow (ST-39). It must go through a narrow passage at ST-38; hence the name Ribbon Opening.
We can also imagine the large intestine and small intestine like ribbons in shape. ST-38 is located between the lower uniting (hé) points of the large and small intestines and is therefore like an opening between the two long, narrow bowels.
According to the The Great Compendium of Acupuncture and Moxibustion (针灸大成 zhēn jiǔ dà chéng), this point may be used to treat wind qì, and thus is an opening to treat wind. The rendering Wind Opening is based on a translation of the character 条 (tiáo) as describing a wind from the northeast. Though not a literal translation, it would reflect this function of the point. See acupoint names: origins, meanings, and translations.