On the medial side of the ankle, in the depression equidistant between the prominence of the medial malleolus and the Achilles tendon.
🧭 How to find it (practical)
Seated or in dorsal decubitus, locate the point at the midpoint between the posterior border of the medial malleolus and the anterior border of the calcaneal tendon, at the level of the apex of the medial malleolus.
🔬 Anatomy
Anterior to the Achilles tendon. Innervated by the saphenous nerve and the tibial nerve. The posterior tibial artery and vein run deep and adjacent.
💉 Needling
Perpendicular insertion, 0.5–1.0 cun (may be directed toward BL-60).
📜 Etymology
Tai (太), great; Xi (溪), ravine. The point lies in the depression between the medial malleolus and the calcaneal tendon, like an immense ravine.
