Duyin dú yīn · 独阴

Location. On the sole, on the plantar surface of the second toe, at the midpoint of the crease of the distal interphalangeal joint.

The name means single yin. The point is on the underside of the foot, in contrast to the yang surface of the toes, and it is a point outside the fourteen channels. Classical sources record it mainly in relation to the lower abdomen and the uterus. As with Zigong (EX-CA1), the classical texts carry a caution about its use in pregnancy; that caution is recorded here as a caution, not as a claim of effect.