SI4

On the ulnar border of the hand, in the depression between the base of the fifth metacarpal bone and the triquetrum, at the border between the red and white flesh.

Run the finger up the shaft of the fifth metacarpal towards the wrist, over the curve of its base, and it drops of its own accord into the cleft between metacarpal and carpus. SI5 lies higher on the same line, at the level of the wrist joint space: one slide finds both.

• base du 5e métacarpien
• os triquétrum
• limite des chairs rouge et blanche

Sources : deadman-manual · focks-atlas — reworded, never copied

On the posteromedial aspect of the wrist, in the depression between the base of the fifth metacarpal bone and the triquetrum bone, at the border between the red and white flesh.

Bone landmarks only: the base of the fifth metacarpal and the triquetrum, with the bony projection the finger passes over on the way up. None of the location sources surveyed names a nerve or a vessel there — that is an absence of data, not an absence of structure.

• base du 5e métacarpien
• os triquétrum

Sources : oms-standard-2008 · focks-atlas — reworded, never copied

What the finger seeks

The cleft between the base of the fifth metacarpal and the carpus: a finger running up the metacarpal passes a bony curve, then drops into the gap.

Put simply — Run up the bone of the little finger towards the wrist: where the finger drops into a gap, you are there.

Sources : deadman-manual · focks-atlas — reworded, never copied

What is unknown

Put simply — The mark is not a dot: it shows what is unknown. Two practitioners looking for this place will not put a finger in exactly the same spot.

Sources : sciotti-2001

Perpendicular. Focks notes that this point is reputedly painful to needle. No depth is published: see the caution.

No depth is published: no critical structure is documented in the verified holdings for this place, and a depth figure is never published without the structure it is set against. Absence of data is not a statement of safety.

Channel functions

Opens the channel and eases pain; clears heat and pathogenic factors from taiyang and reduces swelling.

Put simply — The channel's opening point: it is used along its whole length, from finger to neck.

Sources : deadman-manual · focks-atlas — reworded, never copied

Organ functions

Both works credit it with clearing Damp-Heat — Deadman on the side of jaundice, Focks on the side of the Small Intestine itself.

Put simply — The only organ function both works grant it has to do with damp-heat.

Sources : deadman-manual · focks-atlas — reworded, never copied

Main channel

Yuan-source point of the Small Intestine channel. Both works use it along the whole length of the pathway — fingers, wrist, elbow, shoulder, neck — and for swelling at its upper end: cheek, submandibular region, throat.

Put simply — The point to take when the trouble runs along the whole pathway rather than sitting in one spot.

Sources : deadman-manual · focks-atlas — reworded, never copied

Sinew channel

The Small Intestine sinew channel binds at the wrist: this place sits at the entrance to that binding, on the ulnar side. Neither of the two works describes suffering specific to the wrist along this pathway — they name the little finger, the elbow, the shoulder and the scapula.

Put simply — The sinew pathway binds at the wrist, here; what the sources describe of it happens higher up or further down.

Sources : maciocia-channels · focks-atlas — reworded, never copied

Name, history and character

Wangu, 'Wrist Bone': the name points at the bone the finger meets, not at a function. Having a separate yuan-source point belongs to the yang channels — on a yin channel, the source point and the shu-stream point are one and the same.

Field open in the schema; no matter is recorded for this place.

Anatomical landmark

Focks situe 4IG (SI4/Wangu) au bord ulnaire de la main, dans l'interligne entre le 5e métacarpien et les os carpiens (versant ulnaire du carpe) — repère osseux seulement, aucune structure nerveuse ou vasculaire nommée.

Extrait de contrôle (p. 226) : « On the ulnar border of the hand, between the 5th metacarpal bone and the carpal bones, on the border of the red and white skin. » Vérifié dans l'original le 2026-08-15.

Named structures

• os-metacarpien-5-base
• os-triquetrum

Contemporary medicine

Safety: no critical structure is documented for this place in the verified holdings. Absence of data is not a statement of safety; no depth is published, for want of a critical structure to set against it. Innervation: absent from the location sources surveyed. Clinical concordance: not tested — no verification by Justin.

No risk referenced for this place in the verified holdings. The reservation below states what was searched for.

Author’s note

The source point, and the only one of the five with an action — jaundice — that is explained neither by the channel's pathway nor by the function of the bowel. Deadman says so without resolving it; we record it as it stands rather than manufacture a reason.

Codes