SI5

On the posteromedial aspect of the wrist, in the depression between the triquetrum and the ulnar styloid process, at the level of the ulnar joint space.

With the wrist relaxed and gently moved, the joint space can be felt on the ulnar side. The place lies immediately distal to the ulnar styloid process, on the line that continues the ulnar border of the hand up to the wrist — the same line as SI4, one step lower. Deadman warns that the styloid is not always palpable and often sits slightly behind the place; he sets his own landmark between the head of the ulna and the triquetrum. The gap between the two readings stays under a finger's width.

• processus styloïde de l’ulna
• os triquétrum
• interligne articulaire du poignet

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

On the posteromedial aspect of the wrist, in the depression between the triquetrum bone and the ulnar styloid process.

Bone landmarks only: the ulnar styloid process, the head of the ulna, the triquetrum, the ulnar joint space. None of the location sources surveyed names a nerve or a vessel there — that is an absence of data, not an absence of structure.

• processus styloïde de l’ulna
• tête de l’ulna
• os triquétrum

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

What the finger seeks

The wrist joint space on the ulnar side, immediately distal to the ulnar styloid process; it opens up when the wrist is moved without force.

Displayed divergence — Les auteurs ne bornent pas le creux par les mêmes os (styloïde contre tête de l’ulna) et Deadman signale que le styloïde peut n’être pas palpable. La divergence est affichée parce qu’elle change ce que le doigt cherche, même si l’écart de position reste faible.

Put simply — The hollow of the wrist on the little-finger side, just past the small knob of the forearm bone.

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. 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

Clears heat and reduces swelling.

Put simply — The two works share only one function for it, and it is a short one.

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

Main channel

Jing-river and Fire point of the channel. Both works turn it towards the upper part of the pathway rather than the hand: swelling of the neck and the submandibular region, lockjaw, teeth, ear, eye.

Put simply — A wrist point whose expected effect is at the face and the neck.

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

Sinew channel

The binding of the Small Intestine sinew channel at the wrist passes through this level. 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 passes here, but the sources speak of elsewhere.

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

Name, history and character

Yanggu, 'Yang Valley'. Deadman notes that most classical sources reserve this place for toothache of the upper jaw, and that Sun Simiao, in the seventh century, brought it into formulae aimed at the lower jaw as well.

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

Anatomical landmark

Focks situe 5IG (SI5/Yanggu) directement distal à l'apophyse styloïde de l'ulna, sur le bord ulnaire du poignet — repère osseux seulement (styloïde ulnaire), aucune structure nerveuse ou vasculaire nommée.

Extrait de contrôle (p. 227) : « S.I.-5 is located directly distal to the styloid process of the ulna […] on a line running along the ulnar border of the hand and continuing to the wrist. » Vérifié dans l'original le 2026-08-15.

Named structures

• os-triquetrum
• os-ulna-processus-styloide
• os-ulna-tete

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 'Yang Valley' of the wrist, echoing LI5, 'Yang Stream', and TE4, 'Yang Pool': three places on the yang channels at the same level, whose names Deadman advises learning together. It is also the only one of the five where the authors do not bound the hollow with the same bones — this record says so rather than choosing in silence.

Codes