HT4 Lingdao: At the palm-facing little-finger side, locate the radial side of the flexor carpi ulnaris tendon, one and a half B-cun towards the elbow from the wrist crease. Landmark schematic; not to scale.

HT4 (Lingdao / Spirit Path) Acupuncture Point Guide

October 18, 2026

Practitioner Guide from The Acupuncture Supply Co.

HT4 Lingdao belongs to the Heart channel. This Project Lotus guide focuses on reliable surface landmarks, nearby-point distinctions and safe professional assessment.

Quick reference

Point	HT4 — Lingdao
Channel	Heart — Hand Shaoyin
Traditional classification	Jing-River; Metal
Region	Palmar ulnar forearm
Laterality	Bilateral

Location and landmark sequence

At the palm-facing little-finger side, locate the radial side of the flexor carpi ulnaris tendon, one and a half B-cun towards the elbow from the wrist crease.

Support the limb so the illustrated surface is accessible. Confirm the thumb or little-finger side for hand and forearm points, or the inner or outer ankle for foot points.
Palpate the named joint, bone or tendon landmarks before estimating a position.
At the palm-facing little-finger side, locate the radial side of the flexor carpi ulnaris tendon, one and a half B-cun towards the elbow from the wrist crease.
Check the relationship to nearby points and reassess on the individual patient.

Use the patient’s proportional B-cun measurement. For these forearm locations, the wrist-to-elbow reference interval is twelve B-cun. A centimetre ruler or a universal finger-width estimate cannot replace that assessment.

Distinguishing nearby points

The sequence from wrist to elbow is HT6 at 0.5, HT5 at 1 and HT4 at 1.5 B-cun. All lie radial to FCU.

Traditional context

Jing-River; Metal is the traditional classification used here. Classification helps organise channel theory; it is not evidence that an individual point treats a particular disease. Selection depends on a complete assessment and a coherent treatment principle.

Traditional functions and applications

Within traditional East Asian medicine, this point is described in terms of shen calming; voice support; channel opening.

Traditionally considered for selected Shen presentations and discomfort or restriction along the Heart channel. These are historical treatment concepts, not proven disease-specific effects of this point alone. Select points from the full assessment rather than a symptom list.

Moxibustion

Moxa is not an automatic addition. Assess the treatment principle, skin condition and sensation; use appropriate training, supervision and burn prevention if heat is considered.

Anatomy and essential safety

Forearm tendons, cutaneous nerves and vessels vary between patients. Assess the tissue rather than transferring a fixed image distance. Avoid provoking electric pain, numbness or a sharp neurological sensation. The nearby ulnar neurovascular structures require care; identify the FCU tendon first.

Inspect skin, circulation and sensation; avoid infected, ulcerated or otherwise unsuitable tissue.
Review relevant medication, bleeding risk, pregnancy, surgery and previous reactions.
Use sterile single-use needles, appropriate infection control and safe sharps disposal.
Choose depth, angle and stimulation through accredited training and patient-specific anatomical assessment.

When assessment takes priority

A hot swollen limb with fever, new weakness, persistent numbness, significant trauma or an infected wound needs medical assessment. Acute chest pain, collapse or severe breathlessness requires emergency care; a traditional channel association must never delay referral.