SP4 (Gongsun / Grandfather Grandson) Acupuncture Point Guide
Practitioner Guide from The Acupuncture Supply Co.
Professional acupuncture supplies and clinical reference material for qualified practitioners.
SP4 Gongsun lies along the inner border of the foot. Its identity depends on finding the base of the first metatarsal rather than simply choosing a tender place in the arch. In traditional practice, its connection with the Chong Mai also explains its familiar association with PC6.
Practitioner only. This is an educational reference, not a self-needling guide.
SP4 Gongsun quick reference
| Point name | SP4 — Gongsun (Grandfather Grandson) |
|---|---|
| Channel | Spleen channel of Foot Taiyin |
| Classification | Luo-Connecting point; confluent point of the Chong Mai |
| Region | Medial foot |
| Laterality | Bilateral |
| Core landmark | Depression just forward and below the base of the first metatarsal, at the border of the dorsal and plantar skin. |
Location of SP4 Gongsun
Support the foot so the medial side can be assessed. Follow the first metatarsal back from the great-toe side towards its base. SP4 is the depression immediately distal and inferior to that base, near the junction of the thinner dorsal skin and thicker plantar skin. It is not under the centre of the sole.
Landmark checks
- Keep the first metatarsal base distinct from the more proximal navicular prominence.
- Do not confuse SP4 with SP3, which is nearer the first metatarsophalangeal joint.
- Use the palpable bone and skin boundary together; foot shape changes with loading.
Traditional functions of SP4
- Traditionally harmonises the middle Jiao and regulates Spleen-related Qi.
- Associated with addressing Dampness in an appropriate traditional pattern.
- Linked with regulation of the Chong Mai in extraordinary-vessel theory.
These terms belong to traditional acupuncture theory. They should be distinguished from evidence about clinical outcomes.
Traditional clinical applications
Traditional discussion includes abdominal fullness, nausea and bowel disturbance within a relevant pattern. These associations do not establish a diagnosis or show that SP4 alone treats a digestive disorder. A history of symptoms, eating patterns, medicines and medical investigations remains more informative than local foot tenderness.
Common point combinations
- SP4 + PC6: the established extraordinary-vessel pairing of the Chong Mai and Yin Wei Mai in traditional theory.
- SP4 + ST36: a pairing considered in traditional digestive strategies when the complete pattern supports it.
These are traditional treatment-planning examples, not fixed prescriptions. Assess each point separately and select a combination only when it fits the full presentation and your training.
Anatomy and practitioner notes
The first metatarsal base, nearby joints and small sensory vessels and nerves form the local context. Prominent veins, callus, oedema, previous surgery and changes associated with diabetes can affect assessment. Confirm protective sensation and skin integrity before considering local treatment.
Needling and essential safety
Avoid wounds, infected tissue and areas where sensation or circulation is impaired without an appropriate clinical assessment. Unexplained severe abdominal pain, persistent vomiting, gastrointestinal bleeding or substantial weight loss requires medical investigation. In pregnancy, digestive and pelvic symptoms need an assessment appropriate to that setting; the point's classification does not determine safety.
Technique must follow individual anatomy and accredited training. Use sterile, single-use needles and suitable infection-control measures. Review health history, medicines, skin condition and consent before treatment.
Frequently asked questions
Is SP4 on the same side as the little toe?
No. SP4 is on the medial, or great-toe, side of the foot.
Is Gongsun another name for SP3?
No. SP3 Taibai lies closer to the great-toe joint; SP4 Gongsun is located near the first metatarsal base.
Is this a guide to self-needling?
No. Needling requires appropriate professional training, anatomical assessment and a safe clinical setting.
Continue exploring Project Lotus
Read the PC6 guide and ST36 guide, or browse all Acupuncture Point Guides.
For clinic supplies, browse our professional acupuncture needles and the wider Practitioner Guides.
Professional reference: Written for qualified acupuncture practitioners. Traditional functions and pairing examples describe a clinical tradition; they are not claims of proven efficacy for an individual point. The guide does not replace accredited training, diagnosis, informed consent or a patient-specific treatment plan. Surface illustrations cannot determine safe needle depth or direction.
References and further reading: eLotus CORE: Gongsun (SP4); WHO Standard Acupuncture Point Locations, 2008; revised reprint 2009; NCCIH: Acupuncture — Effectiveness and Safety; NHS: Complementary therapies and safety. Accessed 18 September 2026.
