SP9 Yinlingquan Acupuncture Point Guide| Location & Safety
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SP9, known as Yinlingquan (“Yin Mound Spring”), is the He-Sea and Water point of the Spleen channel. It lies on the medial lower leg, close to the lower border of the medial tibial condyle, and is traditionally selected to transform Dampness, regulate the Spleen and benefit the lower Jiao.
Accurate location depends on palpating the tibial border and condyle rather than estimating from the appearance of the calf. Local vessels, the saphenous nerve region, knee pathology, oedema and varicosities should inform technique. This is a professional reference for appropriately trained practitioners, not a self-treatment or universal needling guide.
SP9 Yinlingquan quick reference
| Point name | SP9 — Yinlingquan (“Yin Mound Spring”) |
|---|---|
| Channel | Spleen channel of Foot Taiyin |
| Classification | He-Sea point; Water point |
| Region | Medial lower leg, close to the knee |
| Laterality | Bilateral |
| Core landmark | Depression between the lower border of the medial tibial condyle and the posterior border of the tibia |
Location of SP9 Yinlingquan
The WHO standard places SP9 on the medial aspect of the leg, in the depression between the lower border of the medial condyle of the tibia and the posterior border of the tibia.
How to locate SP9
- Position the patient supine or side-lying with the knee supported and the medial leg accessible.
- Identify the medial tibial condyle and trace the posterior border of the tibia inferiorly.
- Palpate for the soft depression immediately below the condyle, where the tibial contour changes.
- Confirm that the point is on the medial leg rather than within the knee joint line or on the posterior calf.
- Inspect for swelling, varicosities, skin change, bruising, altered sensation or marked tenderness before treatment.
SP9 is located by bone contours, not by a fixed finger-width measurement. In a muscular or oedematous leg, slow palpation from the tibial border towards the depression is more reliable than visual estimation.
Traditional functions of SP9
- Resolves Dampness and supports transformation and transportation.
- Regulates the Spleen and benefits the middle Jiao.
- Benefits urination and regulates the water passages.
- Benefits the lower Jiao.
- Activates the channel and benefits the medial knee and leg.
These phrases describe traditional East Asian medicine theory. They should not be read as claims that SP9 has been proven to diagnose, prevent or cure a medical condition.
Traditional clinical applications
SP9 may be considered within an individualised treatment plan where the complete pattern includes:
- Heaviness, oedematous sensations or other traditional signs of Dampness.
- Loose stools, reduced appetite or abdominal fullness in a relevant Spleen pattern.
- Urinary difficulty or lower-Jiao Damp-Heat patterns after appropriate medical assessment.
- Medial knee or lower-leg discomfort involving the channel pathway.
- Selected gynaecological or genital presentations when diagnosis and scope of practice support its use.
New unilateral leg swelling, warmth, redness or calf pain may indicate vascular disease and requires urgent assessment rather than routine acupuncture. Persistent urinary symptoms, visible blood in urine, fever or flank pain also require medical evaluation.
Common point combinations
- SP9 + ST36: traditionally used to support Spleen function and address Dampness.
- SP9 + SP6: considered where lower-Jiao Dampness or Spleen deficiency is central to the pattern.
- SP9 + CV9: used in traditional strategies to regulate water passages.
- SP9 + ST40: considered where Dampness and Phlegm are both clinically relevant.
- SP9 + ST25: may be selected where intestinal symptoms occur with Dampness or Damp-Heat.
- SP9 + GB34: a local-distal pairing sometimes used for medial or general knee dysfunction.
These are traditional examples, not fixed prescriptions. Selection, laterality and technique should follow the full diagnosis and the practitioner’s accredited training.
Anatomy and practitioner notes
- The point lies near the medial proximal tibia, with pes anserinus and medial gastrocnemius structures varying around the region.
- The saphenous nerve and great saphenous vein course in the medial leg; their exact relationship varies.
- Differentiate the point depression from the medial tibiofemoral joint line and from tender soft tissue created by knee pathology.
- Ask about recent knee injury, surgery, joint replacement, vascular disease, lymphoedema, anticoagulants and altered sensation.
- Use additional caution where oedema obscures landmarks or tissue resistance.
Needling and essential safety
Needling direction, depth and stimulation must be individualised according to anatomy, tissue response and accredited training. This guide deliberately gives no universal prescription.
- Avoid direct needling into visible or palpable vessels, varicosities, inflamed tissue, wounds or infection.
- Do not direct the needle into the knee joint space or scrape the periosteum unnecessarily.
- Stop and withdraw if the patient experiences sharp, burning or strongly radiating sensory change.
- Modify or avoid local treatment after recent surgery, in significant lymphoedema or when landmarks cannot be identified confidently.
- Use sterile, single-use needles and appropriate clean-field and sharps-disposal procedures.
Moxibustion
Moxibustion is traditionally considered at SP9 in selected Cold-Damp or deficiency patterns. Protect the skin and maintain continuous supervision. Avoid heat where sensation is impaired, circulation is compromised, tissue is inflamed or the pattern makes warming inappropriate.
Research note
SP9 appears in research on knee, urinary and metabolic presentations, usually as one point within a multi-point protocol. This does not establish an independent or condition-specific effect for SP9. Study population, comparator, needling method and outcome quality should be reviewed before drawing clinical conclusions.
Frequently asked questions
Where exactly is SP9?
It is in the palpable depression between the lower border of the medial tibial condyle and the posterior border of the tibia.
What type of point is SP9?
SP9 is the He-Sea and Water point of the Spleen channel.
Is SP9 the same distance below the knee in everyone?
No. It is a landmark-based point, so the contours of the individual tibia and condyle determine its location.
Is this a self-needling guide?
No. Needling requires professional training, anatomical assessment, sterile technique and appropriate clinical governance.
Continue exploring Project Lotus
Visit our Acupuncture Point Guides, or read our ST36 Zusanli Guide, SP6 Sanyinjiao Guide, ST25 Tianshu Guide and ST40 Fenglong Guide.
Practitioners can also browse our professional acupuncture needles and professional moxa range.
Professional disclaimer: This article is provided for qualified acupuncture and healthcare practitioners for general educational purposes. Traditional actions describe established acupuncture theory and are not claims of proven clinical efficacy. It is not medical advice, does not replace accredited training and should not be used as a universal treatment protocol. Practitioners remain responsible for assessment, consent, safe technique, infection control, record keeping, referral and compliance with professional and legal obligations.
Reference standards and safety reading:
World Health Organization. WHO Standard Acupuncture Point Locations in the Western Pacific Region.
World Health Organization. Guidelines on Basic Training and Safety in Acupuncture.
World Health Organization. WHO Benchmarks for the Practice of Acupuncture.