Yin Mound Spring (Sp 9) is a vital acupressure point on the Spleen meridian, traditionally used in Chinese Medicine to promote fluid metabolism and ease knee-related discomfort. Located just below the inner knee and slightly posterior to the tibia, this point is highly regarded for treating water retention, swelling, and pain localized around the knee joint.
Also known by its TCM designation Sp 9, this point is particularly significant in balancing spleen function, clearing dampness, and supporting urinary and digestive health. There are no widely used alternate names for this point outside of TCM abbreviation and translation variants.
Summary Table
| Attribute | Details |
|---|---|
| Pressure Point Name | Yin Mound Spring – Sp 9 |
| Body Area | Knee |
| Exact Location | Below the medial condyle of the tibia, just behind the tibia’s edge |
| Common Uses | Relieves knee pain, fluid retention, edema, and urinary discomfort |
| Stimulation Technique | Firm finger or thumb pressure for 1–3 minutes, 1–2 times daily |
| Contraindications | Avoid in case of local inflammation or acute trauma |
Clinical Significance & Associated Conditions
Yin Mound Spring (Sp 9) is commonly used to address:
- Knee pain and stiffness
- Edema and water retention, particularly in the lower limbs
- Urinary disturbances such as painful urination or incontinence
- Dampness-related disorders, including bloating and sluggish digestion
- Energetic patterns involving Spleen Qi deficiency and damp stagnation
This point connects the Spleen and Kidney systems, playing a vital role in transforming and transporting fluids. It also influences lymphatic and circulatory functions, which may explain its frequent use in managing swelling and local inflammation.
Location
Sp 9 is located:
- On the medial (inner) side of the lower leg
- Just below the medial condyle of the tibia
- In the indentation formed between the tibia and the gastrocnemius muscle
- Approximately two finger-widths below the inner edge of the kneecap and just behind the tibia
Looking for an easier way to use this point in your wellness routine? This pressure point is simple to locate and even easier to apply when guided step-by-step. It’s featured in over 70 evidence-based pressure point protocols inside our Pressure Points Guide app. Whether you’re looking to relieve knee pain, reduce swelling, or improve urination, the app guides you through every session with visuals and audio. Click here to download our app
How to Stimulate It
- Tool: Use your thumb, knuckle, or index finger
- Pressure: Medium to firm, depending on sensitivity
- Duration: Hold for 1–3 minutes, breathing deeply throughout
- Frequency: 1–2 times daily or as part of a larger session
- Posture: Seated or lying down with knee slightly bent
- Often paired with St 36, Sp 6, or K 3 for enhanced fluid regulation
Benefits and Common Uses
- Reduces fluid accumulation in legs and joints
- Relieves knee pain, tension, and stiffness
- Eases urinary tract symptoms such as burning or urgency
- Promotes healthy digestion by resolving internal dampness
- Supports emotional balance by relieving heaviness and mental fog associated with water stagnation
Physiological Functions & Mechanisms
- Regulates Spleen meridian and assists in fluid transformation
- Facilitates lymphatic drainage and circulatory detox
- Stimulates the medial gastrocnemius and popliteal zone affecting knee mobility and circulation
- Modulates neurotransmitters that influence urinary and emotional regulation
Practitioner Insight
In my experience, Sp 9 becomes especially valuable when I’m working with individuals who experience that deep, dull ache in the knees after standing all day—or with those who feel perpetually “heavy” in body and mind. It’s one of those points that brings subtle yet deeply felt relief, especially when paired with breathing and a warm compress.
Safety & Contraindications
- Do not apply pressure if there’s visible inflammation, bruising, or joint trauma
- Avoid prolonged use during pregnancy without practitioner supervision
- Use caution in cases of varicose veins or vascular disorders
- For complete safety instructions, visit our Acupressure Safety Guide
As always, listen to your body and stop if discomfort arises.
Related Points & Techniques
- Sp 6 – Three Yin Intersection: Enhances urinary and digestive synergy
- K 3 – Great Stream: Supports Kidney function and fluid regulation
- St 36 – Leg Three Miles: Boosts vitality and circulation
- Techniques: Combine with deep breathing, moxibustion, or tapping for added benefit
More sessions with Yin Mound Spring (Sp 9) in our Pressure Points Guide App
Scientific Perspective
While specific studies on Sp 9 are limited, evidence supports acupoint stimulation for managing edema, knee osteoarthritis, and urinary symptoms. Studies from PubMed and journals on Traditional Chinese Medicine suggest that stimulating points along the Spleen meridian can influence renal clearance, pain modulation, and peripheral circulation, corroborating traditional usage patterns.