A quiet but powerful point on the thigh, Yinshi (ST-33) warms Cold, moves Qi and eases the knee and leg — especially when Cold and Dampness have settled into the joints and muscles, making movement stiff and painful.
Contraindications
Yinshi (ST-33) is a straightforward thigh point with no special contraindications noted in the classical or modern sources. Standard clean needling technique and keeping to the recommended depth are all that is required.
Name & story
The name 阴市 Yinshi means something like "Yin Market" or "Market of Yin". A market is a place where things gather and are exchanged — and this point is precisely where Yin Cold tends to collect and accumulate in the thigh and knee. The "Yin" here points not to the Yin of Yin-Yang balance, but to the nature of the pathogen: Cold, damp, heavy — the Yin kind of trouble. The point's job is to open that marketplace and move what has stagnated there, warming the channel and restoring free flow.
Point family & character
Yinshi (ST-33) belongs to the Stomach Meridian (ST). It does not carry a special classical category such as Xi Cleft or He-Sea, but it is a recognised channel point on the thigh, valued especially for its strong local action on the knee and thigh and its ability to scatter Cold.
Five-element dynamics
The Stomach Meridian (ST) is the great Yang channel of the Earth element — abundant in Qi and Blood (Xue), running all the way down the front of the leg. When Cold and Dampness invade this channel, the free flow of Qi is blocked, the muscles stiffen and the knee loses its ease. Yinshi (ST-33) sits right in the territory where Cold likes to settle, and being on a Yang channel rich in Qi, it has the power to warm and move what Cold has frozen.
Location
On the front of the thigh, 3 Cun above the superior border of the patella (kneecap), on the line running from the lateral border of the patella toward the anterior superior iliac spine. It sits just above ST-34 (Liangqiu), which is 2 Cun above the patella.
Anatomy & fascia
The point lies in the muscle of the anterior thigh, in the region of the rectus femoris muscle.
Needling
The needle is inserted perpendicularly.
Safe depth
Perpendicular insertion 1 to 1.5 Cun.
Moxa, cupping & Tui Na
Moxa is particularly well suited to this point — the classical sources specifically recommend moxibustion on ST-33 for Cold conditions of the knee and thigh, and for cold abdominal shan disorder. Warming with a moxa stick or cone strongly reinforces the point's action of scattering Cold and moving Qi in the channel.
The golden tip
If the knee or thigh feels stiff, cold and achy — especially in cold or damp weather — try warming the area around ST-33. Find the point 3 Cun (roughly three fingers' width) above the top of the kneecap on the front-outer part of the thigh. Gentle massage or holding a warm pack over this area for a few minutes can help ease stiffness and encourage circulation. In cold conditions, keeping the thighs warm with appropriate clothing is a simple but meaningful step.
For education only — not medical advice. Consult a qualified practitioner.