Achyranthes Root
Overview
Usul, "ox knee," is named for its stem, which has joints like the knee of a crane or an ox — the Donguibogam gives this naming directly, and adds the alias "hundredfold" for the largest, softest, moist roots, which are considered best. The recorded actions center on the lower body: cold-damp wasting of the legs, knees that cannot bend and stretch, and aching of the lower back and spine. A line from the Ipmun adds that it "leads other herbs downward to the loins and legs," and that it is washed with wine before use.
In the Donguibogam
寶鑑
Traditional uses recorded in the Donguibogam
- Eases cold-damp leg wasting and numbness
- Frees the knees
- Fills bone marrow
- Opens menstruation
Traditional applications recorded in the classical text
- Knee pain with difficulty bending
- Low back and spine aching
- Weak legs in the elderly (classical use)
Traditional preparation
Root harvested in the 2nd, 8th or 10th lunar month and shade-dried; roots that are long, large, soft and moist are best. Washed in wine before use.
This describes traditional preparation recorded in the classics, not a recommendation for use today. DonguiHub does not provide dosage guidance — consult a qualified professional before using any herb.
Cautions
Frequently asked questions
Why is it called "ox knee"?
The Donguibogam explains that its stem has swollen joints like a crane's knee or an ox's knee, which gave it the name.
Why is it said to lead herbs downward?
A cited text says it guides other herbs down to the loins and legs, which is why it is paired with leg and lower-back formulas.
Is it used in pregnancy?
The entry states it can cause miscarriage and opens menstruation, so traditional use avoids it in pregnancy.
Sources
- 『동의보감』 탕액편, 허준, 1613 (원문) — 한문 원문
- 한의학고전DB (mediclassics.kr) — 원문 및 국역 자료 참조