BL56 Chengjin translates to 'Support the Sinew'

Reviewed by · Licensed Acupuncturist & TCM Physician · Last reviewed June 2026

BL56 (Chengjin, “Chengjin translates to 'Support the Sinew'”) is an acupuncture point on the Bladder Meridian. It is located on the posterior lower leg, in a depression at the center of the belly of the gastrocnemius muscle, approximately midway between Weizhong (BL40) and Chengshan (BL57). Classically described as being 7 cun superior to the heel. It relaxes the sinews and alleviates cramping, activates the channel and alleviates pain, treats hemorrhoids.

Location

On the posterior lower leg, in a depression at the center of the belly of the gastrocnemius muscle, approximately midway between Weizhong (BL40) and Chengshan (BL57). Classically described as being 7 cun superior to the heel.

Needling

Perpendicular insertion 1.0 to 2.0 cun. Caution is advised to avoid deep insertion, which could injure the tibial nerve and posterior tibial artery and vein that lie deep to the gastrocnemius and soleus muscles.

T
h
e
J
i
a
Y
i
J
i
n
g
,
Q
i
a
n
J
i
n
Y
a
o
F
a
n
g
,
a
n
d
Z
h
e
n
J
i
u
J
u
Y
i
n
g
a
l
l
s
t
a
t
e
t
h
a
t
t
h
i
s
p
o
i
n
t
i
s
c
o
n
t
r
a
i
n
d
i
c
a
t
e
d
f
o
r
n
e
e
d
l
i
n
g
(
'
'
o
r
'
'
)
.

TCM functions

Relaxes the sinews and alleviates cramping, activates the channel and alleviates pain, treats hemorrhoids..

Indications

Convulsions, leg soreness, numbness of the lower leg, cholera with muscle cramping, difficult defecation, heaviness of the leg, pain radiating to the lower abdomen, lumbar and back rigidity, hemorrhoid pain, epilepsy, madness, nasal congestion and nosebleed, axillary swelling, heel pain, leg pain..

Clinical notes

Chengjin is a crucial local point for relaxing the powerful gastrocnemius muscle, making it highly effective for acute calf cramps, spasms, and pain. While classically needling was forbidden, its use for local muscle issues is now common. Its classical indications for hemorrhoids and difficult defecation highlight the Bladder channel's connection to the anus and its role in treating disorders of the lower jiao.

On the Bladder channel

BL56 is one of 67 points on the Bladder Meridian. Nearby points:

Frequently asked questions

Where is BL56 located?

BL56 (Chengjin) is located on the posterior lower leg, in a depression at the center of the belly of the gastrocnemius muscle, approximately midway between Weizhong (BL40) and Chengshan (BL57). Classically described as being 7 cun superior to the heel.

What is BL56 used for?

BL56 relaxes the sinews and alleviates cramping, activates the channel and alleviates pain, treats hemorrhoids. Common clinical indications include convulsions, leg soreness, numbness of the lower leg, cholera with muscle cramping, difficult defecation, heaviness of the leg, pain radiating to the lower abdomen, lumbar and back rigidity, hemorrhoid pain, epilepsy, madness, nasal congestion and nosebleed, axillary swelling, heel pain, leg pain.

How is BL56 needled?

Perpendicular insertion 1.0 to 2.0 cun. Caution is advised to avoid deep insertion, which could injure the tibial nerve and posterior tibial artery and vein that lie deep to the gastrocnemius and soleus muscles. Caution: The Jia Yi Jing, Qian Jin Yao Fang, and Zhen Jiu Ju Ying all state that this point is contraindicated for needling ('禁針' or '禁不可刺').

Which meridian is BL56 on?

BL56 is a point on the Bladder Meridian (Zú Tài Yáng Páng Guāng Jīng).

Interactive body mapConditions & evidenceFind an acupuncturistTCM glossary
⚠️ This page is for general education and is not medical advice. Acupuncture is a traditional practice; evidence varies by condition and study quality, and individual results differ. It does not replace diagnosis or treatment by a licensed professional. Always consult a qualified acupuncturist or physician.