Friday, July 21, 2017

SI 3 (Houxi), Du Mai, and the Small Intestine Sinew Channel

What is it about SI 3 (Houxi), a point along the Small Intestine channel, that makes it the master point for the Du Mai? I feel that the specific anatomy associated with the Small Intestine sinew channel, especially at the upper cervical region, helps give insight.

I interpret the Small Intestine sinew channel as containing the following myofascial structures:

  • Abductor digiti minimi
  • Flexor carpi ulnaris (ulnar head)
  • Triceps
  • Rotator cuff muscles (supraspinatus, infraspinatus, teres minor; subscapularis is not included in this channel)
  • Levator scapula
  • Atlantooccipital joint capsule
  • Digastric and styloid muscles
  • Hyoglossus
  • Buccinator
Image adapted from Gray's Anatomy
The levator scapula, in particular, helps link the Small Intestine sinew channel to the Du Mai. This muscle attaches to the posterior tubercles of C1-C4. From these attachments, there exist many fascial connections to the ligamentous structures of the superior vertebral column. These structures include the joint capsules, transverse ligament, and the midline ligaments (supraspinous, infraspinous, and posterior longitudinal ligament). 

Even tone of the levator scapula at these attachments helps produce balance at the upper reaches of the vertebral column, thus linking the SI channel network to the Du Mai. SI-3 is the Shu-stream point of the Small Intestine channel and "Augment the qi and warm the yang, and transform dampness". These actions would be useful when there is degeneration and inflammation of the ligaments of the spine. Adding BL-62 (Shenmai), the master point of the Yang Qiao, also addresses the suboccipital muscles, which are also integral to balance along the upper the spine. 

When these structures are out of balance, fixation of the atlanto-occipital joint can occur. This can have a local effect at the occiptal region, and can have effects further away, especially at the lumbar spine. In SMAC (Sports Medicine Acupuncture Certification) we teach a protocol to address this which was developed by program founder Matt Callison. Assessment of this is beyond the scope of this post, but treatment involves specific needling techniques at BL-10 and GB-20 to address the short and fibrotic (excess) side and to address the more lengthened (deficient) side. This is combined with the extraordinary vessel point pair SI-3/BL-62. The treatment also includes mobilization of the atlanto-occiptal joint to return proper function.