If you are incorporating the sternocleidomastoid muscle into a comprehensive treatment, how do you know if you are influencing one or another of these channels? Maybe, more important, how would you combine acupuncture to the sternocleidomastoid muscle with distal points? The two criteria I use are symptomology and postural assessment. If you review the trigger point (TrP) referral patterns of the sternocleidomastoid muscle, you will see that it refers pain to a number of regions.1
If a patient complains of frontal headaches and the referral has more of ayangming distribution, then I would likely consider yangming points and specifically ST 41 (jiexi) is indicated. If there are ear complaints (pain, ear stuffiness, positional dizziness), shaoyang distal points would be indicated and SJ 3 (zhongzhu) or SJ 5 (waiguan) are both good considerations. If the patient complains of pain referring to the occiput region, distal point could include taiyang points and UB 60 (kunlun) or UB 62 (shenmai) are both good considerations. In all of these examples, it is suggested to first palpate the sternocleidomastoid muscle and see if this recreates and contributes to the pain referral, as multiple other muscles might be the main pain generator and in that case another set of channel considerations would need investigation.
In addition to pain, it is worth looking to posture for hints on channel involvement. Generally, imbalances between the front and the back of the body (such as a forward head) would involve the relationship between the Urinary Bladder and the Stomach sinew channels. This would particularly be evident with upper cross syndrome (scapular protraction and a forward head position). In this case, the sternocleidomastoid muscle is bilaterally locked-short along with the pectoral muscles.
The sinews of the shaoyang channels traverse the lateral portion of the body and imbalances are frequently seen between the right and the left sides of the body, in this case manifesting with cervical lateral flexion, rotation, and a tilted head. These postural observations are not absolute, but they give important hints that can lead to further investigation.