Tian Zhu (Heavenly/Celestial Pillar, UB 10) has been used extensively throughout history for patients suffering from neck pain. In fact, the classic medical text Huang Di Nei Jing - Ling Shu Ch.26 gives us some incite to its clinical application. A passage states "When the nape of the neck is painful and the neck cannot bend over or raise up, needle the Urinary Bladder channel" (1).
Tian Zhu occupies prime real estate anatomically. It is the only acupuncture point in the cervical region that pertains directly to the Urinary Bladder channel. This point is located 1.3 cun lateral to Du 15 (Yamen) which is located at the interspace of the first and second cervical vertebrae. Facet joints (also known as zygapophysial joints or Z-joints) are located approximately one inch, plus or minus, lateral to the midline. Facet joints are often referred to as "articular pillars" as they appear column like in structure. The C1/C2 facet joint corresponds to the most cranial facet joint of the vertebral column. Being the most superior and closest to the head, an anatomical correlation can be hypothesized between the name "Heavenly Pillar". Facet joint capsules are richly innervated structures and can be a source of pain locally. They often exhibit pain referral patterns and the C1/C2 facet joint can be a possible cause of cervicogenic headaches which Tian Zhu is also frequently used for clinically.
The Semispinalis Capitis muscle runs vertically along the posterior aspect of the neck. It also resembles a column like structure as it makes its way to the occiput. The primary action of this muscle is to extend the head. When strained, cervical flexion or extension may be limited with associated pain. Tian Zhu is precisely located at a common trigger/motor point region in this muscle thanks to the tendinous inscription that may occur approximately level with C2 (2). Pain referral from this muscle often leads to occipital "Taiyang" headaches.
Of course there are many possible sources of pain with sagittal plane motions of the head and neck. A thorough history and physical examination is always recommended. When it comes to a C1/C2 facet dysfunction or trigger points in the Seminspinalis Capitis... don't forget the Heavenly Pillar.
1. Wu Jing-Nuan (1993), Ling Shu or The Spiritual Pivot. Asian Spirituality, Taoist Studies Series.
2. J. Travell, D. Simons, L.Simons (1999). Myofascial Pain and Dysfunction, The Trigger Point Manual Vol. 1: Upper Half of the Body. Lippincott Williams & Wilkins.