Osteoarthritis of the Hand and the Large Intestine Sinew Channel

 This post will discuss hand and finger pain, especially along the Large Intestine channel distribution. This will be relevant to pain associated with osteoarthritis and/or pain associated with myofascial trigger points referrals. We will also look at how certain muscle referral patterns can overlap and combine to increase the amount of pain in a particular region. In this case, we will examine pain in the LI-4 – LI-1 region, which can be associated with the first interosseous muscle, the extensor carpi radialis longus, the brachioradialis, the anterior scalenes, and often a combination of these muscles.

The dorsal interossei originate from the two adjacent metacarpal bones and insert at the proximal phalanx into the tendinous expansion, which is a fibrous branching of the extensor digitorum tendon.^1,2 These intrinsic hand muscles flex the MCP joint, extend the interphalangeal joint, and abduct the phalanges. Heberden's nodules at the distal interphalangeal joint, often identified with osteoarthritis, may be associated with trigger points in the interossei muscles.³ The nodules are sometimes caused by contracture and enlargement of the soft tissue associated with the tendinous expansion on the posterior aspect of the phalanges.² There are some indications that trigger point activity in the muscles attaching to this tendinous expansion, especially the dorsal interossei, contribute to the progression and pain associated with Heberden's nodules.³

Diagram of the finger tendons and ligaments
extracted from Alexander2

Regardless of whether Heberden's nodules are present, each dorsal interosseous muscle refers pain primarily to that side of the finger to which the interosseous muscle attaches.³ In particular, the first interosseous muscle can be a significant generator of pain, primarily to the radial side of the second phalanx, but also deeply into the dorsum and palm of the hand. This muscle is best accessed from its motor point location, which is located at the extrapoint M-UE-50 (Shangbaxie) approximately in the region of LI-3. All of the dorsal interossei motor points are located at the Shangbaxie.⁴

Needle technique for the first interosseous muscle involves locating the head of the second metacarpal and palpating along the bone in a proximal direction until a node is felt (this is fairly close to the head of the metatarsal). This node is the muscle belly of the first interosseous. The guide tube can be placed immediately distal to this node and the needle can be advanced in a proximal and medial direction into the belly of the first dorsal interosseus muscle. A strong da qi sensation will be felt, and often a muscle fasciculation will be illicited once the needle makes contact with the point. This is seen at the end of the video below as the finger suddenly abducts.

Fig. 3

Since the brachioradialis, extensor carpi radialis longus, and anterior scalenes refer pain to the hand in the region of LI-4 – LI1, these muscles should also be checked. The pain referral from these muscles can contribute to the overall pain of this region and can further aggravate the first dorsal interosseous muscle, causing a return of pain even if the local needling of the first dorsal interosseous is successful. All of these muscles are part of the Large Intestine sinew channel and can be accessed at their motor point locations at LI-11 and LU-6 (brachioradialis), LI-10 (extensor carpi radialis longus), and extrapoint jingbi (anterior scalenes)*. ⁴

* Jingbi should only be needled by those with appropriate clinical training and experience, due to its proximity to the pleural dome and the risk of a pneumothorax.

References:

1. Chaitow, L., DeLany, J., & Chaitow, L. (2008). Shoulder, arm, and hand. In Clinical application of neuromuscular techniques: Volume 1 (2nd ed., pp. 529-530). Philadelphia, PA: Churchill Livingstone Elsevier.

2. Alexander, C. J. (1999). Heberden's and Bouchard's nodes. Annals of the Rheumatic Diseases, 58(11), 675-678.

3. Simons, D. G., Travell, J. G., Simons, L. S., & Travell, J. G. (1999). Interosseous muscles of the hand, lumbricals, and abductor digiti minimi. In Travell & Simons' myofascial pain and dysfunction: The trigger point manual (2nd ed., pp. 786-793). Baltimore: Williams & Wilkins.

4. Callison, M. (2007). Wrist and fingers. In Motor point index: An acupuncturist's guide to locating and treating motor points (p. 90). San Diego, CA: AcuSport Seminar Series LLC.

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