The rhombo-serratus
muscle sling is a fascially bound structure consisting of the
serratus anterior and the rhomboid major.1 The serratus
anterior travels anterior to the scapula to attach to the medial
border of the scapula, just next to the attachment of the
rhomboids. Fascial fibers are shared between these two structures and
their continuity can be observed in dissection (Fig. 1).
Fig. 1 |
Fig. 2: From A Manual of Acupuncture by Peter Deadman |
This sling can be
considered as part of the Pericardium sinew channel, though its
function is more consistent with the Sanjiao sinew channel, and it
plays an important role in scapular movement during overhead
activities. The Pericardium sinew channel is described in the Lingshu
as traveling from the arm and
“ascends the yin side of the upper arm to connect with the bottom
of the armpit, and spreads down to the front and the back by clasping
ribs.2 Deadman, in A Manual of
Acupuncture, describes it like this: “follows the antero-medial
side of the upper arm to disperse over the anterior and posterior
aspects of the ribs.3
Fig. 3 |
This
entire action takes place with abduction of the humerus at the
shoulder joint and is an important movement as it prevents impingment
of the rotator cuff, subacromial bursa, and biceps tendon. With
abduction past 30o,
there is 1o
of upward rotation or the scapula for every 2o
of abduction or flexion
of the humerus. This 2:1
ration is known as scapulohumeral rhythm, and it
keeps the subacromial space open, as can be seen in the animation
below.
The serratus anterior often becomes inhibited and fails to take the scapula into upward rotation, therefore contributing to impingement. The upper trapezius also assists with this movement and it can be part of the problem, too. The upper trapezius is a muscle where the Sanjiao and Gallbladder sinew channels converge.
Fig. 4 |
References
1.
Myers,
Thomas W. Anatomy
Trains: Myofascial Meridians for Manual and Movement Therapists.
3rd ed. Edinburgh: Churchill Livingstone, 2014. Print.
2.
Legge,
David, and Karen Vance. Jingjin:
Acupuncture Treatment of the Muscular System Using the Meridian
Sinews.
Sydney: Sydney College, 2010. Print.
3.
Deadman, Peter, Mazin Al-Khafaji, and Kevin Baker. A Manual
of Acupuncture. Hove, East Sussex, England: Journal of Chinese
Medicine Publications, 2007. Print.
4.
Phadke,
V, PR Camargo, and PM Ludewig. “Scapular and Rotator Cuff Muscle
Activity during Arm Elevation: A Review of Normal Function and
Alterations with Shoulder Impingement.” Revista
brasileira de fisioterapia (Sao Carlos (Sao Paulo, Brazil))
13.1 (2009): 1–9. PMC.
Web. 21 Mar. 2016.
5.
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.
I'll think about that threading technique..
ReplyDeleteI like your use of the extra 8.
I wonder what is your opinion about Mukaino...
Thanks, Dori. Sorry it has taken me some time to get back with you. I do not know too much about Mukaino. I have had a few people mention that his book has some similarity to what I discuss. I should get it.
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