FASCIA) AND MUSCLES OF THE BACK. 307 
THE UPPER LIMB. 
FASCLZ AND MUSCLES OF THE BACK. 
FASCLA. 
The superficial fascia of the back presents no peculiarity. It is usually 
of considerable thickness, and contains a quantity of fat. 
The deep fascia closely invests the muscles. It is attached in the middle line 
to the ligamentum nuchee, supraspinous ligaments, and vertebral spines; laterally 
it is attached to the spine of the scapula and the clavicle, and is continued over 
; the deltoid region to the arm. In the neck it is attached above to the supericr 
curved line of the occipital bone, and is continuous laterally with the deep cervical 
- fascia. Below the level of the arm it is continuous round the border of the 
 lJatissimus dorsi muscle, with the fascia of the axilla and of the abdominal wall. 
In the back and loin it constitutes the vertebral aponeurosis or aponeurosis of the 
 latissimus dorsi, concealing the erector spine, forming the posterior layer of the 
lumbar fascia, and attached internally to the vertebral spines, externally to the 
angles of the ribs above, to the lumbar fascia in the loin, and to the iliac crest 
below. 
THE SUPERFICIAL MUSCLES OF THE BACK. 
The posterior muscles connecting the upper limb to the trunk comprise the 
first two layers of the muscles of the back—(1) trapezius and latissimus dorsi, and 
(2) levator anguli scapulee and rhomboidei (major and minor). 
; The trapezius (m. trapezius, cucullaris) is a large triangular muscle. It arises 
from the superior curved line of the occipital bone in its inner third, from the 
external occipital protuberance, from the ligamentum nuche, from the spines of 
the seventh cervical and all the thoracic vertebra, and the corresponding supra- 
spinous ligaments. The origin is by direct fleshy attachment, except in relation to 
the occipital bone, the lowest part of the neck, and the lower thoracic vertebre, in 
which places the origins are tendinous. From their origin the muscular fibres 
- converge towards the bones of the shoulder, to be inserted continuously from before 
_ backwards as follows:—(1) The occipital and upper cervical fibres, into the pos- 
terior surface of the clavicle in its outer third; (2) the lower cervical and upper 
_ thoracic fibres, into the inner side of the acromion process, and the upper border 
of the spine of the scapula in its whole length; and (3) the lower thoracic fibres, by 
a triangular flat tendon, beneath which a bursa is placed, into a rough tuberosity 
at the base of the spine of the scapula. The occipital portion of the muscle may 
be in the form of a separate slip, or may be entirely absent. 
The trapezius is superficial in its whole extent. Its upper lateral border forms 
the posterior limit of the posterior triangle of the neck. The lower lateral border, 
passing over the upper edge of the latissimus dorsi and the vertebral border of the 
scapula, forms a boundary of the so-called triangle of wuscultation completed below 
by the latissimus dorsi, and externally by the vertebral border of the scapula. This 
space is partly filled up by the rhomboideus major. The deep surface of the muscle 
is in contact with the levator anguli scapule, rhomboidei, latissimus dorsi, and 
other deeper muscles. The spinal accessory nerve, branches of the cervical plexus 
(C. 3:4), and of the superficial cervicai and posterior scapular arteries, are 
situated beneath the muscle. 
The latissimus dorsi is a large triangular muscle with a triple origin. It 
_arises—(1) from the vertebral aponeurosis (posterior layer of the lumbar fascia or 
aponeurosis of the latissimus dorsi). This is a thick membrane which conceals the 
erector spine in the lower part of the back. Through it the latissimus dorsi gains 
attachment to the spines of the lower six thoracic vertebra, the spines of the 
lumbar vertebrae, and the tendon of the erector spinee with which the aponeurosis 
blends below. It also arises more externally by fleshy fibres from the posterior 
part of the ihac crest. From this origin the muscle is directed upwards and out- 
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