288 



Muscles of the Back. 



Fibrocartilago iutervertebi alls 

 vertebrae liinibalis IJI et IV 



Cavum 

 articulare 



M. obliquus externus abdominis 



M. psoas minor ji. obliquus iuternus abdominis j 



M. psoas major m. transversus ' < 



Processus transversus 

 vertebrae lumbalis I\' 

 Fascia iliaca 



abdominis 



fl 



''/ 



Cutis 



[ I\r. latissimus dorsi 



^inniculus adiposus 



Tendon of origin of tlie 

 m. transversus abdominis 



Processus spinosus 

 vertebrae lumbalis IV 



Ligamentnm 

 supraspinale 



Anterior layer i 

 Posterior laver I 



of the fascia lumbodorsalis 



1 Fascia superticialis 



M. sacrospinalis 



333. Transverse section through the muscles of 



the lumbar region, (after W. Braune). 



Thi> fascia lumbodorsalis consists of two layers. 



The posterior layer (see also Figs. 329, 331, 332 and 334) lies just below the 

 mm. trapezius, rhomboidei and latissimus dorsi on the posterior surface of them, sacrospinalis, 

 is thin at its beginning at the m. serratus posterior sujierior, where it is continuous with the 

 fascia nucliae (see p. 2S7), forms a sheath below for the m. serratus posterior inferior and, 

 becoming stronger, descends as far as the coccygeal region; on its way it is fused median ward 

 with the spinous processes and supraspinal ligament of the thoracic and lumbar vertebrae and 

 with the crista sacralis media ; below, it fuses Avith the posterior ligaments of the sacriun and 

 with tlie crista iliaca, lateralward with the anguli costaruin and, below the ribs, between them 

 and the crista iliaca, with the anterior layer. It consists above of transverse, below of oblique 

 crossing fibers, mIucIi represent in part the immediate continuation of the mm. serratus posterior 

 inferior iind latissinms dorsi arising from the fascia. 



The anterior layer (see also Figs. 312, 315, 332 and 340) is thinner, lies in front 

 of the m. sacrospinalis, l)ehind tlie mm. (piadratus luraborum and psoas major and extends 

 only from the 12t'i j-j]^ ^q ^jjg crista iliaca, being fastened to both. It arises by four processes 

 from tlie transverse processes of the lst_4th lumbar vertebra, is connected below with the 

 lig. iliolumbale and contnins, above, powerful curved fibrous bands Avhich extend from the 1 st 

 and 2'"' lunil)ar vertebra to the \2^^^ rib, the lujameiitum lumbocpstalc (see Figs. 312, 315 

 and 34ii). Tho tiliers of the anterior layer run essentially transversely, unite lateral from the 

 111. sacrospinalis with th(> fibers of the posterior layer and thus together form the tendon of 

 origin of the m. transversus abdominis; tlie m. obliquus iuternus abdominis arises in part from 

 the posterior surface of the (combined layers. 



