extensor muscles

lower Back pain  syndrome

extensor muscles

EXTENSOR MUSCLES OF THE SPINE

The erector spinae (sacrospinalis) originates from the last two thoracic
,vertebrae, all the lumbar vertebrae, the sacral spines, the sacrum
sacroiliac ligament, and all the medial aspect of the iliac crest. Below
:the twelfth rib the muscle splits into three columns
 ,iliocostal-Iateral band 
, longissimus-intermediate ban
.spinalis-medial band
The iliocostal (lateral) inserts into the angle of the ribs and ultimately
extends to C .... In the thoracic spine the muscle extends over six
(segments (ribs

FIGURE 33. The extensor muscles of the spine

The longissimus (intermediate) inserts into the transverse processes
cephalad to T,. It is the only erector spinae muscle that reaches the
.skull
The spinalis is essentially a flat aponeurosis. Its medial border attaches
to the posterior spines of the thoracic vertebrae. The lateral
margin is free

.FIGURE 34. Deep extensor spinal muscles

Under the erector spinae muscle i s located the transverse spinalis

:which comprises three layers

  ,semispinalis

, multifidus

. rotatores

The semispinalis (superficial layer) arises from the tips of the transverse

processes and inserts into the tips of the spinous process. It spans

.(3to 5 segments (Fig. 33   

The multifidus arises as a thick, fleshy mass on the dorsum of the

sacrum (between the spinous and transverse crest), from the overlying

erector spinae aponeurosis, and from all the transverse processes up to

.C,. This muscle spans three segments to attach to the inferior borderThe rotators spans one segment: from the transverse process of one

.(vertebra to the spinous process of the adjacent vertebra (Fig. 34

In the lumbar spine there are other small muscles: ( 1 ) interspinalis

unite adjacent lumbar spinous processes, and (2) intertransversari

.unite adjacent transverse processes

The thoracolumbar fascia is the dorsal aponeurosis of the transversus

.abdominal muscles