Spine of scapulaInferior angle of scapulaMedial border of scapulaPosition of externaloccipital protuberancePosterior superior iliac spineIliac crest
Fig. 2.67 The back with the positions of vertebral spinous processes and associated structures indicated. A. In a man. B. In a woman with neck flexed. The prominent CVII and TI vertebral spinous processes are labeled. C. In a woman with neck flexed to accentuate the ligamentum nuchae.
Tip of coccyxSII vertebral spinous processTXII vertebral spinous processTVII vertebral spinous processTIII vertebral spinous processTI vertebral spinous processRoot of spine of scapulaInferior angle of scapulaHighest point of iliac crestIliac crestSacral dimpleCVII vertebral spinous processCII vertebral spinous processPosition of externaloccipital protuberanceLIV vertebral spinous processA
Fig. 2.68 Back with the ends of the spinal cord and subarachnoid space indicated. A. In a man.
Back with the ends of the spinal cord and subarachnoid space indicated. B. In a woman lying on her side in a fetal position, which accentuates the lumbar vertebral spinous processes and opens the spaces between adjacent vertebral arches. Cerebrospinal fluid can be withdrawn from the subarachnoid space in lower lumbar regions without endangering the spinal cord.
Tip of coccyxSII vertebral spinous processTXII vertebral spinous processInferior end of spinal cord(normally betweenLI and LII vertebra)Inferior end ofsubarachnoid spaceALIV vertebral spinous process
LIV vertebral spinous processNeedleLV  vertebral spinous processTip of coccyxB
Fig. 2.69 Back muscles. A. In a man with latissimus dorsi, trapezius, and erector spinae muscles outlined.
Back muscles. B. In a man with arms abducted to accentuate the lateral margins of the latissimus dorsi muscles. C. In a woman with scapulae externally rotated and forcibly retracted to accentuate the rhomboid muscles.
Fig. 2.70 MRI of the lumbar spine reveals posterior herniation of the L2-3 disc resulting in compression of the cauda equina filaments.
Table 2.1 Superficial (appendicular) group of back muscles
Table 2.2 Intermediate (respiratory) group of back muscles
Table 2.3 Spinotransversales muscles
Table 2.4 Erector spinae group of back muscles
Table 2.5 Transversospinales group of back muscles
Table 2.6 Segmental back muscles
Table 2.7 Suboccipital group of back muscles
In the clinic
Spina bifida is a disorder in which the two sides of vertebral arches, usually in lower vertebrae, fail to fuse during development, resulting in an “open” vertebral canal (Fig. 2.24). There are two types of spina bifida.
The commonest type is spina bifida occulta, in which there is a defect in the vertebral arch of LV or SI. This defect occurs in as many as 10% of individuals and results in failure of the posterior arch to fuse in the midline. Clinically, the patient is asymptomatic, although physical examination may reveal a tuft of hair over the spinous processes.
The more severe form of spina bifida involves complete failure of fusion of the posterior arch at the lumbosacral junction, with a large outpouching of the meninges. This may contain cerebrospinal fluid (a meningocele) or a portion of the spinal cord (a myelomeningocele). These abnormalities may result in a variety of neurological deficits, including problems with walking and bladder function.
In the clinic