Regional anatomy of the back

Regional / topographic anatomy of the backKey facts about the topographic relations of the back. Fascia. Muscular subcutaneous bursae
~ 4 min

Within the back region, there are several important topographic structures.

Lumbar triangle / Petit triangle / inferior lumbar triangle (trigonum lumbale / trigonum lumbale inferius) is a frequent site of lumbar hernia formation. It has the following borders:

  • The inferior border is the crest of the ilium

  • The medial border is the lateral margin of the aponeurosis of the latissimus dorsi

  • The lateral border is the posterior margin of the external oblique muscle

The bottom of this triangle is formed by the internal oblique muscle

Lumbar triangle / Petit triangle / inferior lumbar triangle (trigonum lumbale / trigonum lumbale inferius)
Lumbar triangle / Petit triangle / inferior lumbar triangle (trigonum lumbale / trigonum lumbale inferius)

Superior lumbar triangle / Grynfeltt-Lesshaft triangle (trigonum lumbale superius). This is also where lumbar hernias frequently occur. It has the following borders:

  • The superior border is the 12th rib

  • The lateral border is the internal oblique muscle

  • The medial border is the external margin of the erector spinae muscle

    The bottom of this triangle is formed by the transverse abdominal muscle

    Superior lumbar triangle / Grynfeltt-Lesshaft triangle (trigonum lumbale superius)
    Superior lumbar triangle / Grynfeltt-Lesshaft triangle (trigonum lumbale superius)

    Auscultatory triangle (trigonum auscultationis) is where the posterior lungs segments are auscultated This triangle has the following borders:

  • The medial border is the lateral margin of the trapezius muscle

  • The inferior border is the superior margin of the latissimus dorsi muscle

  • The lateral border is the medial margin of the rhomboid major muscle

    Auscultatory triangle (trigonum auscultationis)
    Auscultatory triangle (trigonum auscultationis)

    In addition, there are several fascia within the back.

  • Superficial fascia (fascia superficialis) covers the superficial muscles of the back. In the lumbar region under this fascia, a lumbosacral fatty tissue is located

  • Nuchal fascia (fascia nuchae) is located between the superficial and deep muscles of the posterior cervical region (this region is also part of the back)

  • Thoracolumbar fascia (fascia thoracolumbalis) covers the deep muscles of the back and forms a kind of sleeve for the inferior parts of the erector spinae muscles. This fascia has two leaves: superficial and deep

    Thoracolumbar fascia (fascia thoracolumbalis)
    Thoracolumbar fascia (fascia thoracolumbalis)
    Thoracolumbar fascia (fascia thoracolumbalis) – superficial
    Thoracolumbar fascia (fascia thoracolumbalis) - superficial
    Thoracolumbar fascia (fascia thoracolumbalis) – deep
    Thoracolumbar fascia (fascia thoracolumbalis) - deep

    There are subtendinous bursae in the places of attachment of the muscles of the back, which reduce the friction of tendons on the bone. They are more or less present in almost all muscles, but the most basic are:

  • Subtendinous bursa of trapezius (bursa subtendinea m. trapezii), which is located between the spine of the scapula and the ascending fasciculi of the muscle

  • Subcutaneous acromial bursa (bursa subcutanea acromialis), which is located at the site of insertion of the trapezius muscle into the acromion of the scapula

  • Subtendinous bursa of latissimus dorsi (bursa subtendinea m. latissimi dorsi)

Dictionary

Regional anatomy of the back

Lumbar triangle / Petit triangle / inferior lumbar triangle
trigonum lumbale /trigonum lumbale inferius
Superior lumbar triangle / Grynfeltt-Lesshaft triangle
trigonum lumbale superius
Auscultatory triangle
trigonum auscultationis
Superficial fascia
fascia superficialis
Nuchal fascia
fascia nuchae
Thoracolumbar fascia
fascia thoracolumbalis
Subtendinous bursa of the trapezius muscle
bursa subtendinea m. trapezii
Subcutaneous acromial bursa
bursa subcutanea acromialis
Subtendinous bursa of the latissimus dorsi muscle
bursa subtendinea m. latissimi dorsi
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