Upper limb

Anulus fibrosus of thoracic intervertebral discs (T1–L1)

Anulus fibrosus disci intervertebralis (pars thoracica)

Origin

Circular fibrocartilage laminae attached to superior thoracic vertebral body

Insertion

Inferior thoracic vertebral body and costovertebral junction

Function

Encloses thoracic nucleus pulposus; stabilizes the thoracic cage against axial loading

Innervation

Sinuvertebral nerves (T1–T12)

Movement & chain

Allows limited rotational and bending movements constrained by rib cage

Palpation

Not palpated directly

Clinical

Thoracic disc herniation (risk of spinal cord compression/myelopathy); Scheuermann disease with Schmorl nodes.

Segmental innervation

T1–T12

In clinical practice

Thoracic extension mobilization and postural therapy for Scheuermann kyphosis

Region in the model

Upper limb