Lower limb

Zona orbicularis of the hip joint (Orbicular zone / Ring of Weber)

Zona orbicularis articulationis coxae (Ringband van Weber)

Origin

Deep circular fibers of the hip capsule encircling the femoral neck

Insertion

Forms a collar around the narrowest constriction of the femoral neck without bony attachment

Function

Acts as a keyhole/buttonhole locking mechanism that holds the spherical femoral head securely within the acetabulum against traction forces

Innervation

Articular branches of femoral, obturator, and sciatic nerves

Movement & chain

Provides continuous circumferential constriction across all planes of hip motion

Palpation

Intra-articular, non-palpable

Clinical

Resists hip joint distraction; visualized on MRI and preserved or repaired during hip arthroscopic capsulotomy.

Segmental innervation

L2–S1

In clinical practice

Preservation of hip stability following arthroscopic capsular closure

Region in the model

Lower limb