Posterior Oblique Subsystem Integration:

By Brent Brookbush DPT, PT, COMT, MS, PES, CES, CSCS, H/FS

The Posterior Oblique Subsystem (POS) is comprised of:

Function (Brief):

The muscles that comprise the POS are the largest in the body. This subsystem plays a significant role in stabilizing the lumbar spine, sacroiliac joint (SIJ) and hip, as well as transferring force between lower and upper extremities. The POS plays an active role in all pulling and rotational movement patterns (especially turning out), multi-segmental extension (with less lumbar extension - excessive lordosis), and eccentrically decelerates spinal flexion and rotation, as well as hip flexion, adduction and internal rotation (knees bow in and excessive forward lean). The POS is the functional antagonist of the Anterior Oblique Subsystem (AOS).

  • Concentric Function: Pulling, rotation "outward", multi-segmental extension with less reliance on lumbar extension
  • Isometric Function: Transfer force between lower and upper extremities, stabilization of the SIJ, lumbar spine and hips
  • Eccentric Function: Decelerate spine flexion and rotation, as well as hip flexion, adduction and internal rotation

Common Maladaptive Behavior

  • Under-active

Signs of POS Dysfunction

Practical Application

Relationship between the Latissimus Dorsi and Gluteus Maximus via the Thoracolumbar Fascia. Posterior Oblique Subsystem a.k.a. Posterior Oblique Sling a.k.a. Posterior Oblique Synergy Relationship between the Latissimus Dorsi and Gluteus Maximus via the Thoracolumbar Fascia

Research Corner:

Thoracolumbar Fascia:

The superficial