Lecture Notes: Functional Anatomy of the Lumbar and Thoracic Spine

Introduction

• Functional Anatomy: Focus on lumbar and thoracic spine.
• Integration: Lower extremity with upper extremity.
• Key Concept: Hip, pelvis, and lumbar spine function as an integrated unit.
• Pelvis Role: Influences lumbar spine mobility due to its central position in kinetic chain.

Anatomy and Forces

• Lumbar Spine: Has a natural lordotic curve.
• Forces Involved:
  • Ground reaction forces from bottom-up.
  • Body weight forces from top-down.
• Convergence Point: SI joint where lower and upper extremity forces meet.

Pelvis as a Fulcrum

• Pelvis: Central in the kinetic chain, stabilizes and relays forces.
• Sport Implication: Stabilizing the pelvis is crucial for athletic performance.

Functional Movement Screen

• Gray Cook's FMS: The body is a kinetic chain.
• Joint Needs:
  • Mobility or stability based on joint-specific requirements.
  • Ankle needs more mobility; knee needs more stability.

Lumbo-Pelvic Complex

• Core Strength: Essential for effective movement and pain prevention.
• Muscle Involvement: 29 muscles attach to the pelvis.

Low Back Pain

• Prevalence: 80% of adults in the US experience low back pain.
• Athletic Injuries: 10-15% of spine injuries in sports are acute.
• Mental Health Connection: Chronic back pain is linked to depression.

Spine Clinical Anatomy

• Spine Curves:
  • Cervical spine: Lordotic.
  • Thoracic spine: Kyphotic.
  • Lumbar spine: Lordotic.
• Vertebral Structures: L1-L2 are more rigid; L4-L5-S1 are highly mobile.

Vertebrae and Nerve Roots

• C-Spine to Sacral Spine: Different vertebral and nerve root counts.
• Nerve Root Summary: C8 exits below C7.

Lumbar and Sacral Pathologies

• Spinal Dysfunctions: Variants including kyphosis, hyperlordosis, scoliosis.
• Lumbarization and Sacralization:
  • Lumbarization: Extra lumbar vertebrae.
  • Sacralization: L5 fuses to the sacrum.

Intervertebral Discs

• Components:
  • Annulus Fibrosis: Outer fibrous layer.
  • Nucleus Pulposus: Inner gelatinous core.
• Disc Herniation: Protrusion of nucleus can encroach on nerves.
• Biomechanics: Discs resist compression but are vulnerable to torsion and shear forces.

Ligaments of the Spine

• Primary Ligaments:
  • Anterior and Posterior Longitudinal Ligaments.
  • Ligamentum Flavum: Contains elastin for flexibility.
• Function: Provide stability and maintain vertebral alignment.

Muscular Anatomy

• Types of Muscles:
  • Extrinsic: Large, powerful movers.
  • Intrinsic: Stabilizers and proprioceptors.
• Key Muscle Groups:
  • Erector Spinae: Spinalis, Longissimus, Semispinalis.
  • Deep Stabilizers: Multifidus, Rotatores.

Neurology

• Lumbosacral Plexus: Complex network including major nerves like the sciatic and femoral nerves.
• Sciatic Nerve: Emerges from L4-S3, splits into tibial and common peroneal nerves.
• Cauda Equina: Nerve roots below L2 resembling a horse's tail.

Conclusion

• Importance of Understanding Anatomy: Critical for diagnosis and treatment of lumbar and thoracic spine issues.
• Upcoming Topics: Clinical examination of lumbar spine pathologies.

This summary captures the essence of the lecture on the functional anatomy of the lumbar and thoracic spine, emphasizing the importance of the pelvis, spinal curvature, vertebral pathologies, intervertebral discs, ligaments, muscles, and neurology associated with the spine.