Foundation in Kinesiology and Biomechanics - Spine Notes

Learning Outcomes

• 5.1 General Purpose and Function of the Spine

  • Provides mobility
  • Provides stability
  • Transmits and absorbs forces
  • Protects the spinal cord

• 5.2 Primary and Secondary Spinal Curves

  • 7 cervical vertebrae (Cervical lordosis)
  • 12 thoracic vertebrae (Thoracic kyphosis)
  • 5 lumbar vertebrae (Lumbar lordosis)
  • 5 fused sacral vertebrae (Sacrococcygeal kyphosis)
  • 5 fused coccygeal vertebrae

• 5.3 General Features of a Vertebra

  • Components:
  • Anterior body
  • Posterior neural arch
  • Vertebral foramen
  • Pedicle
  • Transverse process
  • Spinous process
  • Lamina
  • Articular processes

• 5.4 Specific Spinal Structures

  • Discuss details regarding the cervical, thoracic, lumbar, and sacral regions, including curves and muscle function.

• 5.5 Role of Muscles in Spine Stabilization

  • Deep Stabilizers: Control small movements, maintaining spinal stability.
  • Primary Movers: Responsible for large movements of the spine.

• 5.6 Malalignment Effects on Posture

  • Poor alignment in one spinal region can lead to compensatory changes in others, affecting overall posture.

Spinal Curves

• Curvature Types:
  • Cervical Lordosis: Forward curve in the neck.
  • Thoracic Kyphosis: Backward curve in the mid-back.
  • Lumbar Lordosis: Forward curve in the lower back.
  • Sacrococcygeal Kyphosis: Curve of the fused sacral and coccygeal vertebrae.

Bony Structures of the Spine

• Basic Structures Include:
  • Anterior Body: Weight-bearing structure of each vertebra.
  • Posterior Neural Arch: Surrounds the spinal canal.
  • Vertebral Foramen: Opening for the spinal cord.
  • Spinous Process: Projects posteriorly for muscle attachment.
  • Transverse Processes: Lateral projections for muscle attachment.
  • Articular Processes: Facilitate facet joint formation.

Intervertebral Discs

• Function:

  • Shock absorption between vertebrae.
  • Facilitate spinal flexibility and motion by allowing movement between the vertebrae.

• Disc Compression Dynamics:

  • Spinal Flexion: Anterior compression, posterior stretch.
  • Spinal Extension: Posterior compression, anterior stretch.

Spinal Ligaments

• Key ligaments include:
  • Anterior and Posterior Longitudinal Ligaments
  • Ligamentum Flavum
  • Supraspinous Ligament
  • Interspinous Ligament
  • Iliolumbar Ligament: Important for stabilizing the lumbar region.

Spinal Kinematics

• Movements Include:

  • Flexion/Extension: Movements in the sagittal plane.
  • Lateral Bending: Movements in the frontal plane.
  • Rotation: Movements in the horizontal plane.

• Coupling Motions: Most common in the spine involves lateral bending and rotation together.

Cervical Region

• Structure:

  • C1-C7, significant for head support and movement.
  • C1 (Atlas): Enables nodding.
  • C2 (Axis): Allows rotation.

• Range of Motion Examples:

  • Flexion: 50°
  • Extension: 60° to 80°
  • Rotation: 80°

Thoracic Region

• Structure:

  • T1-T12; associated with ribcage, protects internal organs.

• Motion Limitations:

  • Limited flexion (~70° to 85°) and extension (~45°) due to rib attachment.

Lumbar Region

• Structure:
  • L1-L5; large vertebrae designed for heavy load-bearing.
  • Lumbosacral Angle: Important for overall lumbar curvature and shear force dynamics.

Sacral Region

• Structure:

  • Five fused vertebrae forming the sacrum, provides stability to the pelvis.

• Motion:

  • Nutation: Anterior movement of the base.
  • Counter Nutation: Posterior movement of the base.

Spinal Muscle Groups

• Categories:
  • Posterior Muscles: Erector spinae, transversospinal group for stability and movement.
  • Anterior Muscles: Scalenes, sternocleidomastoid for flexion and rotation.
  • Lateral Muscles: Obliques assisting with flexion and rotation.

Muscle Functions and Stabilization

• Key Functions:
  • Deep muscles (like the multifidi) aid in segmental control and stability.
  • Erector spinae, quadratus lumborum participating in trunk stability during movement.