Spine Anatomy and Function Overview

Rectus Abdominis

Dominant trunk flexor muscle.

Internal Obliques

Accessory muscle aiding trunk flexion.

External Obliques

Accessory muscle aiding trunk flexion.

Erector Spinae

Primary trunk extensor muscle group.

Quadratus Lumborum

Supports lateral flexion and extension.

Transverse Abdominis

Key for core stability and pressure.

Intra-abdominal Pressure

Increased pressure aiding breathing and lifting.

Cervical Vertebrae

Seven vertebrae in the neck region.

Thoracic Vertebrae

Twelve vertebrae attached to ribs.

Lumbar Vertebrae

Five largest vertebrae for weight bearing.

Sacrum

Five fused bones forming the back pelvis.

Coccyx

Four fused bones forming the tailbone.

Intervertebral Disc

Shock absorbers between vertebrae.

Annulus Fibrosis

Tough outer ring of intervertebral disc.

Nucleus Pulposus

Inner elastic core of intervertebral disc.

Lordotic Curve

Anterior curvature in lumbar spine.

Kyphotic Curve

Posterior curvature in thoracic spine.

Lumbar Lordosis

Exaggerated lordotic curve causing low back pain.

Thoracic Kyphosis

Exaggerated thoracic curve creating a hump.

Scoliosis

Lateral spinal deviation, 'C' or 'S' shaped.

Forward Lean Torque

Torque from gravity creating back strain.

Herniated Disk

Nerve compression due to disc displacement.

Open Chain Motion

Distal segment free to move.

Closed Chain Motion

Distal segment fixed and immobile.

Force Couples

Complementary muscle groups producing desired motion.