SPINAL ANATOMY AND BIOMECHANICS

Dr A Verma

ANATOMY

• Bone– Column– Regional

• Intervertebral Disc• Joints• Ligaments• Muscles

• Body• Neural arch• Bony processes

INTERVERTEBRAL DISC• Location• Structure• Function• Total – 23 discs• ¼ th of the spinal

column's length• Avascular • Nutrients diffuse

through end plates

DISC STRUCTURE

• Nucleus• Annulus• End plates

DISC FUNCTION

• Separation• Mobility

JOINTS

THREE JOINT COMPLEX• Intervertebral Joint• Facet Joints

LIGAMENTS

MUSCLES

• Back muscles• Accessory muscles

SPINAL SEGMENT

FUNCTIONAL SPINAL UNIT

BIOMECHANICS OF SPINE

CARDINAL MOVEMENTS• Flexion-extension• Compression• Axial rotation• Lateral flexion

Types of motion

FLEXION - EXTENSION• Two components– Sagittal rotation - 6 - 10°– Resisted by• Annulus• Facets• Ligaments

•Back Muscles– Translation - 2mm– Resisted by• Facets• Annulus

COMPRESSION

• Underestimated!!!!• Produced by– Body weight– Back muscles

AXIAL ROTATION

• No primary rotators• Range - < 3°• Resisted by – Facets– annulus

SUMMARY

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