Injury

Injury

1. Background

   • Injury is a mechanical disruption of tissue
   • Sudden or gradual
   • Disorders can occur
   • Materials
     • Elastic
     • Plastic
     • Failure

2. Stress/ strain

   • Stress = force / area
   • Strain = delta length / initial length
   • Stress: the mechanical load
   • Strain: the effect of the load

3. Types of load

   • Forces
     • Gravity
     • Muscular
     • External
   • Application
     • Compression
     • Tension
     • Shear
     • Bending
     • Torsion
   • Sudden / stress fractures
   • Bone strength depends on the compact bone

4. Ligament sprains

   • Macro-trauma
   • Repetitive micro-trauma
   • Non-linear dynamics
   • 70% water
   • 25% collagen
   • 5% elastin/protiens

5. Whiplash

   • Unaware victim, struck from behind
   • Cervical spine injury
   • Symptoms
     • Neck and shoulder pain
     • Dizziness
     • Blurred vision
   • Permanent in 25% of cases
   • Occurs in soft tissue

6. Bone fracture

   • Direct/ indirect
   • Injury site
   • Extent of injury
   • Configuration
   • Fragment/ environmental relations