Peter%20L.%20Lane,%20MD,%20FRCPC

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INJURY BIOMECHANICS

• Peter L. Lane, MD, FRCPC

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INJURY BIOMECHANICS
INTRODUCTION

• Why bother ?
• The science of stopping
• Some examples of different mechanics and
  the injuries they produce
• How we can learn more

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WHY BOTHER ?

• Accidents will happen
• People will get hurt
• We'll try to fix them

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"ACCIDENT"

• Sudden event
• Unpredictable
• Unavoidable

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INJURY AS A DISEASE

• AIDS/TB analogy
• Relative importance as a public health
  issue
• Framework of analysis

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CLINICAL RELEVANCE

• Patterns of injury
• Predictive of severity and outcome
• Prevention/injury control

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THE SCIENCE
OF STOPPING

• Speed doesn't kill stopping does
• dv/dt

V
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dV/dT
v
e
l
o
c
i
t
y
time (msec)
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dV/dT
V 15 g
v
e
l
o
c
i
t
y
time (msec)
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dV/dT
V 100 g
v
e
l
o
c
i
t
y
time (msec)
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THE 3 COLLISIONS

• Vehicle with barrier
• bony structures with vehicle interior
• viscera with bony structures

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SLOWING THE STOP

• Environmental factors n median barriers
  n roadside obstacles n traffic flow
• Vehicle factors n windshields n
  "friendly" interior n steering column
• Restraint systems n 3 point belts ?
  air bags

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CRASH TYPE - FRONTAL

• CONTACTS
• windshield
• steering wheel
• dash board
• pedals, firewall

• INJURIES
• face
• brain
• neck
• bony thorax
• lungs, heart, great vessels
• abdominal viscera
• knee, femur, hip, pelvis
• foot, ankle

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CRASH TYPE - SIDE

• CONTACTS
• window/pillar
• door panel/intrusion

• INJURIES
• face
• brain
• neck
• bony thorax
• lungs
• hip
• pelvis

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CRASH TYPE - REAR

• CONTACTS
• head rest up
• head rest down
• seat back
• shoulder belt on

• INJURIES
• scalp contusions
• usually soft tissue
• strain to neck
• none
• chest contusion
• flexion/rotation
• inj to C- spine

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CRASH TYPE - FRONTAL
BELTS ON

• CONTACTS
• shoulder component
• lap component
• lap belt alone

• INJURIES
• clavicle
• bony thorax
• neck - flexion/rotation
• abdominal wall
• solid and hollow
• viscera - compressive
• above plus
• distraction L - spine

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OTHER CRASH TYPES

• Rollover
• Ejection
• Motor cycle
• Bicycle
• Pedestrian

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INJURY BIOMECHANICS
SUMMARY

• Why bother ?
• The science of stopping
• Some examples of different mechanics and
  the injuries they produce
• How we can learn more

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MORE TO BE LEARNED

• Crash investigation
• Correlation with trauma registry data
• Collision data project
• Vehicle changes
• Road design
• Clinical data
• Mechanics of other causes