Chapter 8 - Head Injuries Greatest danger to our physical well- being due to head structures...
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Transcript of Chapter 8 - Head Injuries Greatest danger to our physical well- being due to head structures...
Chapter 8 - Head Injuries
Greatest danger to our physical well-being due to head structures
controlling life sustaining processes
Head Anatomy
• Brain– Cerebrum
• two hemispheres– Frontal– parietal– temporal– occipital
– Meninges• Dura matter• Arachoid: Sub arachoid
space (CSF)• Pia
Head Anatomy
• Brain stem (relays sensory and motor information and life supporting reflex center, cranial nerves)– Midbrain– Pons– Medulla oblongata
• Cerebellum– Subconscious movements– Equilibrium & posture– Motor error detectors– Movement patterns– Emotional: pleasure & anger
Head Injuries
• Causes– Sudden forces to head
– Direct
– Indirect (inertial)• acceleration &
deceleration mechanism
– Head Motion• translation
• rotation
21%
12%
10%7%
50%
FallsViolenceSportsMisc.Car crash
• Mechanical Properties– Skull: stiff yet compressible– Brain: compliant
• Internal stresses• Strain exceeds capacity to
withstand load• Close vs. Open• Primary and Secondary
– Severity: internal damage to neural structures
• Boxing: CTBE or dementia pugilistica
Head Injuries
Trunk Injuries
• Vertebral fractures– Major Health concern
– Proximity to spinal
– Potential to cause severe neural damage, including death
• Axial compressive loads– T11-L3 minimal curvature,
transition zone
Trunk Injuries
• Three Column model– Burst fracture:
compression force causing vertebrae to shatter from within
– High loading rates: intrusion
– Disk degeneration• Healthy: more intrusion
• Old: less intrusion
Type Anterior Middle Posterior
Compression Compression None None orDistraction
Burst Compression Compression None
Seat-Belt None orcompression
Distraction Distraction
Fracturedislocation
Compressionrotationshear
Distractionrotationshear
Distractionrotationshear
Trunk Injuries
• Spinal Deformities– abnormal distributions
patterns or pathological tissue adaptations
– Associated with cardiopulmonary dysfunction
– Scoliosis: Lateral
Trunk Injuries
• Kyphosis– Sagittal plane:
hunchback– Common in women– Osteoporosis– Prevention: exercise
• Scheuermann’s kyphosis: changes in endplates of growing vertebrae
• Lordosis: abnormal extension (swayback)– Lumbar area
– tilting lumbar area• luumbosacral angle
above 30 deg
Trunk Injuries
• Spondylolysis– defect of the vertebrae
lamina (pars articularis)
• Spondylosthesis– translation or slippage
between adjacent segments
• Five types– Dysplastics– Isthmic– degenerative– Traumatic– Pathological
• Young athletes– Isthmic: repeated
loading of pars region, fractures
Trunk Injuries
• Spondylolisthesis– older: L4-L5
degeneration due to arthritis
– Young: L1-S5, end plate lesions
• Loads of the spinal column– comples
– compression
– torsional - shearing
– tensile - excessive spinal motion
• Lumbar region highest forces
Trunk Injuries
• Disks– viscoelastic– annulus fibrosus
• fibrocartilage• criss-crossed orientation
– nucleus pulposus• 70-90% water• mucoprotein & fibers• intrinsic pressure• High tensile stress
(Poisson’s)
– cartilaginous end plate
Trunk Injuries
Trunk Injuries
• Bulging disks:– nucleus pulposus is
displaced from its normal position
– Rotation stress
Trunk Injuries
Type Description
I Acute back sprain (Injury to soft tissue, ligaments etc)
II Disk fluid ingestion
III Annulus disruption
IV Bulging disk
V Fragments from the nucleus or annulus tear off and move into the joint space
VI Displaced fragment into spinal cord
VII Degeneration of disk