In-Depth Notes on Trauma forensics

Introduction to Trauma

• Trauma discussed over two days: today (Tuesday) and Thursday.
• Importance of understanding key terms: trauma vs. alteration.

Definitions

• Trauma: Disruption of living tissue (skin, muscle, bone).
• Alteration: Physical changes to non-living materials (including bone).

Forensic Relevance

• Timing of injuries important for forensic analysis.
• Distinctions between antemortem, perimortem, and postmortem events.

Types of Timing

• Antemortem: Occurring while the person is alive; characterized by healing.
• Example: Broken bone that shows signs of healing.
• Perimortem: At or around the time of death; no healing, can appear similar to postmortem injuries.
• Example: Fractures occurring shortly before death.
• Postmortem: After death; no healing observed.
• Example: Fractures in bones found in archaeological contexts.

Injury Mechanism

• Different types of trauma: blunt force, gunshot wounds, sharp force trauma.
• Importance of examining injury patterns to determine cause.

Identifying Trauma Types

• Key characteristics that differentiate antemortem and postmortem injuries.
• Antemortem: Evidence of healing.
• Perimortem: Characterized by acute angles and lack of healing.
• Postmortem: Often shows patterns caused by environmental elements.

Mechanical Properties of Bone

• Young's Modulus / Elastic Modulus: Describes the relationship between stress and strain in materials like bone.
• Elaboration on plastic deformation and yield point related to bone behavior.

Fracture Types

• Main classifications: incomplete (green stick fractures) and complete (two or more pieces).
• Examples:
• Green Stick Fracture: Incomplete break typical in children.
• Comminuted Fracture: Bone broken into multiple pieces, often due to high force.

Directional Forces Affecting Bone

• Types of forces that affect bone fractures:
• Compression: Bones resist this well.
• Tension: Bones are weaker under tension.
• Bending and Shear: Specific examples of how they affect bone fractures.

Factors Influencing Fractures

• External Factors: Direction, magnitude, rate of applied force.
• Internal Factors: Bone composition, isotropic vs. anisotropic characteristics.
• Importance of understanding anatomical structure, such as trabecular and compact bone.

Trauma Mechanics

• Classification of trauma: blunt force, gunshot wounds, sharp force trauma, and thermal injuries.
• Analyzing patterns of trauma to establish cause and timing.
• Discussed blunt force trauma: defined by a broad area of force spreading slowly over time.

Wrap-Up

• Examination of healing phases after fracture, importance of nutrition and activity during recovery.
• Emphasis on understanding distinct patterns in fractures for forensic cases.