Hering's Principle
Definition
The 1853 observation that a radiating fracture from a subsequent impact is arrested when it reaches a fracture line produced by a prior impact; used to determine the sequence of multiple blows from the arrest relationships between fracture lines.
- Formulated
- 1853
- Applies to
- Radiating skull fractures from blunt-force impacts
- Rule
- A later radiating fracture stops at an earlier fracture line
- Use
- Establishing the temporal sequence of multiple blows
Common questions
Why does a later fracture stop when it reaches an earlier one?+
Bone under an existing fracture line has already lost its ability to transmit stress across that break, so a crack propagating from a subsequent impact loses the mechanical continuity it needs to continue and is arrested at the junction.
Can Hering's principle prove which blow was struck first with a single fracture pair?+
It shows relative order between the two fractures involved in the arrest, telling the examiner which line came first, but it cannot by itself fix an absolute timeline or link a fracture to a specific weapon or assailant without other evidence.
Related terms
- Bearing Surface
- The area of the striking implement that was in contact with the skull at the moment of force transfer; its geometry can...
- Concentric Fracture
- An arc-shaped fracture encircling the impact zone, produced by outer-table bending tension at a distance from the focal impact; always post-dates the...
- Depressed Fracture
- A fracture where the impacted skull segment is driven inward beyond the elastic limit; the geometry of the depression reflects the bearing...
- Diffuse Loading
- Force distributed over a broad contact area (as from a fall onto a flat surface or a broad-surface blow); produces a broader...
- Focal Loading
- Force concentrated on a small contact area of the skull surface (as from a hammerhead, poker, or stone edge); produces a discrete...
- Perimortem Fracture
- A fracture produced at or near the time of death while the bone retains green (fleshed) properties; distinguished by sharp fracture margins...
- Radiating Fracture
- A linear fracture extending outward from the impact point, initiated by inner-table tension as the outer table is compressed; propagates until arrested...
- Wedge Fracture
- The three-dimensional fracture geometry described by Berryman and Symes (1998): a conical inner-table failure zone wider than the outer-table defect, produced by...
- Wolff's Law
- The principle that bone is deposited and resorbed in response to mechanical loading history. Cortical thickness and trabecular orientation follow principal stress...