Sharp force trauma

Question 1

What is sharp force trauma?

Answer 1

injury caused by compression/shearing forces applied to a narrow area of bone that results in a focal of impact with a v-shaped cut mark in bone

Question 2

What is a tell-tale sign of sharp force trauma?

Answer 2

injury that’s linear with well defined straight edge

Question 3

What are striations?

Answer 3

• near microscopic lines that occur within the profile of the trauma impact site

Question 4

What does it mean if striations are vertical?

Answer 4

the object was moving perpendicular to bone, in an up and down stab motion

Question 5

What does it mean if striations are horizontal?

Answer 5

object was moving in a parallel fashion to the bone, in a slashing motion

Question 6

What are secondary fracture line?

Answer 6

• radiate out from impact side and indicate higher level of energy was imparted on the body
• suggests heavier weapon was used/ high force

Question 7

Why are secondary fracture lines useful?

Answer 7

can help determine sequence of blows because propagation follows Puppe’s rule

Question 8

What is wastage?

Answer 8

• pieces of bone that are removed from the primary impact site
• when heavy object is removed after initial strike it detaches more pieces of bone

Question 9

What is hinging?

Answer 9

• incomplete removal of bone fragments near the primary impact site
• more common in wet bone

Question 10

What are the 3 types of sharp force trauma?

Answer 10

1. incision/cut
2. stab/puncture
3. notches/clefts

Question 11

What is an incision/cut?

Answer 11

• longer than wide
• result from applied force to the bone at an oblique angle
• minimal secondary fracture lines, wastage, hinging

Question 12

What are punctures?

Answer 12

• from objects being stabbed into body at perpendicular angle
• more even in width and length
• impact site can reflect shape of object used
• vertical striations and limited wastage