Injury Biomechanics

Question 1

What is the purpose of injury biomechanics?

Answer 1

Assess injury mechanics, dev strategies to reduce structural/functional damage in anatomical structures

Question 2

List a scale that we can use to determine injury severity

Answer 2

AIS - Abreviated Injury Scale, 7 regions, severity listed 1-5, 6 being death.

Used w ISS, summed square of 3 most severe and get score from 0-75.

Question 3

How does Mechanical Load relate to Injury? What are the 3 diagrams we can use to depict.

Answer 3

1. Overstress - acute failure

2. Overuse - chronic overuse failure

Question 4

What is the training advice for reducing mechanical load injuries?

Answer 4

Boom bust pattern (2.7x) for acute failure injuries in first week
Train 2-3x/week, increasing 10-20% each week
If training load doubled in a week, 3-5x likelihood of injury

Question 5

What are the response to acute mechanical load injuries?

Answer 5

Elastic region, Plastic region, Ultimate failure point

Question 6

What are determining factors of the acute response to mechanical load?

Answer 6

Orientation, age, type of tissue

Question 7

Discuss the findings regarding Head Injuries and Combat Sports

Answer 7

Overall: Higher for MMA fighters than for boxers
But MMA > more minor contusion injuries
Boxers more likely to experience serious head injury (concussion/head trauma) leading to loss of consciousness

Question 8

What are the etiology of Brain Injuries

Answer 8

Force (f = ma) or Inertia (L=I x w)

Question 9

Discuss two methods of assessing Head Injuries

Answer 9

Head Severity Index HSI (also called Gadd Severity Index) & Head Injury Criterion HIC

Question 10

How is HSI calculated? What are the reference values?

Answer 10

HSI = head acceleration(2.5) x time
Severe injury if:
HSI > 1000 (direct impact) OR HSI > 1500 (indirect impact)

Question 11

How is HIC calculated? How is it referenced?

Answer 11

Similar calculation as HSI but

Analyze Acceleration-time pulse to determine starting and ending points that yield highest score

Question 12

Why is the HIC important?

Answer 12

Because HSI produces unreasonably high values predicting severe injuries
When scores compared to cadaver experiments

Question 13

If HSI > 1000 (direct impact), what are the probabilities of head injuries?

Answer 13

18% severe - AIS 4
55% serious - AIS 3
90% moderate - AIS 2

Question 14

Can you draw a graph depicting Acceleration-time pulse, HSI, and HIC for a impact between surrogate head and impact surface?

Answer 14

a) show peak value / max g score
b) HSI = area under curve
c) same as B but show t0 and t1 time limits that maximize the HIC score