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Abdominal Impulse Ratio

Overview​

The abdominal impulse ratio is a metric used to assess abdominal loading during impact by comparing the impulse transmitted through the lumbar spine to the impulse carried by the iliac forces. This metric is theoretical and has not been implemented into any standards.

Required Signals​

  • Lumbar Shear (X)
  • Lumbar Moment (Y)
  • Upper Left Iliac Force (X)
  • Upper Right Iliac Force (X)
  • Lower Left Iliac Force (X)
  • Lower Right Iliac Force (X)

Calculation​

  1. Remove bias from all signals
  2. Filter all signals (CFC = 1000)
  3. Find the maximum of lumbar shear and lumbar moment
  4. Calculate IAV for lumbar shear and lumbar moment
  5. Truncate lumbar shear from 0ms to 120ms
  6. Integrate lumbar shear to calculate lumbar Impulse
  7. Sum all iliac forces to get total iliac force
  8. Find the maxiumum total iliac force
  9. Truncate total iliac force from 0ms to 120ms
  10. Integrate total iliac force to calculate iliac Impulse
  11. Calculate abdominal impulse ratio
AbdominalImpulseRatio=maximum(LumbarImpulseIliacImpulse>1)(Equation 1) \tag{Equation 1}Abdominal Impulse Ratio = maximum(\frac{Lumbar Impulse}{Iliac Impulse} > 1)
  1. Calculate IAV with IARV = 2