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Ankle Rotation

Overview​

This metric calculates the amount of ankle rotation experiened during a crash impact. Ankle Rotation values can be used to quantify risk of injury due to unnatrual movement of ankle and inability for surrounding anatomy to cope with movement. [1]

Required Signals​

  • Right and Left Ankle Angle Rotation (Radians) (X, Y, and Z)

Calculation​

  1. Raw signal data is converted into values with unit of degrees to ensure angle data has consistent units
  2. Input signals are filtered using a butterworth filter (CFC = 180)
  3. Filtered signals are stored for each of the x, y, and z axes for both the left and right ankles
  4. Maximum value is found in each each axis (x, y, z) for both ankles
  5. Finds start and finish position for each axis for both ankles
  6. Returns results:
    • maximum rotation (Step 4)
    • start and finish position (Step 5)

ankle rotation

Ankle rotation can happen along the x,y,and z axis" (black)

[1] Funk, J. Ankle Injury mechanisms: Lessions learned from cadaveric studies. Clinical Anatomy, 2011. Volume 24, Issue 3.