Hip Stability

  1. Determine YZ joint center positions of the respective limb’s Ankle, Knee, and Hip
  2. Calculate the respective differences in Y and Z between the Knee and Hip joint centers, and Ankle and Knee joint centers.
  3. Calculate segment angles for the thigh and shank segments by taking the inverse tangent of the Z difference over difference in Y.
  4. Calculate the Knee valgus angle by subtracting the thigh segment angle from the shank segment angle.
  5. Metric calculated for Step Down, Drop Jump, Lateral Shuffle, Triple Jump, Deceleration, Cut.
Score Scoring Definition Significance
0 Knee valgus angle is less than -10 degrees Significant Knee Valgus
1 Knee valgus angle is less than -5 degrees Mild Knee Valgus
2 Knee valgus angle is greater than -5 degrees No Knee Valgus