M. Ambrus (Budapest, HU)
University of Physical EducationPresenter Of 1 Presentation
P247 - Kinect Azure-Based Measurement of Dynamic Valgus Position of the Knee- A Corrigible Predisposing Factor for ACL rupture
Abstract
Purpose
During physical activity when the knees collapse to the medial side, because the muscular system of lower limb is not enough strong to stabilize the hips and knees, the dynamic knee valgus occurs. Knee valgus position is a major predisposing factor for anterior cruciate ligament rupture since shear forces overload the ligaments of the knee. The single leg squat test is a widely used lower- limb test in movement pattern screening, which helps to assess the injury risk of lower-limb.
Methods and Materials
A new evaluation method was applied with Kinect Azure camera during single leg squat. Knee lateral shift was determined by “knee over foot” to “knee medial to foot” position shift. 22 healthy subjects participated in the study. Kinect validity and accuracy were tested by OptiTrack and MVN Xsens motion capture systems.
Results
The average difference in case of pelvis vertical movement between Kinect and OptiTrack is 1.3 ± 0.7 cm, moreover the difference between knee lateral-medial movement is 0.7 ± 0.3 cm. The rate of dynamic valgus was expressed at 15%-30% squat depth. The well-defined squat depth proves the comparability between subjects.
Conclusion
A 2% valgus-shift at 15% squat depth is suggested as a threshold for determining dynamic instability, since subjects who were over this mark showed extensive knee valgus at lower depths while those who were under 2% remained in this neutral range. The current study proves that the Kinect camera is a low-cost, user-friendly motion capture device, moreover it is a great tool to evaluate the dynamic knee valgus.
Presenter Of 1 Presentation
P247 - Kinect Azure-Based Measurement of Dynamic Valgus Position of the Knee- A Corrigible Predisposing Factor for ACL rupture
Abstract
Purpose
During physical activity when the knees collapse to the medial side, because the muscular system of lower limb is not enough strong to stabilize the hips and knees, the dynamic knee valgus occurs. Knee valgus position is a major predisposing factor for anterior cruciate ligament rupture since shear forces overload the ligaments of the knee. The single leg squat test is a widely used lower- limb test in movement pattern screening, which helps to assess the injury risk of lower-limb.
Methods and Materials
A new evaluation method was applied with Kinect Azure camera during single leg squat. Knee lateral shift was determined by “knee over foot” to “knee medial to foot” position shift. 22 healthy subjects participated in the study. Kinect validity and accuracy were tested by OptiTrack and MVN Xsens motion capture systems.
Results
The average difference in case of pelvis vertical movement between Kinect and OptiTrack is 1.3 ± 0.7 cm, moreover the difference between knee lateral-medial movement is 0.7 ± 0.3 cm. The rate of dynamic valgus was expressed at 15%-30% squat depth. The well-defined squat depth proves the comparability between subjects.
Conclusion
A 2% valgus-shift at 15% squat depth is suggested as a threshold for determining dynamic instability, since subjects who were over this mark showed extensive knee valgus at lower depths while those who were under 2% remained in this neutral range. The current study proves that the Kinect camera is a low-cost, user-friendly motion capture device, moreover it is a great tool to evaluate the dynamic knee valgus.