The front kick and roundhouse kick consist mainly of throw-like movements, defined as hip flexion followed by knee extension.
For example, when describing coordinating wrist flexion with elbow flexion and wrist extension with elbow extension, Li et al.
Namely, positive IIC (0 < IIC < 1) primarily coordinates hip flexion with knee extension or hip extension with knee flexion with other hip motions.
The roundhouse kick consisted of simple and monotonic changes in hip motions (hip flexion, internal rotation, and abduction) with knee flexion and extension.
All of the previous arthrometric studies in the literature, however, have examined the knee stability behavior at a limited flexion range of 20-30 degrees, probably due to the design restrictions of the commercially available arthrometers.
It had basically only one degree of freedom through the hinge joint which provided rotation in the sagittal plane and allowed the knee to be flexed to different flexion angles.
At each flexion angle, the arthrometer was positioned on the tibial crest and secured with two Velcro straps.