Animation 6: Model of the knee with all four ligaments modelled as arrays of fibre
Model knee with arrays of fibre representing the ACL, the two
bundles of the PCL, the superficial fibres of the MCL, and the LCL.
Fibres within the PCL and LCL tighten and those within the ACL and MCL
slacken when the tibia is pushed backwards from the neutral position,
and vice versa when the tibia is pulled forward from the neutral