In this study a numerical model of a skier was developed to investigate the effect of different rehabilitation strategies after anterior cruciate ligament (ACL) rupture.
A computer model using a combined finite-element and multibody approach was established. The model includes a detailed representation of the knee structures, as well as all major leg muscles. Using this model, different strategies after ACL rupture were analyzed.
The benefit of muscle training to compensate for a loss of the ACL was shown. The results indicate that an increase of 10% of the physiological cross-sectional area has a positive effect without subjecting other knee structures to critical loads. Simulating the use of a hamstring graft indicated increasing knee loads. A patellar-tendon graft resulted in an increase of the stress on the lateral collateral ligament.
Muscle training of both extensors and flexors is beneficial in medical rehabilitation of ACL-deficient and ACL-reconstructed knees.
The authors are with the Institute for Biomedical Engineering, University and ETH Zurich, Switzerland.