Complex sentence: The anterior cruciate ligament is one of the four main ligaments of the knee, and the ACL provides 85% of the restraining force to anterior tibial displacement at 30 degrees and 90 degrees of knee flexion.
Split into simpler sentences: The anterior cruciate ligament is one of the four main ligaments of the knee. It also provides 85% of the restraining force to anterior tibial displacement at 30 degrees and 90 degrees of knee flexion.