The special function of the ACL As well as providing a restraint to abnormal knee movement, the ACL gives important information to the muscles involved in the reflex control of knee movements. Nerve fibres give the knee a sense of position and movement and this sensory awareness is known as proprioception. It is a normal feature of all joints and helps to give us balance control and confidence in movements.
To some extent, this can be compensated for after ACL injury by special rehabilitation exercises for the hamstrings and quadriceps (thigh) muscles. However, the knee is a complex joint and muscle strength may not be enough alone for individuals who take part in pivoting type sports.