Quantification of Auditory-Motor Coordination as a Potential Return-to-Dance Criterion After Anterior Cruciate Ligament Reconstruction: A Case Report.

For dancers who undergo anterior cruciate ligament (ACL) reconstruction, it is crucial to establish criteria for safely returning to dance without risking reinjury. Given the specific demands of dance, this case study aims to quantify the ability to coordinate knee movements with sounds and to analyze kinematics during the rehabilitation period. A female recreational street dancer participated in this study while undergoing rehabilitation after ACL reconstruction surgery. She performed knee flexion and extension movements to the beat of a metronome while standing, with both the movements and timing of the metronome beats recorded. Findings indicate that the muscle strength of her injured leg approached that of the uninjured side, suggesting steady rehabilitation progress. Although the range of knee joint angles did not differ between the injured and uninjured legs during the task, the injured knee exhibited less flexion and more extension. The participant was unaware of this increased extension in the injured leg. Additionally, the phase relationship between her rhythmic knee movements and the metronome beat changed unintentionally over the course of rehabilitation. Quantifying these unintentional changes in kinematics and their relationship to auditory beats can help establish appropriate criteria for a safe return to dance.