Is poor proprioception associated with worse movement quality of the knee in individuals with anterior cruciate ligament deficiency or reconstruction?

[Purpose] To investigate the association between proprioception and a knee medial to foot position during weight-bearing activities in patients with anterior cruciate ligament reconstruction and anterior cruciate ligament deficiency. [Participants and Methods] Thirty-eight patients with anterior cruciate ligament reconstruction and 13 patients with anterior cruciate ligament deficiency aged 18–40 years were included. Proprioception was assessed by knee kinesthesia measured by the threshold to detection of passive motion. Movement quality was assessed by visual observation of the position of the knee in relation to the foot during the mini squat, the single-leg hop for distance, and the cross-over hop for distance. [Results] In patients with anterior cruciate ligament deficiency, worse kinesthesia was significantly associated with a knee medial to foot position during the single-leg hop for distance. No statistically significant associations were observed between kinesthesia and a knee medial to foot position during the three tasks in patients with anterior cruciate ligament reconstruction. [Conclusion] Poor proprioception may be associated with worse movement quality of the knee in patients with anterior cruciate ligament deficiency, but not in patients with anterior cruciate ligament reconstruction. Differences in sensorimotor function between patients with reconstructed and non-reconstructed anterior cruciate ligament should be considered in training and rehabilitation regimens aiming to enhance performance and prevent further injuries in these patients.