Knee joint position sense (KJPS) after ACL reconstruction
Mechanoreceptors are located in the native anterior cruciate ligament (ACL) and they provide crucial proprioceptive information. Thus, an impairment of the ACL may decrease proprioception. The joint position sense (JPS) is generally heightened in athletes and hence might be even more impaired after an ACL injury and reconstruction, even as they return to high-level play. The purpose of this study was to investigate KJPS ability in elite athletes who have returned to international level play following ACL reconstruction.
Ten elite athletes who had all undergone ACL reconstructive surgery participated (three taekwondo competitors, three footballers, two netballers, one middle distance runner, one judo competitor). Ten healthy participants acted as age, gender and sport matched controls. Lower limb markers were placed on the lower limb. The participant was seated blindfolded on the end of a physiotherapy plinth. The leg was passively moved by the experimenter to a target angle in a specified range at an approximate angular velocity of 10 degrees per second. The leg was then passively returned to the starting angle by the researcher and the participant was instructed to actively move back to the target angle. The process was repeated five times for each target angle.
The ACLR knees had on average a greater mean error score by 5 degrees compared to their contralateral knees and the uninjured control group. The results indicate that the athletes demonstrated reduced static proprioceptive ability, despite having successfully completed a structured rehabilitation program and retuning to play. However, as the injured athletes returned to sports on an international level it might be that the JPS deficiency does not reduce initial functional performance. The JPS ability in athletes returning to sport should be monitored to see if this deficiency pre-disposes them to secondary injury or re-injury.
> From: Relph et al., Knee (2016) (Epub ahead of print). All rights reserved to Elsevier Ltd. Click here for the Pubmed summary.