Explicit motor learning interventions are still relevant for ACL injury rehabilitation: do not put all your eggs in the implicit basket!

ACL ruptures are rapidly increasing.1 ACL injuries can have a profound impact on an athlete’s physical and psychological functioning, and sporting career. Current standard of care following ACL injury is neuromuscular rehabilitation to help athletes regain motor skills. Optimising how rehabilitation is delivered has the potential to further enhance motor relearning and reduce the risk of secondary knee injuries.2 ACL injury rehabilitation programmes aiming to reduce secondary injury risk often involve explicit learning strategies to improve biomechanics and increase neuromuscular control.3 Athletes are mostly instructed to consciously control movements using internally focused, verbal cues that prescribe desired movement patterns (eg, ‘do not bring your knees over your toes’ during squatting). Only with sustained practice does explicit learning result in consistent, fluent, and automatic, motor performance. Recently, practitioners have been encouraged to minimise explicit learning during ACL injury rehabilitation, and use implicit learning interventions such as external focus cues.2 We contend that implicit interventions are not a panacea, and that explicit interventions remain important in ACL injury rehabilitation. We discuss key individual characteristics and contextual constraints that warrant the use of explicit interventions. ### Why would implicit learning be beneficial to ACL rehabilitation? The theoretical advantage of implicit learning interventions is that athletes reach automaticity earlier in the learning process. Accordingly, implicit …