Table 1

Individual constraints that could influence effectiveness of implicit and explicit motor learning interventions

Individual factor
ProprioceptionVerbal working memoryAthlete’s preference
Relevance in ACL rehabilitation
  • ACL serves role in proprioception

  • High prevalence of proprioceptive impairment following ACL injuryS1

  • Capacity differs from person to person

  • High prevalence of ACL injury in young athletesS2, for whom working memory capacity is still developingS3

  • Preference for explicit/implicit learning differs from person to person

  • People with musculoskeletal conditions strongly prefer to consciously control movementsS4.5

Role in motor learning
  • Proprioceptive deficits compromise automatic movement controlS6,7

  • Individuals with deficits benefit from explicit learningS8–10

  • Verbal working memory is key to process explicit movement instructionsS11

  • Individuals with lower working memory capacity benefit from implicit learningS11–13

  • Individuals benefit from learning interventions that match their preference, for example, explicit strategies benefit those who prefer conscious controlS14.15

Clinical recommendation
  • Consider more frequently using explicit learning interventions in case of proprioceptive deficits

  • Screen proprioceptive deficits in both the affected and unaffected knee, using Joint-Position Sense testsS1

  • Consider more frequently using implicit learning interventions for athletes with poor verbal working memory

  • Screen for verbal working memory deficits, for example, using Trail-Making Test BS16 or Automated Operation Span TestS17

  • Consider more frequently using motor learning method that aligns with athlete’s preference

  • Screen preference for conscious control using Movement-Specific Reinvestment ScaleS18

  • References contained in this table can be found in the ‘online supplemental files’.