Faulty proprioceptive information disrupts motor imagery: an experimental study

QuestionDoes faulty proprioceptive input disrupt the internal model of the body that the brain uses to control movement?DesignRandomised, within-participant experimental study.ParticipantsTwenty-two (13 F) healthy adults.InterventionParticipants performed a motor imagery task that involved making left/right judgements of pictured right and left hands in 16 different postures under five conditions involving stimuli being applied to the experimental (L) hand. The five conditions were: vibration (of the wrist extensor tendons to elicit the illusion of wrist flexion), sham (vibration of the ulna styloid), active flexion, passive flexion, and control (no stimulus).Outcome measuresAccuracy and response time of the control (R) hand in making left/right judgements of the pictures.ResultsResponse time during vibration was longer for those who reported the illusion of wrist flexion (n = 18) than for those who did not (p < 0.01) whereas accuracy was unaffected (p = 0.71). In those who reported the illusion, accuracy was unaffected by condition, hand or picture (p > 0.21). Response time during vibration was 910 ms longer (95% CI 730 to 1090) for pictures of the experimental (L) hand (mean 2731 ms, 95% CI 2543 to 2918) than it was for pictures of the control (R) hand (mean 1822 ms, 95% CI 1634 to 2009), and ∼ 580 ms longer (95% CI 380 to 785) for pictures of either hand during any other condition (p