Does ACL-reconstruction Lead To Higher Use Of Neural Resources To Prepare & Initiate Challenging Jump-landings?

Abstract

Increased cortical motor planning has been suggested to compensate the loss of mechanoreceptors after anterior cruciate ligament (ACL) injury in simple motor tasks. PURPOSE: To investigate the cortical processes associated with more sports- and injury-related movements. METHODS: Ten males with ACL-reconstructed knee (28±4 yrs., 25±3 kg/m2, 63±35 months since surgery; ACLR) and 17 knee-injury free controls (28±4 yrs., 26±3 kg/m2; all males) completed 70 counter-movement jumps with single-leg landings on a pressure plate. Pre-planned (landing leg shown before take-off; PP) and non-pre-planned (visual cue during flight, 360 ms prior ground contact; NPP) landings (35 each) were performed in random order. Movement-related cortical potentials (MRCPs) were analysed to quantify the neural involvement needed to initiate the jump (higher negative potentials indicate more motor planning) using electroencephalography. The mean activity was calculated for fronto-central (FC1, FC2) and central electrodes (C3, C4, CZ) in three successive epochs prior to movement onset (acceleration sensor): Early (−1.500 to −1.000 ms; RP1), late readiness potential (−1.000 to −500 ms; RP2) and negative slope (−500 to 0 ms/movement onset; NS). RESULTS: In both groups, MRCPs occured at CZ only. A 3 x 2 ANOVA revealed a main effect for a significant increase of negativity (ACLR: F(16)=36, p<0.001, eta=0.8; controls: F(9)=22, p<0.001, eta=0.6) across the three epochs (ACLRPP: RP1:-0.8, RP2:-1.8, NS:-5.8 μV, p<0.01; ACLRNPP: RP1:-0.9, RP2:-3.2, NS:-8 μV, p<0.01; controlsPP: RP1:-0.2, RP2:-1.8, NS:-5.9 μV, p<0.01; controlsNPP: RP1:-0.2, RP2:-1.1, NS:-4.3 μV, p<0.01). Between groups, no significant effects were found for time (F(26)=0.2, p=0.9), landing condition (F(26)=1.3, p=0.3) nor the interaction of both factors (F(26)=2.0, p=0.2). However, the ACLR-group showed a moderate effect for a higher negativity at all epochs in the NPP condition (d≥0.5). CONCLUSION: Our jump-landing task evoked MRCPs irrespective from group and condition. The trends in our data suggest that ACLR-individuals may use more motor planning resources to initiate a challenging motor task. Research is warranted to elucidate the possible implications of such potential central compensations for injury risk. No funding.