Cortical Motor Planning and Biomechanical Stability during Unplanned Jump Landings in Men with Anterior Cruciate Ligament Reconstruction

Abstract

Context: Athletes with anterior cruciate ligament (ACL) reconstruction (ACLR) exhibit increased cortical motor planning during simple sensorimotor tasks compared with healthy athletes serving as control groups. This may interfere with proper decision making during time-constrained movements, elevating the reinjury risk. Objective: To compare cortical motor planning and biomechanical stability during jump landings between participants with ACLR and healthy individuals. Design: Cross-sectional study. Setting: Laboratory. Patients or Other Participants: Ten men with ACLR (age= 28 6 4 years, time after surgery = 63 6 35 months) and 17 healthy men (age= 28 6 4 years) completed 43 6 4 preplanned (landing leg shown before takeoff) and 51 6 5 unplanned (visual cue during flight) countermovement jumps with single-legged landings. Main Outcome Measure(s): Movement-related cortical potentials (MRCPs) and frontal h frequency power before the jump were analyzed using electroencephalography. Movementrelated cortical potentials were subdivided into 3 successive 0.5-second time periods (readiness potential [RP]-1, RP-2, and negative slope [NS]) relative to movement onset, with higher values indicating more motor planning. Theta power was calculated for the last 0.5 second before movement onset, with higher values demonstrating more focused attention. Biomechanical landing stability was measured via peak vertical ground reaction force, time to stabilization, and center of pressure. Results: Both the ACLR and healthy groups evoked MRCPs at all 3 time periods. During the unplanned task analyzed using P values and Cohen d, the ACLR group exhibited slightly higher but not different MRCPs, achieving medium effect sizes (RP-1: P = .25, d = 0.44; RP-2: P = .20, d = 0.53; NS: P = .28, d = 0.47). The ACLR group also showed slightly higher h power values that were not different during the preplanned (P = .18, d = 0.29) or unplanned (P = .42, d = 0.07) condition, achieving small effect sizes. The groups did not differ in their biomechanical outcomes (P values > .05). No condition 3 group interactions occurred (P values > .05). Conclusions: Our jump-landing task evoked MRCPs. Although not different between groups, the observed effect sizes provided the first indication that men with ACLR might have consistently relied on more cortical motor planning associated with unplanned jump landings. Confirmatory studies with larger sample sizes are warranted.