Advanced Neuromuscular Training Differentially Changes Performance on Visuomotor Reaction Tests and Single-leg Hop Tests in Patients with ACL Reconstruction

Background Advanced neuromuscular training prepares patients with anterior cruciate ligament reconstruction (ACLR) for sport participation. Return-to-sport testing often includes single-leg hop tests, yet combining motor and cognitive tasks (i.e., dual-task) might reveal neurocognitive reliance. Purpose/Hypothesis This study examined changes in performance on visuomotor reactions tests and single-leg hop tests following advanced neuromuscular training in patients with ACLR. The hypothesis was that performance would improve less on reaction tests than on single-leg hop tests. Study Design Quasi experimental, Pretest-Posttest Methods Twenty-five patients with ACLR (11 males) completed 10 sessions of advanced neuromuscular training and pre-and post-training testing. Reaction tests outcomes were from a platform and visual display. The double-leg reaction test involved touching target dots with either leg for 20 seconds; correct touches and errors were recorded. The single-leg reaction test involved hopping on the test leg to 10 target dots; hop time and errors were recorded. Single-leg hop tests included forward, triple, crossover triple, and timed hop; limb symmetry index was recorded. Effect sizes were calculated for corrected touches on the double-leg reaction test, surgical side hop time on the single-leg reaction test, and surgical side hop distance or time on single-leg hop tests. Results Correct touches on the double-leg reaction test significantly increased from pre- to post-training (20.4 +/- 4.3 vs. 23.9 +/- 2.8, p<0.001). Hop time on the single-leg reaction test significantly decreased from pre- to post-training (Surgical leg 13.2 vs. 12.3 seconds, non-surgical leg 13.0 vs. 12.1 seconds, p=0.003). Mean errors did not significantly change on either reaction test (p> 0.05). Cohens d effect sizes in descending order was single-leg hop tests (d=0.9 to 1.3), double-leg reaction test (d=0.9), and single-leg reaction test (d=0.5). Conclusion Motor performance improved after advanced neuromuscular training, but the effect size was less on visuomotor reaction tests than single-leg hop tests. The results suggest persistence of neurocognitive reliance after ACLR and a need for more dual-task challenges in training.