Alterations in Quadriceps Neurologic Complexity After Anterior Cruciate Ligament Reconstruction

2020 ◽  
pp. 1-6
Author(s):  
Steven M. Davi ◽  
Colleen K. Woxholdt ◽  
Justin L. Rush ◽  
Adam S. Lepley ◽  
Lindsey K. Lepley
Keyword(s):  
Anterior Cruciate Ligament ◽  
Anterior Cruciate Ligament Reconstruction ◽  
Ligament Reconstruction ◽  
Vastus Lateralis ◽  
Cruciate Ligament ◽  
Neuromuscular Control ◽  
Electromyographic Activity ◽  
Vastus Medialis ◽  
Cruciate Ligament Reconstruction ◽  
Anterior Cruciate

Context: Traditionally, quadriceps activation failure after anterior cruciate ligament reconstruction (ACLR) is estimated using discrete isometric torque values, providing only a snapshot of neuromuscular function. Sample entropy (SampEn) is a mathematical technique that can measure neurologic complexity during the entirety of contraction, elucidating qualities of neuromuscular control not previously captured. Objective: To apply SampEn analyses to quadriceps electromyographic activity in order to more comprehensively characterize neuromuscular deficits after ACLR. Design: Cross-sectional. Setting: Laboratory. Participants: ACLR: n = 18; controls: n = 24. Interventions: All participants underwent synchronized unilateral quadriceps isometric strength, activation, and electromyography testing during a superimposed electrical stimulus. Main Outcome Measures: Group differences in strength, activation, and SampEn were evaluated with t tests. Associations between SampEn and quadriceps function were evaluated with Pearson product–moment correlations and hierarchical linear regressions. Results: Vastus medialis SampEn was significantly reduced after ACLR compared with controls (P = .032). Vastus medialis and vastus lateralis SampEn predicted significant variance in activation after ACLR (r2 = .444; P = .003). Conclusions: Loss of neurologic complexity correlates with worse activation after ACLR, particularly in the vastus medialis. Electromyographic SampEn is capable of detecting underlying patterns of variability that are associated with the loss of complexity between key neurophysiologic events after ACLR.

scholarly journals Synergism between vastus lateralis and vastus medialis oblique during gait after anterior cruciate ligament reconstruction

2019 ◽  
Vol 26 (4) ◽  
pp. 199-203
Author(s):  
Gustavo Leporace ◽  
Gabriel Gollner Zeitoune ◽  
Thiago Vivacqua ◽  
Leonardo Metsavaht ◽  
Liszt Palmeira de Oliveira ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Anterior Cruciate Ligament Reconstruction ◽  
Ligament Reconstruction ◽  
Stance Phase ◽  
Vastus Lateralis ◽  
Cruciate Ligament ◽  
Vastus Medialis ◽  
Cruciate Ligament Reconstruction ◽  
Activation Ratio ◽  
Anterior Cruciate

Objective: The aim of this study was to compare vastus lateralis and vastus medialis oblique (VL/VMO) muscle co-contraction (MCC) and activation ratio during gait between healthy subjects- control group (CG), and those with anterior cruciate ligament reconstruction (ACLR). Methods: Twenty-three subjects participated in this study, 14 CG and 9 ACLR. The myoelectric activities of the VL and VMO were captured to calculate the MCC. The VL/VMO ratio was obtained by dividing the normalized signals of these two muscles at each point of the curve. The MCC values and the activation ratio in the initial double limb stance, single limb stance, terminal double limb stance and swing were obtained by calculating the arithmetic mean of the intensity values ​​of the common curve in each interval. Results: MCC was significantly lower in the ACLR group during the initial double limb stance phase (p=0.001), with a high effect size (1.72). No significant differences were found for the other comparisons. Conclusions: The results of this study showed that the VL and VMO muscles co-contraction in the initial double limb stance phase of gait was different between the healthy and ACLR individuals. This finding may be related to lower patellofemoral stability during the loading response, increasing the potential risk for the development of injuries in this joint.

scholarly journals Ankle perturbation generates bilateral alteration of knee muscle onset times after unilateral anterior cruciate ligament reconstruction

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5310 ◽  
Author(s):  
Patricio A. Pincheira ◽  
Rony Silvestre ◽  
Susan Armijo-Olivo ◽  
Rodrigo Guzman-Venegas
Keyword(s):  
Anterior Cruciate Ligament ◽  
Anterior Cruciate Ligament Reconstruction ◽  
Healthy Subjects ◽  
Muscle Activation ◽  
Ligament Reconstruction ◽  
Cruciate Ligament ◽  
Neuromuscular Control ◽  
Proprioceptive Information ◽  
Cruciate Ligament Reconstruction ◽  
Anterior Cruciate

Background The aim of this study was to compare muscle activation onset times of knee muscles between the involved and uninvolved knee of patients with unilateral anterior cruciate ligament reconstruction (ACLR), and the uninjured knees of healthy subjects after a controlled perturbation at the ankle level. Methods Fifty male amateur soccer players, 25 with unilateral ACLR using semitendinosus-gracilis graft (age = 28.36 ± 7.87 years; time after surgery = 9 ± 3 months) and 25 uninjured control subjects (age = 24.16 ± 2.67 years) participated in the study. Two destabilizing platforms (one for each limb) generated a controlled perturbation at the ankle of each participant (30°of inversion, 10°plantarflexion simultaneously) in a weight bearing condition. The muscle activation onset times of semitendinosus (ST) and vastus medialis (VM) was detected through an electromyographic (EMG) analysis to assess the neuromuscular function of knee muscles. Results Subjects with ACLR had significant delays in EMG onset in the involved (VM = 99.9 ± 30 ms; ST = 101.7 ± 28 ms) and uninvolved knee (VM = 100.4 ± 26 ms; ST = 104.7 ± 28 ms) when compared with the healthy subjects (VM = 69.1 ± 9 ms; ST = 74.6 ± 9 ms). However, no difference was found between involved and uninvolved knee of the ACLR group. Discussion The results show a bilateral alteration of knee muscles in EMG onset after a unilateral ACLR, responses that can be elicited with an ankle perturbation. This suggests an alteration in the central processing of proprioceptive information and/or central nervous system re-organization that may affect neuromuscular control of knee muscles in the involved and uninvolved lower limbs.

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