Browsing by Author "Neira, Alejandro"
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- ItemEffects of Elbow Crutch Locomotion on Gluteus Medius Activation During Stair Ascending(2022) De La Fuente Cancino, Carlos Ignacio; Neira, Alejandro; Torres, Gustavo; Silvestre, Rony; Roby, Matias; Yañez, Roberto; Herrera, Sofia; Martabit, Virgina; McKay, Isabel; Carpes, Felipe P.Crutches can help with the locomotion of people with walking disorders or functional limitations. However, little is known about hip muscle activation during stair ascending using different crutch locomotion patterns in people without disorders and limitations. Thus, we determined the acute effects of elbow crutch locomotion on gluteus medius (GM) activity during stair ascending. This comparative analytic cross-sectional study enrolled ten healthy men (22.0 ± 0.47 years). Participants climbed up the stairs with elbow crutches using one or two crutches, with ipsilateral or contralateral use, and after loading or unloading a limb. EMG signals were recorded from anterior, middle, and posterior portions of the GM and compared between the crutch conditions. The Kruskal–Wallis test and Dunn’s multiple comparison test were performed (α= 5%). The activation of the GM increased with the ipsilateral use of crutches, with two crutches and three points, and when all the load depended only on one limb. GM activation decreased with contralateral use and in the unload limb. In conclusion, ascending stairs with elbow crutches alters the GM activation. The more critical factors were choosing the crutches’ lateral use, the number of crutches, and if the limb is loaded or unloaded while ascending the stairs. Our findings can be helpful to increase or decrease the GM activation for those who use or will use crutches.
- ItemExploratory Anterior Cruciate Ligament Graft Stress during Medial Knee Rotation with and without Iliotibial Band-Intermuscular Septum Lateral Extra-Articular Tenodesis for Transtibial and Anteromedial Femoral Tunnels(2024) Yanez, Roberto; Silvestre, Rony; Roby, Matias; Neira, Alejandro; Madera, Samuel; de la Fuente, CarlosTraditional lateral extra-articular tenodesis (LET) using fixation elements constrains medial knee rotation laxity after anterior cruciate ligament reconstruction (ACLr). However, the mechanical behavior of an LET made with an iliotibial band-intermuscular septum is unknown using different anterior cruciate ligament (ACL) reconstruction drillings and would be crucial for constraining the rotatory components of direction change movements. Thus, this study aimed to explore the maximum principal stresses and their distribution in grafts during medial knee rotation with and without iliotibial band-intermuscular septum lateral extra-articular tenodesis for the transtibial technique (TT), hybrid transtibial technique (HTT), and anteromedial portal technique (AM) in single-bundle ACLr. The maximum von Mises principal stresses and their distribution under medial knee rotation were described using a finite element model generated from a healthy knee. LET with HTT, TT, and AM decreases stress by 97%, 93%, and 86% during medial rotation compared to each technique without LET, respectively. The stress concentration for the AM portal and TT techniques was located at the femoral tunnel, and for HTT with LET, it was located across the distal thirds of the anterior aspect of the graft. In conclusion, the HTT with LET diminishes graft stress more than the HTT, TT, and AM without LET, and the TT and AM with LET during medial knee rotation. The AM portal, HTT, and TT techniques without LET show higher stress concentration patterns at the femoral tunnel, establishing a biomechanical risk of femoral tunnel enlargement when LET is not performed.
- ItemIs the Rotatory Knee Stability Immediately Decreased Following a Competitive Soccer Match?(2022) Neira, Alejandro; Silvestre, Rony; Debandi, Anibal; Darras, Daniel; Cristi-Sanchez, Iver; Barra, Ignacio; Penailillo, Luis; De La Fuente, CarlosFatigue induced by soccer playing increases physical efforts, which might alter the transverse knee stability, a known factor that promotes knee injuries, particularly anterior cruciate ligament injury. Thereby, primarily, we aimed to determine whether rotatory knee stability decreases immediately following a competitive soccer match in amateur players. Furthermore, we assessed the role of the preferred and non-preferred limbs to kick a ball in rotatory knee stability and the correlation between performance parameters and rotatory knee stability. We hypothesized that the knee stability decreases immediately after a competitive soccer match in amateur players. Eight healthy amateur soccer players (aged 27.2 +/- 4.7 years and with body mass index of 23.8 +/- 1.2 kg m(-2)) were included immediately before and after a competitive soccer match. The rotatory knee stability was assessed in the preferred and non-preferred limbs through the acceleration and jerk of the pivot shift maneuver and by the internal knee rotation of a pivoting landing task. Two-way repeated-measures ANOVA for factors time (before and after the soccer match) and limb (preferred and non-preferred) and multiple comparisons were performed using alpha = 5%. There was a statistical significance for the main factor time in the acceleration (5.04 vs. 6.90 ms(-2), Delta = 1.86 ms(-2), p = 0.020, eta(2) = 0.331) and jerk (18.46 vs. 32.10 ms(-2), Delta = 13.64 ms(-2), p = 0.004, eta(2) = 0.456) of the pivot shift maneuver. Rotatory stability decreases following a competitive soccer match in amateur soccer players under fatigue. Both the acceleration and jerk during the pivot shift maneuver is increased without significant internal knee rotation changes during the pivoting landing task.
- ItemLocal experience of laboratory activities in a BS physical therapy course: integrating sEMG and kinematics technology with active learning across six cohorts(2024) de la Fuente, Carlos; Neira, Alejandro; Machado, Alvaro S.; Delgado-Bravo, Mauricio; Kunzler, Marcos R.; de Andrade, Andre Gustavo P.; Carpes, Felipe P.Introduction Integrating technology and active learning methods into Laboratory activities would be a transformative educational experience to familiarize physical therapy (PT) students with STEM backgrounds and STEM-based new technologies. However, PT students struggle with technology and feel comfortable memorizing under expositive lectures. Thus, we described the difficulties, uncertainties, and advances observed by faculties on students and the perceptions about learning, satisfaction, and grades of students after implementing laboratory activities in a PT undergraduate course, which integrated surface-electromyography (sEMG) and kinematic technology combined with active learning methods. Methods Six cohorts of PT students (n = 482) of a second-year PT course were included. The course had expositive lectures and seven laboratory activities. Students interpreted the evidence and addressed different motor control problems related to daily life movements. The difficulties, uncertainties, and advances observed by faculties on students, as well as the students' perceptions about learning, satisfaction with the course activities, and grades of students, were described. Results The number of students indicating that the methodology was "always" or "almost always," promoting creative, analytical, or critical thinking was 70.5% [61.0-88.0%]. Satisfaction with the whole course was 97.0% [93.0-98.0%]. Laboratory grades were linearly associated to course grades with a regression coefficient of 0.53 and 0.43 R-squared (p < 0.001). Conclusion Integrating sEMG and kinematics technology with active learning into laboratory activities enhances students' engagement and understanding of human movement. This approach holds promises to improve teaching-learning processes, which were observed consistently across the cohorts of students.
- ItemMulticlass Support Vector Machine improves the Pivot-shift grading from Gerdy's acceleration resultant prior to the acute Anterior Cruciate Ligament surgery(2023) Yanez-Diaz, Roberto; Roby, Matias; Silvestre, Rony; Zamorano, Hector; Vergara, Francisco; Sandoval, Carlos; Neira, Alejandro; Yanez-Rojo, Cristobal; De la Fuente, CarlosIntroduction: Rotatory laxity acceleration still lacks objective classification due to interval grading superposition, resulting in a biased pivot shift grading prior to the Anterior Cruciate Ligament (ACL) reconstruction. However, data analysis might help improve data grading in the operative room. Therefore, we described the improvement of the pivot-shift categorization in Gerdy's acceleration under anesthesia prior to ACL surgery using a support vector machine (SVM) classification, surgeon, and literature reference. Methods: Seventy-five patients (aged 30.3 +/- 10.2 years, and IKDC 52.0 +/- 16.5 points) with acute ACL rupture under anesthesia prior to ACL surgery were analyzed. Patients were graded with pivot-shift sign glide ( + ), clunk ( ++ ), and ( +++ ) gross by senior orthopedic surgeons. At the same time, the tri-axial tibial plateau acceleration was measured. Categorical data were statistically described, and the accelerometry and categorical data were associated ( alpha = 5%). A multiclass SVM kernel with the best accuracy trained by orthopedic surgeons and assisted from literature for missing data was compared with experienced surgeons and literature interval grading. The cubic SVM classifier achieved the best grading.Results: The intra-group proportions were different for each grading in the three compared strategies ( p < 0.001). The inter-group proportions were different for all comparisons ( p < 0.001). There were significant ( p < 0.001) associations (Tau: 0.69, -0.28, and -0.50) between the surgeon and SVM, the surgeon and interval grading, and the interval and SVM, respectively.Conclusion: The multiclass SVM classifier improves the acceleration categorization of the ( + ), ( ++ ), and ( +++ ) pivot shift sign prior to the ACL surgery in agreement with surgeon criteria.(c) 2023 Elsevier Ltd. All rights reserved.
- ItemUnique case study: Impact of single-session neuromuscular biofeedback on motor unit properties following 12 days of Achilles tendon surgical repair(2024) De la Fuente, Carlos; Silvestre, Rony; Botello, Julio; Neira, Alejandro; Soldan, Macarena; Carpes, Felipe P.We explored the first evidence of a single-session neuromuscular biofeedback effect on motor unit properties, neuromuscular activation, and the Achilles tendon (AT) length 12 days after undergoing AT surgical repair. We hypothesized that immediate neuromuscular biofeedback enhances motor unit properties and activation without causing AT lengthening. After 12 days AT surgical repair, Medial Gastrocnemius (MG) motor unit decomposition was performed on a 58-year-old male before and after a neuromuscular biofeedback intervention (surface electromyography (sEMG) and ultrasonography), involving unressited plantar flexion. The analysis included motor unit population properties, sEMG amplitude, force paradigm, and AT length. There were increased MG motor unit recruitment, peak and average firing rate, coefficient of variation, and sEMG amplitude, and decreased recruitment and derecruitment threshold in the repaired AT limb. The non-injured limb increased the motor unit recruitment, and decreased the coefficient of variation, peak and average firing rate, inter-pulse interval, derecruitment threshold and sEMG amplitude. The AT length experienced -0.4 and 0.3 cm changes in the repaired AT and non-injured limb, respectively. This single-session neuromuscular biofeedback 12 days after AT surgery shows evidence of enhanced motor unit properties and activation without signs of AT lengthening when unresisted plantar flexion is performed in the repaired AT limb.