Alexis Robert Ortiz - Academia.edu (original) (raw)
Papers by Alexis Robert Ortiz
Background: Incidence of knee injuries in female soccer players is 2-6 times that of male counter... more Background: Incidence of knee injuries in female soccer players is 2-6 times that of male counterparts. The objective was to determine whether an injury prevention program incorporated into the athlete's regular soccer practice is effective for improving landing mechanics. Methods: Two competitive adolescent female soccer teams (n = 30) participated in the study. One team served as the control group while the other team participated in a 6-week injury prevention program. Muscle strength, muscle length, and 3-dimensional kinematics and kinetics during a single legged drop jump and single legged squat task were measured pre and post-intervention. A 2 x 2 repeated measures multivariate analyses of variance (MANOVA's) were used to compare strength and flexibility measures as well as knee joint kinematics and kinetics. Significant multivariate results were followed with appropriate univariate analyses. Results: Quadriceps strength increased significantly (p=.004) following the in...
Esta investigacion de campo llevada a cabo en los diferentes yacimientos de mineral de hierro ubi... more Esta investigacion de campo llevada a cabo en los diferentes yacimientos de mineral de hierro ubicados en el Estado Bolivar, Venezuela en el periodo julio - noviembre 2015, plantea cuatro ejes estrategicos para la gestion integrada del proceso minero, partiendo del diagnostico de las operaciones mineras y la determinacion de las variables clave que intervienen en el mismo. Para ello se realizo un analisis estructural, partiendo de la observacion participativa y talleres de reflexion colectiva con Superintendentes de la Gerencia de Mineria, de la empresa Ferrominera Orinoco. Como resultado, se determinaron cuarenta y ocho variables, en donde prevalecen como variables clave por su grado de motricidad, el sistema de toma de decisiones (2.66%), tipo de excavacion (2.58%), relacion mena/escombro (2.56%), presupuesto asignado (2.52%), y gestion del conocimiento (2.50%). El diagnostico y las variables clave de la gestion minera, permitieron identificar los ejes estrategicos para la optimiz...
HISTORY: A 27-year-old male reports to physical therapy evaluation with R shoulder pain following... more HISTORY: A 27-year-old male reports to physical therapy evaluation with R shoulder pain following an injury during Jiu-jitsu 4 weeks prior. He experienced immediate onset of pain following a submission attempt where his arm was forcefully externally rotated. At time of evaluation, he experienced pain with pressing and pulling exercises in R shoulder that would sometimes radiate down to posteriolateral arm. PHYSICAL EXAMINATION: Initial examination of the R arm revealed hypomobility throughout thoracic and lower cervical spine, tight posterior shoulder capsule with anterior humeral head migration, and limited shoulder ROM secondary to pain. Neural testing resulted in + radial nerve tension, which was reduced with head-tilt, indicating proximal facilitation. His rotator cuff strength was strong and pain-free. He had extreme tenderness to palpation and reproduction of arm symptoms over axillary nerve in quadrangular space. DIFFERENTIAL DIAGNOSIS: 1. Labral tear 2. Rotator cuff tear/imp...
6Th International Conference on Industrial Engineering and Industrial Management Y Del Xvi Congreso De Ingenieria De Organizacion 6th International Conference on Industrial Engineering and Industrial Management Y Del Xvi Congreso De Ingenieria De Organizacion 18 07 2012 20 07 2012 Vigo Espana, 2012
This paper presents the design and results of the implementation of a model for the evaluation an... more This paper presents the design and results of the implementation of a model for the evaluation and improvement of maintenance management in industrial SMEs. A thorough review of the state of the art on maintenance management was conducted to determine the model variables; to characterize industrial SMEs, a questionnaire was developed with Likert variables collected in the previous step. Once validated the questionnaire, we applied the same to a group of seventy-five (75) SMEs in the industrial sector, located in Bolivar State, Venezuela. To identify the most relevant variables maintenance management, we used exploratory factor analysis technique applied to the data collected. The score obtained for all the companies evaluated (57% compliance), highlights the weakness of maintenance management in industrial SMEs, particularly in the areas of planning and continuous improvement; most SMEs are evaluated in corrective maintenance stage, and its performance standard only response to the occurrence of faults.
Open Access Journal of Sports Medicine, 2016
The aim of this study was to establish the concurrent validity and reliability of four different ... more The aim of this study was to establish the concurrent validity and reliability of four different two-dimensional (2D) video-based techniques for quantifying frontal plane knee kinematics during a 40 cm double-legged drop jump. Participants and methods: A convenience sample of 16 healthy participants (nine males and seven females; age: [mean ± standard deviation] 25.5±2 years; body mass index: 24.33±2.98 kg/ m 2) participated in this investigation. A total of five trials during a 40 cm drop jump maneuver with a countermovement jump were used as the functional task. Four knee valgus measures, such as two different frontal plane projection angle measures, knee-to-ankle separation ratio (KASR), and knee separation distance (KSD), were measured using 2D and three-dimensional (3D) systems. To generalize to the greater population of possible evaluators, the testers performing the biomechanical analyses were three novice physical therapists. Intra-and intertester intraclass correlation coefficients (ICCs) were estimated for 2D analysis variables. ICCs were estimated for all measures between systems to determine concurrent validity of the 2D system. Results: All four 2D measures showed good to excellent reliability (ICC: 0.89-0.99). KASR and KSD showed excellent correlation (ICC: 0.96; 95% CI: 0.82-0.98 and ICC: 0.94; 95% CI: 0.90-0.96, respectively) with the 3D system, while both methods of frontal plane projection angle showed poor to moderate correlation (ICC: 0-0.57) with the 3D system. Conclusion: 2D KASR and KSD measures are cost effective, reliable, and highly correlated with the same measures using 3D techniques for the evaluation of knee valgus.
Literatura Mexicana, 2015
Universidad Ciencia Y Tecnologia, Dec 1, 2010
Resumen: En este articulo se presentan el diseno y los resultados de la aplicacion de un modelo p... more Resumen: En este articulo se presentan el diseno y los resultados de la aplicacion de un modelo para la evaluacion y mejora de la gestion de la seguridad y salud en el trabajo; esta investigacion forma parte de un proyecto mas amplio dirigido al diseno de un modelo de sistema inteligente para la evaluacion y mejora de la gestion empresarial, que soporte la toma de decision en las Pymes industriales. Para la determinacion de las variables, elementos y evidencias, se hizo una revision minuciosa de la bibliografia existente sobre seguridad y salud; para hallar las relaciones entre las variables se conformo un equipo de expertos, el cual a traves de la matriz de analisis estructural, determino los valores de motricidad y dependencia de las variables en estudio. Una vez disenado el sistema de evaluacion, se aplico el instrumento a un grupo de diecinueve (19) Pymes del sector metalmecanico, ubicadas en Ciudad Guayana, estado Bolivar, Venezuela, las cuales obtuvieron una calificacion de 57 puntos en promedio, sobre una base de medicion de 100, lo que evidencia la debilidad de los sistemas de gestion de seguridad y salud laboral en las Pymes objeto de estudio. Abstract: This article presents the design and results of the implementation of a model for the evaluation and improvement of safety management and occupational health; this work is part of a wider research aimed at designing an intelligent system model for evaluating and improving corporate governance, which supports decision making in industrial SMEs. For the determination of the variables, elements and evidence, it was a thorough review of the literature on safety and health; to find relationships between variables together a team of experts, which through the matrix structural analysis determined the values of movability and dependence of the variables under study. Once designed the system of measurement, the instrument was applied to a group of nineteen (19) industrial SMEs, located in Ciudad Guayana, Bolivar State, Venezuela, which received a score of 57 points on average, on a basis of measurement 100, highlighting the inadequacy of the systems of safety management and occupational health in SMEs under study.
Puerto Rico health sciences journal, 2010
Incidence of knee injuries in female soccer players is 2-6 times that of male counterparts. The o... more Incidence of knee injuries in female soccer players is 2-6 times that of male counterparts. The objective was to determine whether an injury prevention program incorporated into the athlete's regular soccer practice is effective for improving landing mechanics. Two competitive adolescent female soccer teams (n = 30) participated in the study. One team served as the control group while the other team participated in a 6-week injury prevention program. Muscle strength, muscle length, and 3-dimensional kinematics and kinetics during a single legged drop jump and single legged squat task were measured pre and post-intervention. A 2 x 2 repeated measures multivariate analyses of variance (MANOVA's) were used to compare strength and flexibility measures as well as knee joint kinematics and kinetics. Significant multivariate results were followed with appropriate univariate analyses. Quadriceps strength increased significantly (p = .004) following the injury prevention program whil...
PM&R, 2014
Objective-To compare landing mechanics and neuromuscular recruitment strategies between women wit... more Objective-To compare landing mechanics and neuromuscular recruitment strategies between women with semitendinosus-gracilis anterior cruciate ligament reconstruction (SG-ACLr) and non-injured women during double and single-legged drop jumps. Design-Cross-sectional biomechanical study Setting-Single university-based biomechanics laboratory Participants-Fourteen women 1-5 years post SG-ACLr and 16 non-injured women participated in this study. Methods-After anthropometric measurements, warm-up, and familiarization procedures, participants performed five trials of a double and single-legged drop jumps. Main Outcome Measurements-Dynamic knee valgus was measured as the distance between knee joints during the landing phase of the double-leg drop jumps. Medial knee displacement was the outcome considered during the landing phase of the single-leg drop jumps. For both drop jumps tasks neuromuscular recruitment was evaluated through rectified normalized electromyography (EMG) activity of the quadriceps and hamstrings (amplitude and latency), and quadriceps/hamstrings EMG co-contraction ratio. Results-Although the SG-ACLr group demonstrated a tendency towards a greater dynamic knee valgus during both drop jumps, these differences did not reach statistical significance. EMG data revealed different neuromuscular strategies for each group depending on the specific jump. Conclusions-These findings suggest that women with SG-ACLr have a tendency towards greater dynamic knee valgus which could predispose to additional knee injuries. Rehabilitation
North American journal of sports physical therapy : NAJSPT, 2007
Jumping and landing tasks are commonly used functional measurement tools to assess lower extremit... more Jumping and landing tasks are commonly used functional measurement tools to assess lower extremity performance in female athletes. However, few studies have established the number of trials needed to achieve reliability of measurement for evaluating landing mechanics. To determine the reliability of peak hip and knee joint angles and peak ground reaction forces during two anterior-posterior unilateral functional tasks performed by young women. Sixteen young women (28.5 ± 4.2 years; 162.2 ± 4.8 cm; 59.5 ± 8.1 kg) participated in this investigation. Each participant performed five trials of a 40-cm single leg drop jump and two trials of a ten-repetition, 20-cm, single leg up-down hop task during the same session. Peak hip and knee joint angles, peak vertical ground reaction forces, and ground contact time were measured. Intraclass correlation coefficients (ICC), standard errors of measurement, and 95% confidence intervals were calculated for all variables measured during multiple tria...
PM&R, 2011
Objective-To compare, landing mechanics and electromyographic activity of the lower extremities d... more Objective-To compare, landing mechanics and electromyographic activity of the lower extremities during side hopping and crossover hopping maneuvers, in noninjured women and women with anterior cruciate ligament (ACL) reconstruction. Design-A case-control study. Setting-A 3-dimensional motion analysis laboratory. Participants-Twenty-eight young women (range, 21-35 years) (15 control subjects and 13 subjects with ACL reconstruction). Patients and Methods-All participants performed a side-to-side hopping task that consisted of hopping single-legged 10 times consecutively from side to side across 2 lines marked 30 cm apart on 2 individual force plates. The task was designated as a side hopping when the hop was to the opposite side of the stance leg and as crossover hopping when the hop was toward the side of the stance leg. Main Outcome Measurements-Peak hip-/knee-joint angles; peak knee extension/abduction joint moments; electromyographic studies of the gluteus maximus, gluteus medius, rectus femoris, and hamstring muscles; and quadriceps/hamstring co-contraction ratio were compared between the groups by means of 2 × 2 multivariate analysis of variance tests (group × maneuver).
Journal of Strength and Conditioning Research, 2010
Dynamic knee joint stability may be affected by the onset of metabolic fatigue during sports part... more Dynamic knee joint stability may be affected by the onset of metabolic fatigue during sports participation that could increase the risk for knee injury. The purpose of this investigation was to determine the effects of metabolic fatigue on knee muscle activation, peak knee joint angles, and peak knee internal moments in young women during 2 jumping tasks. Fifteen women (mean age: 24.6 ± 2.6 years) participated in one nonfatigued session and one fatigued session. During both sessions, peak knee landing flexion and valgus joint angles, peak knee extension and varus/valgus internal moments, electromyographic (EMG) muscle activity of the quadriceps and hamstrings, and quadriceps/hamstring EMG cocontraction ratio were measured. The tasks consisted of a singlelegged drop jump from a 40-cm box and a 20-cm, up-down, repeated hop task. The fatigued session included a Wingate anaerobic protocol followed by performance of the 2 tasks. Although participants exhibited greater knee injury-predisposing factors during the fatigued session, such as lesser knee flexion joint angles, greater knee valgus joint angles, and greater varus/valgus internal joint moments for both tasks, only knee flexion during the up-down task was statistically significant (p = 0.028). Metabolic fatigue may perhaps predispose young women to knee injuries by impairing dynamic knee joint stability. Training strength-endurance components and the ability to maintain control of body movements in either rested or fatigued situations might help reduce injuries in young women athletes.
The American Journal of Sports Medicine, 2007
Background Women with anterior cruciate ligament reconstruction have different neuromuscular stra... more Background Women with anterior cruciate ligament reconstruction have different neuromuscular strategies than noninjured women during functional tasks after ligament reconstruction and rehabilitation. Hypothesis Landing from a jump creates high loads on the knee creating dynamic instability in women with anterior cruciate ligament reconstruction, whereas noninjured women have stable knee landing mechanics. Study Design Controlled laboratory study. Methods Fifteen noninjured women and 13 women with anterior cruciate ligament reconstruction performed 5 trials of a single-legged 40-cm drop jump and 2 trials of a 20-cm up-down hop task. Multivariate analyses of variance were used to compare hip and knee joint kinematics, knee joint moments, ground-reaction forces, and electromyographic findings between the dominant leg in noninjured women and reconstructed leg in women with anterior cruciate ligament reconstruction. Results No statistically significant differences between groups were fou...
Proceedings of the 13th Latin American and Caribbean Conference for Engineering and Technology Engineering Education Facing the Grand Challenges What Are We Doing?, 2015
This research analyzes the evolution of the Global Competitiveness Index (GCI) to the economy of ... more This research analyzes the evolution of the Global Competitiveness Index (GCI) to the economy of Puerto Rico, in the period 2009-2014. The index assigns a score to the participating countries in terms of competitiveness, and is published annually by the World Economic Forum. The study results indicate that Puerto Rico has won 10 stages in the competitiveness ranking, from position 42 in 2009 to position 32 in 2014, while the Global Competitiveness Index has risen from 4.5 in 2009 to a value of 4.6 in 2014. The bureaucratic inefficiency and restrictive government regulations for employment are the factors that constitute the greatest obstacle to doing business on the island, and its weight has not changed significantly since 2009, when it totaled 42.8% compared to 2014 (41.2%). The GCI is a valid reference for the establishment of public policies, investment initiatives and implementing strategies for increasing productivity, aimed at generating prosperity on the island.
tipo Likert con las variables identificadas. Una vez validado el cuestionario, se aplicó el mismo... more tipo Likert con las variables identificadas. Una vez validado el cuestionario, se aplicó el mismo a trescientos gerentes y administradores del área de Mercadeo pertenecientes a un grupo de setenta y cinco Pymes del sector industrial, ubicadas en el Estado Bolívar, Venezuela. Para construir el modelo, se utilizó la técnica de análisis multivariante, aplicada a los datos recolectados. Los resultados indican que la gestión de mercadeo en las Pymes carece de una adecuada planificación y no existen mecanismos de control ni de mejora continua. La originalidad del enfoque utilizado consistió en agrupar las variables de acuerdo al ciclo Planificar, Hacer, Verificar, Actuar. La contribución de esta investigación puede valorarse de dos maneras: desde el punto de vista empresarial, al dotar a las Pymes de una herramienta para evaluar y mejorar su gestión de mercadeo; y académico, al proporcionar una guía para comprender mejor las interrelaciones de las variables involucradas en este proceso. A...
las pymes industriales. Es un instrumento adaptado a la cultura, mercado, características y espec... more las pymes industriales. Es un instrumento adaptado a la cultura, mercado, características y especificidades propias de las pymes del sector industrial del Estado Bolívar, Venezuela. Los items de evaluación fueron divididos en cuatro bloques de acuerdo al ciclo Planificar, Hacer, Verificar, Actuar y su validación estadística fue realizada mediante la técnica de análisis multivariante. Una vez validada, se aplicó la herramienta a trescientos setenta y cinco individuos del área de Recursos Humanos en ciento veinticinco cinco Pymes industriales. Los resultados indican que los aspectos de tipo funcional son los que conducen la gestión en lugar de las razones estratégicas de la empresa, y en general, no existe plan de carrera ni sistema de evaluación de desempeño. La caracterización aportada por este estudio permite a las empresas evaluadas conocer cuales son los factores a mejorar en su gestión. ABSTRACT The starting point for a company to improve its competitiveness is the evaluation of...
En este artículo se presentan el diseño y los resultados de la aplicación de un modelo para la ge... more En este artículo se presentan el diseño y los resultados de la aplicación de un modelo para la gestión logística en las pymes industriales. Para identificar las variables del modelo, se llevó a cabo una revisión minuciosa del estado del arte en gestión logística; para caracterizar las pymes, se elaboró un cuestionario tipo Likert con las variables recogidas en el paso anterior. Una vez validado el cuestionario, se aplicó el mismo a un grupo de setenta y cinco (75) pymes del sector industrial, ubicadas en el Estado Bolívar, Venezuela. Para determinar estadísticamente las variables más relevantes de la gestión, se utilizó la técnica del análisis factorial exploratorio, aplicada a los datos recolectados. La calificación obtenida para el conjunto de empresas evaluadas (49% de cumplimiento), pone de relieve la debilidad de la gestión logística en las pymes industriales.
Background: Incidence of knee injuries in female soccer players is 2-6 times that of male counter... more Background: Incidence of knee injuries in female soccer players is 2-6 times that of male counterparts. The objective was to determine whether an injury prevention program incorporated into the athlete's regular soccer practice is effective for improving landing mechanics. Methods: Two competitive adolescent female soccer teams (n = 30) participated in the study. One team served as the control group while the other team participated in a 6-week injury prevention program. Muscle strength, muscle length, and 3-dimensional kinematics and kinetics during a single legged drop jump and single legged squat task were measured pre and post-intervention. A 2 x 2 repeated measures multivariate analyses of variance (MANOVA's) were used to compare strength and flexibility measures as well as knee joint kinematics and kinetics. Significant multivariate results were followed with appropriate univariate analyses. Results: Quadriceps strength increased significantly (p=.004) following the in...
Esta investigacion de campo llevada a cabo en los diferentes yacimientos de mineral de hierro ubi... more Esta investigacion de campo llevada a cabo en los diferentes yacimientos de mineral de hierro ubicados en el Estado Bolivar, Venezuela en el periodo julio - noviembre 2015, plantea cuatro ejes estrategicos para la gestion integrada del proceso minero, partiendo del diagnostico de las operaciones mineras y la determinacion de las variables clave que intervienen en el mismo. Para ello se realizo un analisis estructural, partiendo de la observacion participativa y talleres de reflexion colectiva con Superintendentes de la Gerencia de Mineria, de la empresa Ferrominera Orinoco. Como resultado, se determinaron cuarenta y ocho variables, en donde prevalecen como variables clave por su grado de motricidad, el sistema de toma de decisiones (2.66%), tipo de excavacion (2.58%), relacion mena/escombro (2.56%), presupuesto asignado (2.52%), y gestion del conocimiento (2.50%). El diagnostico y las variables clave de la gestion minera, permitieron identificar los ejes estrategicos para la optimiz...
HISTORY: A 27-year-old male reports to physical therapy evaluation with R shoulder pain following... more HISTORY: A 27-year-old male reports to physical therapy evaluation with R shoulder pain following an injury during Jiu-jitsu 4 weeks prior. He experienced immediate onset of pain following a submission attempt where his arm was forcefully externally rotated. At time of evaluation, he experienced pain with pressing and pulling exercises in R shoulder that would sometimes radiate down to posteriolateral arm. PHYSICAL EXAMINATION: Initial examination of the R arm revealed hypomobility throughout thoracic and lower cervical spine, tight posterior shoulder capsule with anterior humeral head migration, and limited shoulder ROM secondary to pain. Neural testing resulted in + radial nerve tension, which was reduced with head-tilt, indicating proximal facilitation. His rotator cuff strength was strong and pain-free. He had extreme tenderness to palpation and reproduction of arm symptoms over axillary nerve in quadrangular space. DIFFERENTIAL DIAGNOSIS: 1. Labral tear 2. Rotator cuff tear/imp...
6Th International Conference on Industrial Engineering and Industrial Management Y Del Xvi Congreso De Ingenieria De Organizacion 6th International Conference on Industrial Engineering and Industrial Management Y Del Xvi Congreso De Ingenieria De Organizacion 18 07 2012 20 07 2012 Vigo Espana, 2012
This paper presents the design and results of the implementation of a model for the evaluation an... more This paper presents the design and results of the implementation of a model for the evaluation and improvement of maintenance management in industrial SMEs. A thorough review of the state of the art on maintenance management was conducted to determine the model variables; to characterize industrial SMEs, a questionnaire was developed with Likert variables collected in the previous step. Once validated the questionnaire, we applied the same to a group of seventy-five (75) SMEs in the industrial sector, located in Bolivar State, Venezuela. To identify the most relevant variables maintenance management, we used exploratory factor analysis technique applied to the data collected. The score obtained for all the companies evaluated (57% compliance), highlights the weakness of maintenance management in industrial SMEs, particularly in the areas of planning and continuous improvement; most SMEs are evaluated in corrective maintenance stage, and its performance standard only response to the occurrence of faults.
Open Access Journal of Sports Medicine, 2016
The aim of this study was to establish the concurrent validity and reliability of four different ... more The aim of this study was to establish the concurrent validity and reliability of four different two-dimensional (2D) video-based techniques for quantifying frontal plane knee kinematics during a 40 cm double-legged drop jump. Participants and methods: A convenience sample of 16 healthy participants (nine males and seven females; age: [mean ± standard deviation] 25.5±2 years; body mass index: 24.33±2.98 kg/ m 2) participated in this investigation. A total of five trials during a 40 cm drop jump maneuver with a countermovement jump were used as the functional task. Four knee valgus measures, such as two different frontal plane projection angle measures, knee-to-ankle separation ratio (KASR), and knee separation distance (KSD), were measured using 2D and three-dimensional (3D) systems. To generalize to the greater population of possible evaluators, the testers performing the biomechanical analyses were three novice physical therapists. Intra-and intertester intraclass correlation coefficients (ICCs) were estimated for 2D analysis variables. ICCs were estimated for all measures between systems to determine concurrent validity of the 2D system. Results: All four 2D measures showed good to excellent reliability (ICC: 0.89-0.99). KASR and KSD showed excellent correlation (ICC: 0.96; 95% CI: 0.82-0.98 and ICC: 0.94; 95% CI: 0.90-0.96, respectively) with the 3D system, while both methods of frontal plane projection angle showed poor to moderate correlation (ICC: 0-0.57) with the 3D system. Conclusion: 2D KASR and KSD measures are cost effective, reliable, and highly correlated with the same measures using 3D techniques for the evaluation of knee valgus.
Literatura Mexicana, 2015
Universidad Ciencia Y Tecnologia, Dec 1, 2010
Resumen: En este articulo se presentan el diseno y los resultados de la aplicacion de un modelo p... more Resumen: En este articulo se presentan el diseno y los resultados de la aplicacion de un modelo para la evaluacion y mejora de la gestion de la seguridad y salud en el trabajo; esta investigacion forma parte de un proyecto mas amplio dirigido al diseno de un modelo de sistema inteligente para la evaluacion y mejora de la gestion empresarial, que soporte la toma de decision en las Pymes industriales. Para la determinacion de las variables, elementos y evidencias, se hizo una revision minuciosa de la bibliografia existente sobre seguridad y salud; para hallar las relaciones entre las variables se conformo un equipo de expertos, el cual a traves de la matriz de analisis estructural, determino los valores de motricidad y dependencia de las variables en estudio. Una vez disenado el sistema de evaluacion, se aplico el instrumento a un grupo de diecinueve (19) Pymes del sector metalmecanico, ubicadas en Ciudad Guayana, estado Bolivar, Venezuela, las cuales obtuvieron una calificacion de 57 puntos en promedio, sobre una base de medicion de 100, lo que evidencia la debilidad de los sistemas de gestion de seguridad y salud laboral en las Pymes objeto de estudio. Abstract: This article presents the design and results of the implementation of a model for the evaluation and improvement of safety management and occupational health; this work is part of a wider research aimed at designing an intelligent system model for evaluating and improving corporate governance, which supports decision making in industrial SMEs. For the determination of the variables, elements and evidence, it was a thorough review of the literature on safety and health; to find relationships between variables together a team of experts, which through the matrix structural analysis determined the values of movability and dependence of the variables under study. Once designed the system of measurement, the instrument was applied to a group of nineteen (19) industrial SMEs, located in Ciudad Guayana, Bolivar State, Venezuela, which received a score of 57 points on average, on a basis of measurement 100, highlighting the inadequacy of the systems of safety management and occupational health in SMEs under study.
Puerto Rico health sciences journal, 2010
Incidence of knee injuries in female soccer players is 2-6 times that of male counterparts. The o... more Incidence of knee injuries in female soccer players is 2-6 times that of male counterparts. The objective was to determine whether an injury prevention program incorporated into the athlete's regular soccer practice is effective for improving landing mechanics. Two competitive adolescent female soccer teams (n = 30) participated in the study. One team served as the control group while the other team participated in a 6-week injury prevention program. Muscle strength, muscle length, and 3-dimensional kinematics and kinetics during a single legged drop jump and single legged squat task were measured pre and post-intervention. A 2 x 2 repeated measures multivariate analyses of variance (MANOVA's) were used to compare strength and flexibility measures as well as knee joint kinematics and kinetics. Significant multivariate results were followed with appropriate univariate analyses. Quadriceps strength increased significantly (p = .004) following the injury prevention program whil...
PM&R, 2014
Objective-To compare landing mechanics and neuromuscular recruitment strategies between women wit... more Objective-To compare landing mechanics and neuromuscular recruitment strategies between women with semitendinosus-gracilis anterior cruciate ligament reconstruction (SG-ACLr) and non-injured women during double and single-legged drop jumps. Design-Cross-sectional biomechanical study Setting-Single university-based biomechanics laboratory Participants-Fourteen women 1-5 years post SG-ACLr and 16 non-injured women participated in this study. Methods-After anthropometric measurements, warm-up, and familiarization procedures, participants performed five trials of a double and single-legged drop jumps. Main Outcome Measurements-Dynamic knee valgus was measured as the distance between knee joints during the landing phase of the double-leg drop jumps. Medial knee displacement was the outcome considered during the landing phase of the single-leg drop jumps. For both drop jumps tasks neuromuscular recruitment was evaluated through rectified normalized electromyography (EMG) activity of the quadriceps and hamstrings (amplitude and latency), and quadriceps/hamstrings EMG co-contraction ratio. Results-Although the SG-ACLr group demonstrated a tendency towards a greater dynamic knee valgus during both drop jumps, these differences did not reach statistical significance. EMG data revealed different neuromuscular strategies for each group depending on the specific jump. Conclusions-These findings suggest that women with SG-ACLr have a tendency towards greater dynamic knee valgus which could predispose to additional knee injuries. Rehabilitation
North American journal of sports physical therapy : NAJSPT, 2007
Jumping and landing tasks are commonly used functional measurement tools to assess lower extremit... more Jumping and landing tasks are commonly used functional measurement tools to assess lower extremity performance in female athletes. However, few studies have established the number of trials needed to achieve reliability of measurement for evaluating landing mechanics. To determine the reliability of peak hip and knee joint angles and peak ground reaction forces during two anterior-posterior unilateral functional tasks performed by young women. Sixteen young women (28.5 ± 4.2 years; 162.2 ± 4.8 cm; 59.5 ± 8.1 kg) participated in this investigation. Each participant performed five trials of a 40-cm single leg drop jump and two trials of a ten-repetition, 20-cm, single leg up-down hop task during the same session. Peak hip and knee joint angles, peak vertical ground reaction forces, and ground contact time were measured. Intraclass correlation coefficients (ICC), standard errors of measurement, and 95% confidence intervals were calculated for all variables measured during multiple tria...
PM&R, 2011
Objective-To compare, landing mechanics and electromyographic activity of the lower extremities d... more Objective-To compare, landing mechanics and electromyographic activity of the lower extremities during side hopping and crossover hopping maneuvers, in noninjured women and women with anterior cruciate ligament (ACL) reconstruction. Design-A case-control study. Setting-A 3-dimensional motion analysis laboratory. Participants-Twenty-eight young women (range, 21-35 years) (15 control subjects and 13 subjects with ACL reconstruction). Patients and Methods-All participants performed a side-to-side hopping task that consisted of hopping single-legged 10 times consecutively from side to side across 2 lines marked 30 cm apart on 2 individual force plates. The task was designated as a side hopping when the hop was to the opposite side of the stance leg and as crossover hopping when the hop was toward the side of the stance leg. Main Outcome Measurements-Peak hip-/knee-joint angles; peak knee extension/abduction joint moments; electromyographic studies of the gluteus maximus, gluteus medius, rectus femoris, and hamstring muscles; and quadriceps/hamstring co-contraction ratio were compared between the groups by means of 2 × 2 multivariate analysis of variance tests (group × maneuver).
Journal of Strength and Conditioning Research, 2010
Dynamic knee joint stability may be affected by the onset of metabolic fatigue during sports part... more Dynamic knee joint stability may be affected by the onset of metabolic fatigue during sports participation that could increase the risk for knee injury. The purpose of this investigation was to determine the effects of metabolic fatigue on knee muscle activation, peak knee joint angles, and peak knee internal moments in young women during 2 jumping tasks. Fifteen women (mean age: 24.6 ± 2.6 years) participated in one nonfatigued session and one fatigued session. During both sessions, peak knee landing flexion and valgus joint angles, peak knee extension and varus/valgus internal moments, electromyographic (EMG) muscle activity of the quadriceps and hamstrings, and quadriceps/hamstring EMG cocontraction ratio were measured. The tasks consisted of a singlelegged drop jump from a 40-cm box and a 20-cm, up-down, repeated hop task. The fatigued session included a Wingate anaerobic protocol followed by performance of the 2 tasks. Although participants exhibited greater knee injury-predisposing factors during the fatigued session, such as lesser knee flexion joint angles, greater knee valgus joint angles, and greater varus/valgus internal joint moments for both tasks, only knee flexion during the up-down task was statistically significant (p = 0.028). Metabolic fatigue may perhaps predispose young women to knee injuries by impairing dynamic knee joint stability. Training strength-endurance components and the ability to maintain control of body movements in either rested or fatigued situations might help reduce injuries in young women athletes.
The American Journal of Sports Medicine, 2007
Background Women with anterior cruciate ligament reconstruction have different neuromuscular stra... more Background Women with anterior cruciate ligament reconstruction have different neuromuscular strategies than noninjured women during functional tasks after ligament reconstruction and rehabilitation. Hypothesis Landing from a jump creates high loads on the knee creating dynamic instability in women with anterior cruciate ligament reconstruction, whereas noninjured women have stable knee landing mechanics. Study Design Controlled laboratory study. Methods Fifteen noninjured women and 13 women with anterior cruciate ligament reconstruction performed 5 trials of a single-legged 40-cm drop jump and 2 trials of a 20-cm up-down hop task. Multivariate analyses of variance were used to compare hip and knee joint kinematics, knee joint moments, ground-reaction forces, and electromyographic findings between the dominant leg in noninjured women and reconstructed leg in women with anterior cruciate ligament reconstruction. Results No statistically significant differences between groups were fou...
Proceedings of the 13th Latin American and Caribbean Conference for Engineering and Technology Engineering Education Facing the Grand Challenges What Are We Doing?, 2015
This research analyzes the evolution of the Global Competitiveness Index (GCI) to the economy of ... more This research analyzes the evolution of the Global Competitiveness Index (GCI) to the economy of Puerto Rico, in the period 2009-2014. The index assigns a score to the participating countries in terms of competitiveness, and is published annually by the World Economic Forum. The study results indicate that Puerto Rico has won 10 stages in the competitiveness ranking, from position 42 in 2009 to position 32 in 2014, while the Global Competitiveness Index has risen from 4.5 in 2009 to a value of 4.6 in 2014. The bureaucratic inefficiency and restrictive government regulations for employment are the factors that constitute the greatest obstacle to doing business on the island, and its weight has not changed significantly since 2009, when it totaled 42.8% compared to 2014 (41.2%). The GCI is a valid reference for the establishment of public policies, investment initiatives and implementing strategies for increasing productivity, aimed at generating prosperity on the island.
tipo Likert con las variables identificadas. Una vez validado el cuestionario, se aplicó el mismo... more tipo Likert con las variables identificadas. Una vez validado el cuestionario, se aplicó el mismo a trescientos gerentes y administradores del área de Mercadeo pertenecientes a un grupo de setenta y cinco Pymes del sector industrial, ubicadas en el Estado Bolívar, Venezuela. Para construir el modelo, se utilizó la técnica de análisis multivariante, aplicada a los datos recolectados. Los resultados indican que la gestión de mercadeo en las Pymes carece de una adecuada planificación y no existen mecanismos de control ni de mejora continua. La originalidad del enfoque utilizado consistió en agrupar las variables de acuerdo al ciclo Planificar, Hacer, Verificar, Actuar. La contribución de esta investigación puede valorarse de dos maneras: desde el punto de vista empresarial, al dotar a las Pymes de una herramienta para evaluar y mejorar su gestión de mercadeo; y académico, al proporcionar una guía para comprender mejor las interrelaciones de las variables involucradas en este proceso. A...
las pymes industriales. Es un instrumento adaptado a la cultura, mercado, características y espec... more las pymes industriales. Es un instrumento adaptado a la cultura, mercado, características y especificidades propias de las pymes del sector industrial del Estado Bolívar, Venezuela. Los items de evaluación fueron divididos en cuatro bloques de acuerdo al ciclo Planificar, Hacer, Verificar, Actuar y su validación estadística fue realizada mediante la técnica de análisis multivariante. Una vez validada, se aplicó la herramienta a trescientos setenta y cinco individuos del área de Recursos Humanos en ciento veinticinco cinco Pymes industriales. Los resultados indican que los aspectos de tipo funcional son los que conducen la gestión en lugar de las razones estratégicas de la empresa, y en general, no existe plan de carrera ni sistema de evaluación de desempeño. La caracterización aportada por este estudio permite a las empresas evaluadas conocer cuales son los factores a mejorar en su gestión. ABSTRACT The starting point for a company to improve its competitiveness is the evaluation of...
En este artículo se presentan el diseño y los resultados de la aplicación de un modelo para la ge... more En este artículo se presentan el diseño y los resultados de la aplicación de un modelo para la gestión logística en las pymes industriales. Para identificar las variables del modelo, se llevó a cabo una revisión minuciosa del estado del arte en gestión logística; para caracterizar las pymes, se elaboró un cuestionario tipo Likert con las variables recogidas en el paso anterior. Una vez validado el cuestionario, se aplicó el mismo a un grupo de setenta y cinco (75) pymes del sector industrial, ubicadas en el Estado Bolívar, Venezuela. Para determinar estadísticamente las variables más relevantes de la gestión, se utilizó la técnica del análisis factorial exploratorio, aplicada a los datos recolectados. La calificación obtenida para el conjunto de empresas evaluadas (49% de cumplimiento), pone de relieve la debilidad de la gestión logística en las pymes industriales.