3D Foot Anthropometric Measurements Under Two Weight- Bearing Conditions for Ergonomic Design of Foot-Related Products / Mediciones Antropométricas del Pie en 3D Bajo Dos Condiciones de Soporte de Peso para el Diseño Ergonómico de Productos Relacionados con los Pies

SUMMARY: This study collected 3D models of the left and right feet from 317 Chinese youth (155 females and 162 males) under half weight-bearing and no weight-bearing conditions. Thirteen dimensions and one angle were taken for each sample. By measuring 13 foot dimensions and 1 angle, this study comprehensively investigated the differences in foot shape between genders and the bilateral differences, as well as the foot shape differences under different conditions. The results showed that regardless of the condition, male foot dimensions were significantly larger than those of females. However, female foot shape was not simply a scaled-down version of male foot shape. On the contrary, the average angle of female feet was greater than that of males under both conditions, indicating a higher prevalence of hallux valgus in females. Both males and females exhibited significant correlation in foot dimensions between the left and right feet, with minimal differences. Under the half weight-bearing condition, the average foot length, width, and circumference were significantly larger than the corresponding measurements under the no weight-bearing condition, while the average height and angle were significantly smaller. Therefore, when designing footwear and foot-related medical rehabilitation aids, it is important to consider foot shape and dimensions under different conditions as a reference. The results of this study provide manufacturers of foot- related products with more detailed data support and are of significant value to the field of medical foot morphology research.

Este estudio recolectó modelos 3D de los pies izquierdo y derecho de 317 jóvenes chinos (155 mujeres y 162 hombres) en condiciones de carga media de peso y sin carga de peso. Para cada muestra se tomaron trece dimensiones y un ángulo. Al medir 13 dimensiones del pie y 1 ángulo, se investigó exhaustivamente las diferencias en la forma del pie entre ambos sexos y sus diferencias bilaterales, así como las diferencias en la forma del pie en diferentes condiciones. Los resultados mostraron que, independientemente de la condición, las dimensiones del pie de los hombres, estos eran significativamente más grandes que los de las mujeres. Sin embargo, la forma del pie femenino no era simplemente una versión reducida de la forma del pie masculino. Por el contrario, el ángulo promedio de los pies de las mujeres fue mayor que el de los hombres en ambas condiciones, lo que indica una mayor prevalencia de hallux valgus en las mujeres. Tanto hombres como mujeres exhibieron una correlación significativa en las dimensiones del pie, entre el pie izquierdo y el derecho, con diferencias mínimas. Bajo la condición de medio soporte de peso, la longitud, el ancho y la circunferencia promedio del pie fueron significativamente mayores que las medidas correspondientes bajo la condición sin soporte de peso, mientras que la altura y el ángulo promedio fueron significativamente más pequeños. Por lo tanto, al diseñar calzado y dispositivos médicos de rehabilitación relacionados con los pies, es importante tener en consideración la forma y las dimensiones del pie en diferentes condiciones como referencia. Los resultados de este estudio, brindan a los fabricantes de productos relacionados con los pies un soporte de datos más detallado y son de gran valor para el campo de la investigación médica de la morfología del pie.

Strength training of long jump athletes / Treinamento da força dos atletas de salto longo / Entrenamiento de fuerza de los atletas de salto de longitud

ABSTRACT Introduction Lower limb strength training is one of the daily exercises of jumpers. Heavy squats are a standard method of lower body strength training. The squat is the only compound movement that directly trains "hip strength." Objective This study aimed to analyze the effect of weighted squats on lower body strength training in long jumpers. Methods 20 jumpers were selected and randomly divided into a general training group and a weighted squat group. Then, the changes in standing triple jump, lateral jump, and Y-axis swing were analyzed before and after training under an experimental protocol. Results The performance of the weighted squat group was better than that of the general training group about the explosive power of the lower body of long jumpers. The data were statistically divergent (P<0.05). There was no significant difference between the two groups in the Y-balance test related to the lower limbs (P>0.05). Conclusion Squatting exercises with weight can improve the explosive power of lower limbs in jumpers. Long jumpers use a variety of jumping exercises to develop the rapid strength needed for their specialties, and this protocol can be added to training for a better athletic outcome. Level of evidence II; Therapeutic studies - investigating treatment outcomes.

RESUMO Introdução O treinamento de força nos membros inferiores é um dos exercícios diários dos saltadores. Os agachamentos pesados são um método padrão de treinamento da força inferior do corpo. O agachamento é o único movimento composto que treina diretamente a "força do quadril". Objetivo Este estudo teve como objetivo analisar o efeito dos agachamentos ponderados no treinamento da força inferior do corpo em saltadores de salto em distância. Métodos 20 saltadores foram selecionados e aleatoriamente divididos em um grupo de treinamento geral e um grupo de agachamento ponderado. Em seguida, as mudanças no salto triplo em pé, salto lateral e balanço no eixo Y foram analisados antes e depois do treinamento sob um protocolo experimental. Resultados O desempenho do grupo de agachamento com peso foi melhor que o do grupo de treinamento geral no que se refere ao poder explosivo da parte inferior do corpo dos saltadores de salto em distância. Os dados foram estatisticamente divergentes (P<0,05). Não houve diferença significativa entre os dois grupos no teste de balanço em Y relacionados aos membros inferiores (P>0,05). Conclusão Os exercícios de agachamento com peso podem melhorar o poder explosivo dos membros inferiores nos saltadores. Os saltadores de salto longo utilizam uma variedade de exercícios de salto para desenvolver a força rápida necessária para suas especialidades e esse protocolo pode ser adicionado ao treino para um melhor resultado atlético. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción El entrenamiento de la fuerza de los miembros inferiores es uno de los ejercicios diarios de los saltadores. Las sentadillas pesadas son un método estándar de entrenamiento de la fuerza de la parte inferior del cuerpo. La sentadilla es el único movimiento compuesto que entrena directamente la "fuerza de la cadera". Objetivo Este estudio tiene como objetivo analizar el efecto de las sentadillas con peso en el entrenamiento de la fuerza del tren inferior en saltadores de longitud. Métodos Se seleccionaron 20 saltadores y se dividieron aleatoriamente en un grupo de entrenamiento general y un grupo de sentadillas con peso. A continuación, se analizaron los cambios en el triple salto de pie, el salto lateral y el equilibrio en el eje Y antes y después del entrenamiento con un protocolo experimental. Resultados El rendimiento del grupo de sentadillas con peso fue mejor que el del grupo de entrenamiento general en lo que respecta a la potencia explosiva de la parte inferior del cuerpo de los saltadores de longitud. Los datos fueron estadísticamente divergentes (P<0,05). No hubo diferencias significativas entre los dos grupos en la prueba de equilibrio en Y relacionada con las extremidades inferiores (P>0,05). Conclusión Los ejercicios de sentadilla con peso pueden mejorar la potencia explosiva de los miembros inferiores en los saltadores. Los saltadores de longitud utilizan una variedad de ejercicios de salto para desarrollar la fuerza rápida requerida para sus especialidades y este protocolo puede añadirse al entrenamiento para un mejor resultado atlético. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Effects of variable exercise on strength training in throwing athletes / Efeitos do exercício variável no treinamento de força em praticantes de arremesso / Efectos del ejercicio variable en el entrenamiento de fuerza en practicantes de lanzamiento

ABSTRACT Introduction: Throwing is a physical phenomenon with its base resistance and speed, demanding the high explosive force of its practitioners. Objective: Observe the implications of exercise with speed and variable load on the explosive strength training of throwing practitioners. Methods: The author uses scientific literature to execute an experiment on throwing techniques, dividing 24 athletes randomly into control and experimental groups. Variations of discus weight and throwing distances were applied in the groups. The results were compared in SPSS and Excel to perform the corresponding statistical processing. Results: The athletes showed throwing performance with an increasing trend, but not evident enough among the control group. The increase in the experimental group was evident compared to the performance before the experiment. Conclusion: Training with variable speed and variable load exercises positively affects strength training in throwing events. It is recommended to perform variable speed and variable load exercises for athletes in throwing practitioners. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: O arremesso é um fenômeno físico que tem como base a resistência e a velocidade, exigindo elevada força explosiva corporal de seus praticantes. Objetivo: Observar as implicações do exercício com velocidade e carga variável no treinamento de força explosiva dos praticantes de arremesso. Métodos: O autor utiliza embasamento na literatura científica para executar um experimento de técnicas de arremesso esportivo, dividindo 24 atletas aleatoriamente em grupos controle e experimental. Variações de peso dos discos e distâncias de lançamento foram aplicadas nos grupos e a comparação dos resultados foi executada no software SPSS e Excel para realizar o processamento estatístico correspondente. Resultados: Os atletas apresentaram desempenho de lançamento com uma tendência crescente, mas não suficiente evidente entre o grupo controle. Comparado ao desempenho prévio do experimento, o aumento do grupo experimental foi evidenciado. Conclusão: O treinamento com exercícios de velocidade variável e carga variável tem um efeito positivo no treinamento de força em eventos de arremesso, é recomendado realizar exercícios de velocidade variável e carga variável para atletas em praticantes de arremesso. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: El lanzamiento es un fenómeno físico que tiene como base la resistencia y la velocidad, exigiendo una alta fuerza corporal explosiva de sus practicantes. Objetivo: Observar las implicaciones del ejercicio con velocidad y carga variable en el entrenamiento de la fuerza explosiva de los lanzadores. Métodos: El autor utiliza la literatura científica para ejecutar un experimento de técnicas de lanzamiento, dividiendo a 24 atletas al azar en grupos de control y experimental. Se aplicaron variaciones de peso de los discos y distancias de lanzamiento en los grupos y la comparación de los resultados se ejecutó en el software SPSS y Excel para realizar el correspondiente tratamiento estadístico. Resultados: Los atletas mostraron un rendimiento de lanzamiento con una tendencia al alza, pero no es suficientemente evidente entre el grupo de control. En comparación con el rendimiento anterior al experimento, se evidenció el aumento en el grupo experimental. Conclusión: El entrenamiento con ejercicios de velocidad variable y carga variable tiene un efecto positivo en el entrenamiento de la fuerza en las pruebas de lanzamiento, se recomienda la realización de ejercicios de velocidad variable y carga variable para los atletas en las prácticas de lanzamiento. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Effect of weight training on lower limb strength in martial arts athletes / Efeito do treinamento com pesos sobre a força dos membros inferiores em atletas de artes marciais / Efecto del entrenamiento con pesas en la fuerza de las extremidades inferiores en atletas de artes marciales

ABSTRACT Introduction: It is believed that weight training on the lower limbs in martial arts athletes can contribute to a better performance of the whiplash, a specific movement that encompasses pliometry, balance and strength. Objective: Study the effects of weight training on lower limb strength in martial arts athletes when performing the whiplash. Methods: A controlled experiment was conducted involving 100 martial arts athletes, randomly divided into two groups of characteristics without statically relevant differences. The experimental group received weight training, while the control group received no additional intervention to their daily training. Results: The vertical jump in the experimental group increased from 31.24 ± 6.65 cm to 36.00 ± 9.62 cm; the vertical jump in horizontal standing position increased from 195.49 ± 4.16 cm to 196.51 ± 7.49 cm; the approach vertical jump varied from 32.94 ± 9.21 cm to 37.60 ± 11. 50 cm; the jump from the local half squat position was from 34.55 ± 6.40 cm to 40.30 ± 8.14 cm; the maximum force of a squat with weights was from 140.81 ± 10.05 kg to 142.06 ± 10.23 kg; the maximum number of supine leg raises in one minute increased from 43.43 ± 6.15 to 48.05 ± 7.29. Conclusion: Weight training positively influenced lower limb strength in martial arts athletes, whiplash performance was elevated. Weight training is recommended in the daily training of martial arts athletes. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: Acredita-se que o treinamento com pesos nos membros inferiores em atletas de artes marciais possa contribuir para um melhor desempenho do whiplash, um movimento específico que engloba pliometria, equilíbrio e força. Objetivo: Estudar os efeitos do treinamento com pesos sobre a força dos membros inferiores em aletas de artes marciais na execução do whiplash. Métodos: Foi conduzida uma experiência controlada envolvendo 100 atletas de artes marciais, divididos aleatoriamente em dois grupos de características sem diferenças estaticamente relevantes. O grupo experimental recebeu treinamento com pesos, enquanto o grupo de controle não recebeu nenhuma intervenção adicional ao treino cotidiano. Resultados: O salto vertical no grupo experimental elevou-se de 31,24 ± 6,65 cm para 36,00 ± 9,62 cm; o salto vertical em pé horizontal elevou-se de 195,49 ± 4,16 cm para 196,51 ± 7,49 cm; o salto vertical de aproximação variou de 32,94 ± 9,21 cm para 37,60 ± 11. 50 cm; o salto da posição de meio agachamento local foi de 34,55 ± 6,40 cm para 40,30 ± 8,14 cm; a força máxima de um agachamento com pesos foi de 140,81 ± 10,05 kg para 142,06 ± 10,23 kg; o número máximo de elevações de pernas supinas em um minuto elevou-se de 43,43 ± 6,15 para 48,05 ± 7,29. Conclusão: O treinamento com pesos influenciou positivamente na força dos membros inferiores em atletas de artes marciais, o desempenho do whiplash foi elevado. Recomenda-se o treinamento de pesos no treinamento diário dos atletas de artes marciais. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: Se cree que el entrenamiento con pesas sobre los miembros inferiores en atletas de artes marciales puede contribuir para una mejor ejecución del whiplash, un movimiento específico que engloba pliometría, equilibrio y fuerza. Objetivo: Estudiar los efectos del entrenamiento con pesas en la fuerza de los miembros inferiores en atletas de artes marciales al realizar el whiplash. Métodos: Se realizó un experimento controlado con 100 atletas de artes marciales, divididos aleatoriamente en dos grupos de características sin diferencias estadísticamente relevantes. El grupo experimental recibió entrenamiento con pesas, mientras que el grupo de control no recibió ninguna intervención adicional a su entrenamiento diario. Resultados: El salto vertical en el grupo experimental aumentó de 31,24 ± 6,65 cm a 36,00 ± 9,62 cm; el salto vertical horizontal de pie aumentó de 195,49 ± 4,16 cm a 196,51 ± 7,49 cm; el salto vertical de aproximación varió de 32,94 ± 9,21 cm a 37,60 ± 11. 50 cm; el salto desde la posición de media sentadilla local fue de 34,55 ± 6,40 cm a 40,30 ± 8,14 cm; la fuerza máxima de una sentadilla con pesas fue de 140,81 ± 10,05 kg a 142,06 ± 10,23 kg; el número máximo de elevaciones de piernas en decúbito supino en un minuto aumentó de 43,43 ± 6,15 a 48,05 ± 7,29. Conclusión: El entrenamiento con pesas influyó positivamente en la fuerza de las extremidades inferiores de los atletas de artes marciales y elevó el rendimiento de los whiplashs. Se recomienda el entrenamiento con pesas en el entrenamiento diario de los atletas de artes marciales. Nivel de evidencia II; Estudios terapéuticos-investigación de los resultados del tratamiento.

Effects of Implant Sites and Axial Direction on Stress of Maxillary Central Incisors with Immediate Implantation under Immediate Weight-Bearing: A Three-Dimensional Finite Element Analysis / 医用生物力学

Objective To investigate the influence of implant location and axial direction on stress distributions at the implant bone interface of maxillary central incisors with different alveolar fossa morphology by immediate implantation under immediate weight-bearing. Methods With reference to dental cone beam computed tomography (CBCT) image data from a healthy adult, the three-dimensional ( 3D) finite element models of maxillary central incisors with three types of alveolar fossa ( buccal, mediate, and palatal type) by immediate implatation under immediate weight-bearing were established. Different implant sites ( apical site, palatal / labial site) and axial directions (long axis of the tooth, long axis of the alveolar bone) were simulated. The established models were subjected to 100 N force at different angles (0°, 30°, 45°, 60°, 90°). The stresses in the alveolar bone around the implant were analyzed by the ANSYS software. Results Twelve 3D finite element models of maxillary central incisors with different alveolar fossa morphology by immediate implantation under immediate weight-bearing were successfully established. When alveolar fossa with buccal and mediate shape was applied with immediate implantation under immediate weight-bearing, it was easier to obtain good biomechanical properties of the implant-bone interface when implants were placed at palatal site along long axis of the alveolar bone. When alveolar fossa with palatal shape was applied with immediate implantation under immediate weight bearing, the equivalent stresses on peri-implant alveolar bone were much smaller than those on apical site, regardless of whether the implant was placed along long axis of the tooth or the long axis of the alveolar bone. Conclusions Different alveolar fossa morphology, implant location and axial direction will affect characteristics of implant-bone interface of maxillary central incisors with immediate implantation under immediateweight-bearing. In clinical practice, surgical planning on different axial direction and location of implantation should be developed for alveolar fossa with different morphology.

Early weight-bearing walking with inflatable boots after repair of acute Achilles tendon rupture based on the concept of rapid rehabilitation / 中华创伤骨科杂志

Objective:To evaluate early weight-bearing walking with inflatable boots after repair of acute Achilles tendon rupture based on the concept of rapid rehabilitation.Methods:A retrospective study was conducted to analyze the data of 69 patients with acute Achilles tendon rupture who had been treated at Department of Orthopaedics, The Second Fuzhou Hospital Affiliated to Xiamen University from April 2020 to July 2021. There were 56 males and 13 females with a mean age of 37.0(31.0, 47.0) years and a body mass index of (23.7±2.6) kg/m 2. There were 55 cases of closed injury and 14 cases of open injury; 62 cases had simple Achilles tendon injury and 7 cases were complicated with neurovascular tendon injury. The patients were divided into 2 groups according to their rehabilitation methods. The treatment group of 23 cases was subjected to weight-bearing walking with inflatable boots early after repair while the control group of 46 cases to traditional plaster bracket fixation for 4 weeks before weight-bearing walking with inflatable boots. The 2 groups were compared in terms of hospitalization time, wound infection rate, return to sports time, single heel lifting time, Achilles tendon re-rupture rate, Victorian Institute of Sports Assessment (VISA-A), Achilles tendon total rupture score (ATRS), and American Orthopaedic Foot & Ankle Society ankle-hindfoot score (AOFAS-AH). Results:There was no statistically significant difference in the comparison of preoperative general data between the 2 groups, showing comparability ( P>0.05). All patients were followed up for 11 (10, 11) months after surgery. In the treatment group, the hospitalization time [4 (3, 5) days] and single heel lifting time [(12.5±1.4) weeks] were significantly shorter than those in the control group [6 (5, 9) days and (17.0±1.5) weeks], the return to sports time [21 (20, 22) months] was significantly earlier than that in the control group [23 (22, 24) months], and the VISA-A score [(89.4±1.3) points] was significantly higher than that in the control group [(78.5±1.7) points] ( P<0.05). There was no statistically significant difference in the wound infection rate between the 2 groups ( P>0.05). At 3 and 6 months after surgery, respectively, the treatment group had significantly higher ATRS scores [(85.5±1.4) and (89.0±1.6) points] and AOFAS ankle-hindfoot scores [(89.0±1.7) and (92.0±1.5) points] than the control group [(79.3±1.8) and (87.0±1.3) points; (80.2±1.9) and (88.4±1.9) points] (all P<0.05). In all patients, the AOFAS ankle-hindfoot score at 6 months postoperatively was significantly higher than that at 3 months postoperatively ( P<0.05). Achilles tendon re-rupture occurred in none of the patients. Conclusion:After repair of acute Achilles tendon rupture, compared with traditional plaster bracket fixation, early weight-bearing walking with inflatable boots can lead to better short-term clinical outcomes to enhance recovery after surgery without increasing the rate of open wound infection or re-rupture.

Influence of abutment angulation on implant failure in immediately placed and restored implants in the esthetic zone: a randomized clinical trial

Background: Tooth extraction socket in the aesthetic area is a major indication for immediate implant placement greatly improving patient satisfaction and preserving the alveolar ridge. However, the effect of non-axial force on the peri-implant bone with subsequent early implant failure remains unclear. Objective:Evaluate the prognosis of tilted implants immediately placed and restored with angled abutments in comparison to straight implants restored with straight abutments in the esthetic area (anterior or premolars) using computer-aided surgical guides. Material and methods: Badly decayed non-restorable teeth in the aesthetic zone (anterior or premolars) were extracted atraumatically. Immediately after guided implant insertion, the abutments were adjusted and placed according to the allocation group (0, 15, or 25-degree angle) then a temporary crown was performed out of occlusion in centric and eccentric relation. Early implant failure was assessed at three and six months. Results:There was no statistically significant difference between the two groups (P=0.305). Straight and angled abutment groups showed 6 (14.3%) and 8 (20%) failed cases, respectively. The post-hoc subgroup analysis showed no statistically significant difference between angle 15 and angle 25 degree groups where (P=0.686) or between Anterior and Premolar groups (P=0.853). Conclusion: There was no statistically significant difference in the failure rate when comparing angled to straight immediately placed & restored implants. This applies to both anterior and premolar implants

Zygomatic implants in intra-sinus versus extra-maxillary approaches for prosthetic rehabilitation in severely atrophic maxillae: finite element analysis / Implantes cigomáticos en abordajes intra sinusal versus extra maxilar para rehabilitación protésica en maxilares severamente atróficos: análisis de elementos finitos

Objetive: To compare the stresses and deformations generated on the surrounding bone of the zygomatic implants when using an intra sinusal and extra-maxillary approach, through the finite element method. Material and Methods: Computer aided designs (CADs) were constructed using SolidWorks Software of a skull with bone resorption to be rehabilitated through a fixed hybrid prosthesis using two zygomatic and two conventional straight implants. For the boundary conditions (load conditions), symmetry in the sagittal plane was assumed and that all the materials were isotropic, homogeneous and linearly elastic. Two zygomatic implantation techniques were simulated: intra sinusal (Is) and extra maxillary (Em). Vertical and lateral loads of 150 N and 50 N were applied to the finite element models to obtain Von Mises equivalent stress and strain (displacement). Results: The average measurement of the Von Mises stress (MPa) recorded were as follows: Approach of the implant body (Is: 0.24- Em: 0.28,) effort of implant body with vertical load: Is: 0.69 - Em: 0.96; effort of peri-implant surface under horizontal load: Is: 2.11 - Em: 0.94. Average displacement under vertical load of peri-implant surface Is: 0.35 - Em: 0.40, and of implant body Is: 1.34 - Em: 2.04. Average total deformation in approach Is: 2.23 mm - Em: 0.80mm, and average total deformation in the implant body under horizontal load was Is: 0.14 - Em: 0.21. Conclusion: The results of this study indicate that despite the differences that occurred in both stress and strain (displacement) between the intra-sinus and extra-maxillary approaches, the static strength of the bone, which is approximately 150 MPa in tension and 250 MPa in compression was not exceeded. Considering the limitations of finite element analysis, there seems to be no biomechanical reason to choose one approach over the other.

Objetivo: Comparar por el método de elementos finitos los esfuerzos y deformaciones generados sobre el hueso circundante de implantes cigomáticos tratados con un abordaje intra sinusal y extra maxilar. Material y Métodos: Se construyeron los diseños asistidos por computadora (CAD) utilizando el Software SolidWorks de un cráneo con una reabsorción ósea para ser rehabilitado, a través de una prótesis híbrida fija, mediante dos implantes cigomáticos y dos rectos convencionales. Para las condiciones de frontera (condiciones de carga) se asumió simetría en el plano sagital y que todos los materiales eran isotrópicos, homogéneos y linealmente elásticos. Se simularon dos técnicas de implantación cigomática: una intra sinusal (Is) y otra extra maxilar (Em). Se aplicaron cargas verticales y laterales de 150 N y 50 N a los modelos de elementos finitos para obtener el esfuerzo equivalente de Von mises y la deformación (desplazamiento). Resultados: La medición promedio del esfuerzo de Von Mises (MPa) registró: abordaje del cuerpo de implante (Is: 0.24-Em: 0.28) esfuerzo del cuerpo de implante con carga vertical: (Is:0.69 ­ Em: 0.96); esfuerzo de la superficie peri implantar ante carga horizontal (lateral):( Is:2.11 ­ Em:0.94). Desplazamiento promedio ante carga vertical de la superficie peri implantar (Is:0.35 ­ Em:0.40) y del cuerpo del implante (Is:1.34 ­ Em:2.04). Deformación total promedio en mm en abordaje (Is: 2.23 ­ Em:0.80) y deformación total promedio en el cuerpo del implante ante carga horizontal (Is:0.14 ­ Em:0.21). Conclusión: Los resultados de este estudio indican que a pesar de las diferencias que se presentaron tanto en el esfuerzo como en la deformación (desplazamiento) entre los abordajes intra sinusal y extra maxilar, la resistencia estática del hueso, que es de aproximadamente 150 MPa en tensión y 250 MPa en compresión no se superó. Considerando las limitaciones de los AEF, parece no haber razones biomecánicas para elegir uno u otro enfoque.

Radiographic evaluation of immediate loading safety after surgical reduction in acetabular fractures: a comparative-retrospective study / Avaliação radiográfica da segurança na carga imediata após redução cirúrgica em fraturas acetabulares: estudo comparativo-retrospectivo

ABSTRACT Objective Radiographically evaluate the quality of reduction over six weeks of follow-up in patients with surgically treated deviated acetabular fractures who underwent rehabilitation with immediate loading as tolerated and compare this with the results of the unloaded protocol. Methods We retrospectively evaluated the records of 137 patients with deviated acetabular fractures treated with open reduction and internal fixation. Sixty-six (48.2%) patients underwent postoperative rehabilitation with immediate loading as tolerated, while 71 (51.8%) patients completed rehabilitation using a no-load protocol. The quality of the reduction was assessed radiographically by measuring the fracturing step and gap on radiographs taken immediately after surgery and three and six weeks after surgery. Results Comparing the joint step, group 1 had an average of 0.44 ± 1.4 mm, 0.47 ± 1.5 mm, and 0.51 ± 1.6 mm immediately, three and six weeks after surgery, respectively. Group 2 had a mean step of 0.24 ± 0.8 mm, 0.27 ± 0.9 mm, and 0.37 ± 1.2 mm immediately, three, and six weeks after surgery. No statistically significant differences were observed between the groups. With a joint gap, group 1 had a mean of 1.89 ± 1.7 mm, 2.12 ± 1.8 mm, and 2.36 ± 2.1 mm; and group 2 had a mean of 2.16 ± 2.4 mm, 2.47 ± 2.6 mm, and 2.67 ± 2.8 mm in the immediate postoperative period, three, and six weeks, respectively. There was also no statistical difference between groups in these measurements. Conclusion Immediate loading after surgical treatment of deviated acetabular fracture had no negative impact on radiographic reduction parameters and had similar results to the protocol without weight bearing. Level of evidence III; Therapeutic Retrospective Cohort Study.

RESUMO Objetivo Avaliar radiograficamente a qualidade da redução ao longo de 6 semanas de acompanhamento em pacientes com fratura desviada do acetábulo tratados cirurgicamente e submetidos à reabilitação com carga imediata conforme tolerado e comparar com os resultados do protocolo sem carga. Métodos Avaliamos retrospectivamente os prontuários de 137 pacientes com fraturas desviadas do acetábulo que foram tratadas com redução aberta e fixação interna. Sessenta e seis (48,2%) pacientes foram submetidos à reabilitação pós-operatória com carga imediata conforme tolerado, enquanto 71 (51,8%) pacientes completaram a reabilitação utilizando um protocolo sem carga. A qualidade da redução foi avaliada radiograficamente pela medição do degrau da fratura e do gap nas radiografias feitas imediatamente após a cirurgia e três e seis semanas após a cirurgia. Resultados Comparando o degrau articular, o grupo 1 teve uma média de 0,44 ± 1,4 mm, 0,47 ± 1,5 mm e 0,51 ± 1,6 mm imediatamente, três e seis semanas após a cirurgia, respectivamente. O grupo 2 teve um degrau médio de 0,24 ± 0,8 mm, 0,27 ± 0,9 mm e 0,37 ± 1,2 mm imediatamente, três e seis semanas após a cirurgia. Não foram observadas diferenças estatísticas significantes entre os grupos. Com gap articular, o grupo 1 teve uma média de 1,89 ± 1,7 mm, 2,12 ± 1,8 mm e 2,36 ± 2,1 mm; e o grupo 2 de 2,16 ± 2,4 mm, 2,47 ± 2,6 mm e 2,67 ± 2,8 mm nos pós-operatório imediato, três e seis semanas, respectivamente. Também não houve diferença estatística entre os grupos nessas medidas. Conclusão A carga imediata após o tratamento cirúrgico da fratura do acetábulo desviada não teve impacto negativo nos parâmetros de redução radiográfica e teve resultados semelhantes em comparação com o protocolo sem descarga de peso. Nível De Evidência III; Estudo Terapêutico de Coorte Retrospectivo.

Resultados funcionales en el tratamiento ortopédico de las roturas agudas del tendón de Aquiles / Functional results in the orthopedic treatment of acute ruptures of the Achilles tendon

Resumen: Objetivo: Analizar los resultados clínicos y funcionales de los pacientes con rotura aguda del cuerpo del tendón de Aquiles tratados de forma conservadora mediante bota ortopédica y carga precoz. Material y métodos: Estudio observacional prospectivo con 19 pacientes con rotura aguda de tendón de Aquiles tratados de forma ortopédica. Se analizaron las variables demográficas, la escala ATRS (Achilles tendon Total Rupture Score), la función mediante el test de puntillas, masa muscular gemelar y el equino en reposo residual. Los registros clínicos y funcionales se realizaron a las seis semanas, tres, seis y 12 meses. Se realizó un análisis estadístico mediante Stata 14. Resultados: A los 12 meses, 94% de los pacientes realizaban puntillas monopodales, la media de la atrofia gemelar fue de 1.03 cm ± 0.51 respecto a extremidad contralateral y la diferencia de equino residual respecto el lado sano era de 5.63 grados ± 4.17, 83.24% de los pacientes realizaban su práctica deportiva habitual previa a la rotura. La media de ATRS de la muestra era de 87.41 puntos ± 17.78. Se registraron dos rerroturas parciales (11%) a los tres meses de seguimiento que continuaron con tratamiento ortopédico. Conclusiones: El tratamiento ortopédico funcional mediante bota ortopédica y carga precoz presenta buenos resultados clínicos y funcionales, considerándolo un tratamiento válido para las roturas agudas del tendón de Aquiles.

Abstract: Objective: The purpose of this study is to assess the clinical and functional results of patients with acute middle third of Achilles tendon rupture treated conservatively by orthopedic boot and early weight-bearing. Material and methods: This is a prospective observational study with 19 patients with acute Achilles tendon rupture treated by conservative treatment. Demographic variables, ATRS score, function using heel-rise test, calf circumference and Achilles tendon resting angle were analyzed. The clinical and functional registration was performed at six weeks, three, six and 12 months of injury. A statistical analysis was performed. Results: At one year follow-up, the 94% of patients were capable of standing single heel rise, the mean of twin atrophy was 1.03 cm ± 0.51 compared to uninjured side and the difference of Achilles tendon resting angle was 5.63 degrees ± 4.17 compared to contralateral limb. The 83.24% of patients returned to play and the mean of ATRS score was 87.41 points ± 17.78. Two partial re-rupture (11%) were occurred at three months of follow-up, which continued with orthopedic treatment. Conclusions: Based on the results, functional orthopedic treatment using orthopedic boot and early weight-bearing presents good clinical and functional outcomes, considering it a valid treatment for acute Achilles tendon ruptures.

The missing link in the history of the locked intramedullary nail / O elo perdido na história da haste intramedular bloqueada

ABSTRACT Femoral Shaft intramedullary nails were first described by the Aztecs in 16th century, but the modern use of intramedullary nails as the gold standard treatment for femoral shaft fractures began with Gerald Kuntcher in 1939. From the first Kuntcher's study in 1939, to the creation of interlocking nail, a long and some minor developments were described around the world. However, a major development is missing: the first nail to have a rotational and vertical stability locking system was described by Flavio Godoy Moreira, but was never published on an indexed journal for the correct historical reference. Level of Evidence V, Therapeutics Studies, Expert Opinion.

RESUMO A história da haste intramedular bloqueada nas fraturas do fêmur se inicia com os Astecas no século 16, mas o uso moderno que a tornou o padrão ouro no tratamento destas fraturas se inicia com Gerald Kuntcher em 1939. Do estudo inicial de Kutcher até o desenvolvimento da haste bloqueada muitos pequenos desenvolvimentos foram descritos ao redor do mundo. Dentro deste desenvolvimento, a primeira haste a ter um controle vertical e rotacional foi descrito por Flavio Pires de Camargo, e nunca foi publicado em um jornal indexado que permita sua correta referência histórica. Nível de Evidência V, Estudos Terapêuticos, Opinião de especialista.

Weight-bearing cone-beam computed tomography in the foot and ankle specialty: where we are and where we are going - an update / Tomografia computadorizada de feixe cônico com carga corporal na especialidade do pé e tornozelo: situação atual e perspectivas futuras - uma atualização

Abstract Cone-beam computed tomography (CBCT) has been applied in dentistry and medicine for nearly two decades. Its application in the foot and ankle specialty has grown exponentially in recent years. Weight-bearing CBCT allows clinicians to obtain weight-bearing images that can be viewed in all three planes and to construct three-dimensional models, similar to those constructed from traditional CT scans, as well as exposing patients to less radiation than do traditional CT scans. This technology has revolutionized diagnoses, improving the understanding of various lesions and surgical planning in the foot and ankle specialty. Ongoing studies of the use of weight-bearing CBCT in foot and ankle surgery are focused on fully automated and semi-automated three-dimensional measurements, as well as bone segmentation, mapping of the distances/orientation of the joints, and the production of customized implants. The aims of this review article are to show the evolution of this emerging tool in the foot and ankle specialty, to update those in related specialties on its use in current clinical practice, and to indicate where the research community is heading.

Resumo A tomografia computadorizada (TC) de feixe cônico é aplicada na área da odontologia e medicina há cerca de duas décadas, e seu uso na especialidade do tornozelo e pé cresceu de forma exponencial nos últimos anos. A literatura demonstra como a TC de feixe cônico permite obter imagens com apoio do peso corporal total - weight-bearing cone-beam computed tomography - com cortes nos três planos e modelos tridimensionais semelhantes às TCs, associada a menor exposição à radiação, técnica que revolucionou o diagnóstico, o entendimento de diferentes lesões e o planejamento cirúrgico nessa área do conhecimento. As mensurações tridimensionais automáticas e semiautomáticas, a segmentação óssea, o mapeamento das distâncias e orientações articulares e a possibilidade de produção de implantes customizados são o interesse dos estudos em andamento na cirurgia do tornozelo e pé relacionados a essa ferramenta emergente. O objetivo deste artigo é mostrar a evolução do método, atualizar as especialidades de interface sobre uso na prática clínica atual e indicar para onde a comunidade científica está caminhando.

Weight-bearing cone beam ct scans and its uses in ankle, foot, and knee: an update article / Tomografia computadorizada com carga em tornozelo, pé e joelho: um artigo de atualização

ABSTRACT Imaging plays a key role in the preoperative diagnosis, surgical planning, and postsurgical assessment of the foot, ankle, and knee pathologies. Interpreting diagnostic imaging accurately is crucial for the clinical practice of orthopedic surgeons. Although among the most used imaging modalities, radiographic assessments are amenable to errors for various technical reasons and superposition of bones. Computed tomography (CT) is a conventional imaging procedure that provides high-resolution images, but fails in considering a truly weight-bearing (WB) condition. In an attempt to overcome this limitation, WB cone beam CT technology has being successfully employed in the clinical practice for the past decade. Besides economically viable and safe, the WB cone beam CT considers WB conditions and provides high-quality scans, thus allowing an equitable and correct interpretation. This review aims to address extensive description and discussion on WBCT, including imaging quality; costs; time consumption; and its applicability in common foot, ankle, and knee, conditions. With this technology increasing popularity, and considering the extensive literature on medical research, radiologists and orthopedic surgeons need to understand its potential applications and use it optimally. Level of Evidence III, Systematic review of level III studies.

RESUMO Os exames de imagem são essenciais no diagnóstico, planejamento cirúrgico e avaliação pós-cirúrgica das patologias que envolvem pé, tornozelo e joelho. A interpretação acurada utilizando as tecnologias de diagnóstico por imagem disponíveis é crucial para os cirurgiões ortopédicos na sua prática clínica. Embora as radiografias convencionais estejam entre as modalidades de diagnóstico por imagem mais utilizadas, elas estão sujeitas a erros por várias razões técnicas e sobreposição de estruturas ósseas. Apesar de a tomografia computadorizada (TC) fornecer imagens de alta qualidade, ela falha em não considerar a carga corporal fisiológica. A TC de feixe cônico com carga vem sendo utilizada com sucesso desde a última década, superando a limitação da TC convencional. Além de ser econômica e segura, possibilita a aquisição de imagens de alta resolução, com carga, permitindo, assim, uma interpretação correta e equiparável. O objetivo principal dessa revisão é proporcionar uma discussão e descrição ampla de TC com carga, incluindo qualidade de imagem, custos financeiros, tempo consumido em exames, e suas aplicações em patologias comuns do pé, tornozelo e joelho. A TC com carga vem crescendo em popularidade, e é tema de um número extenso de pesquisas científicas, sendo necessário que radiologistas e cirurgiões ortopédicos entendam suas aplicações para melhor uso futuro. Nível de Evidência III, Revisão sistemática de Estudos de Nível III.

Influences of Different Stop Modes on Gait Stability of the Elderly Carrying Heavy Objects / 医用生物力学

Objective To analyze characteristics of muscle activity and changes of corresponding kinematic parameters of the lower limbs for the elderly carrying heavy objects under synchronous stop modes, and explore the effects of hand weight-bearing and stop modes on gait stability and body balance of the elderly. Methods The ankle, knee, hip joint angles and surface electromyography (EMG) signals of bilateral lower limbs were collected under the condition of emergency stop and planned stop by loading 0 kg, 2.5 kg on both hands and 5 kg on right hand. Results Under different weight-bearing modes, the ankle and hip angles of bilateral lower limbs were significantly different (P<0.05), while the knee angles did not change significantly, and different stop modes significantly affected the angle changes in each joint (P <0.001); the average EMG of tibia anterior muscle, lateral femoral muscle, and biceps femoris in braking leg showed higher muscle activity during emergency stop. Conclusions In order to cope with the instability caused by weight-bearing and emergency stop, the elderly will have a corresponding balance mechanism in the lower limbs. During an emergency stop, braking the tibialis anterior muscle of the leg requires a higher muscle activity level to control flexion angle of the ankle joint, thereby reducing amplitude of the ankle joint fluctuation. The single-handed load increases the muscle performance differences between the braking leg and trailing leg, resulting in the lateral instability.

Biomechanical Comparison of Two-Point and Three-Point Fixation for Treating SandersⅢ Calcaneal Fracture / 医用生物力学

Objective To analyze the biomechanical feasibility of two-point fixation by distal radius plate for the treatment of SandersⅢ calcaneal fractures. Methods The three-dimensional (3D) finite element musculoskeletal foot model was established based on CT and MRI images, which comprised bones, muscles, plantar fascia, ligaments and soft tissues. After validation, the SandersⅢ calcaneal fracture models fixed by distal radial plate (two-point fixation) and calcaneal plate (three-point fixation) were established, so as to compare the biomechanical characteristics of two calcaneal models. Results The maximum stress of the two-point fixation and three-point fixation model was 324.70 and 407.90 MPa, respectively. The maximum displacements of the two models were 2.498 and 2.541 mm, respectively. There was no significant difference in the posterior articular surface displacement between the two models. In both models, the Bohler’s angle and Gissane’s angle were within the normal range. Conclusions The two-point fixation by distal radial plate can satisfy the biomechanical stability of calcaneal fracture treatment. Compared with traditional steel plate, the two-point fixation shows the advantage of smaller surgical trauma, more uniform overall stress distribution, early weight-bearing rehabilitation after surgery, which is a novel treatment recommended for treating calcaneal fractures.

Weight Discharge in Postoperative of Plateau Fracture Tibialis: Systematic Review of Literature / Descarga de peso no pós-operatório de fratura de planalto tibial: Revisão sistemática da literatura

Abstract Tibial plateau fractures are a risk to the functional integrity of the knee, affecting the axial alignment and capable of leading to pain and disability of the individual. Early weight bearing and joint mobilization can prevent these functional deficits. the goal of the present study was to conduct a systematic review of the literature about studies that quote the beginning, evolution, and progression criteria for weight-bearing in postoperative period of tibial plateau fractures. We selected articles published in the last 12 years, in Portuguese and English, that described the time of onset and progression of weight-bearing, considering the severity of the fracture. Thirty-six articles were selected. There is no consensus in the literature as to the beginning and evolution of weight-bearing in the postoperative period of tibial plateau fractures; however, a relationship between the severity of the fracture and the fixation method has been observed.

Resumo As fraturas do planalto tibial constituem risco à integridade funcional do joelho, afetando o alinhamento axial e podendo levar à dor e à incapacidade do indivíduo. O suporte de carga e a mobilização articular precoce podem prevenir esses déficits e acelerar o processo de reabilitação. O objetivo do presente trabalho foi realizar uma revisão da literatura sobre estudos que citam o início, evolução e critérios de progressão do suporte de carga no pós-operatório das fraturas de planalto tibial. Foram selecionados artigos publicados nos últimos 12 anos, nos idiomas português e inglês, que descrevessem o tempo de início e progressão do suporte de carga, considerando a gravidade da fratura. Foram selecionados 36 artigos na literatura. Não há consenso na literatura quanto ao início e evolução do suporte de carga no pós-operatório das fraturas do planalto tibial. Contudo, observa-se relação entre a gravidade da fratura e o tempo de início da carga.

Effect of Early Weight-bearing on Appropriate Population with Intertrochanteric Fracture after Surgery / 中国康复理论与实践

Objective:To observe the effect of early weight-bearing on the appropriate population with intertrochanteric fracture after surgery. Methods:From April, 2017 to December, 2018, a total of 45 patients with Evans-Jensen type II intertrochanteric fracture and fracture reduction as positive medial cortex support (PMCS) after proximal femoral nail anti-rotation (PFNA) fixation were randomly divided into control group (n = 22) and experimental group (n = 23). Weight-bearing as tolerated (WBAT) was initiated from six weeks after surgery in the control group, and within 48 h after surgery in the experimental group. The frequency of WBAT in two groups increased gradually from three times a day for ten minutes a time to five times a day for 20 minutes a time until clinical healing of fracture. The length of stay, hospital cost, the fracture healing time and the complication incidence were compared between two groups, as well as the scores of Visual Analogue Scale (VAS) and Harris Hip Score at six weeks, three months and six months after surgery. Results:Compared with the control group, the length of stay was shorter (t = 3.716, P < 0.01), the hospital cost was lower, but no significant difference was found (t = 1.540, P > 0.05), and the fracture healing time was shorter (t = 6.248, P < 0.001) in the experimental group. The complication incidence was lower in the experimental group, but there was no significant difference (χ2= 2.198, P > 0.05). Six weeks, three months and six months after surgery, there was no significant difference in the score of VAS between two groups (t < 1.330, P > 0.05). The score of Harris Hip Score was significantly higher in the experimental group than in the control group six weeks after surgery (t = -5.115, P < 0.001), however, no significant difference was found in other time points (|t| < 1.799, P > 0.05). Conclusion:Early weight-bearing within 48 h after PFNA fixation for Evans-Jensen type II intertrochanteric fractures and reduction with PMCS could shorten the length of stay, shorten the bony healing time and promote early recovery of hip function.

Tissue engineering methods for repair of articular cartilage defect under special conditions / 中国组织工程研究

BACKGROUND: Although desired cartilage repair has been realized via tissue engineering technology, these achievements mainly focus on small-size defect under a normal physical condition. However, cartilage defects are always accompanied by the underlying diseases in clinical practice, such as osteoarthritis and rheumatoid arthritis. Meanwhile, the location, scope, and depth of cartilage defects are uncertain, which brings a great challenge in cartilage tissue repair. OBJECTIVE: To summarize the methods of repairing articular cartilage defects at different locations and under inflammatory condition. METHODS: We searched PubMed and CNKI with the search terms “cartilage defect regeneration, osteochondral, growth plate, weight-bearing area, inflammatory” in Chiense and English to retrieve related papers published before March 2019. A total of 209 papers were retrieved and 86 were included in the final analysis according to inclusion and exclusion criteria. RESULTS AND CONCLUSION: For articular cartilage defects under different special conditions, the repair goals and strategies are different. For repair of full-layer cartilage defects and osteochondral structure defects, multi-layered scaffolds are often used to repair the unique stratified cartilage structure and subchondral bone structure, while avoiding the problem of heterotopic ossification in neonatal cartilage. To avoid deformity after long bone maturation, growth factors such as insulin-like growth factor and bone morphogenetic protein 7 should be added to continuously stimulate the repair of the growth plate and promote bone growth. For cartilage repair in the weight-bearing area, the scaffolds should have good mechanical property, which ensure not to undergo severe deformation and structural damage when loaded. In addition, the new cartilage tissue has sufficient mechanical strength to support sustained longitudinal pressure and wear. For cartilage defects in the inflammatory state, both inflammation management and cartilage defect repair should be considered, and introduction of mesenchymal stem cells can regulate immune function and promote tissue regeneration, such that articular cartilage defect can be completely repaired.

Balance autonómico basal y durante el ejercicio isométrico en jóvenes con diferente reactividad cardiovascular / Basal autonomic balance and during the isometric exercise in young people with different cardiovascular reactivity

RESUMEN Introducción: El sistema nervioso autónomo desempeña un papel importante en los reajustes cardiovasculares al ejercicio. En la hiperreactividad cardiovascular existe una mayor sensibilidad del sistema simpático ante diferentes estímulos estresantes. Objetivo: Determinar las características del control autonómico cardíaco en adultos jóvenes con diferentes grados de reactividad cardiovascular en condiciones basales y durante el ejercicio isométrico. Método: La muestra estuvo constituida por 97 individuos de ambos sexos, y se dividió en tres grupos: normorreactivos, hiperreactivos y con respuesta hipertensiva, de acuerdo a la respuesta presora a la prueba del peso sostenido. A todos los individuos se les realizó un estudio de variabilidad de la frecuencia cardíaca en reposo y durante la prueba isométrica. Se estudiaron las variables en el dominio de la frecuencia: baja, alta, relación baja/alta en reposo, y los parámetros del diagrama de Poincaré en reposo y durante el ejercicio (valores de desviación estándar 1 [SD1], 2 [SD2], y la razón entre ambos). Resultados: En estado basal los individuos hiperreactivos y con respuesta hipertensiva presentaron un predominio simpático sobre la función cardíaca y una menor variabilidad de la frecuencia cardíaca. Durante el ejercicio isométrico disminuyeron los valores de los ejes SD1 y SD2 en todos los grupos y la razón SD1/SD2 decreció en individuos normorreactivos y con respuesta hipertensiva; pero apenas se modificó en los hiperreactivos. Conclusiones: En los individuos con hiperreactividad cardiovascular ya está presente un desbalance autonómico en estado basal y existe una reducción de la modulación autonómica vagal durante el ejercicio, que puede favorecer el desarrollo de la hipertensión arterial.

ABSTRACT Introduction: The autonomic nervous system plays an important role in cardiovascular readjustments to exercise. In cardiovascular hyperreactivity there is a greater sensitivity of the sympathetic system to different stressors. Objective: To determine the characteristics of cardiac autonomic control in young adults with different degrees of cardiovascular reactivity under basal conditions and during isometric exercise. Method: The sample consisted of 97 individuals of both sexes, and was divided into three groups: normoreactive, hyperreactive and with hypertensive response, according to the pressor response to weight-bearing tests. The individuals underwent a complete study of heart rate variability at rest and during isometric test. The frequency domain for the variables was: low, high, low/high resting ratio, and the parameters of Poincaré plots at rest and during exercise (values of standard deviation 1 [SD1], 2 [SD2], and the reason between them). Results: Under basal conditions, hyperreactive individuals with a hypertensive response had a sympathetic predominance over cardiac function and lower heart rate variability. During the isometric exercise SD1 and SD2 axes values decreased in all groups and SD1/SD2 ratio decreased in normoreactive individuals with hypertensive response; but it was hardly modified in those hyper-reactive. Conclusions: Individuals with cardiovascular hyperreactivity have a prior autonomic imbalance under basal conditions and a reduction of autonomic vagal modulation during exercise that may favor the development of arterial hypertension.

Respuesta autonómica cardiovascular durante la prueba isométrica cubana del peso sostenido / Cardiovascular autonomic response during the Cuban dynamic weight-bearing test

RESUMEN Introducción: La prueba del peso sostenido (PPS) es un ejercicio isométrico cubano, similar a la de handgrip, de mucha utilidad para inducir modificaciones hemodinámicas que permiten identificar la hiperreactividad cardiovascular en poblaciones de riesgo. Sin embargo, los cambios en la respuesta autonómica cardiovascular durante la PPS no se encuentran totalmente dilucidados. Objetivo: Determinar la respuesta autonómica cardiovascular durante la prueba isométrica cubana del peso sostenido. Método: Estudio cuasi-experimental (crossover) con 16 sujetos sanos, donde se evaluaron la presión arterial y la variabilidad de la frecuencia cardíaca, 5 minutos antes (reposo) y durante la PPS (2 minutos de maniobra y 3 minutos de recuperación), a través del análisis frecuencial (Fourier) y en tiempo-frecuencia (wavelet) de las bandas de altas (HF: 0,15-0,4 Hz) y bajas frecuencias (LF: 0,04-0,15 Hz), así como el análisis temporal y no-lineal (entropía de Shannon) de la serie de intervalos RR. Resultados: Aunque no existieron diferencias significativas (p>0,05) en los indicadores temporales (SDNN, RMSSD, pNN50), ni en los frecuenciales (LF, HF, LF/HF), se encontraron incrementos (p<0,05) de la presión arterial y una disminución significativa (p<0,05) de la complejidad (entropía) en la PPS con respecto al reposo, asociados con un pico en la LF y la relación LF/HF alrededor de los 2 minutos reflejados con los métodos en tiempo-frecuencia. Conclusiones: Existió un incremento dinámico en la respuesta simpática cardiovascular durante la PPS que se asocian a una disminución de la complejidad de este proceso fisiológico, lo que no es evidente con los métodos lineales tradicionales de la variabilidad de la frecuencia cardíaca.

ABSTRACT Introduction: The dynamic weight-bearing test (WBT) is a Cuban isometric exercise, similar to the hand grip test, which is very useful to induce hemodynamic modifications to identify cardiovascular hyperreactivity in at-risk populations. However, changes in the cardiovascular autonomic response during weight-bearing test are poorly understood. Objective: To determine the cardiovascular autonomic response during the Cuban dynamic WBT. Method: Quasi-experimental crossover trial with 16 healthy subjects; blood pressure and heart rate variability were assessed, 5 minutes before (rest) and during the WBT (2 minutes for maneuver and 3 minutes for recovery), through the frequency (Fourier) and time-frequency (Wavelet) analysis of high-frequency (HF: 0.15-0.4 Hz) and low-frequency (LF: 0.04-0.15 Hz) bands, as well as temporal and non-linear analysis (Shannon entropy) of the RR interval series. Results: Although temporal indicators (SDNN, RMSSD, pNN50) showed no significant differences (p>0.05) nor the frequencies (LF, HF, LF/HF); we found an increase (p<0.05) in blood pressure and a significant decrease (p<0.05) in complexity (entropy) in the WBT with respect to rest, associated with an HF peak and LF/HF ratio at nearly 2 minutes reflected with the time-frequency methods. Conclusions: There was a dynamic increase in the cardiovascular sympathetic response during the WBT associated with a decrease in the complexity of this physiological process, which is not evident with the traditional linear methods of heart rate variability.