Mecánica y energética durante la marcha en cinta caminadora en adultos uruguayos saludables: efecto del IMC y la edad / Mechanics and energy during treadmill walking in healthy uruguayan adults: effect of BMI and age / Mecânica e energia durante a caminhada em esteira em adultos uruguaios saudáveis: efeito do IMC e Idade

La evaluación de la marcha en cinta caminadora puede resultar relevante para la toma de decisiones clínicas. No obstante, factores demográficos como la edad y el IMC pueden alterar la interpretación de los resultados. Nuestro objetivo fue obtener variables espacio- temporales, energéticas y costo de transporte durante la velocidad autoseleccionada en cinta caminadora para una muestra representativa de adultos uruguayos (n=28) y evaluar si diferentes rangos de edades e IMC pueden ser factores a tener en cuenta en pruebas clínicas donde se consideren dichas variables. Participaron 17 hombres y 11 mujeres (39,3 ± 14,8 años, 75,9 ± 12,5 kg, 1,74 ± 0,09 m, IMC 25,2 ± 4,06). Se realizó una reconstrucción 3D del movimiento en forma sincronizada con el consumo energético. Se obtuvieron valores de referencia y luego de agrupar los participantes según su IMC y rango de edad se compararon los datos mediante test de t (p≤0.05). Los resultados revelaron discrepancias significativas en las medidas espacio-temporales y energéticas de los adultos uruguayos al caminar en cinta con respecto a la literatura. La marcha difiere entre adultos jóvenes y de mediana edad en su velocidad autoseleccionada (p=0,03), longitud de zancada (p=0,01), trabajo mecánico externo (<0,001) y recuperación de energía mecánica (0,009), destacando la importancia de considerar la edad en evaluaciones clínicas. El IMC no influyó significativamente en estas variables. Estos hallazgos subrayan la necesidad de ajustar las interpretaciones de las pruebas clínicas de la marcha sobre cinta caminadora en adultos uruguayos de mediana edad (45 a 65 años).

Treadmill gait assessment can be relevant for clinical decision-making. However, demographic factors such as age and BMI may alter result interpretation. Our aim was to obtain spatiotemporal, energetic, and cost of transport variables during self-selected treadmill walking speed for a representative sample of Uruguayan adults (n=28) and to assess if different age ranges and BMI could be factors to consider in clinical tests involving these variables. Seventeen men and eleven women participated (39.3 ± 14.8 years, 75.9 ± 12.5 kg, 1.74 ± 0.09 m, BMI 25.2 ± 4.06). A synchronized 3D motion reconstruction was performed with energy consumption. Reference values were obtained and data were compared using t-tests (p≤0.05), after grouping participants by BMI and age range. Results revealed significant discrepancies in spatiotemporal and energetic measures of Uruguayan adults walking on the treadmill, compared to the literature. Gait differed between young and middle-aged adults in their self-selected speed (p=0.03), stride length (p=0.01), external mechanical work (p<0.001), and mechanical energy recovery (0.009), emphasizing the importance of considering age in clinical evaluations. BMI did not significantly influence these variables. These findings underscore the need to adjust interpretations of treadmill gait clinical tests in middle-aged Uruguayan adults (45 to 65 years).

A avaliação da marcha na esteira pode ser relevante para a tomada de decisões clínicas. No entanto, fatores demográficos como idade e IMC podem alterar a interpretação dos resultados. Nosso objetivo foi obter variáveis espaço-temporais, energéticas e custo de transporte durante a velocidade de caminhada autoselecionada na esteira para uma amostra representativa de adultos uruguaios (n = 28) e avaliar se diferentes faixas etárias e IMC podem ser fatores a serem considerados em testes clínicos que envolvam essas variáveis. Dezessete homens e onze mulheres participaram (39,3 ± 14,8 anos, 75,9 ± 12,5 kg, 1,74 ± 0,09 m, IMC 25,2 ± 4,06). Foi realizada uma reconstrução tridimensional do movimento sincronizada com o consumo de energia. Foram obtidos valores de referência e os dados foram comparados usando testes t (p≤0,05), após agrupar os participantes por IMC e faixa etária. Os resultados revelaram discrepâncias significativas nas medidas espaço-temporais e energéticas dos adultos uruguaios ao caminhar na esteira, em comparação com a literatura. A marcha diferiu entre adultos jovens e de meia-idade em sua velocidade autoselecionada (p=0,03), comprimento da passada (p=0,01), trabalho mecânico externo (<0,001) e recuperação de energia mecânica (0,009), destacando a importância de considerar a idade em avaliações clínicas. O IMC não influenciou significativamente essas variáveis. Esses achados destacam a necessidade de ajustar as interpretações dos testes clínicos de marcha na esteira em adultos uruguaios de meia- idade (45 a 65 anos).

Prevention of Argentinian flag sign in intumescent cataracts using anterior chamber air bubble and cortical fluid release techniques.

BACKGROUND: To investigate the efficiency of a new method for the prevention of argentinian flag sign during the process of continuous, circular, and centered anterior capsulotomy (CCC) on the anterior capsule in cortically liquefied intumescent cataracts. This study was registered in an appropriate registry and the registration number of registration was xyy11[2022]-XJSFX-087; The date of of registration was 2022-04-29. METHODS: Preoperative examinations including slit-lamp examination, ocular A-scan ultrasonography, and Ultrasound Biomicroscopy (UBM) UBM were conducted on 61 patients with intumescent cataracts. Cases with cortically liquefied intumescent cataracts were selected and after staining with indocyanine green, the anterior chamber air bubble technique was used to compress the anterior capsule, and liquefied cortex was aspirated using a puncture needle. Corrected Distance Visual Acuity (CDVA) and intraocular pressure were recorded on postoperative days 1, 1 week, 1 month, and 6 months. Intraoperative and postoperative complications were documented and analyzed. RESULTS: Fifty eyes were identified as having cortically liquefied intumescent cataracts. No cases of the Argentinian flag sign occurred, and standard capsulorrhexis was achieved, facilitating smooth phacoemulsification. All patients achieved satisfactory outcomes at follow-ups of 1 day, 1 week, 1 month, and 6 months postoperatively. Mild corneal edema was observed in three cases on the first postoperative day, with no other complications noted. CONCLUSIONS: The anterior chamber air bubble technique combined with cortical fluid release technique can prevent the occurrence of the Argentinian flag sign in cortically liquefied intumescent cataracts, this method is simple, convenient and economic for the clinical promotion.

Finite element analysis evaluation of hypothetical alternative treatment scenarios for neglected developmental dysplasia of the hip.

OBJECTIVE: The study aimed to evaluate three different degrees of correction in the surgical treatment of neglected developmental dysplasia of the hip (DDH) using finite element models based on computed tomography. METHOD: Three tridimensional FEA models of hypothetical post-operative (PO) outcomes were developed, based on three tridimensional CT of a pediatric patient diagnosed with luxated neglected DDH: One with the acetabular index of the contralateral hip (CLAT); another based on a theoretical Bombelli biomechanical model (BMB); and another recreating the patient's actual PO. RESULTS: The stresses in the affected hip were greater than those in the unaffected hip. CLAT showed the greatest stress and the smallest loading zone (LZ). In contrast, BMB showed the smallest stress and the biggest LZs. CONCLUSIONS: The approach based on the BMB gave the best results in terms of the distribution of the stresses over the hip, whereas the worst was CLAT. Qualitatively, estimating the stability and range of movement of the hip, the PO case was considered the best.

OBJETIVO: Evaluar tres diferentes grados de corrección en el tratamiento quirúrgico de la displasia del desarrollo de la cadera (DDH) inveterada mediante modelos de elementos finitos basados en tomografía computarizada. MÉTODO: Se desarrollaron tres modelos tridimensionales de elementos finitos de resultados posoperatorios hipotéticos, basados en tres tomografías computarizadas tridimensionales de un paciente pediátrico diagnosticado de displasia del desarrollo de la cadera luxada inveterada: uno con el índice acetabular de la cadera contralateral (CLAT), otro basado en un modelo biomecánico teórico de Bombelli (BMB) y otro recreando el posoperatorio real (PO) del paciente. RESULTADOS: Los esfuerzos en la cadera afectada fueron mayores que en la cadera no afectada. El CLAT mostró el mayor esfuerzo y la menor zona de carga. Por el contrario, el BMB mostró el menor esfuerzo y las mayores zonas de carga. CONCLUSIONES: La propuesta basada en el BMB dio los mejores resultados en cuanto a la distribución de los esfuerzos sobre la cadera, mientras que la peor fue el CLAT. Cualitativamente, estimando la estabilidad y la amplitud de movimiento de la cadera, el caso PO se consideró el mejor.

Effects of Virtual Reality on Biomechanical Parameters of Gait in Older Adults: A Systematic Review.

Objectives: To conduct a systematic review of the literature on the effect of virtual reality (VR) on biomechanical gait parameters (BGPs) in older adults. Specifically, the spatial-temporal parameters of gait, gait velocity, kinematics, and ground reaction forces, and examine how they are affected by VR interventions. To evaluate the effectiveness and validity of VR gait training and subsequently its potential integration into rehabilitation therapies. This review is a valuable contribution to the current literature as it does not limit its focus to a particular disease. By examining a wide range of studies, we sought to provide a comprehensive analysis of the effects of VR on the BGP in older adults. Our findings can inform future research on VR gait training and its potential role in rehabilitation for older adults. Data Sources: Two authors independently conducted an electronic search from August 18, 2021, to December 17, 2021, using the PubMed, Scopus, and Web of Science databases, including articles published between January 1997 and July 2021. Study Selection: The search yielded 1226 articles, and after exclusion, 16 articles were included in the analysis. Data Extraction: The Joanna Briggs Institute appraisal tool for randomized controlled trials and experimental studies, and the Cochrane risk of bias tool, version 2, were used to assess the level of evidence and bias in the studies. Data Synthesis: In our synthesis, we included data from 9 studies with a total of 217 subjects. The range of follow-up periods across these studies was 2-10 weeks, and 40% of the studies conducted the study in community-dwelling individuals. Of the randomized controlled trials, 9 had a low-risk level, whereas 1 study had moderate risk. All studies with control groups and low bias levels demonstrated a positive effect of VR intervention on the BGP in older adults. Conclusions: Consistent evidence suggests that VR intervention has positive effects on gait performance in older adults.

Acute effects of the short-foot exercise in runners with medial tibial stress syndrome: A quasi-experimental study.

OBJECTIVES: Analyze whether there are immediate changes in peak soleus activation and peak hindfoot eversion after short-foot exercise (SFE) in runners with medial tibial stress syndrome (MTSS). Secondarily, establish differences in peak soleus activation and peak hindfoot eversion between asymptomatic individuals and those presenting MTSS. DESIGN: Quasi-experimental study. SETTING: University Laboratory. PARTICIPANTS: Thirty-two runners participated: 16 with MTSS and 16 in the no-pain group (NPG). MAIN OUTCOME MEASURES: Soleus activation was measured using electromyography, and hindfoot eversion via 3D kinematic analysis. Participants performed SFE, and running data were collected at 9,12 and 15 km/h pre- and post-intervention. RESULTS: SFE reduced peak soleus activation at 9 (p = 0.017) and 15 km/h (p = 0.019) for the MTSS group and at 15 km/h (p < 0.001) for the NPG, suggesting improved neuromuscular efficiency and potentially reduced tibial stress. SFE did not significantly affect peak hindfoot eversion. Significant correlations were found between ankle dorsiflexion range of motion and muscle activation (r = 0.585 to 0.849, p < 0.05). These findings suggest SFE could improve neuromuscular efficiency and reduce tibial stress, and highlights ankle flexibility's role in muscle activation. CONCLUSIONS: SFE significantly reduces soleus activation, potentially improving neuromuscular efficiency and decreasing tibial stress.

Oblique pole-side crash assessment using the six-year-old HBM PIPER.

Side impact crashes are one of the most dangerous impact scenarios that a child can suffer. Studies by the National Highway Traffic Safety Administration (NHTSA) have shown that the head and Thorax regions are affected severely. The objective of this work is to perform a numerical evaluation of the oblique pole-side test considering the FMVSS 214-P standard to estimate the Head, Neck, and Thorax injuries for a six-year-old child positioned in the rear seat without any Child Restraint System, two configurations were performed for the oblique pole-side impact: a nearside and a far-side positioning configuration. A six-year-old Human Body Model (HBM) denominated Scalable PIPER Child Model, and the Ford Explorer 2003 were used to perform the test in the LS DYNA® software to assess the biomechanics involved in the crash scenarios. The approach considered a comparative case study with the baseline of the six-year-old child PIPER model to ensure that the positioning adjustment has not affected the mesh quality and interior components for the PIPER child model. The outcomes obtained in case 1 show that the modified PIPER child model has slight outcomes at the shoulder and pelvis zone due to the differences in the body positioning and not by the mesh or the interior interaction between the components. The outcomes obtained in case 2 reflect that the nearside setup obtained the higher measurements for the child occupant. The A c 3 m s for Head at nearside test to overcome the Side Criteria established by the Assessment Protocol Child Occupant Protection by Euro NCAP, the kinematics behavior demonstrates the importance of researching children in side crashes to enhance child security, especially in the oblique pole side impact.

Biomechanics and morphological comparisons of the caudal region of titanosaurs from the Cretaceous of Brazil: Paleobiology and paleoecology inferences.

Biomechanical studies in sauropod dinosaurs are mainly focused on neck posture and feeding strategy. Few works investigate other aspects such as tail movement and function, especially in the clade Titanosauria, the most diverse within Neosauropoda. This study applied biomechanical concepts of neutral pose (cartilaginous neutral pose) and range of motion to verify the shape and direction of the caudal region of the advanced titanosaurs Adamantisaurus mezzalirai and Baurutitan britoi, in addition to comparing it with other titanosaurs (e.g., Arrudatitan maximus, Lirainosaurus astibiae, and Trigonosaurus pricei). As a result, the tails analyzed have a sigmoidal-convex shape, probably close to the ground (but not touching it). The sigmoidal-convex shape could increase the moment arm for the M. caudofemoralis longus, making it possible to use the tail as a fifth stabilizing member. This work expands our knowledge about sauropod dinosaurs by exposing a diversity of shapes for the tails of titanosaur sauropods and brings new possibilities for how these dinosaurs could use their tails.

Understanding clinical meaningfulness when targeting the depressor anguli oris muscle (DAO) with neuromodulators: a clinical prospective interventional study.

BACKGROUND: Neuromodulator injections in the US increased by 24% from 2021 to 2022. This rise is attributed to new products and growing acceptance of minimally invasive aesthetic treatments. Recent studies emphasize the importance of facial anatomy for precision and, consequently, a higher efficacy of neuromodulator treatments. This study aims to evaluate the clinical efficacy of a novel previously proposed injection technique targeting the depressor anguli oris (DAO) muscle to improve oral commissure position. This clinical, prospective study included 34 volunteers from the Shinobu Clinic, São Paulo, Brazil. Patients received 3 units of onabotulinumtoxinA per side, injected mid-distance between the oral commissure and jawline, following the labiomandibular sulcus (LMS). Standardized photographs and assessments using the Oral Commissure Severity Scale (OCSS) and Global Aesthetic Improvement Scale (GAIS) were conducted before and 30 days post-treatment. Statistical analyses included t-tests, Wilcoxon Signed Rank test, and generalized linear models. The average increase in commissural height was 5.22% (p < 0.001). OCSS ratings improved significantly from baseline (clinician: 1.21 to 0.72, p < 0.001; patient: 0.93 to 0.69, p < 0.001). However, GAIS scores indicated no significant change (patient: 0.32, observer: 0.38; p = 0.491). The proposed injection technique improves perioral aesthetics objectively and subjectively. However, the lack of significant change in GAIS scores suggests that perceived improvements may not be clinically meaningful to patients. Future studies should focus on patient-centered evaluation methods to better assess aesthetic outcomes.

Plataforma cone morse, a melhor opção para a biomecânica e estética em próteses sobre implante: uma revisão de literatura / Conemorse platform, the best option for biomechanics and aesthetics in implant-supported prostheses: a literature review

A escolha da plataforma protética em implantodontia é fundamental para garantir o sucesso a longo prazo dos procedimentos. Todos os tipos de conexão protética apresentam vantagens e desvantagens, cabendo ao cirurgião-dentista optar pelo o que melhor se adepta ao seu caso. Uma revisão de literatura foi realizada, abrangendo estudos relevantes que compararam essas duas plataformas protéticas em termos de biomecânica e estética. Foram analisadas revisões de literatura e estudos in vitro, sob as palavras-chave "cone morse", "biomechanics", "abuptment". As pesquisas foram feitas nas bases de dados Scielo e PubMed, e os artigos escolhidos deveriam abordar a estabilidade das conexões, a preservação óssea e a estética peri-implantar. Os resultados da revisão demonstram que a plataforma Cone Morse oferece uma interface mais estável, reduz o afrouxamento de parafusos e minimiza a infiltração bacteriana. Com isso, o Cone Morse contribui para a preservação das estruturas ósseas e gengivais ao redor do implante, tornando-se uma escolha valiosa, especialmente em procedimentos de reabilitação estética.

A choice of the prosthetic platform in implant dentistry is fundamental to ensure long-term success of procedures. All types of prosthetic connections have their advantages and disadvantages, and it's up to the dentist to choose what best suits their case. A literature review was conducted, encompassing relevant studies comparing these two prosthetic platforms in terms of biomechanics and aesthetics. Literature reviews and in vitro studies were analyzed using keywords such as "Cone Morse," "biomechanics," and "abutment." The research was conducted on Scielo and PubMed databases, and the selected articles should address connection stability, bone preservation, and peri-implant aesthetics. The review results demonstrate that the Cone Morse platform offers a more stable interface, reduces screw loosening, and minimizes bacterial infiltration. As a result, Cone Morse contributes to the preservation of bone and gingival structures around the implant, making it a valuable choice, especially in aesthetic rehabilitation procedures.

Biomechanical and tomographic findings in Brown-McLean syndrome.

Purpose: Brown-McLean syndrome (BMS) is a clinical condition characterized by peripheral corneal edema with central corneal transparency. This study aims to document the tomographic and biomechanical characteristics of 3 patients with typical BMS features using the Pentacam® AXL and CORVIS ST® (Oculus Optikgeräte GmbH, Wetzlar, Germany). Observations: Three cases of BMS are presented. Case 1 involves a 26-year-old male, Case 2 a 55-year-old male, and Case 3 a 74-year-old male. The patients in Cases 1 and 3 had bilateral BMS, while the patient in Case 2 had BMS in the right eye and aphakic bullous keratopathy in the left eye. All three patients were aphakic following cataract surgery. Notably, Cases 1 and 2 were first-degree relatives (son and father), both with bilateral microspherophakia and resultant bilateral aphakia from pediatric cataract surgery. Tomographic analysis revealed a consistent increase in corneal thickness from the center to the periphery in BMS eyes, marked by an abrupt rise in the corneal thickness spatial profile (CTSP) and percentage thickness increase (PTI) curves from the thinnest point towards the periphery. There was no loss of parallel isopachs, no displacement of the thinnest point of the cornea, and no evidence of focal posterior corneal surface depression, typical signs of generalized corneal edema. Biomechanically, BMS eyes exhibited relatively normal corneal stiffness, integrated radius, Ambrósio's relational thickness to the horizontal profile (ARTh), and maximum deformation amplitude ratio at 2mm from the corneal apex (DA ratio). However, the left eye of the patient in Case 2, which had aphakic bullous keratopathy, showed altered biomechanical parameters indicative of a softer cornea with loss of rigidity. Conclusions and importance: This case series is the first to evaluate the biomechanical and tomographic features of eyes with BMS. Despite the abrupt rise in CTSP and PTI curves from the thinnest point towards the periphery, the relatively normal central corneal biomechanical indices in these BMS eyes are expected when edema is limited to the periphery. These indices become abnormal when there is progression to central corneal edema with bullous keratopathy.

Load Distribution After Serial Resection of the Posterior Horn of the Lateral Meniscus and Subsequent Meniscal Allograft Transplant: A Biomechanical Study.

BACKGROUND: Data are lacking as to when a meniscal allograft transplant (MAT) may be biomechanically superior to a partially resected lateral meniscus. HYPOTHESIS: Lateral MAT using a bone bridge technique would restore load distribution and contact pressures in the tibiofemoral joint to levels superior to those of a partial lateral meniscectomy. STUDY DESIGN: Controlled laboratory study. METHODS: Eleven fresh-frozen human cadaveric knees were evaluated in 5 lateral meniscal testing conditions (native, one-third posterior horn meniscectomy, two-thirds posterior horn meniscectomy, total meniscectomy, MAT) at 3 flexion angles (0°, 30°, and 60°) under a 1600-N axial load. Pressure sensors were used to acquire contact pressure, contact area, and peak contact pressure within the tibiofemoral joint. RESULTS: Limited (one-third and two-thirds) partial lateral posterior horn meniscectomy showed no significant increase in mean and peak contact pressures as well as no significant decrease in contact area compared with the intact state. Total meniscectomy significantly increased mean contact pressure at 0° and 30° (P = .008 and P < .001, respectively), increased peak contact pressure at 30° (P = .04), and decreased mean contact area in all flexion angles compared with the native condition (P < .01). Lateral MAT significantly improved mean contact pressure compared with total meniscectomy at 0° and 30° (P = .002 and P = .003, respectively) and increased contact area at 30° and 60° (P = .003 and P = .009, respectively), although contact area was still significantly smaller (24.1%) after MAT relative to the native meniscus (P = 0.015). However, allograft transplant did not result in better tibiofemoral contact biomechanics compared with limited partial meniscectomy (P > .05). CONCLUSION: The peripheral portion of the lateral meniscus provided the most important contribution to the distribution of contact pressure across the tibiofemoral joint in the cadaveric model. Total meniscectomy significantly increased mean and peak contact pressure in the cadaveric model and decreased contact area. Lateral MAT restored contact biomechanics close to normal but was not superior to the partially meniscectomized status. CLINICAL RELEVANCE: Surgeons should attempt to preserve a peripheral rim of the posterior lateral meniscus. Meniscal allograft transplant appears to improve but not normalize mean contact pressure and contact area relative to total lateral meniscectomy.

Metamaterial design for aortic aneurysm simulation using 3D printing.

INTRODUCTION: The use of three-dimensional (3D) printed anatomic models is steadily increasing in research and as a tool for clinical decision-making. The mechanical properties of polymers and metamaterials were investigated to evaluate their application in mimicking the biomechanics of the aortic vessel wall. METHODOLOGY: Uniaxial tensile tests were performed to determine the elastic modulus, mechanical stress, and strain of 3D printed samples. We used a combination of materials, designed to mimic biological tissues' properties, the rigid VeroTM family, and the flexible Agilus30™. Metamaterials were designed by tessellating unit cells that were used as lattice-reinforcement to tune their mechanical properties. The lattice-reinforcements were based on two groups of patterns, mainly responding to the movement between links/threads (chain and knitted) or to deformation (origami and diamond crystal). The mechanical properties of the printed materials were compared with the characteristics of healthy and aneurysmal aortas. RESULTS: Uniaxial tensile tests showed that the use of a lattice-reinforcement increased rigidity and may increase the maximum stress generated. The pattern and material of the lattice-reinforcement may increase or reduce the strain at maximum stress, which is also affected by the base material used. Printed samples showed max stress ranging from 0.39 ± 0.01 MPa to 0.88 ± 0.02 MPa, and strain at max stress ranging from 70.44 ± 0.86% to 158.21 ± 8.99%. An example of an application was created by inserting a metamaterial designed as a lattice-reinforcement on a model of the aorta to simulate an abdominal aortic aneurysm. CONCLUSION: The maximum stresses obtained with the printed models were similar to those of aortic tissue reported in the literature, despite the fact that the models did not perfectly reproduce the biological tissue behavior.

Are there differences in the kinetic parameters of the vertical jump performed by beach volleyball players on different types of sand?

Beach volleyball (BV) is an intermittent sport characterised by short-duration and highly demanding activities with low intensity periods. Establishing if players' jump ability is influenced by sand granulometry is a useful information for sport scientists, coaches and players. This study aimed to assess the possible differences in the kinetics parameters of the vertical jump on different types of sand performed by BV players. Twelve elite female players performed six countermovement jumps (CMJs) in three different surface conditions (fine sand, reference, coarse sand) in a random counterbalanced order (216 jumps). A generalised mixed model approach detected differences for CMJ model in total duration (p: 0.016), eccentric phase duration (p: 0.007), concentric phase duration (p: 0.011), time to peak power (p: < 0.001), time to peak force (p: 0.014), maximum rate force development concentric phase (p: 0.004), maximum velocity (p: 0.028) and peak power eccentric (p: 0.018). Coarse sand decreases the time spent jumping compared to fine sand, without a penalty to jump height. Coaches and athletes should take this information into account to enhance their understanding of practice strategies and game conditions. One might anticipate a faster pace in games played on coarse sand and a slower pace on fine sand.

2D Kinematic Analysis of the Esbarrada and Volta Sobre Patas Manoeuvres of Criollo Breed Horses Competing in Freio de Ouro.

The esbarrada and volta sobre patas manoeuvres are critical in Criollo horse equestrian activities, yet their kinematics remain largely unexplored. This observational study aimed to kinematically describe the manoeuvres in Criollo breed horses and explore the relationship between static goniometry and dynamics. A 2D kinematic analysis was conducted on 31 Criollo horses performing the manoeuvres using high-speed cameras. Joint angles were measured using static goniometry and analysed in relation to dynamic performance. The esbarrada covered a distance of 4.28 ± 0.99 m in 1.15 ± 0.11 s at a velocity of 3.77 ± 0.55 m/s. Joint angles showed a mean fetlock extension of 75.4° ± 5.3° and hock flexion of 43.2° ± 4.1°. In the volta sobre patas, significant differences were found in turn duration (first: 0.96 ± 0.07 s, second: 1.12 ± 0.09 s, p = 0.03) and thoracic limb suspension (first: 0.23 ± 0.02 s, second: 0.28 ± 0.03 s, p = 0.02). Static goniometry indicated that limb conformation did not significantly correlate with protraction angles during the esbarrada (p = 0.27). The volta sobre patas demonstrated prolonged duration and increased thoracic limb suspension in the second turn. Also, the findings suggest that static conformation does not predict dynamic limb movement during the esbarrada.

Experimental Analysis of Stress Shielding Effects in Screw Spacers Placed in Porcine Spinal Tissue.

Bone cortical tissues reorganize and remodel in response to tensile forces acting on them, while compressive forces cause atrophy. However, implants support most of the payload. Bones do not regenerate, and stress shielding occurs. The aim is to analyze the biomechanical behavior of a lumbar cage to study the implant's stress shielding. The ASTM E-9 standard was used with the necessary adjustments to perform compression tests on lumbar and thoracic porcine spinal vertebrae. Twelve cases were analyzed: six with the metal prosthesis and six with the PEEK implant. A mathematical model based on the Hertz contact theory is proposed to assess the stress shielding for endoprosthesis used in spine pathologies. The lumbar spacer (screw) helps to reduce the stress shielding effect due to the ACME thread. The best interspinous spacer is the PEEK screw. It does not embed in bone. The deformation capability increases by 11.5% and supports 78.6 kg more than a system without any interspinous spacer.

Is there a relationship between knee crepitus with quadriceps muscle thickness and strength in individuals with patellofemoral pain? A cross-sectional study.

OBJECTIVE: To explore the relationship between knee crepitus, quadriceps muscle thickness and isometric strength in individuals with patellofemoral pain (PFP). DESIGN: Cross-sectional. PARTICIPANTS: Individuals with PFP. MAIN OUTCOME MEASURES: Participants with PFP underwent assessments for presence, frequency and severity of knee crepitus. Real-time ultrasound images of the quadriceps muscles (rectus femoris, vastus medialis and lateralis) at rest and during contraction were obtained, muscle thickness was measured in both conditions. Maximal voluntary isometric contraction tests were performed to measure knee extensor strength. The relationship between knee crepitus and quadriceps muscle thickness and knee extensor strength was explored using logistic and linear regressions. RESULTS: Sixty individuals with PFP were included (age: 24; 60% women; 38% with crepitus). Knee crepitus severity was related to rectus femoris and vastus medialis thickness during rest (R2 = 0.19 and 0.09, respectively) and contraction (R2 = 0.16 and 0.07, respectively) and with vastus lateralis during contraction (R2 = 0.08). Isometric knee extensor strength was not related to knee crepitus presence, frequency, or severity. CONCLUSION: Higher severity of knee crepitus is related to lower quadriceps muscle thickness in individuals with PFP. There is no relationship between the presence and frequency of knee crepitus with quadriceps muscle thickness or knee extensor strength.

Mechanomyography-Based Metric Scale for Spasticity: A Pilot Descriptive Observational Study.

(1) Background: The Modified Ashworth Scale (MAS) is commonly used clinically to evaluate spasticity, but its qualitative nature introduces subjectivity. We propose a novel metric scale to quantitatively measure spasticity using mechanomyography (MMG) to mitigate these subjective effects. (2) Methods: The flexor and extensor muscles of knee and elbow joints were assessed with the Modified Ashworth Scale (MAS) during the acquisition of mechanomyography (MMG) data. The median absolute amplitude of the MMG signals was utilized as a key descriptor. An algorithm was developed to normalize the MMG signals to a universal gravitational (G) acceleration scale, aligning them with the limits and range of MAS. (3) Results: We evaluated 34 lower and upper limbs from 22 volunteers (average age 39.91 ± 13.77 years) of both genders. Polynomial regression provided the best fit (R2 = 0.987), with negligible differences (mean of 0.001 G) between the MAS and MMG. We established three numerical sets for the median, minimum, and maximum MMG(G) values corresponding to each MAS range, ensuring consistent alignment of the Modified Ashworth levels with our proposed scale. (4) Conclusions: Muscle spasticity can now be quantitatively and semi-automatically evaluated using our algorithm and instrumentation, enhancing the objectivity and reliability of spasticity assessments.

Examining the Impact of Acute Binge Alcohol Consumption on Trabecular Morphometry and Tensile Strength in Adolescent Sprague Dawley Rat Mandibles / Análisis del Impacto del Consumo Excesivo de Alcohol en la Morfometría Trabecular y la Resistencia a la Tracción en Mandíbulas de Ratas Adolescentes Sprague Dawley

SUMMARY: Underage drinking has become a major public concern having a negative impact on the growth and development of the skeleton. Peak bone mass is attained during adolescence hence the aim of the study was to investigate the effect of acute binge alcohol consumption on trabecular morphometry and tensile strength of the adolescent mandible in the Sprague Dawley (SD) rat. The study comprised of 24 SD rats, aged 7 weeks, placed into either the alcohol-exposed [n=12 (6 males and 6 female)] or pair-fed control group [n=12 (6 male and 6 female)]. The treatment of the groups was as follows; the alcohol exposed group and the pair-fed control were administered a single daily dose of 3 g/kg of 20 % alcohol 3 days a week (alternate days) for 7 days and a caloric equivalent dose of maltose dextrin via oral gavage, respectively. The animals were terminated on day 7 via pentobarbital injection. The mandibles were harvested and scanned using a Nikon XTH 255L 3D-microCT scanner (Nikon Metrology, Leuven, Belgium), and biomechanical tests were done using a Shimadzu universal tensile strength testing machine (China). Following scanning and reconstruction, the trabecular morphometry was assessed using Volume Graphics Studio® software. A 3-point bending test was used to evaluate the tensile strength of the bone. Findings from our study showed changes in some trabecular parameters in the female alcohol-exposed group, while the male groups remained unaffected. No changes in tensile strength were seen when comparing male pair-fed control and alcohol-exposed groups and when comparing female pair-fed control and alcohol-exposed groups. Trabecular and tensile strength differences were observed between the sexes when comparing male pair-fed control and alcohol-exposed groups to female pair-fed control and alcohol-exposed groups. These findings do suggest that acute binge alcohol consumption has detrimental effects on the bone micro-architecture in female alcohol-exposed rats and that differences are seen between the sexes.

El consumo de alcohol entre menores de edad se ha convertido en una importante preocupación pública que tiene un impacto negativo en el crecimiento y desarrollo del esqueleto. La masa ósea máxima se alcanza durante la adolescencia, por lo que el objetivo del estudio fue investigar el efecto del consumo excesivo de alcohol en forma aguda sobre la morfometría trabecular y la resistencia a la tracción de la mandíbula en ratas adolescente Sprague Dawley (SD). El estudio estuvo compuesto por 24 ratas, de 7 semanas de edad, colocadas en el grupo control expuesto al alcohol [n=12 (6 machos y 6 hembras)] y alimentado en parejas [n=12 (6 machos y 6 hembras)]. El tratamiento de los grupos fue el siguiente; al grupo expuesto al alcohol y al control alimentado en parejas se les administró una dosis única diaria de 3 g/kg de alcohol al 20 % 3 días a la semana (días alternos) durante 7 días y una dosis equivalente calórica de maltosa dextrina mediante sonda oral, respectivamente. Los animales fueron sacrificados el día 7 mediante inyección de pentobarbital. Las mandíbulas se recolectaron y se escanearon utilizando un escáner 3D-microCT Nikon XTH 255L (Nikon Metrology, Lovaina, Bélgica), y las pruebas biomecánicas se realizaron utilizando una máquina de prueba de resistencia a la tracción universal Shimadzu (China). Después del escaneo y la reconstrucción, la morfometría trabecular se evaluó utilizando el software Volume Graphics Studio®. Se utilizó una prueba de flexión de 3 puntos para evaluar la resistencia a la tracción del hueso. Los hallazgos de nuestro estudio mostraron cambios en algunos parámetros trabeculares en el grupo de hembras expuestas al alcohol, mientras que los grupos de machos no se vieron afectados. No se observaron cambios en la resistencia a la tracción al comparar los grupos control de machos alimentados en parejas y los grupos expuestos al alcohol y al comparar los grupos control de las hembras alimentadas en parejas y los grupos expuestos al alcohol. Se observaron diferencias trabeculares y de resistencia a la tracción entre los sexos al comparar los grupos control de los machos alimentados en parejas y expuestos al alcohol con los grupos de control de hembras alimentadas en parejas y expuestas al alcohol. Estos hallazgos sugieren que el consumo excesivo de alcohol tiene efectos perjudiciales sobre la microarquitectura ósea en ratas hembras expuestas al alcohol y que se observan diferencias entre los sexos.

Effects of Biomimetic Shoes on Healthy Young Children's Gait.

Objective To compare the spatial-temporal parameters and walking kinematics of toddlers wearing biomimetic shoes, regular shoes (daily use owned shoes), and barefoot. Methods Spatial-temporal parameters (speed, step length, and stride width), the mean vertical displacement of the center of mass (COM), knee flexion peak, and maximal foot height were analyzed. Results Children were not different in biomimetic shoes and barefoot conditions on speed, step length, and COM vertical displacement. There was no difference among conditions on stride width and foot height. The knee flexion peak was greater in shod conditions than barefoot. The regular shoes showed greater COM vertical displacement than biomimetic shoes and barefoot. Conclusion The findings showed that shoes affected the walking pattern in young children, but a shoe with a biomimetic design had a lesser effect on the walking pattern.

Pressure-Induced Stromal Keratopathy after Surface Ablation Surgery.

Introduction: The purpose of this clinical report was to describe an unprecedented case of bilateral pressure-induced stromal keratopathy (PISK) following corneal photorefractive keratectomy, associated with presumed herpetic keratitis, and to present tomographic and biomechanical findings before and after appropriate treatment. Case Presentation: A 33-year-old male patient was referred to our clinic with suspected delayed corneal epithelial healing 3 weeks after an uncomplicated PRK. A central layer of corneal opacity with a presumed fluid-filled interface area was observed upon slit lamp biomicroscopy. Scheimpflug images from the Pentacam® revealed a hyperreflective area beneath the central cornea. Scheimpflug-based corneal tomography, biomechanical assessment using the Pentacam® AXL Wave, and the Corvis ST® were conducted. Goldmann applanation tonometry measured 23/13 mm Hg, while noncontact tonometry intraocular pressure measured with the Corvis ST® (Corvis ST IOPnct) was 40.5/43.5 mm Hg. Treatment with oral valacyclovir, combined with ocular hypotensive therapy, led to a significant reduction in IOP and improved corneal deformation parameters after 1 month. Conclusion: Surgeons should be aware of the inaccuracy of Goldmann applanation tonometry in PISK, which can occur after LASIK or surface ablation.