Rapid Deceleration Research Articles

A Retrospective Cohort Study on the Clinical Characteristics of Patients with Surgical Blunt Bowel and/or Mesenteric Injuries among Motorcyclists and Car Occupants.

(1) Background: Surgical blunt bowel and/or mesenteric injuries (BBMIs) are rare but challenging for trauma surgeons. Surgical BBMI is associated with specific injury mechanisms, such as direct compression by the handlebar in motorcycle accidents or rapid acceleration and deceleration of the impact forces associated with seatbelt injuries in motor vehicle collisions. However, the discussions on the implications of BBMI and the mechanisms of road traffic accidents remain scarce. This retrospective study assessed the clinical and injury characteristics of surgically proven BBMI among motorcyclists and car occupants based on trauma-registered data obtained from a level I trauma center in Taiwan. (2) Methods: Medical data of 72 motorcyclists and 38 car occupants who had surgical BBMI between January 2009 and December 2020 were reviewed. Patient characteristics, injuries, and outcomes in both groups were compared and analyzed. (3) Results: Motorcyclists with surgical BBMI had a significantly higher Injury Severity Score (median [Q1–Q3], 18 (9–27) vs. 16 (9–18), p = 0.044) and lower Glasgow Coma Scale score (15 (11–15) vs. 15 (15–15), p = 0.034]) than car occupants. Motorcyclists with surgical BBMI had a higher incidence of pelvic fractures (18.1% vs. 2.6%, p = 0.032) and upper limb fractures (23.6% vs. 7.9%, p = 0.042) and a significantly higher rate of chest tube insertion than car occupants (29.2% vs. 10.5%, p = 0.027). However, there were no significant differences in the outcomes of morbidity and mortality between motorcyclists and car occupants with surgical BBMI. (4) Conclusions: This study demonstrated there were no significant differences in outcomes between motorcyclists and car occupants with surgical BBMI. However, motorcyclists with surgical BBMI were injured more severely, along with injuries to the head/neck and extremities, than car occupants.

Exploring the controlling mechanisms for gradient evolution in unsteady detonation flows

Proper characterization of the transient interaction between shock front motion and chemical energy release is the key for further understanding of unsteady detonation dynamics. We have shown that the gradients could be the adequate intermediate quantities to reflect the transient interaction between shock front motion and chemical energy release through the Lagrangian particle analysis of the simulated direct detonation initiation (DDI) process in H2–O2–Ar mixtures. Specifically, the “shock change equations” are verified to describe the direct relation between the shock front motion and the gradients immediately behind the shock. Moreover, given the time derivatives of shock speed, the gradient evolution in the induction zone can be reproduced by the gradient evolution equations that are deduced from the Euler equations, no matter if the shock front undergoes rapid deceleration or acceleration. While in the reaction zone where the heat release is significant, it is demonstrated that the evolutions of velocity, pressure, and their gradients can be described by the Zel'dovich–von Neumann–Döring model with a constant wave speed that is below the Chapman–Jouguet speed, no matter if the shock front undergoes rapid deceleration or acceleration. These two distinct controlling mechanisms are verified in both planar and spherical DDI processes, showing their general applicability. This work suggests a new perspective, in terms of gradient evolution, for further understanding the unsteady detonation dynamics.

Experimental and simulation study on heat transfer characteristics of aluminium alloy piston under transition conditions

In order to explore the thermal load change of the diesel engine piston under transitional conditions, and the influence of the position of cooling gallery on the heat transfer characteristics of the piston. An off-road high-pressure common-rail diesel engine is chosen as the research object. The sequence coupling method is used to establish the fluid–solid coupling heat transfer simulation model of the piston-gallery under the transition conditions of cold start, urgent acceleration and rapid deceleration. The Pareto optimization algorithm is introduced to optimize the position of the cooling gallery to reduce the maximum temperature and maximum thermal stress of the piston. The results show that the maximum temperature of the piston can be reduced by reducing the distance between the cooling gallery and the throat area under the maximum torque condition, and that the maximum thermal stress of the piston can be reduced by reducing the distance between the cooling gallery and the throat area or by increasing the distance between the cooling gallery and the ring area. Compared with the original design, the maximum temperature of Design A decreases by 1.28 °C while the maximum thermal stress decreases by 2.07 MPa. The maximum temperature and maximum thermal stress of Design B decreases by 0.22 °C and 0.5 MPa, respectively. The maximum thermal stress of Design C decreases by 2.67 MPa when the maximum temperature increases by 1.15 °C. The maximum change in temperature of the three typical designs and the original design of the piston throat under cold start, urgent acceleration and rapid deceleration conditions reached 207.29 °C, 136.78 °C and 9.89 °C, and the maximum change of thermal stress reached 8.62 MPa, 20.43 MPa, 4.08 MPa, respectively. The maximum change in temperature of the piston first ring groove under cold start, urgent acceleration and rapid deceleration conditions reached 172.00 °C, 83.52 °C and 7.36 °C, and the maximum change in thermal stress reached 22.96 MPa, 43.10 MPa, 5.72 MPa, respectively. The conclusions obtained can provide boundary conditions for further study of the thermal load change law of the same type of pistons, and also provide a theoretical basis for diesel engine piston structure optimization and the performance improvement.

Macro- and Microresearch on Swelling Characteristics and Deformation Mechanism of Red-Bed Mudstone in Central Sichuan, China

Exploring the development of multiscale behaviors of red-bed mudstone is beneficial for in-depth evaluation of swelling capacity and its progressive failure mechanism. In this paper, a macro-micro study was performed on rock samples in central Sichuan, China. The influence of environmental factors such as water content, degree of soaking, and gaseous moisture absorption was discussed. Spatial characterizations were finally described from pore structure and distribution. Experimental results suggested that deformation curve under water immersion had three stages of rapid growth, deceleration growth, and gradual stabilization. It can enter stable deformation within 60~80h and has short-term swelling effects, while gaseous moisture absorption presented long-term performance during 0~700 h. The difference in deformation between partial and complete immersion may be the release of swelling potential caused by humidity gradient and capillary suction. The strain-time curves during water immersion all tended to short-term swelling. Moreover, repeated drying and wetting promoted the time of shrinkage adjustment in the second cycle to be significantly shortened, resulting in a large amount of irreversible plastic deformation. Although initial water content influenced the final stable strain, it only changed the degree of deformation at initial stage. For the microscale structures, the closer to the end, the greater the porosity and the smaller the middle. The average porosity after 0, 1, and 2 dry and wet cycles reached 0.227%, 4.027%, and 6.121%, respectively. Geometric parameters such as volume and surface area of the pores enlarged with the increase of the number of cycles. Small pores gradually evolved into microcracks and large fissures. Besides, the pores developed from “tree-like” to “net-like” structures with continuous cycles.

Dynamic Fracture Analysis of Natural Gas Pipelines Based on a Cohesive Zone Model

Fracture research of natural gas pipelines with cracks is an important part of pipeline integrity evaluation. Based on the cohesive zone model (CZM), a numerical analysis is conducted of the dynamic fracture of X80 steel pipelines under explosion load. The factors considered include the crack propagation length, crack propagation velocity, dynamic crack tip opening angle (CTOA) and gas pressure. The results show that the whole cracking process can be divided into three stages: rapid cracking, stable propagation, and deceleration and stop cracking. When in the rapid cracking stage, the axial cracking of the pipeline is dominant. However, in the stable propagation stage, lateral expansion plays a more significant role. Besides, there exist upper limits on the length and velocity of crack propagation. In addition, it is also found that the time for the inflection point of rapid cracking and stable propagation is later than that to reach the velocity peak. The dynamic CTOA decreases with axial crack propagation, and the steady-state value of the CTOA is positively correlated with the load. The high-pressure gas escapes from the pipeline along the crack, resulting in the increase of air pressure outside the pipeline. Moreover, the peak pressure outside the pipeline is approximately linear its the initial crack length. The present research on the dynamic fracture mechanics behavior of the pipeline provides a necessary supplement for the test.

Evaluation and Management of Watercraft-Related Injuries for Acute Care Surgeons: Towards Improving Care and Implementing Effective Public Health Prevention Policies.

Boating has exposed humans to elemental hazards for centuries. What was once a lifelong craft and time-honored skillset is now, with modern technology, a popular recreational activity. Boating safety has inherent limitations and has been historically challenging to enforce. These circumstances have given way to a rising number of watercraft-associated injuries and fatalities. This review aims to investigate the diagnosis, work-up, and management of watercraft-related injuries, including blunt mechanisms, propeller wounds, water-force trauma, associated marine infections, and submersion injuries, as well as outline gaps in current public health policy on watercraft injuries, potential interventions, and available solutions. Motorboats and personal watercraft differ in size, power modality, and differential risk for injury. Accidents aboard watercraft often share commonalities with motor vehicles and motorcycles, namely: rapid deceleration, ejection, and collision with humans. The complexity of care is added by the austere environment in which many watercraft accidents occur, as well as the added morbidity of drowning and hypothermia. Wounds can also become infected by marine organisms, which require wound care and antimicrobial therapy specific to the aquatic environment in which the injury occurred. The treatment of these patients can be further exacerbated by the prolonged transportation times due to complicated water rescue. There are many measures that can prevent or abate watercraft injuries, but inconsistent regulations and enforcement may impair the success of these interventions. Further research is needed to identify possible solutions to common causes of watercraft injuries, such as inconsistent lifejacket use and bow riding.

火山灰に覆われたアスファルト路面における車両走行性について

The most famous and tallest volcano in Japan is Mt. Fuji. If the volcano erupts, volcanic ash accumulates on pavements and affects to travelling of vehicles, such as causing them to slip and get stuck. Therefore, we collected data by driving over volcanic ash spread on paved roads with a vehicle equipped with instruments that can measure the force applied to the running tires. We used three types of volcanic ash with different grain sizes and cover thickness. The experiments were conducted at constant speeds of 10 to 40 km/h and at rapid acceleration and deceleration. Data were collected not only on flat straight roads but also on curved roads with a radius of 30 m. From these data, the characteristics of rolling resistance, driving force, and side force on an ash-fall road surface can be obtained. This paper presents the driving roads on which the experiments were conducted and the effects of volcanic ash on driving by processing the tire data obtained. As the rolling resistance increases according by thickness of the volcanic ash increases, but as the driving speed increases, the rolling resistance tends to decrease.

Brazilian Jiu-Jitsu–Related Post-Concussion Symptoms Ameliorated With Neurorehabilitation

Discuss neurorehabilitation efficacy in a case of concussion without direct head impact. While there is growing concern about the prevalence and severity of concussion in mixed martial arts, a grappling component, Brazilian Jiu-Jitsu, is not typically perceived as high risk. Rapid acceleration or deceleration without direct head trauma led to a concussion for a 15-year-old male during jiu-jitsu throwing drills. The subject and parents reported difficulty with academic performance, social interactions, and emotional regulation. Symptoms persisted for 4 months before care was sought by the subject and his parents. Without direct head trauma or impact, concussion was not initially suspected. Thirteen sessions of treatment were performed in a neurorehabilitation setting utilizing joint manipulation, vestibular rehabilitation with a whole-body off-axis rotation device, oculomotor exercises, neuromuscular re-education, and electrical stimulation. C3 Logix was utilized as a baseline (immediately preceding second treatment due to equipment difficulties) and at discharge to measure effects of treatment. Data is reported as "(baseline, discharge, percent-change)." Graded Symptom Checklist score out of 162 (91, 20; -78.02%), Trail Making Test A (sec) (26.8, 19.7; -26.49%), Trail Making Test B (sec) (69.9, 37.9; -45.78%), Digit-Symbol Matching speed (# of symbols) (66, 71; +7.58%), Choice reaction time (msec) (452, 397; -12.17), Static:Dynamic Visual Acuity (line difference) (1, 0.4; -60%). Subjectively, the subject and his parents reported improved academic performance, social interactions, and emotional regulation leading to a better home and educational experience for all involved. This case displays positive clinical improvements with a functional neurology approach to outpatient neurorehabilitation. Further investigation into this multimodal rehabilitation for post-concussion symptoms, with and without direct head impact, is recommended. Continued concussion education and awareness are recommended for sports with rapid acceleration or deceleration and limited direct head impact.

Man with Motorcycle Injury

A 33-year-old man was brought in by the emergency medical services with testicular pain approximately 1 hour after a motorcycle crash. The patient described a rapid deceleration mechanism with blunt perineal trauma from the motorcycle seat. On physical examination, the patient was hemodynamically stable with only an isolated 3-cm left inferior hemiscrotal laceration with herniation of the tunica vaginalis (Figure 1). There was no blood at the meatus, and the patient was able to void urine.

Acceleration of tropical cyclones as a proxy for extratropical interactions: synoptic-scale patterns and long-term trends

Abstract. It is well known that rapid changes in tropical-cyclone motion occur during interaction with extratropical waves. While the translation speed has received much attention in the published literature, acceleration has not. Using a large data sample of Atlantic tropical cyclones, we formally examine the composite synoptic-scale patterns associated with tangential and curvature components of their acceleration. During periods of rapid tangential acceleration, the composite tropical cyclone moves poleward between an upstream trough and downstream ridge of a developing extratropical wave packet. The two systems subsequently merge in a manner that is consistent with extratropical transition. During rapid curvature acceleration, a prominent downstream ridge promotes recurvature of the tropical cyclone. In contrast, during rapid tangential deceleration or near-zero curvature acceleration, a ridge is located directly poleward of the tropical cyclone. Locally, this arrangement takes the form of a cyclone–anticyclone vortex pair. On average, the tangential acceleration peaks 18 h prior to extratropical transition, while the curvature acceleration peaks at recurvature. These findings confirm that rapid acceleration of tropical cyclones is mediated by interaction with extratropical baroclinic waves. Furthermore, the tails of the distribution of acceleration and translation speed show a robust reduction over the past 5 decades. We speculate that these trends may reflect the poleward shift and weakening of extratropical Rossby waves.

Brachiocephalic Vein Injury in a 4-Year-Old Male from Motor Vehicle Accident

<h3>Introduction and Objective</h3> We present a case of a 4-year-old male who sustained a blunt injury to the left brachiocephalic vein following a motor vehicle accident. The injury was successfully managed with non-operative therapy consisting of pressure dressing and serial exams. To our knowledge, this is the first report published of blunt trauma resulting in a brachiocephalic vein injury in a child and we present a review of management of these injuries in pediatric patients. <h3>Case Report</h3> A 4-year-old-male presented to our trauma center via ambulance following a head-on-collision in which he was a restrained passenger. The child was hemodynamically stable on arrival, conscious, and complained of left shoulder and right thigh pain. Initial exam and work up was notable for a right femur fracture, left clavicular deformity, left cervical seat belt sign with associated abrasion, and a left chest hematoma above and below the left clavicle. Computed tomography angiography (CTA) of the neck was performed and demonstrated contrast extravasation at the posterolateral aspect of the left brachiocephalic vein at the confluence of the left subclavian and left internal jugular veins. A non-displaced left clavicular fracture was also noted. No other acute traumatic injury was noted to the vasculature of the neck or chest. A pressure dressing was fashioned of layered gauze and placed above and below the clavicle and a cervical collar was then fastened to hold the pressure dressing in place. The patient was admitted to the pediatric intensive care unit and serial exams were performed overnight noting no evidence of hematoma expansion. Hemodynamics and serial hemoglobin checks remained stable during his hospitalization. Orthopedic surgery provided a sling for the left clavicle fracture and inserted an intramedullary nail to the right femur on hospital day two. The child was discharged home on hospital day five. <h3>Discussion</h3> Venous injuries are generally resolved with steady and timely pressure. However, venous injuries located in areas that are anatomically not amenable to direct pressure present a clinical dilemma. The injury in our patient was not only behind the fractured clavicle, but on the posterior aspect of the vein. We elected to apply a pressure dressing on the hematoma both above and below the clavicle, theorizing that it may provide some benefit by compressing the hematoma and providing indirect pressure, essentially recreating the normal anatomy of the retro-clavicular space around the injury. While a rare occurrence, this case highlights the very real occurrence of pediatric central venous injuries associated with rapid deceleration.

Relationship between advancing abutment pressure and deformation of surrounding rock in a roadway: a case study in Helin coal mine in China

The determination of propulsive abutment pressure and deformation characteristics of roadway surrounding rock mass in top-coal caving mining is of great significance for further research on mining stress, roadway support and equipment selection. This paper adopts the method of combining theoretical analysis and field test, taking Helin coal mine j7401 working face as the research object. The relationship between abutment support pressure and roadway surrounding rock mass deformation is revealed by monitoring the stress of transportation and ventilation roadway and observing the deformation of mining roadway. The main conclusions are as follows: when the distance between top-coal caving mining and borehole is about 65 m, the borehole stress begins to exceed the original rock stress, and the peak of the abutment pressure is 15–22 m in front of the working face, ranging from 33 to 39 MPa, which is 3.2–3.8 times the original rock stress. The intersection of propulsive abutment pressure curve and original rock stress curve is located at 8.1 m in front of the working face, the boundary of roadway rapid deformation stage and deceleration deformation stage is 8.9 m ahead of the working face, the distance between the two stages is 0.8 m, and the peak position of propulsive abutment pressure is 19.8 m. The boundary of roadway decelerative deformation stage and stationary small deformation stage is 20.1 m, and the distance between the two stages is 0.3 m. The boundary between the fracture zone and the limit equilibrium zone is the intersection of the propulsive abutment pressure curve and the original rock stress curve. The plastic zone is constituted by the damage zone and the limit equilibrium zone, and the boundary between the plastic zone and the elastic zone is located at the peak of the propulsive abutment pressure. The above study results provide a basis for roadway support and efficient coal mining.

Blunt cardiac trauma: a narrative review.

ObjectiveThis review aims to summarize the literature regarding blunt cardiac trauma (BCT), focusing on the mechanism of injury, presentations, diagnostic, and treatment approaches to provide an up-to-date perspective and to identify the areas requiring further investigation.BackgroundBCT is a relatively rare, but likely underdiagnosed, consequence of blunt chest trauma. BCT occurs in less than 10% of all trauma admissions although it is responsible for approximately 25% of traumatic deaths. BCT often occurs due to forceful impact, rapid deceleration, or crush injuries and the most common causes include motor vehicle accidents, pedestrians struck by motor vehicles, and falls from a significant height. While BCT is certainly an important condition with significant clinical implications, the current literature is limited comprised of mainly case reports. BCTs are often complex cases with various presentations, comorbid injuries, diagnostic modalities, and treatments.MethodsPubMed was searched for retrospective, prospective, randomized control trials, case report studies, and previous related reviews investigating BCT published from January 1, 1985 to February 1, 2021. Exclusion criteria included if the full length manuscript was not available and if insufficient data was provided regarding the patient outcomes or the case presented in case reports.ConclusionsA wide variety of injuries, mechanisms, presentations, and treatments are possible with BCT. Commonalities in initial investigations include a thorough history and physical exam where appropriate, lab work to evaluate patient status, and imaging to diagnose structural injuries. Treatment often begins with stabilization of the patient and rapid initiation of interventions aimed at underlying structural or rhythm abnormalities. As the current literature is limited, further study into BCT is necessary. As BCT is relatively rare and occurs sporadically at individual centers, widespread data collection from BCT patients regarding their treatment and outcomes is essential in order to collect the required data for retrospective or prospective studies. The widespread establishment of multicenter or national databases may be a solution to address the limited data in this field allowing identification of optimal treatments for BCT patients, addressing the limitations in the field of BCT, and allow the continued improvement in the outcomes of patients who experience BCT.

On the optimal spine morphology of rapidly accelerating quadrupeds

Animals exploit spine actuation during rapid locomotion, however this has only recently become a focal point in robotics. Roboticists have used a multitude of spine configurations in their platforms but the optimal design for rapid acceleration and deceleration maneuvers is yet to be discovered. In this paper, we endeavour to find this optimal spine morphology by using large-scale Monte Carlo trajectory optimization simulations on long-time-horizon minimum time problems (start and end at rest while travelling a fixed distance of 30 spine lengths). Broad applicability of the results was ensured by generating 100 sets of robot parameters at random from a carefully selected design space, comparing the performance of the rigid, revolute and prismatic spine morphology. Using bootstrapping techniques, it was determined with a 78.8% probability that the prismatic spine morphology was the optimal spine for these long-time-horizon trajectories. These results will serve as a guide for designers of future, agile quadruped robots.

Obstacle detection and tracking algorithm based on multi‐lidar fusion in urban environment

Adjacent obstacles are difficult to be distinguished, and remote obstacle is easily detected as multiple targets. Besides, occluded obstacles are difficult to track, and tracking velocity of the obstacles in rapid acceleration or deceleration converges slowly in the urban environment. In view of this, an obstacle detection and tracking method based on multi-lidar is proposed. Firstly, based on the vehicle kinematics model, motion compensation is adopted to solve the space-time synchronization problem among lidars after road segmentation, and data level fusion is completed. Next, the obstacles are detected by combining adaptive voxel grid DBSCAN (AVG-DBSCAN) algorithm and Region Growing (RG) algorithm. Then, the Breadth First Search (BFS) algorithm and KD tree are adopted to improve the Evolutionary Hungarian algorithm for the fast association of obstacles. Finally, the occlusion rate and dynamic region selection are used to track obstacles accurately, based on the Kalman Filter of uniform acceleration model. The experimental results on the authors' extracted urban dataset show that the proposed method can effectively fuse multi-lidar data and outperforms other methods in obstacle detection and tracking. Its average accuracy for detection is 97.53% and its average accuracy for tracking is 95.1%. The average duration of the entire process is only 30 ms.

Tails, Flails, and Sails: How Appendages Improve Terrestrial Maneuverability by Improving Stability.

Trade-offs in maneuverability and stability are essential in ecologically relevant situations with respect to robustness of locomotion, with multiple strategies apparent in animal model systems depending on their habitat and ecology. Free appendages such as tails and ungrounded limbs may assist in navigating this trade-off by assisting with balance, thereby increasing the acceleration that can be achieved without destabilizing the body. This comparative analysis explores the inertial mechanisms and, in some cases, fluid dynamic mechanisms by which appendages contribute to the stabilization of gait and perturbation response behaviors in a wide variety of animals. Following a broad review of examples from nature and bio-inspired robotics that illustrate the importance of appendages to the control of body orientation, two specific cases are examined through preliminary experiments: the role of arm motion in bipedal gait termination is explored using trajectory optimization, and the role of the cheetah’s tail during a deceleration maneuver is analyzed based on motion capture data. In both these examples, forward rotation of the appendage in question is found to counteract the unwanted forward pitch caused by the braking forces. It is theorized that this stabilizing action may facilitate more rapid deceleration by allowing larger or longer-acting braking forces to be applied safely.

Risk of Anterior Cruciate Ligament Injury in Female Soccer Athletes: A Review

Soccer is becoming an increasingly popular sport amongst women. Common movements during play, such as jumping and cutting, require rapid acceleration and deceleration of multiple lower-limb joints. The anterior cruciate ligament (ACL), which contributes to stabilization of the knee, is often injured during these events. ACL injury typically requires costly surgery, extended time away from sports, and jeopardizes long-term joint health. Due to sex-specific factors such as menstruation and anatomical disadvantages, women are more susceptible to tearing their ACL. Injury often occurs in non-contact scenarios during rapid acceleration or deceleration movements. Research has examined these movements and established several kinematic and kinetic mechanisms as well as muscle activation patterns that frequently occur at the time of injury, however results tend to vary based on population. This article summarizes recent and relevant literature of ACL injury mechanisms and highlights the lack of specific research in the high-risk female soccer athlete population. Due to inconclusive risk factors, injury prevention programs within this population have been inconsistent. ACL injury risk for female soccer athletes should be closer examined so that more specific injury risks can be established, and effective protective measures can be taken. Raised awareness of this need may capture attention in the research and medical communities and potentially stimulate the development of strategies that limit future ACL injury and thus the challenges it brings to the high-risk female soccer athlete.

Risk of Anterior Cruciate Ligament Injury in Female Soccer Athletes: A Review

Soccer is becoming an increasingly popular sport amongst women. Common movements during play, such as jumping and cutting, require rapid acceleration and deceleration of multiple lower-limb joints. The anterior cruciate ligament (ACL), which contributes to stabilization of the knee, is often injured during these events. ACL injury typically requires costly surgery, extended time away from sports, and jeopardizes long-term joint health. Due to sex-specific factors such as menstruation and anatomical disadvantages, women are more susceptible to tearing their ACL. Injury often occurs in non-contact scenarios during rapid acceleration or deceleration movements. Research has examined these movements and established several kinematic and kinetic mechanisms as well as muscle activation patterns that frequently occur at the time of injury, however results tend to vary based on population. This article summarizes recent and relevant literature of ACL injury mechanisms and highlights the lack of specific research in the high-risk female soccer athlete population. Due to inconclusive risk factors, injury prevention programs within this population have been inconsistent. ACL injury risk for female soccer athletes should be closer examined so that more specific injury risks can be established, and effective protective measures can be taken. Raised awareness of this need may capture attention in the research and medical communities and potentially stimulate the development of strategies that limit future ACL injury and thus the challenges it brings to the high-risk female soccer athlete.

The issues and complexities of establishing methodologies to differentiate between vertical and horizontal impact mechanisms in the analysis of skeletal trauma: An introductory femoral test

Understanding skeletal trauma characteristics is fundamental for the examination and interpretation of blunt force trauma (BFT). BFT is the most complex type of trauma to interpret based on the analysis of skeletal fractures alone, with comminuted fractures presenting additional complications to assess and interpret. Considerable variation exists within each type of BFT injury dependent on direction, magnitude of force, plus a myriad of biological/environmental factors. Given the complex processes governing the nature of BFT skeletal injuries determining whether differences between impact mechanisms and skeletal trauma can be quantified requires investigation. Aim: this study aims to determine the feasibility of quantifying outcomes between two separate loading conditions by using a formula created from transformed variables recorded from specific trauma cases involving BFT to the femur. Methodology: Displacement, comminution, and femoral midshaft area data were recorded from full body postmortem computed tomography scans of 103 individuals (males, mean age 42.5, and females, mean age 48.9) where cause of death was the result of rapid horizontal deceleration impact events (pedestrian motor vehicular accidents, n = 59) and vertical (>3-metre falls, n = 44). These measurements were standardised and transformed into a continuous variable. Independent t-tests, binary logistic regression and K Nearest- Neighbours (KNN) were used to analyse the data. Results: The standardised values showed mean group differences between falls (9.62) and pedestrian motor vehicular impacts (pedestrian MVAs) (9.53), however, these results were not statistically significant. The results indicate that similarities in variance between types of trauma outcomes and impact mechanisms demonstrate low equivalency (samples have limited differences), and the overall limitations in relying on using single elements to explain complex skeletal trauma outcomes.

A stratigraphic example of the architecture and evolution of shallow water mouth bars

AbstractImproved understanding of mouth bar morphodynamics, and the resulting stratigraphic architectures, is important for predicting the loci of deposition of different sediment fractions, coastal geomorphic change and heterogeneity in mouth bar reservoirs. Facies and architectural analysis of exceptionally well‐exposed shallow water (ca 5 m depth) mouth bars and associated distributaries, from the Xert Formation (Lower Cretaceous), of the Maestrat Basin (east‐central Spain), reveal that they grew via a succession of repeated autogenic cycles. An initial mouth bar accretion element forms after avulsion of a distributary into shallow standing water. Turbulent expansion of the fluvial jet and high bed friction results in rapid flow deceleration, and deposition of sediment in an aggradational to expansional bar‐form. Vertical bar growth causes flattening and acceleration of the jet. The accelerated flow scours channels on the bar top, which focuses further expansion of the mouth bar at individual loci where the channels break through the front of the mouth bar. Here, new mouth bar accretion elements form, downlapping and onlapping against a readily recognizable surface of mouth bar reorganization. Vertical growth of the new mouth bar accretion elements causes flattening and re‐acceleration of the jet, leading to channelization, and initiation of the next generation of mouth bar accretion elements. Thus the mouth bar grows, until bed‐friction effects cause backwater deceleration and super‐elevation of flow in the feeding distributary. Within‐channel sedimentation, choking and upstream avulsion of the feeding channel, results in mouth bar abandonment. In this study, mouth bars are formed of at least two to three accretion elements, before abandonment happened. The results of this study contrast with the notion that mouth bars form by simple vertical aggradation and radial expansion. However the architecture and facies distributions of shallow water mouth bars are a predictable product of intrinsic processes that operate to deposit them.