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For a century, scientists pondered whether bird flight evolved by animals gliding down from trees or by creatures running and flapping from the ground up. A landmark 1974 paper reset the debate to focus on the evolution of the flight stroke instead. Fiftieth anniversary of an advance in understanding how flight evolved. [ABSTRACT FROM AUTHOR]

Biomech Model Mechanobiol 1-17 10 Lin CY, Mathur M, Malinowski M, Timek TA, Rausch MK (2022) The impact of thickness heterogeneity on soft tissue biomechanics: a novel measurement technique and a demonstration on heart valve tissue. This review is very timely as animal tissues have often been tested in soft tissue mechanics due to the unavailability of human tissues and it is not always clear how the obtained results relate to the properties of human tissues. [Extracted from the article]

The single-incision anterior cruciate ligament (ACL) reconstruction evidently has its shortcomings. In an attempt to improve the biomechanical but also the biological state of the knees after an ACL-reconstruction, double, even triple-bundle reconstructions have been popularised recently. As a positive side effect, details concerning ACL-insertion anatomy were brought back into the focus. In our opinion it would be more straight forward and logical to replace the non-anatomical single-incision technique with a more anatomic single-bundle ACL-reconstruction technique. [ABSTRACT FROM AUTHOR]

The article presents abstracts on medical topics including the effect of increasing posterior tibial slope on anterior cruciate ligament strain, the influence of pre-operative laxity on anterior cruciate ligament reconstruction outcomes, and the quantitative detection of the pivot shift phenomenon by simple image analysis.

A response from the author of the article "Feather structure, biomechanics and biomimetics: the incredible lightness of being" that was published in the 2014, volume 155 issue, is presented.

Wearable robots have obtained increasing research attention for the potential to provide the wearer with greater strength, higher extensibility, and handleability. Wearable extra robotic limbs (Ex-Limb) as a new type of wearable robot become a hot research issue in recent years. Ex-Limb reconstructs various advantages of robots on the wearer as an extra body part due to the potential of the intelligent robot in promoting working efficiency by automation technology. This paper defines the concept of Ex-Limb and introduces the Ex-Limb from 5 aspects including the development process, the structural design features, the performance parameters, and the application scenario, which are the main considerations of human–robot interaction based on the reported works in the past decade. This paper also systematically summarizes and underlines the current research progress based on different classifications, and mainly analyzes the key technologies including human–robot interactive adapting (HRiA), human–robot interactive perception (HRiP), human–robot interactive control (HRiC), and human–robot collaboration (HRC), thus describing the practical challenges faced by Ex-Limb and giving a prospect of the main technical aspects to be improved in future. It is concluded that human–robot integration is the base of high-level human–robot collaboration, and the interaction between the human brain and the intelligent brain of Ex-Limb would improve the capabilities of Ex-Limb to sense the wearer’s intention and collaborate with the wearer. The essence of HRC is the natural interaction process of integrating the biological system and the physical system, making the physical system become a part of the biological system. [ABSTRACT FROM AUTHOR]

Walking is a fundamental aspect of human movement, and understanding how irregular surfaces impact gait is crucial. Existing gait research often relies on laboratory settings with ideal surfaces, limiting the applicability of findings to real-world scenarios. While some irregular surface datasets exist, they are often small or lack biomechanical gait data. In this paper, we introduce a new irregular surface dataset with 134 participants walking on surfaces of varying irregularity, equipped with inertial measurement unit (IMU) sensors on the trunk and lower right limb (foot, shank, and thigh). Collected during the North American Congress on Biomechanics conference in 2022, the dataset aims to provide a valuable resource for studying biomechanical adaptations to irregular surfaces. We provide the detailed experimental protocol, as well as a technical validation in which we developed a machine learning model to predict the walking surface. The resulting model achieved an accuracy score of 95.8%, demonstrating the discriminating biomechanical characteristics of the dataset's irregular surface gait data. [ABSTRACT FROM AUTHOR]

Background: The tethered swimming (TS) is an ergometer where swimming is simulated in an ecological environment, commonly used for assessing force in water. Objective: This systematic review aims at a critical appraise of the literature on the biomechanical and physiological variables obtained from many protocols and tests assessing force–time curve in TS. Methods: We explored the databases of PubMed, EMBASE, SPORTDiscus, Web of Science, and Academic Search Premier (PROSPERO protocol CRD42020204826), and manually searched the reference papers list. Observational studies with swimming protocols and tests were included (with any follow-up and published in the full version). The following exclusion criteria would be used, but they were not necessary, as no case met these criteria. Our search was based on the adapted Downs and Black Quality Assessment Checklist. Results: In total, 55 articles were examined extensively for fitting the established inclusion criteria. Quality of the articles included ranged from 35.7 to 85.7% (65.7 ± 13.3%). Most studies addressing TS were assessed [peak = 41 and average force = 39], whereas only a very few studies referred to measures of [force impulse = 21, fatigue index = 11, force development rate = 5], and physiological variables [oxygen consumption = 10, blood lactate concentration = 8, and heart rate = 6]. The studies were carried out with durations of 10 s, 15 s, 20 s, 25 s, 30 s, 55 s, 1, 2, or 3 min, related to the duration to perform 10 and 20 complete strokes in front crawl swimming technique. Conclusion: Based on the general results of this systematic review, the impulse seems to be the most reliable measure and presented linear correlation with swimming speed. In contrast, the TS physiological responses show compatibility for the aerobic response, critical force, and maximal oxygen uptake determination. [ABSTRACT FROM AUTHOR]

This paper serves as a resource guide for Sports Engineering educators. The paper covers key topics in Sports Engineering, including ball impact, friction, safety and materials. A variety of resource types are presented to reflect modern methods of learning and searching for information, including textbooks, research and review papers, websites and videos. The field could benefit from more resources specifically designated for teaching Sports Engineering, particularly textbooks. [ABSTRACT FROM AUTHOR]

The recent sports science literature conveys a growing interest in robust statistical methods to analyze smooth, regularly-sampled functional data. This paper focuses on the inferential problem of identifying the parts of a functional domain where two population means differ. We considered four approaches recently used in sports science: interval-wise testing (IWT), statistical parametric mapping (SPM), statistical nonparametric mapping (SnPM) and the Benjamini-Hochberg (BH) procedure for false discovery control. We applied these procedures to both six representative sports science datasets, and also to systematically varied simulated datasets which replicated ten signal- and/or noise-relevant parameters that were identified in the experimental datasets. We observed generally higher IWT and BH sensitivity for five of the six experimental datasets. BH was the most sensitive procedure in simulation, but also had relatively high false positive rates (generally > 0.1) which increased sharply (> 0.3) in certain extreme simulation scenarios including highly rough data. SPM and SnPM were more sensitive than IWT in simulation except for (1) high roughness, (2) high nonstationarity, and (3) highly nonuniform smoothness. These results suggest that the optimum procedure is both signal and noise-dependent. We conclude that: (1) BH is most sensitive but also susceptible to high false positive rates, (2) IWT, SPM and SnPM appear to have relatively inconsequential differences in terms of domain identification sensitivity, except in cases of extreme signal/noise characteristics, where IWT appears to be superior at identifying a greater portion of the true signal. [ABSTRACT FROM AUTHOR]

We focus on the distances in flow direction and its vertical direction on three fish school arrangements, and correlate the fish school in uniform flow with fluid forces which can be divided into two components, drag and thrust, by three-dimensional fluid–structure interaction simulations. It is found that the distance in flow direction has larger impact on both two components than the distance in vertical to that direction. Drag and thrust are reduced and improved in fish school swimming more than single fish swimming, as the distance in flow direction becomes larger. Pressure and velocity fields that are generated around fish school favorable to propulsion under such conditions are also investigated in the present paper. [ABSTRACT FROM AUTHOR]

Inertial sensors are powerful motion measurement devices. They are well-known in vehicle guidance and enable a detailed capture of position, attitude, velocity, and acceleration. Due to modern technology, navigation systems based on these sensors became increasingly small, light, and inexpensive. So, they suggest themselves for motion analysis in sports as an arising application area. Considering the last decades, this paper outlines and discusses the introduction and typical usage of inertial and integrated navigation systems in sports and biomechanics respectively. [ABSTRACT FROM AUTHOR]

Head impact measurement devices enable opportunities to collect impact data directly from humans to study topics like concussion biomechanics, head impact exposure and its effects, and concussion risk reduction techniques in sports when paired with other relevant data. With recent advances in head impact measurement devices and cost-effective price points, more and more investigators are using them to study brain health questions. However, as the field's literature grows, the variance in study quality is apparent. This brief paper aims to provide a high-level set of key considerations for the design and analysis of head impact measurement studies that can help avoid flaws introduced by sampling biases, false data, missing data, and confounding factors. We discuss key points through four overarching themes: study design, operational management, data quality, and data analysis. [ABSTRACT FROM AUTHOR]

The actuation of traditional anthropomorphic hands is relatively complex, and there is little research on humanoid skin. In view of the above problems, this study proposed an anthropomorphic hand with biological and kinematic characteristics of the human hand, including structural skeletal parts and humanoid skin. Firstly, the overall structure and control system of the anthropomorphic hand were designed. Then, the humanoid skin was fabricated and its physical and mechanical properties were tested. Based on the overall structure of the rope-driven anthropomorphic hand, its motion characteristics were simulated and analyzed using multi-body dynamics software ADAMS/Cable. Finally, control experiment verifies the performance of the anthropomorphic hand described in this paper. The results are that the proposed anthropomorphic hand can reproduce the movement characteristics of the human hand well, and can grip objects of different shapes, different sizes and different weights stably, with a maximum grip force of 11.91 N measured. [ABSTRACT FROM AUTHOR]

Introduction: Distal femur fractures are challenging injuries historically associated with high rates of nonunion and varus collapse with operative management. As a result, clinical and research interest in dual plating (DP) of distal femur fractures has seen a dramatic increase in recent years. The purpose of this study was to systematically review the literature regarding vascular anatomy and biomechanics of distal femur fractures treated with DP constructs. Materials and methods: A systematic literature review of two medical databases (PubMed & Scopus) was performed to identify peer-reviewed studies on the anatomy and biomechanics regarding DP of distal femur fractures. A total of 1,001 papers were evaluated and 14 papers met inclusion criteria (6 anatomy and 8 biomechanics). Methodological quality scores were used to assess quality and potential bias in the included studies. Results: In the biomechanical studies, DP constructs demonstrated greater axial and rotational stiffness, as well as less displacement and fewer incidences of failure compared to all other constructs. Vascular studies showed that the femoral artery crosses the mid-shaft femur approximately 16.0–18.8 cm proximal to the adductor tubercle and it is located on average 16.6–31.1 mm from the femoral shaft at this location, suggesting that medial plate application can be achieved safely in the distal femur. The methodological quality of the included studies was good for biomechanical studies (Traa score 79.1; range 53–92.5) and excellent for anatomical studies (QUACs score 81.9; range 69.0–88.5). Conclusions: Existing biomechanics literature suggests that DP constructs are mechanically stronger than other constructs commonly used in the treatment of distal femur fractures. Furthermore, medial distal femoral anatomy allows for safe application of DP constructs, even in a minimally invasive fashion. Dual plating should be considered for patients with distal femur fractures that have risk factors for instability, varus collapse, or nonunion. [ABSTRACT FROM AUTHOR]

Amputation of a limb may have a negative impact on the psychological and physical well-being, mobility and social life of individuals with limb amputations. Participation in sports and/or regular physical activity has a positive effect on the above mentioned areas in able-bodied individuals. Data concerning participation in sports or regular physical activity together with its benefits and risks for individuals with limb amputations are scarce. No systematic review exists that addresses a wide range of outcomes such as biomechanics, cardiopulmonary function, psychology, sport participation and sport injuries. Therefore, the aim of this article is to systematically review the literature about individuals with limb amputations and sport participation. MEDLINE (PubMed), EMBASE, CINAHL® and SportDiscus® were searched without time or language restrictions using free text words and MeSH terms. The last search date was 31 March 2010. Books, internet sites and references of included papers were checked for papers relevant to the topic under review. Papers were included if the research topic concerned sports and a minimum of ten individuals with limb amputations were part of the study population. Papers were excluded if they included individuals with amputations of body parts other than upper or lower limbs or more distal than the wrist or ankle, or if they consisted of case reports, narrative reviews, books, notes or letters to the editor. Title, abstract and full-text assessments were performed by two independent observers following a list of preset criteria. Of the 3689 papers originally identified, 47 were included in the review. Most of the included studies were older than 10 years and had cross-sectional designs. Study participants were generally younger and often had more traumatic amputations than the general population of individuals with limb amputations. Heterogeneity in population characteristics, intervention types and main outcomes made data pooling impossible. In general, sports were associated with a beneficial effect on the cardiopulmonary system, psychological well-being, social reintegration and physical functioning. Younger individuals with unilateral transtibial amputations achieve better athletic performance and encounter fewer problems when participating in sports compared with older individuals with bilateral transfemoral amputations. Regardless of their amputation level, individuals with limb amputations participate in a wide range of recreational activities. The majority of them were not aware of the sport facilities in their area and were not informed about available recreational activities. Sport prosthetic devices were used mostly by competitive athletes. For football, the injury rate and pattern of the players with an amputation were similar to those of able-bodied players. Individuals with limb amputations appear to benefit both physically and psychologically from participation in sports and/or regular physical activity. Therefore, sports should be included in rehabilitation programmes, and individuals with limb amputations should be encouraged to pursue a physically active life following hospital discharge. [ABSTRACT FROM AUTHOR]

In this paper, we describe a proof-of-concept for the implementation of a wearable auditory biofeedback system based on a sensor-instrumented insole. Such a system aims to assist everyday users with static and dynamic exercises for gait rehabilitation interventions by providing auditory feedback based on plantar pressure distribution and automated classification of functional gait disorders. As ground reaction force (GRF) data are frequently used in clinical practice to quantitatively describe human motion and have been successfully used for the classification of gait patterns into clinically relevant classes, a feed-forward neural network was implemented on the firmware of the insoles to estimate the GRFs using pressure and acceleration data. The estimated GRFs approximated well the GRF measurements obtained from force plates. To distinguish between physiological gait and gait disorders, we trained and evaluated a support vector machine with labeled data from a publicly accessible dataset. The automated gait classification was then sonified for auditory feedback. The potential of the implemented auditory feedback for preventive and supportive applications in physical therapy was finally assessed with both expert and non-expert participants. A focus group revealed experts' expectations for the proposed system, while a usability study assessed the clarity of the auditory feedback to everyday users. The evaluation shows promising results regarding the usefulness of our system in this application area. [ABSTRACT FROM AUTHOR]

The larval stage is thought to play a significant role in radiations of Diptera (Insecta), but for the Cyclorrhapha (Diptera), a well-supported and diversified clade, evaluating larval roles is hindered by low taxon sampling, unresolved morphology and presumed similarity. This paper reviews investigations of the cyclorrhaphan larval head based on wider taxon sampling and functional assessment. It examines whether misunderstandings and superficial levels of analysis may have overestimated these difficulties. Functional assessment is a technique for investigating larvae and begins the process of making larvae better known as living organisms. For instance, functional assessments of larvae in the lower Cyclorrhapha helps resolve structures including the antenna and mandible whose homology is unclear. The levels of sclerotisation, alignment and fusion of head structures can predict feeding mechanisms and help turn the enigmatic cyclorrhaphan larval head into an analysable component. [ABSTRACT FROM AUTHOR]

Fundamental knowledge about in vivo kinematics and contact conditions at the articulating interfaces of total knee replacements are essential for predicting and optimizing their behavior and durability. However, the prevailing motions and contact stresses in total knee replacements cannot be precisely determined using conventional in vivo measurement methods. In silico modeling, in turn, allows for a prediction of the loads, velocities, deformations, stress, and lubrication conditions across the scales during gait. Within the scope of this paper, we therefore combine musculoskeletal modeling with tribo-contact modeling. In the first step, we compute contact forces and sliding velocities by means of inverse dynamics approach and force-dependent kinematic solver based upon experimental gait data, revealing contact forces during healthy/physiological gait of young subjects. In a second step, the derived data are employed as input data for an elastohydrodynamic model based upon the finite element method full-system approach taking into account elastic deformation, the synovial fluid's hydrodynamics as well as mixed lubrication to predict and discuss the subject-specific pressure and lubrication conditions. [ABSTRACT FROM AUTHOR]

Over the past decade, there has been a rapid increase in applications of multibody system dynamics to the predictive simulation of human movement. Using predictive "what-if" human dynamic simulations that do not rely on experimental testing or prototypes, new medical interventions and devices can be developed more quickly, cheaply, and safely. In this paper, we provide a comprehensive review of research into the predictive multibody dynamic simulation of human movements, with applications in clinical practice, medical and assistive device design, sports, and industrial ergonomics. Multibody models of human neuromusculoskeletal systems are reviewed, including models of joints, contacts, and muscle forces or torques, followed by a review of simulation approaches that use optimal control methods and a cost function to predict human movements. Modelling and optimal control software are also reviewed, and directions for future research are suggested. [ABSTRACT FROM AUTHOR]

In this paper, the material length scale parameter of the modified couple stress theory for trabecular bones is studied. For this reason, experimental data for the buckling of single wet and dry trabeculae from the subchondral region of the human medial tibial plateau are used from the literature. A material length scale parameter is extracted using the modified couple stress theory-based buckling relation and the experimental results. This parameter can capture the size-dependent behavior of trabeculae and can be beneficial for micro-mechanical investigation of trabecular bones. In addition, this paper proposes a size-dependent length scale parameter for trabeculae to estimate the buckling behaviors of dry and wet trabeculae, more accurately. Therefore, this paper confirms that the softening (weakening) effects of the modified couple stress theory and size-dependent behavior of the material length scale parameter can be considered for some special cases, and additionally, a correct value for the length scale parameter of the trabecula is revealed. [ABSTRACT FROM AUTHOR]

Background: Large and complex defects requiring reconstruction are challenging for orthopaedic surgeons. The use of human acellular dermal (HAD) matrices to augment large soft tissue defects such as those seen in massive rotator cuff tears, knee extensor mechanism failures and neglected Tendo-Achilles tears has proven to be a valuable tool in surgeons reconstructive armamentarium. Different methods for allograft decellularization and preservation alter the native properties of the scaffold. Traditional processing and preservation methods have shown to have drawbacks that preclude its widespread use. Some of the common issues include inferior biomechanical properties, the risk of rejection, limited customization, difficulty in storing and transporting, the requirement of pre-operative preparation, and last but not the least increased cost. Methods: We describe a novel processing and preservation method utilizing a two-step non-denaturing decellularization method coupled with preservation using a water-sequestering agent (glycerol) to remove immunogenic components while retaining biomechanical properties. The efficiency of this novel process was compared with the traditional freeze-drying method and verified by histological evaluation and biomechanical strength analysis. Results: The absence of cellular components and matrix integrity in hematoxylin and eosin-stained glycerol-preserved HAD (gly-HAD) samples compared to freeze-dried HAD (FD-HAD) demonstrated effective yet gentle decellularization. Biomechanical strength analysis revealed that gly-HADs are stronger with an ultimate tensile load to the failure strength of 210 N compared to FD-HAD (124N). The gly-HADs were found to have an optimal suture–retention strength of 126 N. Finally, sterility testing of the resultant grafts was checked to ensure a sterility assurance level of 10−6 to establish implantability. Conclusion: The novel processing and preservation technique is described in this paper to create a Human Acellular Dermis with higher biomechanical strength and superior histological characteristics. The processing and preservation technique ensured high sterility assurance levels to establish implantability. [ABSTRACT FROM AUTHOR]

The fallopian tube (FT) plays a crucial role in the reproductive process by providing an ideal biomechanical and biochemical environment for fertilization and early embryo development. Despite its importance, the biomechanical functions of the FT that originate from its morphological aspects, and ultrastructural aspects, as well as the mechanical properties of FT, have not been studied nor used sufficiently, which limits the understanding of fertilization, mechanotrasduction, and mechanobiology during embryo development, as well as the replication of the FT in laboratory settings for infertility treatments. This paper reviews and revives valuable information on human FT reported in medical literature in the past five decades relevant to the biomechanical aspects of FT. In this review, we summarized the current state of knowledge concerning the morphological, ultrastructural aspects, and mechanical properties of the human FT. We also investigate the potential arising from a thorough consideration of the biomechanical functions and exploring often neglected mechanical aspects. Our investigation encompasses both macroscopic measurements (such as length, diameter, and thickness) and microscopic measurements (including the height of epithelial cells, the percentage of ciliated cells, cilia structure, and ciliary beat frequency). Our primary focus has been on healthy women of reproductive age. We have examined various measurement techniques, encompassing conventional metrology, 2D histological data as well as new spatial measurement techniques such as micro-CT. [ABSTRACT FROM AUTHOR]

Weight bearing CT (WBCT) of the lower extremity is gaining momentum in evaluation of the foot/ankle and knee. A growing number of international studies use WBCT, which is promising for improving our understanding of anatomy and biomechanics during natural loading of the lower extremity. However, we believe there is risk of excessive enthusiasm for WBCT leading to premature application of the technique, before sufficiently robust protocols are in place e.g. standardised limb positioning and imaging planes, choice of anatomical landmarks and image slices used for individual measurements. Lack of standardisation could limit benefits from introducing WBCT in research and clinical practice because useful imaging information could become obscured. Measurements of bones and joints on WBCT are influenced by joint positioning and magnitude of loading, factors that need to be considered within a 3-D coordinate system. A proportion of WBCT studies examine inter- and intraobserver reproducibility for different radiological measurements in the knee or foot with reproducibility generally reported to be high. However, investigations of test–retest reproducibility are still lacking. Thus, the current ability to evaluate, e.g. the effects of surgery or structural disease progression, is questionable. This paper presents an overview of the relevant literature on WBCT in the lower extremity with an emphasis on factors that may affect measurement reproducibility in the foot/ankle and knee. We discuss the caveats of performing WBCT without consensus on imaging procedures and measurements. [ABSTRACT FROM AUTHOR]

It is important to optimise the functional recovery process to enhance patient outcomes after major injury such as anterior cruciate ligament reconstruction (ACLR). Restoring movement quality during sporting-type movements is important prior to return-to-sport (RTS) after ACLR. Alterations in movement quality during an array of functional tasks are common amongst ACLR patients at or near the time of RTS and are associated with worse outcomes after ACLR. The inability to correct movement issues prior to RTS is likely due to the use of incomplete programmes or a lack of volume and intensity of movement re-training programmes. Although most clinicians and researchers understand that re-training movement after ACLR is important (e.g., the 'why'), there is often a disconnect with understanding the 'how' and 'what' of movement re-training post ACLR. The aim of this paper was to discuss factors relevant to movement dysfunction and re-training after ACLR and provide recommendations for clinicians to restore movement quality of patients after ACLR, prior to RTS. The paper recommends: (i) considering the factors which influence the expression of movement quality, which revolve around individual (e.g., neuromuscular, biomechanical, sensorimotor and neurocognitive factors), task-specific and environmental constraints; (ii) incorporating a three-staged movement re-training approach aligned to the ACLR functional recovery process: (1) addressing the neuromuscular and biomechanical and sensorimotor control factors which affect movement quality and motor learning, (2) including a progressive movement re-training approach to re-learn an array of functional tasks optimising coordination and motor learning (3) performing the final aspect of rehabilitation and movement training on the field, in realistic environments progressively simulating the sporting movement demands and environmental constraints; and (iii) effectively designing the movement programme for optimal load management, employing effective coach and feedback techniques and utilising qualitative movement analysis for transition between exercises, stages and for RTS. [ABSTRACT FROM AUTHOR]

Smoothed particle hydrodynamics (SPH), as one of the earliest meshfree methods, has broad prospects in modeling a wide range of problems in engineering and science, including extremely large deformation problems such as explosion and high velocity impact. This paper aims to provide a comprehensive overview on the recent advances of SPH method in the fields of fluid, solid, and biomechanics. First, the theory of SPH is described, and improved algorithms of SPH with high accuracy are summarized, such as the finite particle method (FPM). Techniques used in SPH method for simulating fluid, solid and biomechanics problems are discussed. The δ-SPH method and Godunov SPH (GSPH) based on the Riemann model are described for handling instability issues in fluid dynamics. Next, the interface contact algorithm for fluid-structure interaction is also discussed. The common algorithms for improving the tensile instability and the framework of total Lagrangian SPH are examined for challenging tasks in solid mechanics. In terms of biomechanics, the governing equations and the coupling forces based on SPH method are exemplified. Then, various typical engineering applications and recent advances are elaborated. The application of fluid mainly depicts the interaction between fluid and rigid body as well as elastomer, while some complicated fluid-structure interaction ocean engineering problems are also presented. In the aspect of solid dynamics, galaxy, geotechnical mechanics, explosion and impact, and additive manufacturing are summarized. Furthermore, the recent advancements of SPH method in biomechanics, such as hemodynamically and gut health, are discussed in general. In addition, to overcome the limitations of computational efficiency and computational scale, the multiscale adaptive resolution, the parallel algorithm and the automated mesh generation are addressed. The development of SPH software in China and abroad is also summarized. Finally, the challenging task of SPH method in the future is summarized. In future research work, the establishment of multi-scale coupled SPH model and deep learning technology in solid and biodynamics will be the focus of expanding the engineering applications of SPH methods. [ABSTRACT FROM AUTHOR]

As datasets increase in size and complexity, biomechanists have turned to artificial intelligence (AI) to aid their analyses. This paper explores how explainable AI (XAI) can enhance the interpretability of biomechanics data derived from musculoskeletal simulations. We use machine learning to classify the simulated lateral pinch data as belonging to models with healthy or one of two types of surgically altered wrists. This simulation-based classification task is analogous to using biomechanical movement and force data to clinically diagnose a pathological state. The XAI describes which musculoskeletal features best explain the classifications and, in turn, the pathological states, at both the local (individual decision) level and global (entire algorithm) level. We demonstrate that these descriptions agree with assessments in the literature and additionally identify the blind spots that can be missed with traditional statistical techniques. [ABSTRACT FROM AUTHOR]

Introduction: Traumatic cervical artery dissections carry significant morbidity and mortality among blunt trauma victims. The current paper illustrates a case with a young male who presented with atlantoaxial dislocation associated with ipsilateral carotid and vertebral artery dissections complicated by middle cerebral artery (MCA) infarction. Case Report: We report a young male who presented to the emergency department with ipsilateral carotid and vertebral artery dissections complicated by middle cerebral artery (MCA) stroke associated with atlantoaxial dislocation after jumping into the water from a height. A young patient presented to us 1 year after sustaining an injury. We did posterior C1/2 fusion using the technique described by Harms and Goel to treat his atlantoaxial dislocation. The patient tolerated the surgery well and was discharged on postoperative day 4. Conclusions: We highlighted the complicated course of the simultaneously traumatic dissections of ipsilateral cervical arteries along with atlantoaxial dislocation, the biomechanics of this combination of injuries, and their management strategy. [ABSTRACT FROM AUTHOR]

Systematically review the comparison of anterior and posterior framed walker in terms of biomechanical analysis and energy expenditure and to discuss the implications for clinical practice. A systematic literature search was performed to identify studies that evaluated the gait pattern, upper extremity (UE) kinetics and kinematics and energy consumption. Outcome measures and treatment results for them were identified. 6 studies met the criteria and were included in this systematic review. Gait analysis, UE kinetics and kinematics and energy consumption were all assessed in 4 different papers. Gait parameters were comparable between walkers but declined torso tilt was found in the posterior walker group. In UE joints, two groups showed no significant difference but adaptive therapeutic posterior walker helped decrease UE burden. Most of papers prefer posterior walkers because of low oxygen cost. For better gait pattern, less UE burden and energy consumption, the adaptive therapeutic posterior walker is relatively the proper choice among all. For future studies, crossover studies or randomized controlled trails (RCTs) with larger sample size and more accurate measurement equipment may provide more persuasive evidence. Long term effects of walker users can also be investigated. [ABSTRACT FROM AUTHOR]

Measuring head impacts in sports can further our understanding of brain injury biomechanics and, hopefully, advance concussion diagnostics and prevention. Although there are many head impact sensors available, skepticism on their utility exists over concerns related to measurement error. Previous studies report mixed reliability in head impact sensor measurements, but there is no uniform approach to assessing accuracy, making comparisons between sensors and studies difficult. The objective of this paper is to introduce a two-phased approach to evaluating head impact sensor accuracy. The first phase consists of in-lab impact testing on a dummy headform at varying impact severities under loading conditions representative of each sensor's intended use. We quantify in-lab accuracy by calculating the concordance correlation coefficient (CCC) between a sensor's kinematic measurements and headform reference measurements. For sensors that performed reasonably well in the lab (CCC ≥ 0.80), we completed a second phase of evaluation on-field. Through video validation of impacts measured by sensors on athletes, we classified each sensor measurement as either true-positive and false-positive impact events and computed positive predictive value (PPV) to summarize real-world accuracy. Eight sensors were tested in phase one, but only four sensors were assessed in phase two. Sensor accuracy varied greatly. CCC from phase one ranged from 0.13 to 0.97, with an average value of 0.72. Overall, the four devices that were implemented on-field had PPV that ranged from 16.3 to 91.2%, with an average value of 60.8%. Performance in-lab was not always indicative of the device's performance on-field. The methods proposed in this paper aim to establish a comprehensive approach to the evaluation of sensors so that users can better interpret data collected from athletes. [ABSTRACT FROM AUTHOR]

This paper presents the design, fabrication and experimental characterization of an electro-thermally actuated microgripper suitable for single-cell manipulation. The analysis of the mechanical properties of cells is of great interest both in medicine and biology because the study of the cellular mechanical behaviour and resistance is necessary in these fields. Microgrippers (Bio-MEMS) have an important role in the manipulation of biological tissues and cells. In recent works, the research group simulated the mechanical behavior of grippers and the different actuation strategies. Considering the dimensional specifications and targets imposed by actuation and biocompatibility, in this paper, a microgripper based on electro-thermal actuation is studied. Starting from previous numerical results, a novel SU8 structure is designed and realized according to the micro-fabrication constraints and then the structure is simulated using the finite element method (FEM)-based thermo-structural simulations in ANSYS. Therefore, the fabrication method and steps are presented and the gripper has been developed and tested. Finally, the tip displacements of the gripper, electro-thermally actuated in different operating conditions, are compared with those obtained by means of numerical FEM simulations. A good agreement is obtained between simulations and experimental results. [ABSTRACT FROM AUTHOR]

Swallowing is a complex neuromuscular activity regulated by the autonomic nervous system. Millions of adults suffer from dysphagia (impaired or difficulty swallowing), including patients with neurological disorders, head and neck cancer, gastrointestinal diseases, and respiratory disorders. Therapeutic treatments for dysphagia include interventions by speech-language pathologists designed to improve the physiology of the swallowing mechanism by training patients to initiate swallows with sufficient frequency and during the expiratory phase of the breathing cycle. These therapeutic treatments require bulky, expensive equipment to synchronously record swallows and respirations, confined to use in clinical settings. This paper introduces a wireless, wearable technology that enables continuous, mechanoacoustic tracking of respiratory activities and swallows through movements and vibratory processes monitored at the skin surface. Validation studies in healthy adults (n = 67) and patients with dysphagia (n = 4) establish measurement equivalency to existing clinical standard equipment. Additional studies using a differential mode of operation reveal similar performance even during routine daily activities and vigorous exercise. A graphical user interface with real-time data analytics and a separate, optional wireless module support both visual and haptic forms of feedback to facilitate the treatment of patients with dysphagia. [ABSTRACT FROM AUTHOR]

Background: Running overuse injuries (ROIs) occur within a complex, partly injury-specific interplay between training loads and extrinsic and intrinsic risk factors. Biomechanical risk factors (BRFs) are related to the individual running style. While BRFs have been reviewed regarding general ROI risk, no systematic review has addressed BRFs for specific ROIs using a standardized methodology. Objective: To identify and evaluate the evidence for the most relevant BRFs for ROIs determined during running and to suggest future research directions. Design: Systematic review considering prospective and retrospective studies. (PROSPERO_ID: 236,832). Data Sources: PubMed. Connected Papers. The search was performed in February 2021. Eligibility Criteria: English language. Studies on participants whose primary sport is running addressing the risk for the seven most common ROIs and at least one kinematic, kinetic (including pressure measurements), or electromyographic BRF. A BRF needed to be identified in at least one prospective or two independent retrospective studies. BRFs needed to be determined during running. Results: Sixty-six articles fulfilled our eligibility criteria. Levels of evidence for specific ROIs ranged from conflicting to moderate evidence. Running populations and methods applied varied considerably between studies. While some BRFs appeared for several ROIs, most BRFs were specific for a particular ROI. Most BRFs derived from lower-extremity joint kinematics and kinetics were located in the frontal and transverse planes of motion. Further, plantar pressure, vertical ground reaction force loading rate and free moment-related parameters were identified as kinetic BRFs. Conclusion: This study offers a comprehensive overview of BRFs for the most common ROIs, which might serve as a starting point to develop ROI-specific risk profiles of individual runners. We identified limited evidence for most ROI-specific risk factors, highlighting the need for performing further high-quality studies in the future. However, consensus on data collection standards (including the quantification of workload and stress tolerance variables and the reporting of injuries) is warranted. [ABSTRACT FROM AUTHOR]

Finite element modeling is a precious tool for the investigation of the biomechanics of the musculoskeletal system. A key element for the development of anatomically accurate, state-of-the art finite element models is medical imaging. Indeed, the workflow for the generation of a finite element model includes steps which require the availability of medical images of the subject of interest: segmentation, which is the assignment of each voxel of the images to a specific material such as bone and cartilage, allowing for a three-dimensional reconstruction of the anatomy; meshing, which is the creation of the computational mesh necessary for the approximation of the equations describing the physics of the problem; assignment of the material properties to the various parts of the model, which can be estimated for example from quantitative computed tomography for the bone tissue and with other techniques (elastography, T1rho, and T2 mapping from magnetic resonance imaging) for soft tissues. This paper presents a brief overview of the techniques used for image segmentation, meshing, and assessing the mechanical properties of biological tissues, with focus on finite element models of the musculoskeletal system. Both consolidated methods and recent advances such as those based on artificial intelligence are described. [ABSTRACT FROM AUTHOR]

Coronary arteries have high curvatures, and hence, flow through them causes disturbed flow patterns, resulting in stenosis and atherosclerosis. This in turn decreases the myocardial flow perfusion, causing myocardial ischemia and infarction. Therefore, in order to understand the mechanisms of these phenomena caused by high curvatures and branching of coronary arteries, we have conducted elaborate hemodynamic analysis for both (i) idealized coronary arteries with geometrical parameters representing realistic curvatures and stenosis and (ii) patient-specific coronary arteries with stenoses. Firstly, in idealized coronary arteries with approximated realistic arterial geometry representative of their curvedness and stenosis, we have computed the hemodynamic parameters of pressure drop, wall shear stress (WSS) and wall pressure gradient (WPG), and their association with the geometrical parameters of curvedness and stenosis. Secondly, we have similarly determined the wall shear stress and wall pressure gradient distributions in four patient-specific curved stenotic right coronary arteries (RCAs), which were reconstructed from medical images of patients diagnosed with atherosclerosis and stenosis; our results show high WSS and WPG regions at the stenoses and inner wall of the arterial curves. This paper provides useful insights into the causative mechanisms of the high incidence of atherosclerosis in coronary arteries. It also provides guidelines for how simulation of blood flow in patient's coronary arteries and determination of the hemodynamic parameters of WSS and WPG can provide a medical assessment of the risk of development of atherosclerosis and plaque formation, leading to myocardial ischemia and infarction. The novelty of our paper is in our showing how in actual coronary arteries (based on their CT imaging) curvilinearity and narrowing complications affect the computed WSS and WPG, associated with risk of atherosclerosis. This is very important for cardiologists to be able to properly take care of their patients and provide remedial measures before coronary complications lead to myocardial infarctions and necessitate stenting or coronary bypass surgery. We want to go one step further and provide clinical application of our research work. For that, we are offering to cardiologists worldwide to carry out hemodynamic analysis of the medically imaged coronary arteries of their patients and compute the values of the hemodynamic parameters of WSS and WPG, so as to provide them an assessment of the risk of atherosclerosis for their patients. Graphical abstract Theme and aims: Coronary arteries have high curvatures, and hence flow through them causes disturbed flow patterns, resulting in stenosis and atherosclerosis. This in turn decreases the myocardial flow perfusion, causing myocardial ischemia and infarction. Therefore, in order to understand the mechanisms of these phenomena caused by high curvatures and branching of coronary arteries, we have conducted elaborate hemodynamic analysis for both (i) idealized coronary arteries with geometrical parameters representing curvatures and stenosis, and (ii) patient-specific coronary arteries with stenoses. Methods and results: Firstly, in idealized coronary arteries with approximated realistic arterial geometry representative of their curvedness and stenosis, we have computed the hemodynamic parameters of pressure drop, wall shear stress (WSS) and wall pressure gradient (WPG), and their association with the geometrical parameters of curvedness and stenosis. Then, we have determined the wall shear stress and wall pressure gradient distributions in four patient-specific curved stenotic right coronary arteries (RCAs), that were reconstructed from medical images of patients diagnosed with atherosclerosis and stenosis, as illustrated in Figure 1, in which the locations of the stenoses are highlighted by arrows. Figure 1: Three-dimensional CT visualization of arteries in patients with suspected coronary disease. The arteries can be seen as a combination of various curved segments with stenoses at unspecific locations highlighted by arrows. Our results show high WSS and WPG regions at the stenoses and inner wall of the arterial curves, as depicted in Figure 2. Therein, the encapsulations show (i) high WSS, and (ii) high WPG regions at the stenosis and inner wall of the arterial curves. Figure 2: WSS and WPG surface plot of realistic arteries (a), (b), (c) and (d), wherein the small squared parts are enlarged to show the detailed localized contour plots at the stenotic regions. Therein, the circular encapsulations show (i) high WSS and (ii) high WPG regions at the stenosis and inner wall of the arterial curves. Conclusion and novelty: This paper provides useful insights into the causative mechanisms of the high incidence of atherosclerosis in coronary arteries. It also provides guidelines for how simulation of blood flow in patient coronary arteries and determination of the hemodynamic parameters of WSS and WPG can provide a medical assessment of the risk of development of atherosclerosis and plaque formation, leading to myocardial ischemia and infarction. The novelty of our paper is our showing how in actual coronary arteries (based on their CT imaging), curvilinearity and narrowing complications affect the computed WSS and WPG associated with risk of atherosclerosis. This is very important for cardiologists to be able to properly take care of their patients and provide remedial measures before coronary complications lead to myocardial infarctions and necessitate stenting or coronary bypass surgery. [ABSTRACT FROM AUTHOR]

The anterolateral ligament (ALL) was first described in 1879 in the context of Segond fractures, which correlate with a 75–100% chance of an anterior cruciate ligament (ACL) tear or a 66–75% chance of a meniscal tear. The purpose of this paper is to provide an updated comprehensive review on the anterolateral ligament complex of the knee focusing on the: (1) anatomy of the ALL/ALC; (2) associated biomechanics/function; and (3) important surgical considerations in contemporary anterior cruciate ligament (ACL) reconstruction and total knee arthroplasty (TKA). A systematic review of studies on ALL was conducted on Pubmed/MEDLINE and Cochrane databases (May 7th, 2020 to February 1st, 2022), with 20 studies meeting inclusion/exclusion criteria. Studies meeting inclusion criteria were anatomical/biomechanical studies assessing ALL function, cadaveric and computer simulations, and comparative studies on surgical outcomes of ALLR (concomitant with ACL reconstruction). Eight studies were included and graded by MINOR and Newcastle–Ottawa scale to identify potential biases. The anatomy of the ALL is part of the anterolateral ligament complex (ALC), which includes the superficial/deep iliotibial band (including the Kaplan fiber system), iliopatellar band, ALL, and anterolateral capsule. Multiple biomechanical studies have characterized the ALC as a secondary passive stabilizer in resisting tibial internal rotation. Given the role of the ALC in resisting internal tibial rotation, lateral extra-articular procedures including ALL augmentation may be considered for chronic ACL tears, ACL revisions, and a high-grade pivot shift test. In the context of TKA, in the event of injury to the ALC, a more constrained implant or soft-tissue reconstruction may be necessary to restore appropriate knee stability. [ABSTRACT FROM AUTHOR]

At what inclination does climbing begin? In this paper, we investigate the transition from walking to climbing in two species of parrot (Agapornis roseicollis and Nymphicus hollandicus) that are known to incorporate both their tail and their craniocervical system into the gait cycle during vertical climbing. Locomotor behaviors ranging in inclination were observed at angles between 0° and 90° for A. roseicollis, and 45°–85° degrees for N. hollandicus. Use of the tail in both species was observed at 45° inclination, and was joined at higher inclinations (> 65°) by use of the craniocervical system. Additionally, as inclination approached (but remained below) 90°, locomotor speeds were reduced while gaits were characterized by higher duty factors and lower stride frequency. These gait changes are consistent with those thought to increase stability. At 90°, A. roseicollis significantly increased its stride length, resulting in higher overall locomotor speed. Collectively these data demonstrate that the transition between horizontal walking and vertical climbing is gradual, incrementally altering several components of gait as inclinations increase. Such data underscore the need for further investigation into how exactly "climbing" is defined and the specific locomotor characteristics that differentiate this behavior from level walking. [ABSTRACT FROM AUTHOR]

In this paper, we present a biomechanical analysis of the upper body, which includes upper-limb, neck and trunk, during the execution of overhead industrial tasks. The analysis is based on multiple performance metrics obtained from a biomechanical analysis of the worker during the execution of a specific task, i.e. an overhead drilling task, performed at different working heights. The analysis enables a full description of human movement and internal load state during the execution of the task, thought the evaluation of joint angles, joint torques and muscle activations. A digital human model is used to simulate and replicate the worker's task in a virtual environment. The experiments were conduced in laboratory setting, where four subjects, with different anthropometric characteristics, have performed 48 drilling tasks in two different working heights defined as low configuration and middle configuration. The results of analysis have impact on providing the best configuration of the worker within the industrial workplace and/or providing guidelines for developing assistance devices which can reduce the physical overloading acting on the worker's body. [ABSTRACT FROM AUTHOR]

The affine transformation hypothesis is usually adopted in order to link the tissue scale with the fibers scale in structural constitutive models of fibrous tissues. Thanks to the recent advances in imaging techniques, such as multiphoton microscopy, the microstructural behavior and kinematics of fibrous tissues can now be monitored at different stretching within the same sample. Therefore, the validity of the affine hypothesis can be investigated. In this paper, the fiber reorientation predicted by the affine assumption is compared to experimental data obtained during mechanical tests on skin and liver capsule coupled with microstructural imaging using multiphoton microscopy. The values of local strains and the collagen fibers orientation measured at increasing loading levels are used to compute a theoretical estimation of the affine reorientation of collagen fibers. The experimentally measured reorientation of collagen fibers during loading could not be successfully reproduced with this simple affine model. It suggests that other phenomena occur in the stretching process of planar fibrous connective tissues, which should be included in structural constitutive modeling approaches. [ABSTRACT FROM AUTHOR]

Background: Several disc disease nomenclatures and approaches for LDH exist. The traditional midline bone-destructive procedures together with approaches requiring extreme muscular retraction are being replaced by muscle sparing, targeted, stability-preserving surgical routes. The increasing speculation on LDHs and the innovative corridors described to treat them have lead to an extensive production of papers frequently treating the same topic but adopting different terminologies and reporting contradictory results. Methods: The review of such literature somehow confounding gave us the chance to regroup by surgical corridors the vast amount of approaches for LDH differently renamed over time. Likewise, LDHs were simplified in intra-foraminal (ILDH), extra-foraminal (ELDH), and intra−/extra-foraminal (IELDH) in relation to precise anatomical boundaries and extent of bulging disc. Results: Through the analysis of the papers, it was possible to identify ideal surgical corridors for ILDHs, ELDHs, and IELDHs, distinguishing for each approach the exposure provided and the technical advantages/disadvantages in terms of muscle trauma, biomechanical stability, and nerve root preservation. A significant disproportion was noted between studies discussing traditional midline approaches or variants of the posterolateral route and those investigating pros and cons of simple or combined alternative corridors. Although rarely discussed, these latter represent valuable strategies particularly for the challenging IELDHs, thanks to the optimal compromise between herniation exposure and bone-muscle preservation. Conclusions: The integration of adequate mastery of traditional approaches together with a greater confidence through unfamiliar surgical corridors can improve the development of combined mini-invasive procedures, which seem promising for future targeted LDH excisions. [ABSTRACT FROM AUTHOR]

Sub-segmental analysis of excitation source may contain significant speaker-specific information pertaining to speaker verification. In this paper, the excitation source feature has been explored for design of speaker verification system (SVS). The baseline of the system is extraction of speaker-specific information from LP-residual features by modelling the speakers through different supervised and unsupervised models, based on which they will be accepted or rejected. Direct LP-residual (DLR) as well as DCT coefficients of LP-residual (DCTLR) are approximated as the excitation source features for the system. The models are processed in two different level of analysis, namely, sentence level analysis as well as voice-segment level approach (VSLA), with the variations in the frame size of the input. Effects of the change of frame size in the input vectors are observed. Studies are carried over telephonic database collected in practical environment. A comparative analysis has been presented for the combination of models, features and the two levels of analysis for the given data. The experimental study suggests that application of VSLA on unsupervised models with DCTLR as input, provides a performance which is 14.21 % better than sentence level analysis of the models. [ABSTRACT FROM AUTHOR]

The maternal vasculature undergoes tremendous growth and remodeling (G&R) that enables a > 15-fold increase in blood flow through the uterine vasculature from conception to term. Hemodynamic metrics (e.g., uterine artery pulsatility index, UA-PI) are useful for the prognosis of pregnancy complications; however, improved characterization of the maternal hemodynamics is necessary to improve prognosis. The goal of this paper is to develop a mathematical framework to characterize maternal vascular G&R and hemodynamics in uncomplicated human pregnancies. A validated 1D model of the human vascular tree from the literature was adapted and inlet blood flow waveforms at the ascending aorta at 4 week increments from 0 to 40 weeks of gestation were prescribed. Peripheral resistances of each terminal vessel were adjusted to achieve target flow rates and mean arterial pressure at each gestational age. Vessel growth was governed by wall shear stress (and axial lengthening in uterine vessels), and changes in vessel distensibility were related to vessel growth. Uterine artery velocity waveforms generated from this model closely resembled ultrasound results from the literature. The literature UA-PI values changed significantly across gestation, increasing in the first month of gestation, then dramatically decreasing from 4 to 20 weeks. Our results captured well the time-course of vessel geometry, material properties, and UA-PI. This 1D fluid-G&R model captured the salient hemodynamic features across a broad range of clinical reports and across gestation for uncomplicated human pregnancy. While results capture available data well, this study highlights significant gaps in available data required to better understand vascular remodeling in pregnancy. [ABSTRACT FROM AUTHOR]

Several approaches are currently employed to address the predictive simulation of human motion, having in common their high computational demand. Muscle modeling seems to be an essential ingredient to provide human likeness to the obtained movements, at least for some activities, but it increases even more the computational load. This paper studies the efficiency and accuracy yielded by several alternatives of muscle modeling in the forward-dynamics analysis of captured motions, as a method that encompasses the computationally intensive character of predictive simulation algorithms with a known resulting motion which simplifies the comparisons. Four muscle models, the number of muscles, muscle torque generators, muscular synergies, and look-up tables for musculotendon lengths and moment arms are considered and analyzed, seeking to provide criteria on how to include the muscular component in human multibody models so that its effect on the resulting motion is captured while keeping a reasonable computational cost. Gait and vertical jump are considered as examples of slow- and fast-dynamics motions. Results suggest that: (i) the rigid-tendon model with activation dynamics offers a good balance between accuracy and efficiency, especially for short-tendon muscles; (ii) including muscles in the model leads to a decrease in efficiency which is highly dependent on the muscle model employed and the number of muscles considered; (iii) muscle torque generators keep the efficiency of skeletal models; (iv) muscular synergies offer almost no advantage for this problem; and (v) look-up tables for configuration-dependent kinematic magnitudes have a non-negligible impact on the efficiency, especially for simplified muscle models. [ABSTRACT FROM AUTHOR]

During physiological or 'natural' childbirth, the fetal head follows a distinct motion pattern—often referred to as the cardinal movements or 'mechanisms' of childbirth—due to the biomechanical interaction between the fetus and maternal pelvic anatomy. The research presented in this paper introduces a virtual reality-based simulation of physiological childbirth. The underpinning science is based on two numerical algorithms including the total Lagrangian explicit dynamics method to calculate soft tissue deformation and the partial Dirichlet–Neumann contact method to calculate the mechanical contact interaction between the fetal head and maternal pelvic anatomy. The paper describes the underlying mathematics and algorithms of the solution and their combination into a computer-based implementation. The experimental section covers first a number of validation experiments on simple contact mechanical problems which is followed by the main experiment of running a virtual reality childbirth. Realistic mesh models of the fetus, bony pelvis and pelvic floor muscles were subjected to the intra-uterine expulsion forces which aim to propel the virtual fetus through the virtual birth canal. Following a series of simulations, taking variations in the shape and size of the geometric models into account, we consistently observed the cardinal movements in the simulator just as they happen in physiological childbirth. The results confirm the potential of the simulator as a predictive tool for problematic childbirths subject to patient-specific adaptations. [ABSTRACT FROM AUTHOR]

The paper deals with an investigation on the role of interactive sculpting and radial basis function (RBF) mesh morphing in the field of biomechanical computer-aided simulations. In this context, mesh morphing can be effectively used in predictive medicine workflows where a patient-specific numerical model is taken as reference to understand the physics of interest by means of simulation-driven techniques. The proposed methodology is intended for addressing the interactive geometry modification in combination with a force-feedback device and it is applied to anatomical structures. The concept is demonstrated showing a fast remodelling workflow of the human femur. The interactive process allows to steer the morphing of a template FEA model onto the patient geometry by positioning a set of landmark points. A first morphing action allows to warp the solid model according to the RBF deformation field produced by landmarks, a final projection on the target surface is performed to complete the task. The approach proven to be quick, effective and ergonomic thanks to the haptic device and the high level of interactivity. New patient specific CAE models are generated in a very short time preserving the very good quality of the computational mesh. [ABSTRACT FROM AUTHOR]

Adolescent cricket pace bowlers are prone to non-contact shoulder, low back and lower-limb injuries. Exercise-based injury prevention programmes (IPPs) are effective for reducing non-contact injuries in athletes; however, a specific programme for adolescent pace bowlers has not been published. This paper therefore seeks to provide a rationale for the development of an exercise-based IPP specific for adolescent pace bowlers. It also outlines design principles and provides an example exercise programme that can be implemented at the community level. In addition, the paper addresses other injury prevention techniques concerned with the prescription of appropriate bowling loads and the modification of poor bowling biomechanics. Performing an exercise-based IPP before cricket training could reduce injury rates in adolescent pace bowlers. Eccentric strengthening exercises can be employed to target injuries to the posterior shoulder muscles, hip adductors and hamstring muscles. The risk of low back, knee and ankle injury could also be reduced with the inclusion of dynamic neuromuscular control exercises and trunk extensor endurance exercises. Other prevention strategies that need to be considered include the modification of poor bowling biomechanics, such as shoulder counter-rotation and lateral trunk flexion. Coaches and players should also aim to quantify bowling load accurately and coaches should use this information to prescribe appropriate individualised bowling loads. Specifically, players would benefit from avoiding both long periods of low load and acute periods when load is excessively high. Future evidence is needed to determine the effectiveness of the example programme outlined in this paper. It would also be beneficial to investigate whether the modification of bowling biomechanics is achievable at the non-elite level and if bowling load can be accurately measured and manipulated within a community-level population. [ABSTRACT FROM AUTHOR]

Biomechanics is a young field that entails the study of the mechanical aspects of the life and health sciences. The growth of this field can be attributed to the growth of cutting-edge technologies that enable scientists to investigate the mechanics of life with increasing acuity. Founded in 1961, the journal Experimental Mechanics (EM) has had an important role in the growth and scholarship of the field of biomechanics. From the mid-1960’s to mid-1970’s, relevant publications in EM focused on characterizing potential bioimplants and exploring the mechanical properties of connective tissues. The next two decades witnessed a clear drop in biomechanics papers in EM, perhaps due to the rise of biomechanics-specific societies and journals that offered a more dedicated audience while EM sought a more varied readership. More recently, there has been a resurgence of biomechanics publications in EM, including 3 recent special issues devoted to the subject. The journal has brought forth an impressive range of biomechanics related papers including cellular and nanoscale studies, characterization of biological tissues and novel biomaterials, and most importantly, the development of novel technologies and devices that are applicable across the entire field. Digital image correlation and digital volume correlation are examples of techniques presented in EM that have been applied to numerous biomechanics problems. Although the field has exhibited exponential growth in the past 15 years, a myriad of scientific questions, especially on the cellular and subcellular level, remain to be answered. EM should cultivate its future role in shaping this exciting field. [ABSTRACT FROM AUTHOR]

Background: Patellar tendinopathy (PT) is common and debilitating for jumping athletes. Intriguingly, despite its high prevalence and many research studies, a causal explanation for PT presence remains elusive. Objective: Our objective was to investigate whether landing biomechanics among jumping athletes are associated with PT and can predict onset. Methods: We conducted a systematic review with evidence gap map and meta-analysis. We searched three databases from inception to May 2021 for observational studies or trials evaluating landing biomechanics in jumping athletes with PT (JPTs). We assessed quality with a modified Downs and Black checklist, risk of bias with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool, and evidence levels with van Tulder's criteria and provided an evidence gap map. Results: One prospective cohort (moderate quality), one cross-sectional cohort (moderate quality), and 14 case–control (four high-, seven moderate-, and three low-quality) studies, including 104 JPTs, 14 with previous PT, 45 with asymptomatic patellar tendon abnormality (PTA), and 190 controls were retained. All studies had a high risk of bias. Meta-analysis showed an association between lower ankle dorsiflexion and the presence of tendinopathy during drop and spike landings, and JPTs had reduced knee joint power and work during volleyball approach or drop landings (moderate evidence). Limited evidence suggested that JPTs had lower patellar tendon loads during drop landings. Strong or moderate evidence showed no relation between PT and sagittal plane peak knee and hip angles or range of motion; hip, knee, or ankle angles at initial contact (IC); knee angular velocities, peak trunk kinematics, or trunk angles at IC; sagittal plane hip, knee, or ankle moments; and peak vertical ground reaction force (vGRF) and vGRF impulse. Identified gaps were that no study simultaneously investigated athletes with previous PT, current PT, and PTA, and studies of joint angular velocities at IC, ankle and hip angular velocities after touchdown, leg stiffness, loading rate of forces, and muscle activation are lacking. Conclusion: Despite the voluminous literature, large number of participants, multitude of investigated parameters, and consistent research focus on landing biomechanics, only a few associations can be identified, such as reduced ankle dorsiflexion–plantarflexion range. Further, the quality of the existing literature is inadequate to draw strong conclusions, with only four high-quality papers being found. We were unable to determine biomechanical factors that predicted PT onset, as longitudinal/prospective studies enabling causal inference are absent. The identified gaps indicate useful areas in which to explore causal relationships to inform intervention development. Therefore, high-quality prospective studies are essential to definitively determine whether landing biomechanics play a part in the development, recurrence, or management of PT and represent a potential therapeutic or preventive target alongside non-biomechanical factors. [ABSTRACT FROM AUTHOR]