Biomechanical Aspects Research Articles

Epidemiology of Injuries in National Collegiate Athletic Association Women's Gymnastics: 2014-2015 Through 2018-2019.

Women's gymnastics athletes in the National Collegiate Athletic Association (NCAA) constitute a unique population of NCAA athletes given the nature and dynamics of the sport. Routine examination of women's gymnastics injuries is important for identifying the evolving burden of injuries in this sport. Exposure and injury data collected in the NCAA Injury Surveillance Program during 2014-2015 through 2018-2019 were analyzed. Injury counts, rates, and proportions were used to describe injury characteristics; injury rate ratios were used to examine differential injury rates. The overall injury rate was 8.00 per 1000 athlete-exposures; injury incidence was greater in competitions than in practices (injury rate ratio = 1.84; 95% CI = 1.48, 2.29), though practice injury rates increased during 2015-2016 through 2018-2019. Most injuries were classified as strains (16.5%), sprains (16.4%), and inflammatory conditions (12.3%), with overuse injuries prevalent among practice injuries (22.5%). Concussions (8.4%) were the most commonly reported specific injury. The increasing trend in practice injury incidence is noteworthy although competition injury rates were higher overall. Findings also suggest that the etiologies of overuse injuries and inflammatory conditions as well as the biomechanical aspects of concussions warrant further attention.

Early Deformation of Deep Brain Stimulation Electrodes Following Surgical Implantation: Intracranial, Brain, and Electrode Mechanics.

IntroductionAlthough deep brain stimulation is nowadays performed worldwide, the biomechanical aspects of electrode implantation received little attention, mainly as physicians focused on the medical aspects, such as the optimal indication of the surgical procedure, the positive and adverse effects, and the long-term follow-up. We aimed to describe electrode deformations and brain shift immediately after implantation, as it may highlight our comprehension of intracranial and intracerebral mechanics.Materials and MethodsSixty electrodes of 30 patients suffering from severe symptoms of Parkinson’s disease and essential tremor were studied. They consisted of 30 non-directional electrodes and 30 directional electrodes, implanted 42 times in the subthalamus and 18 times in the ventrolateral thalamus. We computed the x (transversal), y (anteroposterior), z (depth), torsion, and curvature deformations, along the electrodes from the entrance point in the braincase. The electrodes were modelized from the immediate postoperative CT scan using automatic voxel thresholding segmentation, manual subtraction of artifacts, and automatic skeletonization. The deformation parameters were computed from the curve of electrodes using a third-order polynomial regression. We studied these deformations according to the type of electrodes, the clinical parameters, the surgical-related accuracy, the brain shift, the hemisphere and three tissue layers, the gyration layer, the white matter stem layer, and the deep brain layer (type I error set at 5%).ResultsWe found that the implanted first hemisphere coupled to the brain shift and the stiffness of the type of electrode impacted on the electrode deformations. The deformations were also different according to the tissue layers, to the electrode type, and to the first-hemisphere-brain-shift effect.ConclusionOur findings provide information on the intracranial and brain biomechanics and should help further developments on intracerebral electrode design and surgical issues.

Comparison of Parametric Indices of Anthropometric and Biomechanical Characteristics of Female Basketball Players, Volleyball Players and Handball Players

Objective: This study aimed to Compare parametric indices of anthropometric and biomechanical characteristics of female basketball, volleyball, and handball players. Methods: This research is purposive comparative-descriptive study. A total of 100 female students (35 handball players, 37 volleyball players, and 28 basketball players) participated in this study. The normality of the data distribution was examined using the Kolmogorov-Smirnov test. The Mean±SD and percentage rank to describe the information, multiple correlation coefficient to reduce the overlapping data, and analysis of the main components of the data to determine the leading indicators of anthropometric and biomechanical characteristics of female handball, volleyball, and basketball players and ANOVA was used to compare the corresponding leading indices in different age groups. Results: Ten parameters for female handball and volleyball players and nine parameters for female basketball players were highlighted as the leading indicators. Head width, leg length, ankle width, scapular fat for basketball and handball players, biceps and weight for handball and volleyball players, abdominal fat, leg length for volleyball and basketball players, and height introduced as the leading common indicators among all groups of players. The results related to the variance extracted in each of the main components of anthropometric features after rotation showed that the main parameters related to anthropometric characteristics in female handball players are: height, weight, knee-to-ground height, head width, Head circumference, waist circumference, leg length, ankle width, scapular fat, and biceps fat; in female volleyball players are: height, weight, trunk width at the navel, sitting pelvis width, elbow circumference, knee circumference, foot arc circumference, leg length, biceps fat, triceps fat; in female basketball players are: height, elbow circumference, head width, trunk circumference at chest level, trunk circumference at navel level, leg length, ankle width, scapular fat, and abdominal fat; and in players of the three groups of athletes are: height, knee-to-ground height, elbow circumference, head circumference, waist circumference, trunk circumference at chest level, scapular fat and maximum forearm circumference. Conclusion: The height is the leading standard index between different female handball, volleyball, and basketball players. Most of the anthropometric characteristics are various, related to the type of sport. Also, the biomechanical characteristics vary according to the unique skills in each discipline. In some sports, the biomechanical factors vary due to the features of the common sport and the design of specific training programs. Every sport needs to evaluate and study the anthropometric and biomechanical aspects of individuals.

Literature review on hydrostatic vaginal and anorectal injuries caused by personal watercraft

IntroductionThe use of personal watercrafts (PWCs) has increased in popularity, size and engine power over time. Hydrostatic injuries when the passenger falls into water and the pelvic floor is directly hurt by the water jet remain rarely reported in literature but potentially lethal. Perineal, gynaecological and rectosigmoid regions present significant points of anatomical weakness to the force vector of the water. Biomechanical aspects on water-associated injuries on PWC may include disruption of the perineal soft tissues, inefficient anal sphincter and hydrodynamic insufflation.MethodsThis is a study involving a literature review from 1972 to 2020 using suitable search terms to identify all hydrostatic PWC injuries following PRISMA guidelines. Data were extracted from suitable articles on mechanism of injury, injuries sustained, treatment and outcomes.ResultsThirty-two patients with major perineal, gynaecological and/or digestive injuries due to hydrostatic PWC traumas were identified. Major risk factors were female gender (84.4%), young age (25.5 years), being a rear passenger and wearing a standard swimsuit (100%). The injuries were digestive tract only (81.3%), gynaecological only (46.9%) or combined (28.1%). The interdisciplinary surgical management must include a vaginal and anal exploration under general anaesthesia and an exploratory surgery. Vaginal repair (41.9%) may be associated with a transanal anorectal suturing for lacerations of the intraperitoneal rectum (40.6%). A defunctioning stoma was performed in 62.5% and consisted of a loop sigmoidostomy (43.5%) or Hartmann’s procedure (34.8%) depending on laceration complexity.ConclusionsPWC-related hydrostatic injuries are still rare but associated with a mortality rate of 6.3% which rises to 25% if initial haemodynamic instability was present. Expert guidelines such as adding an automated engine shut-off switch for the rear passenger and wearing a protective and safety clothing should be more widely respected.

Effects of Cyanoacrylate in Rabbits with Induced Achilles Tendon Rupture.

BackgroundIn this study, we aimed to investigate the effects of N-butyl-2-cyanoacrylate (cyanoacrylate) on the biomechanical and histopathological aspects of tendon healing in a rabbit model of Achilles tendon injury.Material/MethodsIn total, 36 rabbits were randomized to experimental (cyanoacrylate) and control groups (n=36 tendons in each group). A simple suture was used in the control group and a simple suture plus cyanoacrylate was used in the experimental group.Nine rabbits from each group were euthanized at week 4 and week 6 after surgery for histopathological and biomechanical testing.ResultsGranulation tissue formation was significantly greater in the experimental group in week 4 and week 6 than in the control group. Foreign body giant cell formation was significantly higher in the experimental group in week 4 and week 6. The maximum rupture force was significantly higher in the experimental group in week 4 and week 6 than in the control group. Elasticity and stiffness were comparable between groups in week 4; however, stiffness, but not elasticity, was significantly higher in the experimental group in week 6.ConclusionsIn the short term, cyanoacrylate enhanced tendon endurance in both a histopathological and biomechanical manner. We conclude that the early initiation of rehabilitation in patients may be safe in cases of cyanoacrylate use for surgical repair of tendon injury.

Development and Application of Digital Human Models in the Field of Vehicle Collisions: A Review.

In the human-vehicle-road system of collisions, the human is the most important factor, and digital human models (DHMs) are developed with the aim of preventing or at least reducing human injury. Because most of the relevant literature is focused mainly on collisions in traffic accidents (TAs), only some of the literature reviewed in this paper involves research results on other aspects of collisions. In this review, based on the background of DHMs and the application of DHMs regarding human injury biomechanics in collisions field, research results regarding the development of DHMs are described, the methods for verifying such models are introduced, and the application of the research results is discussed based on the aspect of human injury biomechanics. From the research literature, the development and validation of DHMs and their application in human injury biomechanics are summarized, and future research trends are proposed and discussed.

A new device for measuring forces in the footrest during on-water kayaking

Several studies have investigated paddle force on the water. However, a limited number of studies have investigated on-water footrest forces. The purpose of this study was to design, implement, and validate a device which measures forces applied to the footrest during on-water kayaking without hindering the athletes’ performance. A Nelo footrest was modified and equipped with two load cells. The footrest was calibrated by loading it with known weights perpendicular to the surface of the footrest. A portable custom-built data acquisition system was built. The data acquisition system was placed in a box behind the seat in the kayak. The system was able to measure the paddling technique related to the legs during on-water testing and distinguish between different intensities. The system developed in the current study can help to improve kayak sprint performance in new ways, as the system elucidates forces within the kayak. Moreover, the system can provide clarification of the biomechanical aspects of the leg push during sprint kayaking.

Biomechanical Aspects of the Foot Arch, Body Balance and Body Weight Composition of Boys Training Football.

Background: The aim of the study is to assess the body balance and podological parameters and body composition of young footballers in the context of the control of football training. Methods: The study examined the distribution of the pressure of the part of the foot on the ground, the arch of the foot, and the analysis of the body composition of the boys. The pressure center for both feet and the whole body was also examined. The study involved 90 youth footballers from Olsztyn and Barczewo in three age groups: 8–10 years, 11–13 years old, and 14–16 years. The study used the Inbody 270 body composition analyzer and the EPSR1, a mat that measures the pressure distribution of the feet on the ground. Results: The results showed statistically significant differences in almost every case for each area of the foot between the groups of the examined boys. The most significant differences were observed for the metatarsal area and the left heel. In the case of stabilization of the whole body, statistically significant differences were noted between all study groups. In the case of the body composition parameters, in the examined boys, a coherent direction of changes was noticed for most of them. The relationships and correlations between the examined parameters were also investigated. The significance level in the study was set at p < 0.05. Conclusions: Under the training rigor, a statistically significant increase in stability was observed with age. The total length of the longitudinal arch of both feet of the examined boys showed a tendency to flatten in direct proportion to the age of the examined boys. Mean values of the body composition parameters reflect changes with the ontogenetic development, basic somatic parameters (body height and weight) and training experience, and thus with the intensity and volume of training. This indicates a correct training process that does not interfere with the proper development of the body in terms of tissue and biochemical composition.

Reconstructing natural aesthetics of posterior teeth with direct composite restorations (a case report)

One of the most common methods of dental treatment in a minimally invasive concept is a direct restoration of carious damaged teeth or teeth with dental trauma. In this article represents a clinical case of old unsatisfactory restorations replacement in teeth 36, 37 followed by restoration of hard tissue class II defects using direct composite restoration taking into account aesthetic and biomechanical aspects.

Visual characteristics of rowing technique for young kayakers aged 15–16

21 kayak coaches took part in the questionnaire survey, whose coaching experience ranged from 1 to 40 years, including 4 - Honored Coaches of Ukraine, 8 - the highest category and 9 - the first category (Kyiv, Poltava, Vinnytsia, Sumy). The survey was conducted to collect information on technical features training of young kayakers aged 15–16 at the stage of preliminary basic training. Visual characteristics of rowing techniques for kayakers aged 15–16 by Ukrainian coaches showed that their knowledge is mostly in line with modern scientific ideas, but there are also deviations in the model characteristics of rowing techniques, special wiring of the paddle blade, respectively, it requires further improvement of approaches based on the use of objective quantitative criteria for evaluating the technique of motor actions of rowers in the training and competitive process. It should be noted that trainers in the visual characterization of rowing techniques mainly focus on the biomechanical aspects of muscle and joint work, without considering the features of rowing movements. Accordingly, only 32% of coaches surveyed say that with the help of a wing-shaped paddle blade you can get extra lifting force, due to which the rowing becomes more powerful, and 68% say that the rowing should take place along the side of the boat, but with the traditional design of the oar. The parameters of technical training of kayakers aged 15–16, consisting of the main elements of rowing technique, optimal angles of biomechanical effort, angles of attack of the paddle, error correction, wiring of the paddle blade, can serve as objective criteria for assessing the technical component of sports improvement.

Finger injuries with a focus on ligamentous structures

Ligamentous lesions of the fingers are common everyday injuries and usually the result of distortion or overloading. Numerous examination methods are available for dedicated radiological diagnosis of sometimes complex injury patterns. To review radiological diagnosis of the ligamentous structures of the finger joints including the presentation of anatomical, biomechanical and therapeutic aspects. Presentation of the anatomy and biomechanics as well as the most common trauma mechanisms of the ligamentous structures. Review of the literature, discussion of recent work and diagnostic expert recommendations. The most relevant ligamentous structures are collateral ligaments, pulley ligaments, volar plates and tendons. The goal of radiologic diagnosis is to accurately define the injury pattern and to differentiate between simple and complicated ligamentous lesions. In unclear cases, magnetic resonance imaging (MRI) has become standard for further diagnostics, which may allow depiction of ligamentous structures in submillimetre resolution. Today, differential diagnosis includes all radiological modalities, which ensures the determination of an adequate therapy and prevention of sequel at ahigh standard.

Minute ventilation/carbon dioxide production in patients with dysfunctional breathing.

Dysfunctional breathing refers to a multi-dimensional condition that is characterised by pathological changes in an individual's breathing. These changes lead to a feeling of breathlessness and include alterations in the biomechanical, psychological and physiological aspects of breathing. This makes dysfunctional breathing a hard condition to diagnose, given the diversity of aspects that contribute to the feeling of breathlessness. The disorder can debilitate individuals without any health problems, but may also be present in those with underlying cardiopulmonary co-morbidities. The ventilatory equivalent for CO2 (V eqCO2 ) is a physiological parameter that can be measured using cardiopulmonary exercise testing. This review will explore how this single measurement can be used to aid the diagnosis of dysfunctional breathing. A background discussion about dysfunctional breathing will allow readers to comprehend its multidimensional aspects. This will then allow readers to understand how V eqCO2 can be used in the wider diagnosis of dysfunctional breathing. Whilst V eqCO2 cannot be used as a singular parameter in the diagnosis of dysfunctional breathing, this review supports its use within a broader algorithm to detect physiological abnormalities in patients with dysfunctional breathing. This will allow for more individuals to be accurately diagnosed and appropriately managed.

Functional morphology of the raptorial forelegs in Mantispa styriaca (Insecta: Neuroptera)

The insect leg is a multifunctional device, varying tremendously in form and function within Insecta: from a common walking leg, to burrowing, swimming or jumping devices, up to spinning apparatuses or tools for prey capturing. Raptorial forelegs, as predatory striking and grasping devices, represent a prominent example for convergent evolution within insects showing strong morphological and behavioural adaptations for a lifestyle as an ambush predator. However, apart from praying mantises (Mantodea)—the most prominent example of this lifestyle—the knowledge on morphology, anatomy, and the functionality of insect raptorial forelegs, in general, is scarce. Here, we show a detailed morphological description of raptorial forelegs of Mantispa styriaca (Neuroptera), including musculature and the material composition in their cuticle; further, we will discuss the mechanism of the predatory strike. We could confirm all 15 muscles previously described for mantis lacewings, regarding extrinsic and intrinsic musculature, expanding it for one important new muscle—M24c. Combining the information from all of our results, we were able to identify a possible catapult mechanism (latch-mediated spring actuation system) as a driving force of the predatory strike, never proposed for mantis lacewings before. Our results lead to a better understanding of the biomechanical aspects of the predatory strike in Mantispidae. This study further represents a starting point for a comprehensive biomechanical investigation of the convergently evolved raptorial forelegs in insects.

Overuse Elbow Injuries in Youth Gymnasts

Background: Gymnastics is a unique sport that places significant loads across the growing elbow, resulting in unique overuse injuries, some of which are poorly described in the current literature. Purpose: To provide a comprehensive review of the unique overuse elbow injuries seen in youth gymnasts and to provide an up-to-date synthesis of the available literature and clinical expertise guiding treatment decisions in this population. Study Design: Narrative review. Methods: A review of the PubMed database was performed to include all studies describing elbow biomechanics during gymnastics, clinical entities of the elbow in gymnasts, and outcomes of operative and/or nonoperative treatment of elbow pathology in gymnasts. Results: Participation in gymnastics among youth athletes is high, being the sixth most common sport in children. Early specialization is the norm in this sport, and gymnastics also has the highest number of participation hours of all youth sports. As a result, unique overuse elbow injuries are common, primarily on the lateral side of the elbow. Beyond common diagnoses of radiocapitellar plica and osteochondritis dissecans of the capitellum, we describe a pathology unique to gymnasts involving stress fracture of the radial head. Additionally, we synthesized our clinical experience and expertise in gymnastics to provide a sport-specific rehabilitation program that can be used by providers treating surgical and nonsurgical conditions of the elbow and wishing to provide detailed activity instructions to their athletes. Conclusion: Overuse injuries of the elbow are common in gymnastics and include osteochondritis dissecans of the capitellum, radiocapitellar plica syndrome, and newly described radial head stress fractures. A thorough understanding of the psychological, cultural, and biomechanical aspects of gymnastics are necessary to care for these athletes.

In Vitro Human Joint Models Combining Advanced 3D Cell Culture and Cutting-Edge 3D Bioprinting Technologies.

Joint-on-a-chip is a new technology able to replicate the joint functions into microscale systems close to pathophysiological conditions. Recent advances in 3D printing techniques allow the precise control of the architecture of the cellular compartments (including chondrocytes, stromal cells, osteocytes and synoviocytes). These tools integrate fluid circulation, the delivery of growth factors, physical stimulation including oxygen level, external pressure, and mobility. All of these structures must be able to mimic the specific functions of the diarthrodial joint: mobility, biomechanical aspects and cellular interactions. All the elements must be grouped together in space and reorganized in a manner close to the joint organ. This will allow the study of rheumatic disease physiopathology, the development of biomarkers and the screening of new drugs.

Small details with great effects on speed running

Abstract. In sprint events, the start is a special issue, which has led us to conduct a more in-depth study of some biomechanical aspects that, on the one hand, may have permissive effects on performance or, conversely, may have a restrictive influence, depending on the stance adopted by the sprinter when getting into the “set” position for the block start. Ensuring optimal angles at the joints of the body segments enables the runner to quickly react when the starter’s gun is fired, but especially to achieve the most efficient flexion-extension sequence of the lower limb joints (hip-knee-ankle) concurrently with providing the necessary balance that allows focusing attention on the sound of the gun. Carefully watching how the block start positions are approached, it has been found that no two athletes have the same stance at the “set” command and the same dynamics of the first steps. The different approaches to the speed running technique are mainly dependent on each athlete’s morphofunctional characteristics, which will leave their mark on efficiency and specific training sessions. There are many situations in which some say that only a particular position allows them “to feel that they push best the starting block”, while others try to imitate the start positions of certain sprinters they have seen in various television broadcasts just because they have noticed something special in their performance as compared to other athletes, but without understanding the degree of efficiency of those movements.

Kinetics, kinematics, and knee muscle activation during sit to stand transition in unilateral and bilateral knee osteoarthritis

BackgroundThe sit to stand transition (STS) is a task performed by those with knee osteoarthritis (KOA) with biomechanical modifications that may influence the lower limb load distribution. As a weight bearing task mainly performed in the sagittal plane, the presence of unilateral or bilateral KOA may lead to asymmetry during its performance. Research questionAre the biomechanical and neuromuscular aspects of the sit to stand transition (STS) different between participants with unilateral and bilateral KOA? MethodsTwenty-eight participants were allocated as follows: unilateral KOA (OAUNI; n = 12) and bilateral KOA (OABI; n = 16). All participants were evaluated by means of kinematics (Qualisys Motion Capture System, Qualisys Medical AB, SUE), kinetics (Bertec Corporation's model 4060−08 Mod., USA), and electromyography (TrignoTM Wireless System, DelSys Inc., USA) during the STS. The variables calculated were the symmetry indices of the total support moment (TSM) and ground reaction force (ISGRF and ISTSM, respectively), magnitude of the TSM, individual joint contribution to the TSM, peak trunk flexion, hip, knee, and ankle range of motion, duration in seconds, the magnitudes of activation of the extensor and flexor muscles, knee extensors: flexor co-contraction indices and isometric knee extensor peak torques. Participants also answered the WOMAC questionnaire and performed the 30-second STS test (STS30). ResultsThe OABI got up from a chair with a lower TSM magnitude in the most affected limb (p = 0.040), used greater trunk flexion amplitude (p ≤ 0.034), and presented lower isometric KET (p = 0.039) and worse self-reported pain (p = 0.011) and physical function (p = 0.015). SignificanceParticipants with unilateral and bilateral KOA differ regarding lower limb kinetics and trunk kinematics while getting up from a chair, without modification in the lower limb intersegmental coordination or symmetry regarding ground reaction force or TSM distribution.

Basic surface electrocardiogram interpretation for the pharmacist.

The electrocardiogram (ECG) is an invaluable tool for clinicians that provides important information about a patient's heart. As clinical pharmacists play an ever-increasing role in cardiovascular care, ECG interpretation is an important skill with which to become familiar. The ECG provides information on both electrical and biomechanical aspects of the heart. Electrical information such as the rhythm, rate, and axis of the electrical activity can all be provided by the ECG. Biomechanical information about the heart, such as the presence of ventricular hypertrophy and repolarization changes that may be associated with ischemia or myocardial injury, can also easily be gleaned from the ECG. Furthermore, the ECG plays a central role in both the diagnosis and treatment of common clinical conditions such as atrial fibrillation, ischemic heart disease, and QT interval prolongation. The ECG is one of the most commonly performed diagnostic tests, and clinicians should become familiar with its basic interpretation.

Biomechanical models of in vitro constructs for spinopelvic osteosynthesis

Spinopelvic lesions are the result of high-energy vertical trauma with axial skeletal overload where the spine impacts onto the sacrum, dissociating the lumbar spine from the pelvis. Therefore, lumbopelvic instrumentations are aimed to counteract these vertical forces, although various biomechanical aspects of the combinations of different constructs (with or without iliosacral screws) or the number of lumbar fixation levels (L5 or the combination of L5 with L4) are subject to controversy. The number of patients in each published series is too short, and the nature of the fixation is very different from one article to another, making comparison very difficult. In this paper the methodology for laboratory studies is discussed. The design of the test bench fixture, biomechanical testing protocol and data analysis are very important when inference to the clinical setting is desired.

A farewell to arms and legs: a review of limb reduction in squamates.

Elongated snake-like bodies associated with limb reduction have evolved multiple times throughout vertebrate history. Limb-reduced squamates (lizards and snakes) account for the vast majority of these morphological transformations, and thus have great potential for revealing macroevolutionary transitions and modes of body-shape transformation. Here we present a comprehensive review on limb reduction, in which we examine and discuss research on these dramatic morphological transitions. Historically, there have been several approaches to the study of squamate limb reduction: (i) definitions of general anatomical principles of snake-like body shapes, expressed as varying relationships between body parts and morphometric measurements; (ii) framing of limb reduction from an evolutionary perspective using morphological comparisons; (iii) defining developmental mechanisms involved in the ontogeny of limb-reduced forms, and their genetic basis; (iv) reconstructions of the evolutionary history of limb-reduced lineages using phylogenetic comparative methods; (v) studies of functional and biomechanical aspects of limb-reduced body shapes; and (vi) studies of ecological and biogeographical correlates of limb reduction. For each of these approaches, we highlight their importance in advancing our understanding, as well as their weaknesses and limitations. Lastly, we provide suggestions to stimulate further studies, in which we underscore the necessity of widening the scope of analyses, and of bringing together different perspectives in order to understand better these morphological transitions and their evolution. In particular, we emphasise the importance of investigating and comparing the internal morphology of limb-reduced lizards in contrast to external morphology, which will be the first step in gaining a deeper insight into body-shape variation.