Technical Execution Research Articles

Imitation jumps in ski jumping: Technical execution and relationship to performance level

ABSTRACT Imitation jumps are frequently used in training for ski jumping. Yet, the dynamics of these jumps differ considerably. Thus, the relevance of imitation jumps for ski jumping performance is not elucidated. The aim of this study was to investigate the relationship between the technical execution of imitation jumps and ski jumping performance level. We compared the imitation jumps of 11 ski jumpers of different performance levels using a Spearman correlation transform of time traces of the kinetics (measured using force cells and motion capture) of imitation jumps. The kinetic aspects that were related to performance centred on the moment arm of ground reaction force to the centre of mass before the onset of the push-off, angular momentum early in push-off, thigh angle during the main period of push-off and vertical velocity towards the end of push-off. We propose that the thigh angle may be a key element allowing high development of linear momentum while preparing for appropriate aerodynamic position. Furthermore, the findings suggest that the kinetic development prior to (and during) push-off is more important than the kinematic end state at take-off.

Եվրոպական մոդեռնիզմի արձագանքները XX դարի Իրանի նկարչության մեջ (1920-1980 թվականներ)

The paper studies the impact of various stylistic trends of the European innovative art of the XX century, 1920s-1980s in particular, on visual arts of Iran. The objective of the study is a) to examine the activity of masters Hossein Behzad, Andre Sevryugin and Hasanali Vaziri, who taught at the School of Painting and Sculpture, founded on the initiative of Kyamal al Molq in Tehran; b) to assess the contribution to Iranian visual arts of the pioneers of innovative movement in Iran Kalal Ziapuri, Ahmad Esfandiari, Markos Grigoryan and Sohrab Sepehri, as well as the pioneers of the Saggahane movement Hossein Zenderudi and Parviz Tanavoli. To conduct the investigation, the widely applied in art criticism descriptive, graphical and analytic-comparative methods were employed. As a result of the analysis, it has been established that the European influence on the art of Iranian artists is predominantly to be found in the outward appearance and technical execution. While adhering in their creation to this or that trend of European modernism, such as impressionism, post-impressionism, cubism, abstractionism and surrealism, they, however, in order to preserve their cultural identity, draw upon the centuries-old national traditions.

Analysis of headers in high-performance football: evidence from the English Premier League

ABSTRACT This study aimed to gather information about game situations where headers in high-performance football were performed and to characterise how headers were executed in different game situations. A multidimensional observational system was designed to characterise the header situation and technical execution. A sample of 920 headers were randomly collected from the English Premier League 2017–2018 season, using InStat Scout® website platform. Frequency analysis of headers showed that (1) most led to ball losses; (2) almost half was performed during set plays, especially in goal kicks and throw-ins; (3) a substantial amount was executed to prevent spatial progress of opponents when employing direct attacks with long passes. Chi-square analyses revealed significant associations (p < 0.05) between the following variables: header purpose and player position (large effect size – ES), movement and jump type (medium ES), game state and player movement, game state and jump type, space of occupation and opponent players as well as header type, header purpose and jump type, header purpose and opponent players, pass and jump type, pass and opponent players, and pass and player position (small ES). Based on the current findings, coaches are strongly encouraged to design representative training environments for headers considering position-specific needs, and to promote practice tasks and game strategies for maintaining/regaining ball possession after a player’s intentional header.

Single- versus double-injection costoclavicular block: a randomized comparison

BackgroundThe costoclavicular approach targets the brachial plexus in the proximal infraclavicular fossa, where the lateral, medial, and posterior cords are tightly bundled together. This randomized trial compared single- and double-injection...

Reconstruction osseuse métacarpienne par membrane induite sans ciment

Hand ballistics traumas often produce complex limb injuries and large segmental bone defects. The induced membrane (IM) technique is a simple and effective procedure for reconstruction of segmental bone defects. Usually polymethylmethacrylate (PMMA) cement is required for the first stage of the surgery. We describe four metacarpal bone reconstructions with the IM technique but without PMMA cement after ballistic trauma in a low-resources setting. Two patients were treated in a forward surgical unit for gunshot wounds of the hand. A 33 years old man presented a 4th and 5th metarcarpal bone fracture with critical bone defect and a 25 years old man presented a 2nd and 3rd metacarpal bone and soft tissue defect. In addition to the surgical initial management, we performed the IM technique with a syringe's body in polypropylene (PP) instead of PMMA cement that was not available in this situation. A thick membrane was observable six weeks after the spacer implantation. We performed the bone graft in one case with an iliac crest and in the other with a tibial cortical and cancelous graft. Bone union was achieved in the two cases for the four metacarpal bones. We report cases treated in an austere environment where PMMA cement was not available. This PP induced membrane technique as first been described in a public communication at the SICOT congress by Mozumder et al. It involved critical bone defects from the lower limb. The IM technique has proven its efficiency in hand and wrist bone defect reconstruction but its success is based on strict compliance with technical execution. Our plastic spacers met the requirements of surgical technique. After six weeks, an IM membrane macroscopically similar to cement's IM was found in all cases. The PP spacer shows interesting characteristics: it does not contain antibiotics, it does not heat the surrounding tissues and it is not expensive and easily available. The use of a PP spacer allowed us to achieve bone union in four critical metacarpal bone defects related to ballistic trauma. This procedure respects the technical execution of the IM technique. It is achievable in very low-resources settings. Further biomolecular studies are necessary to assess the PP IM biological properties.

State of the Art: Reconstruction with Synthetic PORP and TORP

The purpose of this review article is to present salient pearls of successful ossiculoplasty, with particular attention paid to reconstructive strategies with synthetic partial ossicular prostheses and total ossicular prostheses. A refined level of dexterity and an appropriate attention to detail are needed to optimize audiometric outcomes in ossiculoplasty, as is a fundamental understanding of middle ear mechanics and the consistent anatomical relationships that exist in the middle ear, but perhaps the most important determinant of long-term hearing outcomes in ossiculoplasty is the middle ear environment. Successful ossiculoplasty requires a prudent and thoughtful approach to all phases of the patient’s care, and the final audiometric result is a synergistic product requiring both careful preoperative assessment, thoughtful prosthesis selection, and proficient technical execution.

A Review of Countermovement and Squat Jump Testing Methods in the Context of Public Health Examination in Adolescence: Reliability and Feasibility of Current Testing Procedures.

BackgroundIn the context of a public health physical fitness (PF) examination in adolescence, a countermovement jump (CMJ) and a squat jump (SJ) are two vertical jump (VJ) tests widely used to evaluate lower limb muscle strength and power, respectively. The main criticism of both the CMJ and SJ test is the lack of test standardization. Therefore, the objectives of this review are: (a) to gather information about both jumps; (b) to investigate whether it is possible to identify common procedures referred to in the CMJ and SJ technical execution, and (c) to design standard operating procedures (SOPs) to promote CMJ and SJ standardization in an adolescent population aged 12–18 years.MethodsThe review partially adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement (PRISMA). Due to growing attention in monitoring physical health through field tests in recent years, articles were collected using the PubMed, Web of Science, and Scopus databases from January 2009 to July 2019. Original articles in which CMJ or SJ were used to assess the muscular strength in adolescents were eligible for further analysis. Articles written in English was imposed as a limit.ResultsA total of 117 studies met the inclusion criteria. The description of the CMJ and SJ test procedures was different within the literature, with discrepancies in the jump technique, number of jumps, and measurement devices used.ConclusionsA lack of method standardization for both the CMJ and the SJ test was identified. Based on the literature, SOPs for both VJs were proposed. These are useful in the context of public health PF examination in adolescents, as they facilitate an unbiased comparison of jump performance data between published studies.

Passing and tackling qualities discriminate developmental level in a rugby league talent pathway

ABSTRACTThis study compared the passing and tackling qualities of talent identified rugby league (RL) players within a developmental pathway. From a total of 88 players, three developmental levels were defined: under 18 years (U18; n = 27), under 20 years (U20; n = 29), and state league (SL; n = 32). All participants performed skills tests that measured passing and tackling qualities. A MANOVA modelled the main effect of developmental level (three levels: U18, U20 and SL) with receiver operating characteristic (ROC) curves then built for variables that showed a significant effect. A significant effect was noted for passing over four to 12 m (V= 0.303, F = 2.406, P< 0.05), with the SL players outperforming their U18 and U20 counterparts. The ROC curves generated an area under the curve of greater than 63% for each passing test criterion, indicating greater than chance discrimination. The choice of tackle and technical execution of tackle discriminated the SL players from the U18 and U20 groups. Utilising the criteria for objective measures for fundamental skill assessment throughout RL development is likely to assist with the junior-to-senior transition of talented RL players.

The Relationship Between Swimming Performance and Time Parameters of the Start and Turn

Summary The start and the turn are factors that influence performance in different swimming disciplines. The aim of this study was to find out the relationship of selected time parameters of the start and the turn with sport performance of 100 m and 1 500 m freestyle finalists in the Olympic Games 2016. Monitored parameters of the start were the start reaction, time under water after the start, and time at a distance of 15 m after the start. The monitored parameters of the turn were the time of 5 m before the turn, the duration of the turn, the time under water after the turn, and time reached at a distance of 15 m after the turn. There was any significant correlation of the resulting time to 1 500 m and the observed start indicators. The significant correlation of the resulting time to 1 500 m and the observed turn indicators was time 5 m before the turn r = 0.952 (p = 0.000); the duration of the turn r = 0.830 (p = 0.011); time at a distance of 15 m after the turn r = 0.886 (p = 0.003). The significant correlation of the resulting time to 100 m and the observed start indicators was time under water after the start r = −0.714 (p = 0.047). The significant correlation of the resulting time to 100 m and the observed turn indicators was the duration of the turn was r = 0.905 (p = 0.002). The results point out the existing relations between 100 m freestyle and time under water after start and duration of the turn. And for 1 500 m existing relations with time 5 m before the turn, the duration of the turn and time at a distance of 15 m after the turn. Therefore, our recommendations for sports practice include development of speed, power and coordination skills with technical execution of the start and the turn into regular swimming training.

Defeito Medial da Sobrancelha: Reconstrução com Retalho Pediculado de Avanço V-Y

INTRODUÇÃO: A sobrancelha é a subunidade estética frontal mais importante, desempenhando papel fundamental na estética facial e proteção ocular. Embora seja das áreas da face menos acometidas pelo cancro cutâneo, é das que mais desafio coloca em cirurgia reconstrutiva.CASO CLÍNICO: Homem de 71 anos, caucasiano, submetido a exérese de carcinoma basocelular infiltrativo envolvendo o terço medial da sobrancelha direita e região frontal suprajacente. Procedeu-se ao encerramento do defeito cirúrgico com retalho pediculado de avanço V-Y do músculo orbicular do olho. Não se registaram complicações pós-operatórias. Os resultados estéticos e funcionais foram bastante aceitáveis.DISCUSSÃO: O retalho pediculado de avanço V-Y é um dos poucos procedimentos utilizados no encerramento de defeitos cirúrgicos da sobrancelha. A execução técnica deve ser cuidadosa e requer conhecimento anatómico adequado, pois, só assim, será possível alcançar resultados estéticos e funcionais favoráveis.

The Influence of the Ambipolar Field on the Levitation Conditions of Dust Particles in the Positive Column of the Glow Discharge With a Change the Spatial Orientation of the Discharge Tube

Experiments were carried out in dusty plasmas of both the stratified and homogeneous positive columns (PCs) in a U-shaped discharge tube during its rotation from the vertical to the horizontal position. It is shown that in all cases the radial ambipolar field prevents charged dust particles from falling on the tube walls. For a vertically oriented tube, a dust cloud is observed only in a strong field of strata and is absent in a homogeneous plasma. In a horizontally oriented tube, the dust particles drift toward the anode in an axial external field. In this case, dust particles are trapped at the point of transition from the horizontal to the vertical section of the tube, in both the stratified and homogeneous PCs. It was concluded that for a V-shaped design of a cylindrical tube, an ambipolar dust trap, which is simple in technical execution, can be implemented, which makes it possible to hold dust particles in its lower part.

General versus sports-specific injury prevention programs in athletes: A systematic review on the effects on performance.

IntroductionInjury prevention programs (IPPs) are an inherent part of training in recreational and professional sports. Providing performance-enhancing benefits in addition to injury prevention may help adjust coaches and athletes’ attitudes towards implementation of injury prevention into daily routine. Conventional thinking by players and coaches alike seems to suggest that IPPs need to be specific to one’s sport to allow for performance enhancement. The systematic literature review aims to firstly determine the IPPs nature of exercises and whether they are specific to the sport or based on general conditioning. Secondly, can they demonstrate whether general, sports-specific or even mixed IPPs improve key performance indicators with the aim to better facilitate long-term implementation of these programs?MethodsPubMed and Web of Science were electronically searched throughout March 2018. The inclusion criteria were randomized control trials, publication dates between Jan 2006 and Feb 2018, athletes (11–45 years), injury prevention programs and included predefined performance measures that could be categorized into balance, power, strength, speed/agility and endurance. The methodological quality of included articles was assessed with the Cochrane Collaboration assessment tools.ResultsOf 6619 initial findings, 22 studies met the inclusion criteria. In addition, reference lists unearthed a further 6 studies, making a total of 28. Nine studies used sports specific IPPs, eleven general and eight mixed prevention strategies. Overall, general programs ranged from 29–57% in their effectiveness across performance outcomes. Mixed IPPs improved in 80% balance outcomes but only 20–44% in others. Sports-specific programs led to larger scale improvements in balance (66%), power (83%), strength (75%), and speed/agility (62%).ConclusionSports-specific IPPs have the strongest influence on most performance indices based on the significant improvement versus control groups. Other factors such as intensity, technical execution and compliance should be accounted for in future investigations in addition to exercise modality.

Nodo integrador de la información geográfica del Agro: Geoportal IDE MINAGRI de Chile

La Infraestructura de Datos Espaciales del Ministerio de Agricultura (IDE MINAGRI) de Chile, reúne a la información geográfica y servicios del Ministerio en una única plataforma tecnológica on-line interoperable. A través de esta plataforma se pone a disposición de los usuarios información geográfica consolidada y estandarizada, siendo la expresión espacial de la intervención del ministerio a nivel de políticas planes y programas, para gestionar y facilitar la toma de decisiones, principalmente entre autoridades ministeriales y profesionales del agro. La IDE MINAGRI se hace visible a través de su geoportal (&lt;http://ide.minagri.gob.cl&gt;) y el responsable de la coordinación, mejora continua y ejecución técnica es el Centro de Información de Recursos Naturales (CIREN).

Analysis of Human Performance Deficiencies Associated With Surgical Adverse Events

Potentially preventable adverse events remain a formidable cause of patient harm and health care expenditure despite advances in systems-based risk-reduction strategies. To analyze and describe the incidence of human performance deficiencies (HPDs) during the provision of surgical care to identify opportunities to enhance patient safety. This quality improvement study used a new taxonomy to inform the development and implementation of an HPD classifier tool to categorize HPDs into errors associated with cognitive, technical, and team dynamic functions. The HPD classifier tool was then used to concurrently analyze surgical adverse events in 3 adult hospital affiliates-a level I municipal trauma center, a quaternary care university hospital, and a US Veterans Administration hospital-from January 2, 2018, to June 30, 2018. Surgical trainees presented data describing all adverse events associated with surgical services at weekly hospital-based morbidity and mortality conferences. Adverse events and HPDs were classified in discussion with attending faculty and residents. Data were analyzed from July 9, 2018, to December 23, 2018. The incidence and primary and secondary causes of HPDs were classified using an HPD classifier tool. A total of 188 adverse events were recorded, including 182 adverse events (96.8%) among 5365 patients who underwent surgical operations and 6 adverse events (3.2%) among patients undergoing nonoperative treatment. Among these 188 adverse events, 106 (56.4%) were associated with HPDs. Among these 106 HPD adverse events, a total of 192 HPDs (mean [SD], 1.8 [0.9] HPDs per HPD event) were identified. Human performance deficiencies were categorized as execution (98 HPDs [51.0%]), planning or problem solving (55 HPDs [28.6%]), communication (24 HPDs [12.5%]), teamwork (9 HPDs [4.7%]), and rules violation (6 HPDs [3.1%]). Human performance deficiencies most commonly presented as cognitive errors in execution of care or in case planning or problem solving (99 of 192 HPDs [51.6%]). In contrast, technical execution errors without other associated HPDs were observed in 20 of 192 HPDs (10.4%). Human performance deficiencies were identified in more than half of adverse events, most commonly associated with cognitive error in the execution of care. These data provide a framework and impetus for new quality improvement initiatives incorporating cognitive training to mitigate human error in surgery.

Design, Dissemination, and Disinformation in Viral Maps

Design, Dissemination, and Disinformation in Viral Maps

Designing and Validating a Basketball Learning and Performance Assessment Instrument (BALPAI).

IntroductionThe assessment of learning in basketball in the PE class, and in training sessions of young players, requires valid, reliable, and trustworthy tools. The purpose of this research was to design and validate the Basketball Learning and Performance Assessment Instrument (BALPAI) that assesses simultaneously decision making, technical execution and efficacy. The play actions are codified using a categorical system, awarding a score for each category (1 = inadequate action; 2 = neutral action 3 = adequate action). An example of a summative procedure for assessing decision making in dribbling is: (1) Dribbling to a place where there is defensive pressure and there is a free teammate able to receive the pass; (2) Dribbling to a place where there is defensive pressure or a free teammate able to receive the pass; (3) Dribbling through a space where there is no defensive pressure and no free teammate able to receive the pass.MethodsA pilot study was performed following this procedure. A group of 13 experts participated in the assessment of the 33 elements (66 items) included in the BALPAI. Aiken’s V formula was used to analyze content validity, and internal consistency was calculated using Cronbach’s α. Inter-observer reliability was determined among three observers who used the BALPAI to record the play actions in a 3 × 3 basketball match (N = 45 possessions) and was calculated with the Multirater κfree, obtaining an almost perfect agreement with values between 0.84 and 1.ResultsThe BALPAI has very high internal consistency (0.969), Interobserver reliability was almost perfect (>0.84 in all items) and Aiken’s V coefficient (>0.71 in all items) attained a high value.ConclusionThe BALPAI proved to be a valid tool, with high internal consistency and reliability that makes it possible to perform a complete assessment of basketball in PE classes.

Drawing North America by Hand

Abstract. In February 2019, I put the finishing touches on a map that took four and a half years to complete. What began as a passion project ended up taking over my life, as I became utterly submerged in a cartographic odyssey: North America: Portrait of a Continent. Drawn entirely with colour pencil and fine-liner pen, this 1500 × 1200 mm (59 × 47 inch) map contains tens of thousands of items of content, from the Arctic to Central America, even the deepest reaches of the ocean. 600 individualised cityscapes populate the map, and the content varies widely. All range of animals, plants, culture, history, industry, symbology, and more are laid out across a flowing terrain. It pulls from a vast sweep of the physical and cultural geography of the continent, and is intended to encourage geographic enthusiasm in a broad audience. Inspired by several years I spent travelling the continent, I’m finally able to reflect on it now it is complete. As prints begin to roll out, there is much to discuss about the origins, technical execution, intents and experiences of drawing North America by hand.

Creating sources of inspiration through eCollage, the FEA model, and a future visioning concept design project

This article presents an approach to creating sources of inspiration through a collaborative concept design that was developed and observed during a future visioning concept design project concerning the theme of “performance wear,” which was conducted at the University of Helsinki for second-year textile student teachers. During the project, the students created future scenarios; used the functional, expressive, and aesthetic (FEA) consumer needs model for apparel design (Lamb and Kallal in Cloth Text Res J 10(2):42–47, 1992) when considering what performance wear could be like in a future scenario; and created digital collages (eCollages) to present their concepts. In the course that followed the concept design project, the students designed and made actual clothes using the concepts developed during the concept design project as one of their sources of inspiration. The outcomes of the process are described in this article through four research questions: (1) What type of future scenarios did the teams create, what types of eCollages did the teams make, and how did the teams use information and communication technologies (ICT) in their collages? (2) How did the use of eCollages enrich the concept presentations? (3) How were the three dimensions of the FEA model utilized and presented in the eCollages and team presentations? (4) How did the future visions of the concepts and the eCollages act as sources of inspiration in the students’ clothing designs? Five of the six teams studied created a global future scenario that envisioned the world as a dystopia. The high level of technical and visual executions of all the eCollages was surprising. The ECollages played an important role in every team presentation and enriched them considerably. The FEA model, on the other hand, both provided a supporting framework for the concepts and guided the students to direct their attention to apparel within their future scenarios, as well as to consider different dimensions of it. The concepts especially inspired students to create aesthetic elements to their design and to consider the expressiveness and functionality of the garments from the concept’s perspective. The students also challenged themselves to find technical solutions to design ideas they created through being inspired by the concepts. Furthermore, the students often described gaining inspiration from the story or atmosphere of the concept or other non-visual elements of it, and thereby it seems that our approach indeed succeeded in promoting multi-sensory inspiration.

Expanding production value: The culture and scale of television and new media

Web, or networked, distribution technologies have challenged the power of US media corporations, which set high technical standards for production value, a measure of content quality. Legacy TV companies privilege complex, seamless technical execution supported by large crews of workers – lighting, sound, design, visual effects – but exclude as producers culturally marginalised creators perceived as too risky for the big investment necessary to execute it. The internet disrupts these dynamics by allowing for the distribution of smaller scale TV and video productions that are independently or inexpensively made. In smaller scale work, cultural production value asserts more importance, as producers create with and for their community.

Kinematic analysis of the "attack to the legs" from wrestling: impact of prior judo expertise

Background and Study Aim: In the framework of motor skill learning and transfer, the objective of the present work is to highlight the kinematics during the technical execution of an "attack to the legs" in wrestling and compare expert wrestlers with wrestlers having a prior judo expertise. Moreover, this study aims to evaluate the effects of training on these characteristics. Material and Methods: 10 male subjects were divided in two groups of five: the first group contains wrestlers with at least 7 years of wrestling practice. The second group contains two-year practice wrestlers with 5-year prior judo experience. Subjects had to perform a movement of attack towards the opponent’s legs (free style wrestling). A three-dimensional analysis was carried, the displacement of seven passive markers placed over anatomical points was quantified (3-D motion analyzer, sampling rate 25Hz). The following parameters were calculated: angulation of the hip and of the knee, velocity and acceleration of the shoulder and of the wrist. The experiment was conducted twice: at the beginning of the wrestling training schedule and ten weeks later. Results: Results showed marked differences between the two groups in the kinematics of the movement. These results suggest interference between prior automatisms and learning new skill. The prior experience in judo would have influenced posture in this group. In the framework of skill transfer and dexterity, this study appears promising to investigate the processes involved in this motor control. Conclusions: Although wrestling and judo are two sport disciplines that belong to the same group of combat sport, this work underlines the specificity of learning and indicates that acquisition of motor abilities in a speciality is not transferred inevitably in a positive way in another speciality of the same group