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Clinical predictors in young help-seeking people referred to the Lancashire Early Assessment and Detection Clinic : a service evaluationJohnson, Caroline January 2013 (has links)
Two main psychopathology-based approaches to detection of the prodrome have emerged; the Ultra High Risk (UHR) and Basic Symptom approaches. Conversion risk varies between studies using these approaches and in one centre conversion rates are reported to be decreasing year on year. There is a need examine the conversion risk across studies to establish a pooled estimate of risk for instruments designed to detect the prodrome of psychosis. To maximise the detection of those thought to present a risk of psychosis the Lancashire Early Assessment and Detection (LEAD) clinic uses an UHR instrument, the Comprehensive Assessment of at Risk Mental States (CAARMS) and A Basic Symptom instrument, the Schizophrenia Proneness Instrument (SPI-A). The thesis had two broad aims 1) to conduct a systematic review with meta-analysis of the research field to date and identify areas for further research, 2) to establish the accuracy of the LEAD clinic predictions. The meta-analysis involved a systematic search of MEDLINE, EMBASE, PsychINFO and CINHAL identifying studies of psychopathology-based instruments for the detection of the psychosis prodrome. The service evaluation examined for conversion to psychosis in patients examined for Basic Symptoms (SPI-A), attenuated positive symptoms (CAARMS), schizotypy (SPQ-A) and social functioning (SOFAS).The meta-analysis found that both the UHR and Basic Symptom approaches yield similar results. The differences in the positive predictive values (PPV) of the two approaches were not significant (Basic Symptoms, 0.34, UHR 0.25). The service evaluation found over a third (n=58) of referrals to the LEAD clinic to be psychotic at baseline and sixty-four patients to have an at risk mental state (ARMS). Conversion risk for CAARMS was 36.67%. and was 28.57% for SPI-A. The COGDIS criterion of SPI-A was found to be the most predictive with a PPV of 0.43, a sensitivity of 0.80. When patients met a combination of both COGDIS and CAARMS the likelihood ratio increased to 5.25 although the sensitivity was low (0.47).Overall, the findings of the thesis indicate that both the Basic Symptom and UHR approaches are valid for use in routine clinical settings for the assessment of psychosis risk. The thesis found that a combination of both approaches could provide future opportunities research. The SPQ-A schizotypy assessment was found to correlate with the attenuated symptom criterion of CAARMS and evidence suggests that the SPQ-A score increases closer to transition. The SPQ-A could offer opportunities for developing efficient methods of monitoring progression of prodromal symptoms.
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The Impact Of Teacher Incentive Pay Programs On The Learning Gains Of Low-performing Middle School StudentsMiller, Donna W. 01 January 2010 (has links)
President Barack Obama committed hundreds of millions of dollars to the Teacher Incentive Fund (TIF), yet a few fundamental questions remain unanswered—was the federal program effective? Did student test scores improve? Since the late 19th century, teachers have been paid for their classroom services regardless of how well—or poorly— their students performed. Nearly a century later, advocates of education reform continue to champion teacher compensation policies that link salary to student achievement. Researchers have identified two motivation theories that must be present in order to have a successful incentive pay program: goal theory and expectancy theory. The presence or absence of these theories, have produced mixed results at both the federal and state levels. Although the Florida Department of Education crafted its own statewide incentive pay plan, three public school districts have received multimillion dollar awards via competitive TIF grants. The purpose of this dissertation was to determine if any differences in learning gains existed between the 2008 and 2009 Florida Comprehensive Assessment Test® (FCAT® ) Math scores among the students of math teachers at one urban Central Florida Title I middle school who participated in TIF when compared to the students of math teachers who did not participate in TIF. The dissertation also analyzed FCAT® Math scores from 2005 through 2009 in one Central Florida school district to determine if any trends existed among the Title I middle schools participating in TIF; if any trends existed iv among the Title I middle schools that did not participate in TIF; and if any trends existed between the two groups when compared to each other. The literature review and results of this study found that learning gains existed among students whose teachers participated in TIF. In fact, at one urban Central Florida middle school, students of math teachers who did not participate in TIF also demonstrated learning gains. In addition, seven of the ten Title I middle schools from the same Central Florida district had increased FCAT® Math scores with the implementation of the TIF grant along with the three Title I middle school that were not eligible to participate. This research suggested that the teacher incentive program implemented in a Central Florida district had a positive impact on learning gains of low-performing students. The results of the independent-samples tests revealed that there was no statistical difference in the math scores based on participation in TIF. Students of the math teachers who participated in TIF demonstrated at least one year‘s academic growth. Likewise, the findings were similar for students of teachers who opted not to participate as learning gains increased in this group as well. As a result of these findings, recommendations for further study include end-of-the-year interviews with TIF-eligible teachers whose students had learning gains, but chose not to participate. Suggestions for additional research include surveying teachers whose students had higher scores in the absence of an incentive program, analyzing the test scores of other subject areas, and researching other school districts in Florida that were awarded the TIF grant.
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An Exploratory Quantitative And Qualitative Analysis Of Student Performance In Single-gender Classrooms In One Florida Elementary Aschool Sic] 2006-2009Haynes, Lloyd 01 January 2011 (has links)
The purpose of this study was to determine the relationship of participation in single-gender classrooms on student performance on the reading and mathematics developmental scale scores (DSS) of third, fourth, and fifth grade students on the Florida Comprehensive Assessment Test (FCAT). The FCAT is a standardized test that is administered to all grade 3 through grade 10 public school students in the state of Florida and has been used to assess students‟ achievement in reading and mathematics. Students in grades 4, 8, and 10 have also been assessed in science and writing. This study was concerned only with FCAT reading and mathematics scores. The elementary school whose standardized test scores were utilized in this study was comprised of working class families. The standardized test scores were generated by third, fourth, and fifth grade students who were enrolled in (a) single-gender all boys‟ classes, (b) single-gender all girls‟ classes, and (c) mixed-gender or traditional classes that contained both boys and girls. The analysis of data presented in this study was inconclusive with respect to the advantage of the single-gender educational setting over the mixed-gender educational setting. The analysis of the data produced the following results. During the school years 2005-2006, 2006-2007, 2007-2008, and 2008-2009, there were 80 opportunities for a given class type to achieve the highest reading DSS mean, reading DSS median, mathematics DSS mean, or mathematics DSS median. The single-gender boys‟ class achieved the highest DSS 44 times (55%), the mixed-gender classes achieved the highest iv DSS 29 times (36%), and the single-gender girls‟ class achieved the highest DSS 7 times (9%).
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Music Standards Implementation And The Relationship To Fourth Grade Florida Comprehensive Assessment Test Scores From 2004 To 20Phillips, Neal 01 January 2008 (has links)
This study examined the possible relationships among the perceived implementation levels of elementary music standards and Florida Comprehensive Assessment Test (FCAT) scores for fourth graders in reading, mathematics, and writing for the years 2004, 2005, and 2006. Survey data for the study were obtained from 32 school district music supervisors from large, medium, and small districts who returned fully or partially completed questionnaires. The study was focused on the relationships, if any, between a school district's mean scale scores in reading, mathematics, and writing from 2004 to 2006 in grade 4 and (a) elementary music standards implementation, (b) the average amount of time spent in elementary school music classes per week, (c) demographic and economic factors, and (d) the reported average amount of time spent in elementary school music classes per week. Findings of the study indicated that, when all variables were considered, a relationship existed among district music supervisors' views on two variables, degree of music standards implementation and the amount of time allotted per month for elementary music in respondents' school districts in 2004, 2005, and 2006; and (a) the percentage of students achieving at proficient or higher on FCAT reading who were also identified as free and reduced lunch in 2004, 2005, and 2006, (b) the percentage of students achieving at proficient or higher on FCAT mathematics who were also identified as free and reduced lunch in 2004, 2005, and 2006, and (c) the percentage of students achieving at proficient or higher on FCAT writing who were also identified as Hispanic in 2004, 2005, and 2006. Finally, implications for educational decision making were offered and recommendations were made for future studies dealing with elementary music standards implementation in Florida's schools. These recommendations included (a) investigating reasons for achievement gaps on FCAT between majority and minority ethnic groups and between minorities themselves, (b) exploring socio-economic factors affecting FCAT scores, (c) continuing research giving special attention to brain research involving music and its impact on the brain, (d) determining why high-stakes testing is necessary, and (e) devising controlled studies both in Florida and nationwide that would compare the elementary students receiving consistent and varied teaching in music with those students not receiving consistent musical instruction. Controlled and experimental group studies of pre-schoolers should be conducted to determine the extent to which the use of musical rhythms impacts the rate of language acquisition.
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The Relationship Between Thinking Maps And Florida Comprehensive Assessment Test Reading And Math Scores In Two Urban Middle SchoolsDiaz, Anna 01 January 2010 (has links)
The purpose of this study was to determine what difference, if any, exists between the implementation and use of Thinking Maps® and students' academic achievement in Reading and Mathematics as measured over time by the Florida Comprehensive Assessment Test® (FCAT). Thinking Maps® is a registered trademark of Thinking Maps, Inc. The data were examined after three years of Thinking Maps® implementation and instruction. The design of this study was quantitative, with a nonrandomized control group, pretest-posttest design (Ary, Jacobs, & Razavieh, 2002) that examined the effects on student Reading and Mathematics FCAT scores in one middle school that implemented Thinking Maps® throughout all grade levels and core subjects for three years as compared to student Reading and Mathematics FCAT scores in a second middle school that did not implement the Thinking Maps® program throughout all grade levels and core subjects for three years. MANOVA and Chi-square tests were used to examine student FCAT scores. This study focused on one major question: Do students who have been instructed in the use of Thinking Maps® have higher academic achievement as measured by the Florida Comprehensive Assessment Test® (FCAT) than those that have not been instructed in the use of Thinking Maps®? Results of this study indicated that students who have been instructed in the use of Thinking Maps® do not have higher academic achievement as measured by the Florida Comprehensive Assessment Test® (FCAT) than those who have not been instructed in the use of Thinking Maps®. The researcher concluded that other methods of evaluating the implementation of Thinking Maps® and student achievement should be explored.
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Реализация программы “зелёной модернизации” в существующих зданиях (на примере “Офисного здания Университета в г. КНР Шаньдунь”) : магистерская диссертация / Implementation of the “green modernization” program in existing buildings (on the example of the “University Office Building in Shandong, China”)Ли, Ц., Li, Q. January 2022 (has links)
Разработан метод оценки программы ‘зеленой модернизации’ существующих зданий, оцените программы "зеленой модернизации" существующих зданий, чтобы выбрать наилучший программы реализации. / A method has been developed for evaluating the program of "green modernization" of existing buildings, evaluate the program of "green modernization" of existing buildings in order to choose the best implementation program.
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Validity and Utility of the Comprehensive Assessment of School Environment (CASE) SurveyMcGuffey, Amy R. January 2014 (has links)
No description available.
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The effects of a culturally translated school counselor-led intervention on the academic achievement of fourth and fifth grade Haitian studentsUnknown Date (has links)
The purpose of this study was to evaluate the impact of the Haitian Hybrid Student Success Skills (HHSSS) program on the academic achievement of 4th and 5th grade Haitian students. This intervention included both the Student Success Skills (SSS) classroom program in English (Brigman & Webb, 2004), followed by the Haitian SSS small group translation Teknik Pou Ede Eláev Reyisi (Brigman, Campbell, & Webb 2004, 2009). School counselors in the treatment schools implemented the HHSSS program in grades 4 and 5 after receiving training from the study researcher. A series of ANOVA and ANCOVA analyses then were conducted to determine whether there were significant differences between the treatment group, the comparison group 1, and the comparison group 2 in reading and math using the Florida Comprehensive Assessment Test (FCAT) as a benchmark. Statistically significant differences were found between: (a) the treatment group and comparison group 1 in reading, (b) the treatment group and vii comparison group 2 in reading, and (c) between both comparison group 1 and comparison group 2 in reading. This study provides empirical support showing that students who are taught key cognitive and self management skills in their native language can begin to close the academic gap regardless of their language background. Furthermore, it supports the positive impact school counselors can have on student success by implementing an evidence-based program. / by Velouse Jean-Pierre Jean-Jacques. / Vita. / Thesis (Ph.D.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.
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The impact of teacher retention on student achievement in high school mathematicsUnknown Date (has links)
The purpose of this study was to examine the relationship between teacher retention and student achievement as measured by the Florida Comprehensive Achievement Test (FCAT) Math Developmental Scale Scores (DSS). This study examined the impact of teacher transience on high school student math scores over a three-year period and considered the effect of teacher years of experience in relation to transience and achievement. For the purposes of this study teachers were identified into the following four classifications: Stayers, Within District Movers, Cross District Movers, or Beginning teachers. The findings indicated that students of beginning teachers scored significantly lower on the ninth grade math test than students of teachers in the other three classifications. At the 10th grade level there was no significant difference among the teacher transience groups. Based upon the findings, the following conclusion resulted from the study. Since an analysis of the data indicated that teacher retention is likely to improve ninth grade student score gains on the FCAT Math assessment, it is recommended that High School administrators carefully review the teaching assignments of ninth grade math teachers, especially in this era of high stakes testing and accountability. / by Francisco J. Rodrâiguez. / Thesis (Ed.D.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.
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Einfluss von Traktion auf das Bewegungsverhalten im Fußball / Influence of traction properties on movement patterns in soccer – Interaction between sole configurations of soccer boots and 3rd generation artificial turfMüller, Clemens 15 December 2010 (has links) (PDF)
Einfluss von Traktion auf das Bewegungsverhalten im Fußball - Interaktion zwischen Sohlenkonfigurationen von Fußballschuhen und Kunstrasen der dritten Generation
Einleitung/Zielstellung:
In den letzten Jahren hat die Entwicklung von Kunstrasen im Fußball enorm an Bedeutung zugenommen. Dabei sind qualitativ hochwertige Kunstrasenplätze (3. Generation, FIFA 2-Star) von der FIFA zum offiziellen Spielbetrieb zugelassen. Neuste Verletzungsstudien und Spielanalysen zeigen, dass sich die Eigenschaften von Kunstrasen und Naturrasen im Bezug auf Verletzungshäufigkeit und Spielgeschehen nicht gravierend unterscheiden (Ekstrand et al. 2006, FIFA 2009d). Doch sind Bewegungsverhalten und Bewegungsstrategien der Spieler auf Kunstrasen im Fußball noch nicht vollkommen verstanden. Ein Hauptkriterium für das Bewegungsverhalten des Sportlers sind die Traktionsverhältnisse – die Interaktion zwischen Schuh und Spielfläche (Sterzing et al. 2007). Hierfür nimmt die Sohlenkonfiguration eines Fußballschuhs, die durch Anzahl, Länge, Anordnung und Material der Nocken modifizierbar ist, eine zentrale Rolle ein. Die Traktionsverhältnisse haben dabei einen Einfluss auf die Leistungsfähigkeit und die Belastung des Sportlers (Shorten et al. 2003). Auf Kunstrasen verwenden Sportler Fußballschuhe mit einer Sohlenkonfiguration, die für Naturrasen entwickelt worden ist. Zum Zeitpunkt dieser Arbeit gab es nur vereinzelte und unsystematische Forschungen bezüglich Sohlenkonfigurationen für Kunstrasen. Somit herrscht eine Diskrepanz zwischen einer „neuen“ verwendeten Spielfläche und „alten“ getragenen Schuhen.
In der Bewegungswissenschaft dient eine komplexe Sportschuhforschung dazu, Kriterien wie Traktionsverhältnisse zu untersuchen. Die komplexe Sportschuhforschung setzt sich dabei aus sportmotorischen, subjektiven, biomechanischen und mechanischen Messungen zusammen. Generell richtet sich dabei der Fokus von biomechanischen Messungen auf die genutzte Traktion, von mechanischen Messungen auf die verfügbare Traktion. In diesem Zusammenhang ist das Konzept von verfügbarer und genutzter Traktion von Fong et al. (2009) aufgezeigt. Geeignete Traktionsverhältnisse hinsichtlich einer besseren Leistungsfähigkeit spiegeln sich in höheren biomechanischen Scherkräften und einer besseren subjektiven Bewertung wider. Diese höheren biomechanischen Scherkräfte ermöglichen dem Sportler eine schnellere Laufzeit zu erzeugen. Ungeeignete Traktionsverhältnisse hinsichtlich einer erhöhten Belastung für den Sportler können sich durch eine Kombination oder Verbindung von einer relativ starken Fixierung des Schuhs mit der Spielfläche und erhöht auftretenden Gelenksmomenten der unteren Extremitäten auszeichnen.
Das Ziel dieser Arbeit war die Untersuchung von Traktionsverhältnissen verschiedener Sohlenkonfigurationen von Fußballschuhen auf Kunstrasen. Dabei standen sowohl die Leistungsfähigkeit als auch die Belastung des Sportlers im Fokus der Arbeit. Außerdem ist der Einfluss von verschiedenen Rahmenbedingungen, wie Traktionsverhältnisse und verschiedene Bewegungsaufgaben (zeitliche Verzögerung durch Reaktion), auf die Bewegungsausführung von Sportlern bei schnellen Umkehrbewegungen analysiert worden.
Methodik:
Die Arbeit beinhaltet in einem Zeitrahmen von drei Jahren, drei aufeinander aufbauende Studien mit unterschiedlichem Untersuchungsdesign. Inhalte und Fragestellungen der einzelnen Studien ergaben sich aus den Erkenntnissen der jeweils davor durchgeführten Studie. Einzelne Messungen der Studien fanden entweder im Labor oder auch teilweise auf Sportplätzen als Feldtest statt.
Studie 1 untersuchte die Traktionsverhältnisse von drei gängigen Sohlenkonfigurationen (Multinocken, Nocken, Stollen) und eines Prototypen (Kunstrasenmodell) hinsichtlich der Leistungsfähigkeit und funktionaler Nutzung. Inhalte waren ein sportmotorisches, subjektives, biomechanisches und mechanisches Testverfahren. Grundlegende Traktionsvariablen der einzelnen Testverfahren waren die Laufzeit der Probanden durch einen Slalom- und Sprintparcours, die subjektive Einschätzung der Probanden hinsichtlich der Traktionseignung der Sohlenkonfigurationen, Bodenreaktionskraftvariablen, wie horizontale Scherkräfte und der Kraftwert aus Scherkraft dividiert durch Vertikalkraft, bei verschiedenen fußballspezifischen Bewegungsausführungen und mechanische Traktionsvariablen wie Reibungskoeffizienten und Kraftanstiegsraten.
In Studie 2 wurde das Bewegungsverhalten bei verschiedenen Sohlenkonfigurationen (Schuh ohne Nocken, Kunstrasenmodell, Nocken, Stollen) mit Hilfe einer biomechanischen Messung (Bewegungsanalyse) bei einer schnell ausgeführten Umkehrbewegung analysiert. Ziel war es, Bewegungsadaptationen aufgrund unterschiedlicher Traktionsverhältnisse kinematisch und kinetisch zu quantifizieren. Grundlegende Untersuchungsaspekte waren hierbei die Gelenksmomente der unteren Extremitäten, die horizontale Fußtranslation, definiert als relative Bewegung des Schuhs auf der Spielfläche während des Bodenkontakts und Winkelverläufe einzelner Segmente und Gelenke.
In Studie 3 wurde der Einfluss auf das Bewegungsverhalten bei reaktiven Bewegungsausführungen gegenüber aktiven Bewegungsausführungen mit verschiedenen Sohlenkonfigurationen (Kunstrasenmodell, Nocken) bei einer schnell ausgeführten Umkehrbewegung untersucht. Für diese Studie diente erneut ein biomechanisches Testverfahren (Bewegungsanalyse) zur Analyse von kinematischen und kinetischen Variablen von Reaktion und Sohlenkonfigurationen.
Für alle drei Studien stand insgesamt ein Probandenpool aus 58 männlichen Fußballspielern (Alter: 22.4 ± 3.3Jahre, Größe: 177.2 ± 4.6cm, Gewicht: 71.4 ± 5.6kg, Fußballpraxis: 6.4 ± 3.7h/Woche) zur Verfügung.
Für die statistische Auswertung konnte mittels der Varianzanalyse für Mehrfachmessungen (ANOVA) und gegebenenfalls einer Post-Hoc Analyse nach Bonferroni zwischen den Sohlenkonfigurationen für sportmotorische und biomechanische Variablen diskriminiert werden. Für subjektive Testverfahren wurde der Friedman-Test verwendet, um zwischen Sohlenkonfigurationen zu unterscheiden. Die statistische Auswertung des mechanischen Testverfahrens erfolgte deskriptiv. In Studie 3 wurden die Daten mit einer zweifaktoriellen ANOVA mit Messwiederholung (Schuh und Reaktion) analysiert. Außerdem wurde in dieser Studie zusätzlich das Joint Coupling verwendet (Heiderscheidt et al. 2002).
Ergebnisse:
Traktionsverhältnisse auf Kunstrasen der dritten Generation beeinflussen die Leistungsfähigkeit des Sportlers und die Belastungen für den Körper des Sportlers. Flächig verteilte Sohlenkonfigurationen, wie das Multinocken- und Kunstrasenmodell, ermöglichen dem Sportler im Vergleich zu Sohlenkonfigurationen mit sehr langen Stollen, schneller einen Laufparcours zu durchlaufen. Schneller Laufzeiten werden außerdem auch subjektiv von den Sportlern wahrgenommen. Mit diesen Sohlenkonfigurationen erzielen die Sportler außerdem höhere biomechanische Scherkräfte. Hohe mechanische Traktionswerte spiegeln sich dabei nicht zwangsläufig in einer besseren Leistungsfähigkeit der Sportler.
Niedrige Traktionsverhältnisse erzeugen bei schnellen Umkehrbewegungen einen vertikaleren Fußaufsatz und reduzierte Gelenksmomente durch ein erhöhtes „Rutschrisiko“. Dies führt zu einem Verlust an Leistungsfähigkeit. Hohe und exzessive Traktionsverhältnisse weisen sowohl eine relativ starke Fixierung des Schuhs mit der Spielfläche als auch hohe Gelenksmomente während des Richtungswechsels auf. Bewegungsadaptationen zwischen Fußballschuhen treten primär im distalen Bereich der unteren Extremitäten auf.
Reaktive Bewegungsausführungen zeichnen sich aufgrund einer längeren Reaktionsphase gegenüber aktiven Bewegungsausführungen mit einem ungünstigen Fußaufsatz aus. Dies zeichnet sich bei Umkehrbewegungen durch eine geringere Tibiarotation und Fußadduktion in die neue Bewegungsrichtung aus. Während der Umkehrbewegung wird diese ungünstige Stellung der unteren Extremitäten primär durch einen verstärkten Eversionswinkel im Sprunggelenk kompensiert. Bei reaktiven Bewegungsausführungen sind außerdem die Momente im Knie- und Sprunggelenk erhöht. Unterschiede im Bewegungsmuster bei Sohlenkonfigurationen, die sich im Aufbau nicht stark unterscheiden, können bei verschiedenen Rahmenbedingungen nicht gefunden werden.
Diskussion:
Sohlenkonfigurationen beeinflussen das Bewegungsverhalten auf Kunstrasen. Niedrige Traktionsverhältnisse spiegeln sich in einem vorsichtigeren Bewegungsverhalten durch ein erhöhtes „Rutschrisiko“ wider, zu hohe Traktionsverhältnisse implizieren durch eine starke Fixierung des Sportlers mit der Spielfläche ebenfalls ein vorsichtigeres Bewegungsmuster. Nach dem Konzept von Fong et al. (2009) zeigen flächig und eben verteilte Sohlenkonfigurationen eine biomechanisch höhere genutzte Traktion. Im Gegensatz dazu, weisen Sohlenkonfigurationen mit langen Stollen eine höhere mechanisch verfügbare Traktion auf. Diese hohen mechanischen Traktionseigenschaften verhindern dabei aber den Sportler mit seiner bestmöglichen Leistung zu agieren. Flächig und eben verteilte Sohlenkonfigurationen wirken sich somit auf Kunstrasen der dritten Generation hinsichtlich der Leistungsfähigkeit und der Belastung für den Körper positiv aus. Dabei erzeugen hohe biomechanische Scherkräfte eine schnellere Abstoppbewegung oder eine kraftvollere Abstoßbewegung, die sich bei schnellen Umkehrbewegungen positiv auf die Bewegungsausführung auswirkt. Laufzeiten durch Parcours (Krahenbuhl 1974, Sterzing et al. 2009) und biomechanische Scherkräfte (Valiant 1988, Morag & Johnson 2001, Shorten et al. 2003) dienen als geeigneten Variablen, um Traktionsverhältnisse hinsichtlich der Leistungsfähigkeit zu untersuchen. Sowohl die Eindringtiefe der Nocken in die spezielle Verfüllung von Kunstrasen als auch die Verteilung der Nocken (Abstand Vorfuß- Rückfußnocken) können dabei die Traktionsverhältnisse von Fußballschuhen beeinflussen. Gelenksmomente und die horizontale Fußtranslation sind geeignete Indikatoren für die Belastungen der unteren Extremitäten während schnellen Richtungswechseln (Torg & Quedenfeld 1971, Ryder et al. 1997). Dabei erzeugen Sohlenkonfigurationen mit hohen mechanisch verfügbaren Traktionsverhältnisse eine niedrige horizontale Fußtranslation und erhöhte Gelenksmomente. Primär finden Adaptationsprozesse durch unterschiedliche Traktionsverhältnisse von Fußballschuhen im distalen Bereich der unteren Extremitäten statt. Dies könnte in Verbindung zu den Aussagen von Studien stehen, die im Fußball dem Sprunggelenk die größte Verletzungshäufigkeit zusprechen (Ekstrand et al. 2006). Reaktive Bewegungsausführungen können als weiteren möglichen Faktor für Verletzungen im Fußball herangezogen werden (Besier et al. 2001a). Hierfür richtet sich bei reaktiv durchgeführten Richtungswechseln erneut der Fokus auf das Sprunggelenk. Durch eine zeitliche Verzögerung bei reaktiven Bewegungen ist die Stellung der unteren Extremitäten des Sportlers im Vergleich zu aktiven Bewegungen weniger in die neue Bewegungsrichtung gebracht. Diese ungünstigere Stellung versucht der Sportler primär über eine verstärkte Eversion des Sprunggelenks zu kompensieren. Diese Kompensation kann für den Sportler ein erhöhtes Belastungsprofil im Sprunggelenk bedeuten (Giza et al. 2003). Allgemein lässt sich feststellen, dass sich ähnliche Sohlenkonfigurationen bei Probandentests hinsichtlich von Traktionsmessungen nur marginal unterscheiden. Eine Kombination von einer Vielzahl an möglichen Adaptationsprozessen, die sich in der Summe nivellieren, scheinen hierbei die Traktionseigenschaften von leicht unterschiedlichen Sohlenkonfigurationen zu überschatten. Eine Kombination aus sportmotorischem, subjektivem, biomechanischem und mechanischem Testverfahren ermöglicht eine allgemeingültige Aussage über Traktionsverhältnisse von Sohlenkonfigurationen auf Kunstrasen.
Zusammenfassung:
Traktionsverhältnisse, modifizierbar durch unterschiedliche Sohlenkonfigurationen, können die Leistungsfähigkeit der Sportler und die Belastungen der unteren Extremitäten beeinflussen. Auf Kunstrasen der dritten Generation erweisen sich eben und flächig verteilte Sohlenkonfigurationen als Vorteilhaft. Die Belastungen der unteren Extremitäten können sich durch reaktive Bewegungsausführungen weiter erhöhen. / Influence of traction properties on movement patterns in soccer – Interaction between sole configurations of soccer boots and 3rd generation artificial turf
Introduction/Objective:
In recent years the development of artificial soccer turfs got an enormous enhancement. Thereby, high quality types of artificial soccer turfs (3rd generation, FIFA 2-star) were approved for official game play by the FIFA. Latest injury studies and game analysis studies showed that characteristics between artificial turf and natural grass do not differ for injury rates and playing style (Ekstrand et al. 2006, FIFA 2009d). However, movement patterns and movement strategies of soccer players on artificial turf are yet not fully understood. Main criteria for movement patterns of soccer players are traction properties – the player-surface interaction (Sterzing et al. 2007). Therefore, sole configurations of a soccer boot modifiable in numbers, length, geometry and material of studs plays an influencing role. Traction properties influence performance aspects and loads acting on the players’ body (Shorten et al. 2003). On artificial turf players normally use soccer boots with sole configurations designed for playing on natural grass. At the time of this project there were only isolated and unsystemmatic researches according to sole configurations for artificial turf. Thus, there is a discrepancy between a “new” surface and “old” shoes in soccer.
In human locomotion a comprehensive assessment of athletic footwear is used to analyse criteria such as traction properties. Comprehensive assessment of athletic footwear contains motor performance, perception, biomechanical and mechanical testing. Generellay, biomechanical measurements focus on utilized traction, mechanical measurements on available traction. In this context, the concept of available and utilized traction is distinguished by Fong et al. (2009). Suited traction properties with regard to performance aspects might be reflected in higher utilized biomechanical shear forces and better perception. These higher biomechanical shear forces enable the player to run faster. Unsuited traction properties with regard to higher loads acting on the players’ body might be displayed by a combination or a linkage of relative fixed shoes with the ground and higher joint moments at the lower extremities.
The objective of this doctoral thesis was to investigate traction properties of various sole configurations of soccer boots on artificial turf. Thereby, performance aspects as well as loads acting on the players’ body were on the focus of this doctoral thesis. Additionally, the influence of various basic conditions like traction properties and movement requirements (time constraint due to reaction) on movement pattterns were analyzed during dynamic changes of direction.
Methods:
This doctoral thesis contained three interdependent studies with several methods in a time period of three years. Topics and questions of each single study were resulted in the findings of the respective study before. Single testing sessions took place either in laboratory environment or partly on the pitch as field testing.
In study 1 traction properties of three current available sole configurations (hard ground, firm ground and soft ground) and one prototype (artificial turf) were investigated with regard to performance aspects. Topics were motor performance, perception, biomechanical and mechanical testing. Fundamental traction variables of the testing sessions were running times of subjects through a slalom and acceleration course, traction perception of subjects according to liking of the sole configurations, ground reaction forces variables like horizontal shear forces and force ratio, shear force divided by vertical force, during several soccer-specific movements and mechanical traction variables like traction coefficients and force rising rates.
In study 2 movement patterns of various sole configurations (soccer boot without studs, artificial turf, firm ground and soft ground) were analyzed via biomechanical testing (motion analysis) during dynamic turning movements. The purpose of this study was to quantify movement adaptations based on different traction properties. Fundamental research aspects were joint moments of the lower extremities, horizontal foot translation, defined as the relative motion of the shoe on the surface during ground contact and angles of several segments and joints of the lower extremities at touchdown and during turning.
In study 3 the influence on movement patterns during reactive movements compared to active movements wearing various sole configurations (artificial turf, firm ground) during dynamic turning movements were investigated. For this study also biomechanical testing (motion analysis) served for analysis of kinematic and kinetic variables of reaction and sole configurations.
For all three studies a subject pool of 58 male soccer players (age: 22.4 ± 3.3years, height: 177.2 ± 4.6cm, weight: 71.4 ± 5.6kg, experience: 6.4 ± 3.7h/week) was available.
Statistical analysis was done by a one way repeated measured ANOVA and a post-hoc test by Bonferroni for motor performance and biomechanical variables to discriminate between sole configurations, if this was appropriate. For subjective testing, Friedman-test were used to differentiate between sole configurations. For mechanical testing, descriptive statistics were applied. In study 3 the data were analyzed according to two factors (shoe and reaction). Additionally, in this study vector coding was done (Heiderscheidt et al. 2002).
Results:
On 3rd generation artificial turf, traction properties influenced performance aspects of players and loads acting on the players’ body. Plane distributed sole configurations like hard ground and artificial turf design enabled the players to run faster through a traction course compared to aggressive sole configurations. Faster running times were well reflected by players’ perception. Plane distributed sole configurations were also perceived to be better suited on artificial turf. Additionally, these sole configurations provoked statistically higher biomechanical shear forces. High mechanical traction properties did not automatically lead to better performance aspects of the players.
During dynamic changes of direction, too low traction properties provoked more vertical alignment with respect to perpendicular of the lower extremities and lower joint moments. High and excessive traction properties displayed a relative fixed shoe-ground interface as well as high joint moments during dynamic changes of direction. Movement adaptations with regard to soccer boots were primary shown in the distal part of the lower extremities.
Reactive movement patterns showed an unsuited foot and leg placement at initial ground contact based on a longer phase of reaction compared to active movement patterns. This unsuited foot and leg placement was shown by reduced tibial rotation and foot adduction through new running direction. During turning this unsuited foot and leg placement were primary corrected by an increased ankle eversion angle. Additionally, higher knee and ankle joint moments were observed for reactive movement patterns. Differences in movement patterns for sole configurations, which are pretty similar in composition, were not found during reactive movements.
Discussion:
Sole configurations influence movement patterns and movement strategies on artificial turf. Low traction properties indicate more cautious movement behaviour due to risk of slipping, too high traction, implicated by high foot fixation of the player with the surface, indicate also more cautious movement behaviour. Referring the concept of Fong et al. (2009) plane distributed sole configurations provoke higher biomechanical utilized traction. In contrast, pronounced sole configurations with long studs provoke high mechanical available traction. However, these high and excessive mechanical traction properties disabled the subjects to perform with their best capacity. Therefore, plane and evenly distributed sole configurations showed positive aspects for performance and loads acting on the players’ body on 3rd generation artificial turf. Therefore, high biomechanical shear forces produce faster stops or more dynamic propulsion, which influence the performance positively during dynamic changes of direction. Running times through traction courses (Krahenbuhl 1974, Sterzing et al. 2009) and biomechanical shear forces (Valiant 1988, Morag & Johnson 2001, Shorten et al. 2003) were suited variables to detect traction properties according to performance. Penetration of studs into the ground as well as distribution of studs (distance between fore- and rearfoot studs) may play an influencing role on traction properties for soccer boots. Joint moments and horizontal foot translation are suited indicators for the loads acting on lower extremities during dynamic changes of direction (Torg & Quedenfeld 1971, Ryder et al. 1997). Thereby, sole configurations with too high mechanical traction show a combination of decreased horizontal foot translation and increased joint moments. These adaptation processes based on traction properties of soccer boots are primary shown in distal part of the lower extremities. There might be a linkage to reports showing ankle injuries are most common in soccer (Ekstrand et al. 2006). Additionally, reactive movement patterns may be another risk factor for injuries in soccer (Besier et al. 2001a). Due to time constraint for reactive movement patterns the foot and leg placement of the lower extremities are rotated to a lesser extend in new running direction compared to active movement patterns. This unprepared foot and leg placement were primary compensated by an increased eversion at ankle. This compensation might mean increased ankle loadings (Giza et al. 2003). In general it has been showed that pretty similar sole configurations only differ marginal with regard to traction properties during subjects testing. A combination of several adaptation processes, which levelled out in sum, might overshadow traction properties of marginal different sole configurations. A combination of motor performance, perception, biomechanical and mechanical testing allow to give a generally statement about traction properties of sole configurations on artificial turf.
Conclusion:
Traction properties, modifiable by different sole configurations, could play an influencing role for performance aspects of the players and for the loads of the lower extremities. On 3rd generation artificial turf plane and evenly distributed sole configurations work better than pronounded sole configurations. Loads of the lower extremities could be increased by reactive movement patterns.
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