DEVELOPMENT OF AN INSTRUMENT TO MEASURE THE „QUASI-STATIC“ SENCE OF BALANCE

INTRODUCTION: A measuring instrument was developed to record oscillations with regard to the projection of the center of gravity of the body (on an axis to the position where the subject stands). The measuring instrument works like a seesaw. The axis runs along the standing position. Variations are recorded by two linear positional sensors placed under the construction. The standing surface can be rotated up to 5.6°, and additionally, swaying is dampened by springs. METHODS: In the study the above-mentioned construction was compared with the Kistler force platform, with which the body’s center of gravity is projected onto the base ground. Nineteen subjects took part in the study, which required them to stand on one foot for 40 seconds with closed eyes; each subject repeated this five times, each time trying to maintain his balance. The test was repeated one week later. Different features of both measuring instruments were compared. These were among other things the mean variation of measurements, the average of the mean, the length of the curve of the projection and the greatest divergence from the mean. RESULTS: As a result it can be stated that each feature states a different aspect of the motor quality ‘quasi-static balance’. The degree of definiteness among features of one measuring instrument differed between 2% and 95%. A significant correlation between the features of both measuring instruments was detectable in a significant way for two features. Retest reliability could be detected for almost all features with high significance (p < .01). Quality criteria were fulfilled, in the sense of classical test theory, i.e., reliability, validity and objectivity. Furthermore, the measuring system weighs only 5 kg and is thus easy to transport. CONCLUSIONS: This study shows that the developed measuring instrument is suitable as an alternative measuring system to the Kistler force platform in the measuring of quasi-static balance on one axis. REFERENCES: Bös, K. (1987). Handbuch sportmotorischer Tests. Göttingen: Dr. C. J. Hogrefe. Fetz, F. (1994). Sensomotorisches Gleichgewicht im Sport. Vienna: Österreichischer Bundesverlag

LOADS ON THE LUMBAR SPINE DURING BUNGEE JUMPING

INTRODUCTION: The purpose of this study was to quantify the load that occurs on the lumbar spine during bungee jumping and to compare these results with loads that occur during trampoline and vertical jumps. METHODS: For each of ten bungee jumpers representing two weight classes, three dimensional acceleration measurements were recorded by an accelerometer attached to their skin at the iliac spine. Similarly, two dimensional (vertical and sagittal) acceleration measurements were recorded for trampoline and vertical jumps of subjects representing different heights and landing performances. The following loading parameters were analyzed:maximum vertical acceleration, maximum sagittal acceleration, calculated vertical forces on the lumbar vertebral bodies in relation to the tensile strength for bungee jumping, calculated vertical forces on the lumbar vertebral bodies in relation to the compresive strength for trampoline and vertical jumps, relative vertical forces on the lumbar intervertebral discs. In addition, for bungee jumping, the differences between the two weight classes and the influence of body weight on vertical acceleration were examined. RESULTS: 1. During bungee jumping the vertical acceleration maxima and the relative vertical forces of vertebral bodies and intervertebral discs were significantly or high significantly greater in the lower weight class (50 - 80 kg) compared to the higher weight class (80-110 kg). 2. During bungee jumping, in both groups, the correlation between body weight and vertical acceleration maximum was negative; in the lower weight class, there was a high correlation (r = -0.995; p < 0.01) between these parameters. 3. The mean of the vertical acceleration maxima for bungee jumping (2.7 g) was lower than the corresponding means in trampoline (5.8 – 8.7 g), and the hard (3.7 – 11.1 g) and most of the soft vertical jump landings (3.3 – 7.3 g). 4. The mean of the maximal sagittal acceleration for bungee jumping (2.5 g) was higher than one group in trampoline (1.5 g), most of the soft (1 – 2.2 g) and two of the hard vertical juimp landing performances (1.1 – 1.9 g). 5. The mean of the relative vertical forces on the lumbar vertebral bodies for bungee jumping (30.3 %) was lower than in trampoline (38.3 – 59.2 %), in most of the hard vertical landing performances (34.5 – 67.3 %) and lower in the soft landing performances from 1.1 m to 1.5 m (33.2 – 44.4 %). 6. The mean of the relative vertical forces on the lumbar intervertebral discs during bungee jumping (34 %) was higher than the corresponding means in trampoline (17.1 – 27.0 %), and hard (10.0 – 29.9 %) and soft (6.5 – 19.6 %) vertical landing performances

BIOMECHANICAL ANALYSIS OF SPRINTING TO IMPROVE THE INDIVIDUAL TECHNIQUE

INTRODUCTION: The aim of this study is to record dynamic and cinematic parameters during sprinting with maximum velocity. The sprint start is also examined. The motion analysis aims for an improvement of the individual technique METHODS: 21 male and 3 female runners took part in this study. Cinematic and dynamic parameters were recorded during start and fast running. In the sagitall plane the following parameters were analysed: joint-angles, velocities and acceleration of joints, centres of joints, joint forces and joint moments. These parameters were recorded with two high-speed cameras (250 Hz) and a 3- dimensional force platform (measuring area 240x80 cm). The experimental set-up allowed the recording of two successive steps on the force platform while the dynamical- and kinematical-data was synchronously obtained. Additionally the reaction time was measured. The reaction time is the time from the start signal to the moment the rear leg leaves the block,. The high-speed video data were interpreted with the software package winanalyze from Mikromak. RESULTS: Very different rotary actions of the shoulders to balance the hip action were observed. The main differences between the single athletes became evident in the velocities and the accelerations of the hip and the knee-angles. Particularly variable forces in the direction of movement (retarding stroke) came forward between the different athletes. The observed tendencies will be verfied in another study in June. OUTLOOK: After the inquiry of the general fitness of the sprinters the development of a special training-program for each athlete is intended in the next step. It will be based on the Multi-Joint-Concept form R. P. Narcessian. REFERENCES: Hay, J. G. (1993). The Biomechanics of Sports Techniques. Englewood Cliffs, N.J.: Prentice-Hall

Red-Sequence Galaxies at High Redshift by the COMBO-17+4 Survey

We investigate the evolution of the galaxy population since redshift 2 with a focus on the colour bimodality and mass density of the red sequence. We obtain precise and reliable photometric redshifts up to z=2 by supplementing the optical survey COMBO-17 with observations in four near-infrared bands on 0.2 square degrees of the COMBO-17 A901-field. Our results are based on an H-band-selected catalogue of 10692 galaxies complete to H=21.7. We measure the rest-frame colour (U_280-V) of each galaxy, which across the redshift range of our interest requires no extrapolation and is robust against moderate redshift errors by staying clear of the 4000A-break. We measure the colour-magnitude relation of the red sequence as a function of lookback time from the peak in a colour error-weighted histogram, and thus trace the galaxy bimodality out to z~1.65. The (U_280-V) of the red sequence is found to evolve almost linearly with lookback time. At high redshift, we find massive galaxies in both the red and the blue population. Red-sequence galaxies with log M_*/M_sun>11 increase in mass density by a factor of ~4 from z~2 to 1 and remain nearly constant at z<1. However, some galaxies as massive as log M_*/M_sun=11.5 are already in place at z~2.Comment: 18 pages, 11 figures, accepted for publication in Ap

Wie kann die dynamische Festkörper-modellierung beim motorischen Lernen behilflich sein? Fertigkeitserwerb mit hilfe dynamischer Modellierung

The purpose of this research project was to bridge the gap between motion analysists and athletes and coaches by establishing a platform for the communication amongst the three parties. The first part of this project depicted that: 1) differences amongst the external view (motion analysists), internal sight (athletes) and internal sight from external view (coaches) were caused by the inertial (environment-fixed) and the non-inertial (body-fixed) system; 2) joint rotations were not identical with the muscular moment, therefore, passive rotations can occur; 3) critical phases in a skill control, which can be revealed by using modeling simulation, should be emphasized during learning; and 4) dynamic modeling has the potential to link and to unify the three views and supply a more holistic picture of human motor control. Based on these results, a learning model was constructed in the second part of the project. The essence of the model is to supply learners with the control signal (muscle moments) obtained from individual anthropometrical data and should-be-learned kinematics. Such an individualized learning process consists of: 1) obtaining kinematic characteristics of a should-be-learned skill using motion capture, 2) substituting the model’s anthropometrical data with a learner’s data, and applying inverse dynamic analysis to the model for obtaining muscle moments – the individualized control signal, and 3) applying the control information in the skill learning. The model was validated in a motor learning study. The study unveiled that dynamic modeling is well suited for improving communication with athletes and coaches as well as for improving efficiency of learning.Uvod Svrha ovog istraživačkog projekta bila je premostiti jaz između znanstvenika koji se bave istraživanjima pokreta te sportaša i trenera uspostavljanjem platforme za komunikaciju između triju skupina. U prvom dijelu projekta (Shan i sur., 2004) utvrđeno je da: 1) su razlike između vanjske perspektive (analitičari pokreta), unutarnjeg pogleda (dojam sportaša) i unutarnjeg gledišta iz vanjske perspektive (treneri) uzrokovane inercijalnim (nepomičan u odnosu na okolini) i neinercijalnim (nepomičan u odnosu na sportaševo tijelo) sustavom, kao i uparivanjem segmenata tijela; 2) rotacije zglobova nisu jednake mišićnim momentima, stoga se mogu pojaviti pasivne rotacije; 3) kritične faze u kontroli vještine, koje se mogu otkriti korištenjem simulacije modela, iznimno su važne za učenje i da ih se treba u tom procesu naglašavati i 4) dinamičko modeliranje može poslužiti kao platforma za povezivanje i ujednačivanje tri različita pogleda te pridonijeti stvaranju cjelovitije slike o ljudskoj motoričkoj kontroli. Stoga, radi uspostavljanja što bolje komunikacije sa sportašima i trenerima, analitičari pokreta ne bi trebali stati na deskriptivnoj razini, koja nudi jedino kinematičke parametre vještine. Takva deskripcija dokazano odstupa od sportaševa osjećaja kontrole ili trenerova iskustva. Iskusni su treneri svjesni da je za pojednostavljivanje motoričkog učenja ključno učeniku / sportašu prenijeti znanje o tome koji su specifični mišići uključeni u pokret, kolika je sila potrebna te kakvo je stvarno vremensko-prostorno usklađivanje (timing) nužno za motoričku kontrolu. Ti aspekti pokreta pripadaju kontrolnim parametrima i mogu se izvesti iz dinamičkog i inverznog dinamičkog modeliranja. Takav scenarij sugerira da se dinamičko modeliranje može koristiti kao platforma za unapređenje komunikacije između analitičara pokreta i onih koji to realiziraju u praksi. U drugom di-jelu projekta (predstavljenom u ovom broju) konstruiran je model za učenje koji je utemeljen na razmatranjima iz prvog rada. Bit je modela opskrbiti onoga koji uči upravljačkim informacijama - mišićnim momentima. Takve se informacije mogu pojedinačno priskrbiti primjenom inverzne dinamičke analize na konstruiranom modelu tako da individualne antropometrijske karakteristike i kinematički parametri koje treba naučiti budu ulaz za modelnu analizu. Na taj se način dizajnira individualiziran program učenja koji sadrži: 1) dobivanje kinematičkih karakteristika vještine koju treba naučiti korištenjem zahvaćanja pokreta (motion capture) i analize, 2) zamjenjivanje modelnih antropometrijskih podataka podacima osobe koja uči i primjenu inverzne dinamičke analize na model kako bi se utvrdili zglobno-mišićni momenti, što onome koji uči daje individualizirane važne kontrolne informacije i 3) primjenu kontrolne informacije u procesu učenja vještine. Rezultati i rasprava Model je procijenjen u istraživanju iz područja motoričkog učenja. Uzorak ispitanika činilo je 20 studenata sporta, podijeljenih u dvije grupe. U okviru eksperimenta istraživala su se dva aspekta učenja – znanje o pokretu i izvedba pokreta. Prva je grupa učila vještinu na konvencionalan način, koristeći se samo vizualnim informacijama. Druga je grupa uz vizualne informacije dobila i dodatne informacije o kontroli mišića. Istraživanje je evaluirano fenomenološki (pomoću upitnika) i objektivno (ekspertnom analizom video zapisa). Rezultati su pokazali da je prema, mišljenju ispitanika, metoda koja je uz vizualne nudila i kinematičke informacije kao i informacije o kontroli mišića bolja i da omogućuje bolje razumijevanje vještine. U okviru objektivne analize eksperti su procijenili da je izvedba grupe koja je imala dodatne informacije bolja od izvedbe ispitanika koji su učili na uobičajen način. Zaključak S obzirom na usporedbu subjektivne i objektivne procjene, može se zaključiti da se informacije o mišićnim momentima, dobivene na osnovi inverznog dinamičkog modeliranja, mogu koristiti kao kontrolni obrazac te da olakšavaju komunikaciju između tri skupine sudionika motoričkog učenja i da proces učenja pojednostavljuju.Die Absicht dieses Projekts war, die Kluft zwischen den Bewegungsanalysten, den Sportlern und Trainern zu überbrücken, um eine Platform für die Kommunikation zwischen den drei Parteien herzustellen. Im ersten Teil des Projekts wurde klar, dass 1) die Unterschiede zwischen der äußeren Sicht (den Bewegungsanalysten), der inneren Sicht (den Sportlern) und der inneren Sicht aus äußerem Betrachtungspunkt (den Trainern) von (umweltgebundenen) Inertialsystemen und (körpergebundenen) Nicht-Intertialsystemen verursacht sind; 2) dass die Gelenkrotationen mit den Muskelmomenten nicht identisch sind, weshalb passive Rotationen aufkommen können; 3) dass man Nachdruck auf kritische Phasen der Fertigkeitskontrolle während des Erwerbs setzen sollte, was man mit Hilfe der Modellierungssimulation erzielen kann; 4) dass die dynamische Modellierung imstande ist, die drei Sichten zu verbinden und zu vereinigen, um dadurch das holistische Bild von der menschlichen motorischen Kontrolle zu gewinnen. Aufgrund dieser Ergebnisse, wurde im zweiten Teil des Projekts ein Lernmodell entworfen. Der Kern des Modells ist, den Lernenden ein Kontrollsignal (Muskelmomente) zur Verfügung zu stellen, das sich aus individuellen anthropometrischen Angaben und einer noch-zu-erwerbenden Kinematik ergibt. Ein solcherarts individualisierter Erwerbsprozess setzt voraus, dass 1) man die kinematischen Eigenschaften einer zu erwerbenden Fertigkeit mit Hilfe der Bewegungserfassung bestimmt, 2) dass man die anthropometischen Angaben des Modells mit denen des Lernenden ersetzt, und die inverse dynamische Analyse auf das Modell anwendet, um Muskelmomente, bzw. ein individualisiertes Kontrollsignal zu bekommen, und 3) das man die Kontrollinformation beim Fertigkeitserwerb anwendet. Das Modell wurde in der motorischen Lernstudie gültig gemacht. Die Studie zeigte, dass sich die dynamische Modellierung sehr gut eignet, um die Kommunikation zwischen den Sportlern und Trainern zu verbessern, sowie den Lernprozess zu fördern

Wie kann die dynamische Festkörper-Modellierung beim motorischen Lernen behilflich sein?- Leistungsdiagnose mit Hilfe der dynamischen Modelllierung

There are two main problems for biomechanists in motor learning practice. One is theory vs. experience, the other is the determination of dominative information directly helpful in the practice. This project aimed at addressing these problems from a quantitative aspect by using motion capture and biomechanical rigid body modeling. The purposes were to identify differences in the description of movements amongst motion analysists (external view), athletes (internal sight) and coaches (internal sight from external view; Lippens, 1997) and to identify applicable and germane information for the practitioners. A trampoline skill of a vertical takeoff and landing on the back was selected for the project. The skill was captured and modeled using a five-segment model: head-trunk, arm, thigh, shank and foot. Through the application of dynamic and inverse dynamic analysis, timely variations in joint angles and muscle moments (shoulder, hip, knee and ankle) were calculated to determine description differences among the three views and seek a possible linkage within them. Results show that the inertial and non-inertial systems as well as the coupling of body segments established the differences among the three views and that joint rotations are not identical with the muscular moments, therefore, passive rotations (McGeer, 1990) can occur, and lastly, knowledge of muscular moments at \u27critical\u27 and passive phases should be emphasized during motor learning. It is concluded that biomechanical modeling should be a platform to link all three views and supply a more holistic picture on human motor control.Uvod Praktičari u sportu obično se u primjeni analize pokreta i biomehaničkog znanja u području motoričkog učenja susreću s dvije vrste problema. Jedan je suprotstavljenost teorije i iskustva, tj. udaljenost dobivenih rezultata analize/teorijskih predviđanja i iskustva/\u27osjećaja kontrole\u27. Drugi se odnosi na određivanje dominantne informacije koja izravno pomaže učenju motoričkih vještina. S biomehaničkog gledišta postoje tri aspekta koje treba uzeti u obzir: \u27antropometrijska biome-hanika\u27, \u27biomehanika pokreta\u27 i \u27preventivna biomehanika\u27. Antropometrijska biomehanika bavi se mogućnošću transfera vještina iz jednog biogeometrijskog sustava u drugi. Biomehanika pokreta opisuje karakteristike pokreta s ciljem da utvrdi dominantne informacije o učenju. Preventivna biomehanika proučava biomehanička opterećenja i pokazuje može li opterećenje omogućiti uspješno učenje bez opasnosti od ozljeđivanja. Hoće li ti aspekti biti uspješno primijenjeni u sportskoj praksi, ovisi o komunikaciji među istraživačima koji analiziraju pokret, s jedne strane, i sportaša i trenera, s druge. Na temelju kinematičkih mjerenja gibanja u prostoru, istraživači koji analiziraju pokret opisuju kretanje u koordinatnom sustavu fiksnom u odnosu na okolinu (vanjsko gledište). Međutim, sportaš/ sportašica kontrolira svoje mišiće u sustavu fiksnom u odnosu na njegovo/njezino tijelo (unutarnje gledište / unutarnji dojam). Postoji, međutim, i treći izvor informacija. Na temelju dugogodišnjeg iskustva, trener može prevesti opaženi pokret iz okoline u područje mišićne kontrole u tjelesnom sustavu (unutarnje gledište iz vanjske perspektive) (Lippens, 1997). Praksa, međutim, pokazuje da postoje neke komunikacijske poteškoće između sustava koje su uzrokovane različitim objašnjenima proizašlima iz različitih gledišta, a to remeti efikasnost motoričkog učenja u praksi. Ovaj rad pristupa tom problemu na kvantitativan način koristeći kombinaciju kinematičkih mjerenja gibanja u prostoru i modeliranja tijela krutim segmentima. Vještina skakanja na trampolinu, točnije sposobnost vertikalnog odraza i doskoka na leđa, odabrana je za analizu u ovom radu. Svrha prvog dijela istraživanja bila je utvrditi razlike u opisu kretnji s obzirom na vanjsko gledište, unutarnje gledište/dojam te unutarnje gledište iz vanjske perspektive. Svrha drugog dijela bila je, na temelju tih spoznaja, identificirati informacije koje će biti korisne vježbačima u praksi. Metode Poznato je da se kinematičko mjerenje gibanja u prostoru i modeliranje tijela krutim segmentima može koristiti kako bi se utvrdile najvažnije karakteristike kontrole zglobova pri izvođenju vještine koja se promatra. Na temelju kinematičkih parametara moguće je utvrditi promjene položaja zglobova u vremenu. Koristeći se osnovnim pravilima fizike, možemo jednostavne podatke o položaju prevesti u termine modelnih pokreta krutih segmenata tijela. Za potrebe ovog rada konstruiran je model od pet segmenata: glava-trup, ruka, bedro, potkoljenica i stopalo za izračunavanje kutova u zglobovima ramena, kuka, koljena i gležnja. Dobivene vremenske varijacije u kutovima tih zglobova često se koriste u okviru kinematičke analize pokreta za utvrđivanje karakteristika pokreta i obrasca njegove kontrole (vanjsko gledište). Kako bi se provela temeljita analiza, u ovom je radu korišteno inverzno modeliranje za utvrđivanje mreže momenata zglobova i mišića, što je kvantitativna vrijednost za grupni učinak rada zglobno-mišićnog sustava. Ta varijabla je unutarnji uzrok za pokretanje zglobova i trebala bi biti čvrsto povezana sa sportaševim \u27osjećajem kontrole\u27. Tako se izračunata mreža momenata mišića može koristiti kao reprezentant unutarnjega gledišta. Ako se promjena u kutu pokreta zgloba i momenta mišića može objasniti Newtonovom dinamičkom jednadžbom, koja se koristi u kinematičkoj analizi sila i momenata gibanja u prostoru, tada bi se vanjsko gledište moglo izjednačiti s unutarnjim. U izračunavanju parametara modeliranja, parametri inercije tijela (jedna vrsta ulaznih podataka) procijenjeni su uz pomoć antropometrijskih \u27normi\u27 dobivenih u statističkim studijama (Zatsiorsky i Seluyanov, 1983; Shan i Nicol, 1998). Promjenom antropometrijskih podataka (stas), a uz održavanje kontrole zglobova konstantnom, moguće je uz pomoć modela odrediti jesu li položaji perifernih dijelova tijela jednaki ili ne. Kako je individualno iskustvo pojedinca usko povezano s njegovom/njezinom biogeometrijskom strukturom, takva modelna simulacija može se koristiti kako bi se istražio utjecaj trenera na objašnjavanje vještine (unutarnje gledište iz vanjske perspektive). Rezultati i rasprava Rezultati ovog istraživanja pokazali su da vanjsko gledište, utvrđeno kinematičkom analizom gibanja u prostoru, nije jednako sportaševu osjećaju kontrole (unutarnje gledište). Uzroci tih razlika jesu sile inercije, kao i uzajamno djelovanje segmenata unutar složenog, višesegmentnog sustava (fizikalni efekt lanca). Drugo, rotacije zglobova nisu jednake mišićnim momentima; mogu se poja-viti i pasivne rotacije (McGeer, 1990). Pasivna rotacija je pokret u zglobu koji ne zahtijeva nikakvu kontrolu ni energetsku opskrbu. Prednost pasivnih fenomena u motoričkom učenju leži u pojednostavljivanju motoričke kontrole zahvaljujući mogućnosti da se u fazama pasivnosti kontrola zanemari. Pasivni pokret odvaja sportašev osjećaj (kontrolu) od opisa pokreta koji se temelji na kinematičkim karakteristikama utvrđenima kinematičkim analizama pokreta. Takve (pasivne) faze moguće je odrediti jedino momentom mišića (zgloba) koji se može dobiti inverznom dinamičkom analizom. Treće, individualno je iskustvo pod snažnim utjecajem tjelesne visine. To nas vodi do raznolikih unutarnjih gledišta iz vanjske perspektive. Stoga bi treniranje vještina trebalo biti prilagođeno antropometrijskim obilježjima sportaša. I na koncu, u motoričkom učenju trebalo bi naglašavati poznavanje mišićnih momenata i \u27kritičnih faza\u27. Kritična faza je trenutak u izvedbi u kojoj i minimalno odstupanje kontrole pokreta može dovesti do potpuno drugačijeg ishoda. I opet valja naglasiti da takve faze nije moguće uočiti \u27izvana\u27, dok ih se dinamičkom simulacijom može vrlo jednostavno utvrditi. Zaključak Može se zaključiti da kinematička analiza pokreta pribavlja informacije o kinematičkim karakteristikama motoričke vještine, međutim, ne može dati uvid u uzročno-posljedične odnose. To uzrokuje razmimoilaženje između vanjskog gledišta i unutarnjega gledišta ili sportaševa dojma. I antropometrijska obilježja utječu na individualno iskustvo, pa su modifikacije u primjeni nužne. Jedan od načina povezivanja vanjskog gledišta, unutarnjeg gledišta i unutarnjeg gledišta iz vanjske perspektive jest i biomehaničko modeliranje ljudskog tijela krutim segmentima.Im Prozess des motorischen Lernens befassen sich die Biomechaniker mit zwei Hauptproblemen. Das erste Problem liegt in der Theorie gegenüber Praxis und das andere in der Bestimmung der dominanten Information, die in der Praxis nützlich ist. Die Absicht dieses Projekts war es, diese Probleme quantitativ anzugehen, mit Hilfe der Bewegungserfassung und der biomechanischen Festkörper-Modellierung. Damit wollte man die Unterschiede bei der Bewegungsbeschreibung zwischen den Bewegungsanalysten (die äußere Sicht), den Sportlern (die innere Sicht) und den Trainern (die innere Sicht aus äußerem Betrachtungspunkt; Lippens, 1997) bestimmen und anwendbare und relevante Informationen für die Sporttreibenden sammeln. Der Trampolinsprung -Senkrechte Strecksprung zur Rückenlage -wurde für das Projekt ausgewählt. Der Sprung wurde gelehrt und nachgeahmt nach einem fünfteiligen Modell: Kopf-Rumpf, Arm, Oberschenkel, Unterschenkel und Fuß. Die dynamischen und inversen dynamische Analysen wurden angewandt und dadurch zeitliche Variationen in Gelenkwinkeln und Muskelmomenten (Schulter, Hüfte, Knie und Gelenk) berechnet, um die Beschreibungsunterschiede zwischen den drei Sichten zu bestimmen, und nach einer möglichen Verbindung zwischen ihnen suchen. Den Ergebnissen nach liegt der maßgebende Unterschied zwischen den drei Betrachtungsweisen sowohl in Inertialsystemen als auch in Nicht-Inertialsystemen, sowie in der Verbindung der Körpersegmente. Die Gelenkrotationen sind mit den Muskelmomenten nicht identisch, weshalb passive Rotationen (McGeer, 1990) aufkommen können. Letztlich soll man im Prozess des motorischen Lernens Nachdruck auf die Kenntnis von Muskelmomenten in \u27kritischen\u27 und passiven Phasen setzen. Daraus kann gefolgert werden, dass biomechanische Modellierung eine Plattform dafür sein sollte, alle Sichten zu verbinden und dadurch das holistische Bild von der menschlichen motorischen Kontrolle zu gewinnen

Optical Hall conductivity of systems with gapped spectral nodes

We calculate the optical Hall conductivity within the Kubo formalism for systems with gapped spectral nodes, where the latter have a power-law dispersion with exponent n. The optical conductivity is proportional to n and there is a characteristic logarithmic singularity as the frequency approaches the gap energy. The optical Hall conductivity is almost unaffected by thermal fluctuations and disorder for n=1, whereas disorder has a stronger effect on transport properties if n=2

A Blueprint to Address Research Gaps in the Development of Biomarkers for Pediatric Tuberculosis

Childhood tuberculosis contributes significantly to the global tuberculosis disease burden but remains challenging to diagnose due to inadequate methods of pathogen detection in paucibacillary pediatric samples and lack of a child-specific host biomarker to identify disease. Accurately diagnosing tuberculosis in children is required to improve case detection, surveillance, healthcare delivery, and effective advocacy. In May 2014, the National Institutes of Health convened a workshop including researchers in the field to delineate priorities to address this research gap. This blueprint describes the consensus from the workshop, identifies critical research steps to advance this field, and aims to catalyze efforts toward harmonization and collaboration in this are

Multicenter Evaluation of the Fully Automated PCR-Based Idylla EGFR Mutation Assay on Forman-Fixed, Paraffin-Embedded Tissue of Human Lung Cancer

Before initiating treatment of advanced non-small-cell lung cancer with tyrosine kinase inhibitors (eg, erlotinib, gefitinib, osimertinib, and afatinib), which inhibit the catalytic activity of epidermal growth factor receptor (EGFR), clinical guidelines require determining the EGFR mutational status for activating (EGFR exons 18, 19, 20, or 21) and resistance (EGFR exon 20) mutations. The EGFR resistance mutation T790M should be monitored at cancer progression. The Idylla EGFR Mutation Assay, performed on the Idylla molecular diagnostics platform, is a fully automated (<2.5 hours turnaround time) sample-to-result molecular test to qualitatively detect 51 EGFR oncogene point mutations, deletions, or insertions. In a 15-center evaluation, Idylla results on 449 archived formalin-fixed, paraffin-embedded tissue sections, originating from non-small-cell lung cancer biopsies and resection specimens, were compared with data obtained earlier with routine reference methods, including next-generation sequencing, Sanger sequencing, pyrosequencing, mass spectrometry, and PCR-based assays. When results were discordant, a third method of analysis was performed, when possible, to confirm test results. After confirmation testing and excluding invalids/errors and discordant results by design, a concordance of 97.6% was obtained between Idylla and routine test results. Even with <10 mm(2) of tissue area, a valid Idylla result was obtained in 98.9% of the cases. The Idylla EGFR Mutation Assay enables sensitive detection of most relevant EGFR mutations in concordance with current guidelines, with minimal molecular expertise or infrastructure