Kinematic chains in ski jumping in-run posture

The concept of kinematic chains has been systematically applied to biological systems since the 1950s. The course of a ski jump can be characterized as a change between closed and open kinematic chains. The purpose of this study was to determine a relationship between adjacent segments within the ski jumper’s body’s kinematic chain during the in-run phase of the ski jump. The in-run positions of 267 elite male ski jumpers who participated in the FIS World Cup events in Innsbruck, Austria, between 1992 and 2001 were analyzed (656 jumps). Two-dimensional (2-D) kinematic data were collected from the bodies of the subjects. Relationships between adjacent segments of the kinematic chain in the ski jumper’s body at the in-run position are greater nearer the chain’s ground contact. The coefficient of determination between the ankle and knee joint angles is 0.67. Changes in the segments’ positions in the kinematic chain of the ski jumper’s body are stable during longitudinal assessment. Changes in shank and thigh positions, in the sense of increase or decrease, are the same.Web of Science391736

Varijabilnost gibanja konja u hodu tijekom hipoterapijskog jahanja

The impulses emitted from the back of a horse during hippotherapy stimulate the rider’s postural reflex mechanisms, resulting in balance and coordination training. The objectives of this study were to evaluate the movement variability of the horse’s back and limbs and to determine significant relationships between the movement of the selected body points on the horse. Two English thoroughbreds and twelve female riders participated in six sessions of hippotherapy. Three-dimensional (3-D) videography was used to assess movement of the selected points on the horse’s back and limbs. The spatiotemporal parameters of the horse’s walk showed no significant changes throughout the entire measuring process. Horse movement within a given session was stable, and overall, inter-individual (between-horse) variability was greater than intra-individual variability. The maximum differences in the vertical displacement of the horse’s back across individual sessions were significant. With respect to the range of movement of the caudal part of the horse’s back, it is necessary to consider the instability of movements during longitudinally repeated sessions.Impulsi s leđa konja za vrijeme hipoterapijskog jahanja podražuju jahačeve posturalne refleksne mehanizme, što rezultira treningom ravnoteže i koordinacije. Ciljevi ovog istraživanja bili su vrednovati varijabilnosti gibanja leđa i udova konja i utvrditi značajnost veza između gibanja odabranih točaka na tijelu konja. Dva čistokrvna engleska konja i dvanaest jahačica sudjelovalo je u šest hipoterapijskih sesija. Trodimenzionalna videografija se koristila za utvrđivanje gibanja izabranih točaka na konjskim leđima i udovima. Kinematički parametri konjskog hoda nisu se značajno mijenjali tijekom cijelog procesa mjerenja. Gibanje konja tijekom jedne sesije bilo je stabilno i, generalno, inter-individualna varijabilnost kinematičkih parametara između konja bila je veća nego intra-individualna varijabilnost između mjerenja u svih 6 sesija. Maksimalne razlike u okomitim pomacima leđa konja između pojedinačnih sesija bile su značajne. Promatra li se donji dio leđa konja, potrebno je u obzir uzeti nestabilnost gibanja tijekom ponovljenih jahačkih sesija

Non-nosocomial healthcare-associated infective endocarditis in Taiwan: an underrecognized disease with poor outcome

<p>Abstract</p> <p>Background</p> <p>Non-nosocomial healthcare-associated infective endocarditis (NNHCA-IE) is a new category of IE of increasing importance. This study described the clinical and microbiological characteristics and outcome of NNHCA-IE in Taiwan.</p> <p>Methods</p> <p>A retrospective study was conducted of all patients with IE admitted to the Kaohsiung Veterans General Hospital in Kaohsiung, Taiwan over a five-year period from July 2004 to July 2009. The clinical and microbiological features of NNHCA-IE were compared to those of community-acquired and nosocomial IE. Predictors for in-hospital death were determined.</p> <p>Results</p> <p>Two-hundred episodes of confirmed IE occurred during the study period. These included 148 (74%) community-acquired, 30 (15%) non-nosocomial healthcare-associated, and 22 (11%) nosocomial healthcare-associated IE. <it>Staphylococcus aureus </it>was the most frequent pathogen. Patients with NNHCA-IE compared to community-acquired IE, were older (median age, 67 vs. 44, years, <it>p </it>< 0.001), had more MRSA (43.3% vs. 9.5%, <it>p </it>< 0.001), more comorbidity conditions (median Charlson comorbidity index [interquartile range], 4[2-6] vs. 0[0-1], <it>p </it>< 0.001), a higher in-hospital mortality (50.0% vs. 17.6%, <it>p </it>< 0.001) and were less frequently recognized by clinicians on admission (16.7% vs. 47.7%, <it>p </it>= 0.002). The overall in-hospital mortality rate for all patients with IE was 25%. Shock was the strongest risk factor for in-hospital death (odds ratio 7.8, 95% confidence interval 2.4-25.2, <it>p </it>< 0.001).</p> <p>Conclusions</p> <p>NNHCA-IE is underrecognized and carries a high mortality rate. Early recognition is crucial to provide optimal management and improve outcome.</p

Regulation of Coronary Blood Flow

The heart is uniquely responsible for providing its own blood supply through the coronary circulation. Regulation of coronary blood flow is quite complex and, after over 100 years of dedicated research, is understood to be dictated through multiple mechanisms that include extravascular compressive forces (tissue pressure), coronary perfusion pressure, myogenic, local metabolic, endothelial as well as neural and hormonal influences. While each of these determinants can have profound influence over myocardial perfusion, largely through effects on end-effector ion channels, these mechanisms collectively modulate coronary vascular resistance and act to ensure that the myocardial requirements for oxygen and substrates are adequately provided by the coronary circulation. The purpose of this series of Comprehensive Physiology is to highlight current knowledge regarding the physiologic regulation of coronary blood flow, with emphasis on functional anatomy and the interplay between the physical and biological determinants of myocardial oxygen delivery. © 2017 American Physiological Society. Compr Physiol 7:321-382, 2017

Oksidacijski stres u lakirera izloženih niskim razinama olova

Lead toxicity is a public health problem particularly to the children and to occupationally exposed adults. Evidence is mounting successively regarding the adverse health effects of lead at low levels. This study was undertaken to assess the antioxidant status of lead-exposed residential and commercial painters of Lucknow city in Uttar Pradesh, India. Thirty-five painters aged 20 to 50 years who had blood lead levels ≤400 µg L-1 were selected for the study from a population of 56 male painters initially screened for blood lead. The control group included an equal number of subjects of the same age group without any occupational exposure to lead. We studied the association between low lead level exposure and antioxidant status and found that blood lead levels in painters were approximately seven times as high as in controls [(219.2 ± 61.9) µg L-1 vs. (30.6±10.1) µg L-1, respectively]. Among the biomarkers of lead toxicity a significant decrease in the level of delta-aminolevulinic acid dehydratase [(9.13±4.62) UL-1 vs. (39.38±5.05) UL-1] and an increase in the level of zinc protoporphyrin [(187.9±49.8) µg L-1 vs. (26.4±5.5) µg L-1] were observed in painters compared to controls. Among antioxidant enzymes, painters showed a significant decrease in catalase [(56.77±11.11) UL-1 vs. (230.30±42.55) UL-1] and superoxide dismutase [(0.64±0.19) UL-1 vs. (2.68±0.62) UL-1] compared to controls. Lipid peroxidation was monitored by measuring thiobarbituric acid reactive substances (TBARS) that were expressed in terms of malondialdehyde (MDA) equivalents. Concentration of MDA in plasma was higher in painters than in controls [(7.48±1.31) nmol mL-1 vs. (3.08±0.56) nmol mL-1]. Significant changes were also observed in reduced and oxidised glutathione levels. The strong association between blood lead levels and oxidative stress markers in this population suggests that oxidative stress should be considered in the pathogenesis of lead-related diseases among people with low level environmental exposure to lead.Toksičnost olova javnozdravstveni je problem, napose u djece i odraslih osoba koje su im izložene profesionalno. Sve je više dokaza o štetnom djelovanju olova pri niskim razinama. Svrha je ovog ispitivanja bila procijeniti antioksidacijski status u lakirera iz grada Lucknowa u indijskoj pokrajini Uttar Pradesh. Iz skupine od 56 muškaraca lakirera u dobi od 20 do 50 godina s pozitivnim početnim nalazima olova u krvi, za ispitivanje su izabrana 35-orica čije su razine iznosile ≤400 µg L-1. Izabran je i jednaki broj kontrolnih ispitanika iz iste dobne skupine, koji nisu bili profesionalno izloženi olovu. Ispitana je povezanost izme|u izloženosti niskim razinama olova i antioksidacijskoga stanja te je utvrđeno da su razine olova u krvi lakirera [(219,2±61,9) µg L-1] bile oko sedam puta više negoli u kontrolnih ispitanika [(30,6±10,1) µg L-1]. Od biopokazatelja toksičnosti olova u lakirera je zamijećen značajan pad razina delta- ALAD [(9,13±4,62) UL-1 prema (39,38±5,05) UL-1] te rast razina cinkova protoporfirina [(187,9±49,8) µg L-1 prema (26,4±5,5) µg L-1] u odnosu na kontrolne ispitanike. Od antioksidacijskih enzima u lakirera je značajno pala aktivnost katalaze [(56,77±11,11) UL-1 prema (230,30±42,55) UL-1] i superoksid dismutaze [(0,64±0.19) UL-1 prema (2,68±0,62) UL-1] u odnosu na kontrolu, dok je produkt lipidne peroksidacije u plazmi (izv. thiobarbituric acid reactive substances, TBARS) izražen kao koncentracija malondialdehida (MDA) porastao [(7,48±1,31) nmol mL-1 prema (3,08±0,56) nmol mL-1]. Značajne su promjene također zamijećene u smanjenim razinama glutationa i njihovoj oksidaciji. Snažna povezanost razina olova u krvi s pokazateljima oksidacijskoga stresa upućuje na to da u osoba s niskom razinom izloženosti olovu iz okoliša kod razmatranja patogeneze bolesti povezane s olovom u obzir valja uzeti oksidacijski stres

Kinematic analysis of the flight phase of the Nordic combined and ski jump on a large hill (HS-134 m) during the 2009 Nordic World Ski Championships

The purpose of this study was to assess the execution of the flight phase in the Nordic combined (NC) among three groups of competitors, representing different skill levels, and to compare them with three groups of ski jumpers (SJs). Thirty NC and thirty SJ competitors, who performed ski jumps on an HS-134 m jumping hill, were divided into three subgroups based on jump length execution. Two-dimensional (2-D) kinematic data were collected from the lower extremities, trunks, and skis of the competitors. The SJ group had a smaller lower extremity angle ( p < 0.05), which results in the larger center of mass anterior movement ( p < 0.05) in comparison to the NC competitors. The NC competitors achieved jump lengths comparable to those of the SJ competitors by having significantly higher in-run velocities

Druckmessungen an den Kontaktflächen zwischen Pferd und Reiter – eine Literaturübersicht

The use of systems for pressure measurement between the rider ’s body and the back of the horse is a relatively new procedure. The size and transfer of the load inside the horse-pad-saddle -rider system can be assessed in various ways. This paper provides a review of literature published from 1994 to 2010 that discusses using pressure mapping systems for measuring the contact load between the horse and its rider. Literature was obtained using common scientific databases such as Web of Science, SCOPUS and PubMed entering the key words: “horse”, “pressure”, and “back ”. The first published studies aimed to verify sensor parameters and to minimize animal- and operator-induced errors. In order to obtain valid and reliable data, it is important to perform pressure measurements under highly standardized conditions. Moreover using properly established guidelines for calibrating and placing sensors is crucial for receiving valid data. Subsequent studies focused on the influence of various types of saddles, pads, blankets and adjustments of saddle fit on the loading of the horse’s back. Results of these studies showed that using pressure mapping systems provide a useful evaluation of the load applied to the area of contact between the horse and rider. A properly fitted saddle with a pad can serve as a shock absorber. Literature findings suggest that improving the fit of a saddle by using a saddle pad needs to be individually adapted for each horse and rider. Considering the current status of literature on the use of pressure mapping systems in horseback riding future research should concentrate on using data obtained by biomechanical modelling of contact surfaces, including their interactions; on determining a “normal pattern” of pressure distribution on the equine back; and on finding a way to include individual parameters of the horse and its rider into the overall assessment.Die Größe und die Einwirkung der Belastung im System Pferd - Unterlage - Sattel - Reiter muss aus verschiedenen Blickwinkeln betrachtet werden. Diese Arbeit präsentiert eine Übersicht die Anwendung von Drucksystemen zur Messung der Kontaktbelastungen zwischen Pferd und Reiter. Die Auswahl der Studien erfolgte unter Verwendung der Suchbegriffe „horse“, „pressure“ und „back“ in den Datenbanken Web of Science, Scopus und PubMed. Im ersten Teil dieses Artikels werden Studien präsentiert, die sich mit der die Entwicklung von Druckmesssystemen für den Reitsattel beschäftigen. Der erste, notwendige Schritt vor der Anwendung dieser Druckmesssysteme ist die Überprüfung der Parameter, um etwaige Fehlerquelle festzustellen und so Bedienungsfehler ausschließen zu können. Um zuverlässige und gültige Daten zu erhalten, müssen methodische Regeln (wie z. B.: korrekte Kalibrierung und korrekte Sensor-Platzierung) eingehalten werden. Im nächsten Teil dieses Artikels wird Betonung auf die Beurteilung der biologischen Systeme (Reiter, Pferd) und deren Interaktion mit dem Sattel als rigide Struktur gelegt. Es werden erste wissenschaftliche Studien, die Druckmessungen beim Reiten, bei unterschiedlichen Sätteln, Sattelkissen, Satteldecken und Änderungen, die durch verschiedene Sattelpolsterungen verursacht werden, untersuchen, diskutiert. Ein schlecht aufliegender Sattel ist ein Grund für Rückenschmerzen, die zur Senkung der Lebensqualität und der Rittigkeit des Pferdes führen. Die Stabilität des Reitersitzes kann mit Hilfe des Druckmesssystem quantifiziert werden. Sie ist für die Kommunikation zwischen Reiter und Pferd wichtig. Von gleicher Bedeutung ist auch Einfluss des Reiters auf die Belastung. Um das Verständnis verschiedener Einflüsse auf Ätiologie und Pathogenese des Pferderückens zu erhöhen, können biomechanische Modelle zur dynamischen Simulation verwendet warden. Auch zur Dokumentation von Hippotherapie ist der Einsatz des Druckmesssystems vorteilhaft. Eine Zunahme der Gesamtkraft zwischen Patient und Pferderücken drückt erhöhtes Selbstvertrauen (Sicherheit) des Reiters aus. Dies ist eine der positiven Wirkungen der Therapie. Aus den Ergebnissen der im Review diskutierten Studien geht hervor, dass die Anwendung der Druckmesssysteme zur Bewertung der Belastung des Pferderückens und des Reiters Bedeutung hat. Zukünftige Forschung sollte sich auf die Einbindung der gesammelten Daten in biomechanische Modelle konzentrieren, umso individuelle Interaktionsmuster besser abgrenzen zu können.Web of Science28559358

The variability of a horse’s movement at walk in hippotherapy

The impulses emitted from the back of a horse during hippotherapy stimulate the rider’s postural reflex mechanisms, resulting in balance and coordination training. The objectives of this study were to evaluate the movement variability of the horse’s back and limbs and to determine significant relationships between the movement of the selected body points on the horse. Two English thoroughbreds and twelve female riders participated in six sessions of hippotherapy. Three-dimensional (3-D) videography was used to assess movement of the selected points on the horse’s back and limbs. The spatiotemporal parameters of the horse’s walk showed no significant changes throughout the entire measuring process. Horse movement within a given session was stable, and overall, inter-individual (between-horse) variability was greater than intra-individual variability. The maximum differences in the vertical displacement of the horse’s back across individual sessions were significant. With respect to the range of movement of the caudal part of the horse’s back, it is necessary to consider the instability of movements during longitudinally repeated sessions.Web of Science44215414