Refine
Document Type
- Article (16)
- Postprint (9)
- Doctoral Thesis (2)
- Other (1)
Is part of the Bibliography
- yes (28) (remove)
Keywords
- reliability (28) (remove)
Institute
- Department Sport- und Gesundheitswissenschaften (6)
- Humanwissenschaftliche Fakultät (5)
- Department Psychologie (3)
- Strukturbereich Kognitionswissenschaften (3)
- Fakultät für Gesundheitswissenschaften (2)
- Institut für Ernährungswissenschaft (2)
- Institut für Informatik und Computational Science (2)
- Department Linguistik (1)
- Hasso-Plattner-Institut für Digital Engineering GmbH (1)
- Hasso-Plattner-Institut für Digital Engineering gGmbH (1)
This study aimed to determine the relative and absolute reliability of ultrasound (US) measurements of the thickness and echogenicity of the plantar fascia (PF) at different measurement stations along its length using a standardized protocol. Twelve healthy subjects (24 feet) were enrolled. The PF was imaged in the longitudinal plane. Subjects were assessed twice to evaluate the intra-rater reliability. A quantitative evaluation of the thickness and echogenicity of the plantar fascia was performed using Image J, a digital image analysis and viewer software. A sonography evaluation of the thickness and echogenicity of the PF showed a high relative reliability with an Intra class correlation coefficient of 0.88 at all measurement stations. However, the measurement stations for both the PF thickness and echogenicity which showed the highest intraclass correlation coefficient (ICCs) did not have the highest absolute reliability. Compared to other measurement stations, measuring the PF thickness at 3 cm distal and the echogenicity at a region of interest 1 cm to 2 cm distal from its insertion at the medial calcaneal tubercle showed the highest absolute reliability with the least systematic bias and random error. Also, the reliability was higher using a mean of three measurements compared to one measurement. To reduce discrepancies in the interpretation of the thickness and echogenicity measurements of the PF, the absolute reliability of the different measurement stations should be considered in clinical practice and research rather than the relative reliability with the ICC.
This study aimed to determine the relative and absolute reliability of ultrasound (US) measurements of the thickness and echogenicity of the plantar fascia (PF) at different measurement stations along its length using a standardized protocol. Twelve healthy subjects (24 feet) were enrolled. The PF was imaged in the longitudinal plane. Subjects were assessed twice to evaluate the intra-rater reliability. A quantitative evaluation of the thickness and echogenicity of the plantar fascia was performed using Image J, a digital image analysis and viewer software. A sonography evaluation of the thickness and echogenicity of the PF showed a high relative reliability with an Intra class correlation coefficient of 0.88 at all measurement stations. However, the measurement stations for both the PF thickness and echogenicity which showed the highest intraclass correlation coefficient (ICCs) did not have the highest absolute reliability. Compared to other measurement stations, measuring the PF thickness at 3 cm distal and the echogenicity at a region of interest 1 cm to 2 cm distal from its insertion at the medial calcaneal tubercle showed the highest absolute reliability with the least systematic bias and random error. Also, the reliability was higher using a mean of three measurements compared to one measurement. To reduce discrepancies in the interpretation of the thickness and echogenicity measurements of the PF, the absolute reliability of the different measurement stations should be considered in clinical practice and research rather than the relative reliability with the ICC.
The intensity of cosmic radiation may differ over five orders of magnitude within a few hours or days during the Solar Particle Events (SPEs), thus increasing for several orders of magnitude the probability of Single Event Upsets (SEUs) in space-borne electronic systems. Therefore, it is vital to enable the early detection of the SEU rate changes in order to ensure timely activation of dynamic radiation hardening measures. In this paper, an embedded approach for the prediction of SPEs and SRAM SEU rate is presented. The proposed solution combines the real-time SRAM-based SEU monitor, the offline-trained machine learning model and online learning algorithm for the prediction. With respect to the state-of-the-art, our solution brings the following benefits: (1) Use of existing on-chip data storage SRAM as a particle detector, thus minimizing the hardware and power overhead, (2) Prediction of SRAM SEU rate one hour in advance, with the fine-grained hourly tracking of SEU variations during SPEs as well as under normal conditions, (3) Online optimization of the prediction model for enhancing the prediction accuracy during run-time, (4) Negligible cost of hardware accelerator design for the implementation of selected machine learning model and online learning algorithm. The proposed design is intended for a highly dependable and self-adaptive multiprocessing system employed in space applications, allowing to trigger the radiation mitigation mechanisms before the onset of high radiation levels.
Background:
Exercising at intensities where fat oxidation rates are high has been shown to induce metabolic benefits in recreational and health-oriented sportsmen. The exercise intensity (Fat peak ) eliciting peak fat oxidation rates is therefore of particular interest when aiming to prescribe exercise for the purpose of fat oxidation and related metabolic effects. Although running and walking are feasible and popular among the target population, no reliable protocols are available to assess Fat peak as well as its actual velocity (V PFO ) during treadmill ergometry. Our purpose was therefore, to assess the reliability and day-to-day variability of V PFO and Fat peak during treadmill ergometry running.
Methods:
Sixteen recreational athletes (f = 7, m = 9; 25 ± 3 y; 1.76 ± 0.09 m; 68.3 ± 13.7 kg; 23.1 ± 2.9 kg/m 2 ) performed 2 different running protocols on 3 different days with standardized nutrition the day before testing. At day 1, peak oxygen uptake (VO 2peak ) and the velocities at the aerobic threshold (V LT ) and respiratory exchange ratio (RER) of 1.00 (V RER ) were assessed. At days 2 and 3, subjects ran an identical submaximal incremental test (Fat-peak test) composed of a 10 min warm-up (70 % V LT ) followed by 5 stages of 6 min with equal increments (stage 1 = V LT , stage 5 = V RER ). Breath-by-breath gas exchange data was measured continuously and used to determine fat oxidation rates. A third order polynomial function was used to identify V PFO and subsequently Fat peak . The reproducibility and variability of variables was verified with an int raclass correlation coef ficient (ICC), Pearson ’ s correlation coefficient, coefficient of variation (CV) an d the mean differences (bias) ± 95 % limits of agreement (LoA).
Results:
ICC, Pearson ’ s correlation and CV for V PFO and Fat peak were 0.98, 0.97, 5.0 %; and 0.90, 0.81, 7.0 %, respectively. Bias ± 95 % LoA was − 0.3 ± 0.9 km/h for V PFO and − 2±8%ofVO 2peak for Fat peak.
Conclusion:
In summary, relative and absolute reliability indicators for V PFO and Fat peak were found to be excellent. The observed LoA may now serve as a basis for future training prescriptions, although fat oxidation rates at prolonged exercise bouts at this intensity still need to be investigated.
Adaptive Force (AF) reflects the capability of the neuromuscular system to adapt adequately to external forces with the intention of maintaining a position or motion. One specific approach to assessing AF is to measure force and limb position during a pneumatically applied increasing external force. Through this method, the highest (AFmax), the maximal isometric (AFisomax) and the maximal eccentric Adaptive Force (AFeccmax) can be determined. The main question of the study was whether the AFisomax is a specific and independent parameter of muscle function compared to other maximal forces. In 13 healthy subjects (9 male and 4 female), the maximal voluntary isometric contraction (pre- and post-MVIC), the three AF parameters and the MVIC with a prior concentric contraction (MVICpri-con) of the elbow extensors were measured 4 times on two days. Arithmetic mean (M) and maximal (Max) torques of all force types were analyzed. Regarding the reliability of the AF parameters between days, the mean changes were 0.31–1.98 Nm (0.61%–5.47%, p = 0.175–0.552), the standard errors of measurements (SEM) were 1.29–5.68 Nm (2.53%–15.70%) and the ICCs(3,1) = 0.896–0.996. M and Max of AFisomax, AFmax and pre-MVIC correlated highly (r = 0.85–0.98). The M and Max of AFisomax were significantly lower (6.12–14.93 Nm; p ≤ 0.001–0.009) and more variable between trials (coefficient of variation (CVs) ≥ 21.95%) compared to those of pre-MVIC and AFmax (CVs ≤ 5.4%). The results suggest the novel measuring procedure is suitable to reliably quantify the AF, whereby the presented measurement errors should be taken into consideration. The AFisomax seems to reflect its own strength capacity and should be detected separately. It is suggested its normalization to the MVIC or AFmax could serve as an indicator of a neuromuscular function.
Adaptive Force (AF) reflects the capability of the neuromuscular system to adapt adequately to external forces with the intention of maintaining a position or motion. One specific approach to assessing AF is to measure force and limb position during a pneumatically applied increasing external force. Through this method, the highest (AFmax), the maximal isometric (AFisomax) and the maximal eccentric Adaptive Force (AFeccmax) can be determined. The main question of the study was whether the AFisomax is a specific and independent parameter of muscle function compared to other maximal forces. In 13 healthy subjects (9 male and 4 female), the maximal voluntary isometric contraction (pre- and post-MVIC), the three AF parameters and the MVIC with a prior concentric contraction (MVICpri-con) of the elbow extensors were measured 4 times on two days. Arithmetic mean (M) and maximal (Max) torques of all force types were analyzed. Regarding the reliability of the AF parameters between days, the mean changes were 0.31–1.98 Nm (0.61%–5.47%, p = 0.175–0.552), the standard errors of measurements (SEM) were 1.29–5.68 Nm (2.53%–15.70%) and the ICCs(3,1) = 0.896–0.996. M and Max of AFisomax, AFmax and pre-MVIC correlated highly (r = 0.85–0.98). The M and Max of AFisomax were significantly lower (6.12–14.93 Nm; p ≤ 0.001–0.009) and more variable between trials (coefficient of variation (CVs) ≥ 21.95%) compared to those of pre-MVIC and AFmax (CVs ≤ 5.4%). The results suggest the novel measuring procedure is suitable to reliably quantify the AF, whereby the presented measurement errors should be taken into consideration. The AFisomax seems to reflect its own strength capacity and should be detected separately. It is suggested its normalization to the MVIC or AFmax could serve as an indicator of a neuromuscular function.
Background
Elderly patients are a growing population in cardiac rehabilitation (CR). As postural control declines with age, assessment of impaired balance is important in older CR patients in order to predict fall risk and to initiate counteracting steps. Functional balance tests are subjective and lack adequate sensitivity to small differences, and are further subject to ceiling effects. A quantitative approach to measure postural control on a continuous scale is therefore desirable. Force plates are already used for this purpose in other clinical contexts, therefore could be a promising tool also for older CR patients. However, in this population the reliability of the assessment is not fully known.
Research question
Analysis of test-retest reliability of center of pressure (CoP) measures for the assessment of postural control using a force plate in older CR patients.
Methods
156 CR patients (> 75 years) were enrolled. CoP measures (path length (PL), mean velocity (MV), and 95% confidence ellipse area (95CEA)) were analyzed twice with an interval of two days in between (bipedal narrow stance, eyes open (EO) and closed (EC), three trials for each condition, 30 s per trial), using a force plate. For test-retest reliability estimation absolute differences (& UDelta;: T0-T1), intraclass correlation coefficients (ICC) with 95% confidence intervals, standard error of measurement and minimal detectable change were calculated.
Results
Under EO condition ICC were excellent for PL and MV (0.95) and good for 95CEA (0.88) with & UDelta; of 10.1 cm (PL), 0.3 cm/sec (MV) and 1.5 cm(2 )(95CEA) respectively. Under EC condition ICC were excellent (> 0.95) for all variables with larger & UDelta; (PL: 21.7 cm; MV: 0.7 cm/sec; 95CEA: 2.4 cm(2))
Significance
In older CR patients, the assessment of CoP measures using a force plate shows good to excellent test retest reliability.
Internet connectivity of cloud services is of exceptional importance for both their providers and consumers. This article demonstrates the outlines of a method for measuring cloud-service connectivity at the internet protocol level from a client's perspective. For this, we actively collect connectivity data via traceroute measurements from PlanetLab to several major cloud services. Furthermore, we construct graph models from the collected data, and analyse the connectivity of the services based on important graph-based measures. Then, random and targeted node removal attacks are simulated, and the corresponding vulnerability of cloud services is evaluated. Our results indicate that cloud service hosts are, on average, much better connected than average hosts. However, when interconnecting nodes are removed in a targeted manner, cloud connectivity is dramatically reduced.
The Test of Masticating and Swallowing Solids (TOMASS) is a validated assessment tool measuring the efficiency of solid bolus intake by four quantitative parameters: discrete bites, masticatory cycles, swallows and time to ingest a single cracker. A normative database for adults (20-80+ years) has previously been established. The objective of this study was to investigate the applicability and reliability of the TOMASS in children and adolescents (TOMASS-C) and to establish the normative database for this younger population. We collected data from 638 participants (male: 311, female: 327) in five age groups (4-18 years) with five different but very similar test crackers in four countries. Significant effects of bolus type (cracker), age group and gender on the TOMASS parameters were identified, requiring stratification of the TOMASS-C database by these variables. Intra-rater reliability was excellent (ICC > 0.94) for all parameters; inter-rater reliability was moderate for "number of swallows" (ICC = 0.54), good for "bites" (ICC = 0.78) and "time" (ICC = 0.82), and excellent for "masticatory cycles" (ICC = 0.96). The "Test of Masticating and Swallowing Solids in Children (TOMASS-C)" was identified to be a reliable diagnostic tool for the comprehensive measurement of discrete oral stage components of solid bolus ingestion, standardised by a large normative database that covers age groups from preschoolers to young adults. While differences between gender groups were less pronounced than in the adult population, previous results relating to changes in masticatory and swallowing as a function of age are confirmed by our data.
Eine sportartspezifische Anforderungsanalyse ist die Grundlage für die Leistungsdiagnostik und eine wichtige Voraussetzung für die Trainingssteuerung im Spitzensport. Im Rahmen der Leistungsdiagnostik in der Zweikampfsportart Judo besitzen judospezifische Anrissleistungen bei Anrissbewegungen ein hohes Potenzial, um Defizite im Kraft-Weg-Verlauf bzw. in den kinetischen Parametern (z. B. mechanische Arbeit, dynamische Maximalkraft) zu identifizieren und ableitend daraus entsprechende trainingsmethodische Anpassungen zur Verbesserung vorzunehmen. Die Rumpfstabilität und die Rumpfkraft stellen wichtige Leistungsvoraussetzungen für sportliche Bewegungen dar, um den optimalen Transfer von Kräften und Drehmomenten von den unteren Extremitäten über den stabilen Rumpf hin zu den oberen Extremitäten zu ermöglichen. Im Trainingsprozess der Judoka erfährt das spezifische Krafttraining immer mehr Aufmerksamkeit, um die sportartrelevanten Muskelgruppen zu entwickeln und somit die finale Effektivität einer Wurftechnik zu verbessern.
Die wesentliche Zielstellung dieser Arbeit bestand darin, die Leistungsdiagnostik im Judo zu optimieren und effektive Trainingsprogramme zur Verbesserung von judospezifischen Anrissbewegungen zu entwickeln. Im Einzelnen wurde dafür eine systematische Anforderungsanalyse für die Sportart Judo erarbeitet. Basierend auf dieser Analyse wurden die Validität und die Reliabilität von kinetischen Parametern während Anrissbewegungen mit einem judospezifischen Ergometer-System (JERGo) untersucht. Zudem wurden die Zusammenhänge zwischen der Rumpfkraft und kinetischen Parametern bei judospezifischen Anrissbewegungen analysiert. Schließlich wurde die Wirksamkeit eines spezifischen Anrisstrainings am JERGo-System gegenüber einem Anrisstraining mit Partner auf kinetische Parameter und Muskelaktivität überprüft.
Die sportartspezifische Anforderungsanalyse wurde unter Berücksichtigung der metabolischen und muskulären Anforderungen sowie sportartspezifischen Verletzungsrisiken erarbeitet. An den zwei Querstudien bzw. einer Längsschnittstudie nahmen gesunde männliche Judoka mit unterschiedlichem Expertiseniveau teil. Die kinetischen Parameter bei judospezifischen Anrissbewegungen wurden mit dem JERGo-System in allen Experimentalstudien erfasst. Die Rumpfkraft wurde mit einem isokinetischen Dynamometer gemessen, um Assoziationen zwischen der Rumpfkraft und judospezifischen Anrissleistungen zu bestimmen. Zudem wurde die Aktivität ausgewählter Rumpf-/Schultermuskeln bei der Anrissbewegung im Standfür die Validierung des JERGo-Systems und für die Überprüfung der Effekte eines Anrisstrainings erfasst. Die Ermittlung von sportmotorischen Leistungen erfolgte durch die Übungen Liegend-Anreißen und Klimmziehen, um die Wirkungen eines judospezifischen Anrisstrainings auf sportartunspezifische Kraftleistungen zu untersuchen.
Unter Berücksichtigung der muskulären Anforderungen im Judo wird die Ausführung einer explosiven Anrissbewegung bzw. Wurftechnik durch die koordinierte Aktivität vieler Muskelgruppen und vor allem durch die unteren Extremitäten sowie den Rumpf realisiert. Aus trainingswissenschaftlicher Sicht ist das JERGo-System ein valides und reliables Messinstrument für die Diagnostik von kinetischen Parametern während judospezifischer Anrissbewegungen. Die Rumpfkraft, insbesondere bei der Rumpfrotation, ist mit kinetischen Parametern bei judospezifischen Anrissbewegungen assoziiert. Ein Anrisstraining am JERGo-System zeigt in den kinetischen Parametern und Muskelaktivierungen vor allem bei der Anrissbewegung im Stand signifikant größere Zuwachsraten im Vergleich zu einem Anrisstraining mit Partner.
Die Ergebnisse dieser Arbeit zeigen, dass die Verbesserung der muskulären Leistungsfähigkeit (z. B. Explosivkraft) in den unteren Extremitäten und der Rumpfmuskulatur eine wichtige Basis für judospezifische Anrissleistungen bei Anrissbewegungen und Wurftechniken darstellt. Zudem empfiehlt es sich, dass JERGo-System zur Diagnostik von kinetischen Parametern bei judospezifischen Anrissbewegungen in die judospezifische Testbatterie einzubinden. Weiterhin kann davon ausgegangen werden, dass durch rumpfextensions- und vor allem durch rumpfrotationskräftigende Übungen unter maximal schellkräftigender Muskelaktivierung Einfluss auf kinetische Parameter bei judospezifischen Anrissbewegungen genommen wird. Letztendlich empfiehlt es sich, ein Antrisstraining am JERGo-System in den judospezifischen Trainingsprozess zu integrieren.