Factors Affecting Cyclists’ Chances of Success in Match-Sprint Tournaments

2019 ◽  
Vol 14 (4) ◽  
pp. 472-477 ◽  
Author(s):  
Kathryn E. Phillips ◽  
Will G. Hopkins
Keyword(s):  
Elite Athlete ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Time Trial ◽  
Strongly Correlated ◽  
Factors Affecting ◽  
Female Head ◽  
Intraclass Correlation Coefficients ◽  
The Difference ◽  
Athlete Performance

Purpose: To further the understanding of elite athlete performance in complex race environments by examining the changes in cyclists’ performance between solo time trials and head-to-head racing in match-sprint tournaments. Methods: Analyses were derived from official results of cyclists in 61 elite international sprint tournaments (2000–2016), incorporating the results of 2060 male and 1969 female head-to-head match races. Linear mixed modeling of log-transformed qualification and finish ranks was used to determine estimates of performance predictability as intraclass correlation coefficients. Correlations between qualifying performance and final tournament rank were also calculated. Chances of winning head-to-head races were estimated adjusting for the difference in the cyclists’ qualifying times. All effects were evaluated using magnitude-based inference. Results: Minor differences in predictability between qualification time trial and final tournament rank were suggestive of more competitiveness among men in the overall tournament. Performance in the qualification time trial was strongly correlated with, but not fully indicative of, performance in the overall tournament. Correspondingly, being the faster qualifier had a large positive effect on the chances of winning a head-to-head race, but small substantial differences between riders remained after adjustment for time-trial differentials. Conclusions: The present study provides further insight into how real-world competition data can be used to investigate elite athlete performance in sports where athletes must directly interact with their opponents. For elite match-sprint cyclists, qualifying time-trial performance largely determines success in the overall tournament, but there is evidence of a consistent match-race ability that modifies the chances of winning head-to-head races.

scholarly journals Assessment of reliability and validity of the 5-scale grading system of the point-of-care immunoassay for tear matrix metalloproteinase-9

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Minjeong Kim ◽  
Ja Young Oh ◽  
Seon Ha Bae ◽  
Seung Hyeun Lee ◽  
Won Jun Lee ◽  
...  
Keyword(s):  
Matrix Metalloproteinase ◽  
Calibration Curve ◽  
Point Of Care ◽  
Interobserver Reliability ◽  
Intraclass Correlation ◽  
Reliability And Validity ◽  
Correlation Coefficients ◽  
Grading System ◽  
Intraclass Correlation Coefficients ◽  
The Difference

AbstractWe evaluated the reliability and validity of the 5-scale grading system to interpret the point-of-care immunoassay for tear matrix metalloproteinase (MMP)-9. Six observers graded red bands of photographs of the readout window in MMP-9 immunoassay kit (InflammaDry) two times with 2-week interval based on the 5-scale grading system (i.e. grade 0–4). Interobserver and intraobserver reliability were evaluated using intraclass correlation coefficients. The interobserver agreements were analyzed according to the severity of tear MMP-9 expression. To validate the system, a concentration calibration curve was made using MMP-9 solutions with reference concentrations, then the distribution of MMP-9 concentrations was analyzed according to the 5-scale grading system. Both intraobserver and interobserver reliability was excellent. The readout grades were significantly correlated with the quantified colorimetric densities. The interobserver variance of readout grades had no correlation with the severity of the measured densities. The band density continued to increase up to a maximal concentration (i.e. 5000 ng/mL) according to the calibration curve. The difference of grades reflected the change of MMP-9 concentrations sensitively, especially between grade 2 and 4. Together, our data indicate that the subjective 5-scale grading system in the point-of-care MMP-9 immunoassay is an easy and reliable method with acceptable accuracy.

scholarly journals Reproducibility and reliability of three-dimensional soft tissue landmark identification using three-dimensional stereophotogrammetry

2016 ◽  
Vol 86 (6) ◽  
pp. 1004-1009 ◽  
Author(s):  
Asli Baysal ◽  
Ahmet Oguz Sahan ◽  
Mehmet Ali Ozturk ◽  
Tancan Uysal
Keyword(s):  
Soft Tissue ◽  
Statistical Significance ◽  
Intraclass Correlation ◽  
Three Dimensional ◽  
Correlation Coefficients ◽  
Intraclass Correlation Coefficients ◽  
Paired Samples ◽  
Landmark Identification ◽  
The Difference ◽  
Intraexaminer Reliability

ABSTRACT Objective: To evaluate the intraexaminer repeatability and interexaminer reproducibility of soft tissue landmarks on three-dimensional (3-D) stereophogrammetric images. Materials and Methods: Thirty-four stereophotogrammetric images were taken and 19 soft tissue points were identified. The images were obtained using the 3-DMD Face (3-DMD TM Ltd, Atlanta, Ga) system. Two examiners marked 34 images manually with a mouse-driven cursor 4 weeks apart. Intraexaminer marking differences were calculated and classified as <0.5 mm, 0.5–1 mm, and >1 mm. Intraclass correlation coefficients were calculated for intraexaminer reliability. A paired-samples t-test was used to evaluate the difference between the examiners. Interexaminer reproducibility was evaluated by kappa analysis. Statistical significance was set at P < .05. Results: Only one landmark (labiale superior) had an intraexaminer marking difference less than 0.5 mm. Existing landmarks had an intraexaminer difference less than 1 mm, but higher than 0.5 mm. The intraclass correlation coefficients (ICCs) indicated good intraexaminer repeatability for both observers. The ICC range for examiners 1 and 2 was 0.986–1.000 and 0.990–1.000, respectively. Kappa scores showed good interexaminer agreement, especially on the z-axis. Conclusions: Except labiale superior, the soft tissue landmarks used in this study were shown to have moderate reproducibility, but the difference between the landmarks was less than 1 mm, and they had clinically acceptable reproducibility.

scholarly journals Thumb Proprioception in Hypermobile and Non-Hypermobile Adults: An Observational Study

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Leon Fonseka ◽  
Nicola Massy-Westropp ◽  
Steve Milanese ◽  
Arjun Burlakoti
Keyword(s):  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Joint Hypermobility ◽  
Angular Distance ◽  
Test Reliability ◽  
Joint Position ◽  
Convenience Sample ◽  
Intraclass Correlation Coefficients ◽  
The Difference ◽  
Design And Methods

Aims and Background Hypermobility is a common presentation in the community and is reported related to higher rates of injury and musculoskeletal pain, however the mechanism underpinning this relationship remains unclear. Poor proprioception in hypermobile joints has been proposed as a potential mechanism. This study aims to determine if there is a difference in proprioceptive acuity, as measured by joint position reproduction, in adults with generalised joint hypermobility. Design and methods A convenience sample of 26 university students and staff (mean age 29.23 years, range 18-47) were recruited, of which 12 participants displayed generalised joint hypermobility, and 14 did not. A laser light, mounted to the dominant thumb, was used to test joint position reproduction sense by pointing to targets using a unilateral active-active position reproduction protocol. Results/Findings Test reliability across a range of targets was poor to good (intraclass correlation coefficients ranged from 0.1163 to 0.7256), indicating significant variability between participants. No significant differences was found in absolute angle of error between generalised joint hypermobility and non-generalised joint hypermobility participants. For direction of error in relation to the proprioceptive targets, only 30° thumb extension above horizontal was found to be significantly different between the hypermobile and non-hypermobile groups, with hypermobile participants tending to underestimate distance to target. Age and sex were not correlated to thumb proprioception. Application and Conclusion The difference found in direction of error and tendency to underestimate angular distance may be protective against straying into possibly injurious end-ranges; however, larger studies are recommended to confirm this.

scholarly journals Repeatability of OPD-Scan III and its agreement with Pentacam in measuring keratometry, astigmatism and axis in patients with cataract and moderate to high astigmatism

2020 ◽  
Author(s):  
YU Song ◽  
Panpan Li ◽  
Yuanyuan Tu ◽  
Ying Wu ◽  
Lili Huang ◽  
...  
Keyword(s):  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
High Accuracy ◽  
Wilcoxon Test ◽  
Spearman Correlation ◽  
Limits Of Agreement ◽  
Intraclass Correlation Coefficients ◽  
Bland Altman Method ◽  
The Difference ◽  
Cataract Patients

Abstract Purpose To assess accuracy of OPD-Scan III in measuring keratometry, astigmatism and axis in patients with cataract and moderate to high astigmatism Materials and Methods Measurements were taken with OPD-Scan III and Pentacam in cataract patients with keratometric astigmatism (KA) more than 0.75 D. Keratometry in the steepest axis (Ks) and flattest axis (Kf), KA and axis, which are power vector components of astigmatism (J0 and J45), were evaluated. Intraclass correlation coefficients (ICCs) were used to assess repeatability. The Wilcoxon test was used to assess differences, the Spearman correlation was used to assess correlations, and the Bland-Altman method was used to assess agreement. Results Seventy eyes of 63 patients were included to analyze the repeatability of the two devices. The ICCs of Ks, Kf, KA, axis, J0 and J45 were 0.991, 0.995, 0.946, 0.883, 0.946 and 0.892, respectively, with OPD-Scan III. Seven hundred and thirty-two eyes of 516 patients were included to analyze the difference, correlation and agreement of the two devices. There were significant differences between the two devices in terms of Ks, Kf, axis, J0 and J45 (all p < 0.01). There were significant correlations between the two devices in each parameter (all p < 0.01). The 95% limits of agreement (LOAs) for Ks, Kf, KA, astigmatic axis, J0 and J45 were (-0.34, 0.44) D, (-0.24, 0.38) D, (-0.46, 0.48) D, (-10.20, 12.92)°, (-0.24, 0.24) D, and (-0.27, 0.35) D respectively.The 95% LOAs for the degree of IOL caculated according to parameter measured by OPD-Scan III and Pentacam was (-0.32, 0.22) D. Conclusions OPD-Scan III has a high accuracy for measuring keratometry, but its accuracy for measuring astigmatism and axis is poor in eyes with moderate to high astigmatism.

Factors Affecting Reliability of the Biodex Balance System: A Summary of Four Studies

2000 ◽  
Vol 9 (3) ◽  
pp. 240-252 ◽  
Author(s):  
Martha R. Hinman
Keyword(s):  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Stability Index ◽  
Retest Reliability ◽  
Factors Affecting ◽  
Balance System ◽  
Intraclass Correlation Coefficients ◽  
Balance Tests ◽  
Test Retest Reliability ◽  
Biodex Balance System

Purpose:To describe differences in test-retest reliability of balance measures produced by the Biodex Balance System.Methods:Subjects performed balance tests in 4 studies, each involving two 30-second tests under varying conditions. Test-retest reliability coefficients were calculated for the overall stability index (SI) under each condition. Test-retest reliability was computed for subjects' limits of stability (LOS).Results:Intraclass correlation coefficients (ICC3,1) ranged from .44 to .89 for static balance tests; variability between the 2 tests ranged from 21% to 37%. Tests at lower stability levels or without visual input produced the highest ICCs. ICCs for the LOS tests ranged from .64 to .89. These measures were less variable (6% to 8%) than the static measures of balance.Conclusions:Test-retest reliability of the SI produced by the Biodex Balance System is acceptable for clinical testing and is comparable to other balance measures currently in use.

Performance Relationships in Timed and Mass-Start Events for Elite Omnium Cyclists

2017 ◽  
Vol 12 (5) ◽  
pp. 628-633 ◽  
Author(s):  
Kathryn E. Phillips ◽  
Will G. Hopkins
Keyword(s):  
Positive Relationship ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Time Trial ◽  
Finish Time ◽  
Intraclass Correlation Coefficients ◽  
Final Rank ◽  
Performance Results ◽  
Suitable Measure ◽  
Track Cycling

Purpose:To explore the extent to which factors that determine performance transfer within and between time-trial and mass-start events in the track-cycling Omnium.Methods:Official finish rank in the 3 time-trial events, in the 3 mass-start events, and in the competition overall were collated in 20 international Omnium competitions between 2010 and 2014 for 196 male and 140 female cyclists. Linear mixed modeling of the log-transformed finish time for the time-trial events and of log-transformed finish rank for all events and final rank provided estimates of within-athlete race-to-race changes in performance and average betweenathletes differences across a season. These estimates were converted to various correlations representing relationships within and between the various events and final rank.Results:Intraclass correlation coefficients, representing race-to-race reproducibility of performance, were similar whether derived from finish rank or finish time for the time-trial events. Log-transformed finish ranks are therefore a suitable measure to assess and compare performance in time-trial and mass-start events. Omnium cyclists were more predictable in their performances from race to race in the timed events, whereas reduced predictability was observed in mass-start events. Interevent correlations indicated stronger links in performance between the timed disciplines, whereas performance in any of the mass-start events had only a slight positive relationship with performance in the other massstart events and little or no relationship with the timed events.Conclusions:Further investigation is warranted to determine whether factors related to performance in mass-start events can be identified to improve reproducibility or whether variability in performance results from random chance.

Verification of the accuracy and reliability of the TrackMan tennis radar

2020 ◽  
pp. 175433712095300
Author(s):  
Munenori Murata ◽  
Hiroo Takahashi
Keyword(s):  
Measurement Accuracy ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Spin Axis ◽  
Altman Analysis ◽  
Bland Altman Analysis ◽  
Practical Applications ◽  
Intraclass Correlation Coefficients ◽  
The Difference ◽  
Proven Method

TrackMan, a device used to measure the kinematics of a ball in flight, has recently been used for research and coaching purposes in tennis, and the number of studies on this device is expected to increase. This study is focused on verifying the accuracy of TrackMan; three participants performed services with various velocities and angular velocity combinations. TrackMan and a proven method based on computer vision were used to measure the speed, spin rate, and spin axis of the ball. The results obtained using each method were compared using regression analysis, intraclass correlation coefficients, and Bland–Altman analysis. The speed and spin rate of the two methods agreed well; the degree of error would not be problematic in practical applications. However, TrackMan underestimated the speed if it was unable to detect the hitting position. The spin axis measured by TrackMan was unstable under low spin rate conditions (<3000 rpm). Furthermore, the standard deviation of the spin axis measurement error exceeded the difference between the average slice and kick service spin axes reported in the previous study, so the spin axis measurement accuracy was very low for research purposes, even when the spin rate was above 3000 rpm. For those who are aware of the existence of outliers, TrackMan can be useful for coaching because it provides instant feedback. Similarly, the measured rotational speed and spin rate could be used in the study.

scholarly journals The Psychometric Properties of the Persian Migraine-Specific Quality of Life Questionnaire Version 2.1 in Episodic and Chronic Migraines

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Alireza Zandifar ◽  
Samaneh Sadat Masjedi ◽  
Faraidoon Haghdoost ◽  
Fatemeh Asgari ◽  
Navid Manouchehri ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Psychometric Properties ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Episodic Migraine ◽  
Life Questionnaire ◽  
Intraclass Correlation Coefficients ◽  
Questionnaire Version ◽  
The Difference

Background. Migraine-specific quality of life (MSQ) is a valid and reliable questionnaire. Linguistic validation of Persian MSQ questionnaire, analysis of psychometric properties between chronic and episodic migraine patients, and capability of MSQ to differentiate between chronic and episodic migraines were the aims of this study.Method. Participants were selected from four different neurology clinics that were diagnosed as chronic or episodic migraine patients. Baseline data included information from MSQ v. 2.1, MIGSEV, SF-36, and symptoms questionnaire. At the third week from the baseline, participants filled out MSQ and MIGSEV. Internal consistency (Cronbach alpha) and test-retest reproducibility (intraclass correlation coefficients) were used to assess reliability. Convergent and discriminant validities were also assessed.Results. A total of 106 participants were enrolled. Internal consistencies of MSQ among all patients, chronic and episodic migraines, were 0.92, 0.91, and 0.92, respectively. Test-retest correlation of MSQ dimensions between visits 1 and 2 varied from 0.41 to 0.50. Convergent, item discriminant, and discriminant validities were approved. In all visits MSQ scores were lower in chronic migraine than episodic migraine; however, the difference was not statistically significant.Conclusion. Persian translation of MSQ is consistent with original version of MSQ in terms of psychometric properties in both chronic and episodic migraine patients.

Intra- and Inter-Examiner Repeatability of Diagnostic Peri-implant Clinical Measurement: A Pilot Study

2021 ◽  
Author(s):  
Riccardo Di Gianfilippo ◽  
Houssam Askar ◽  
James Henderson ◽  
Debora Franceschi ◽  
Hom-Lay Wang ◽  
...  
Keyword(s):  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Factors Affecting ◽  
Intraclass Correlation Coefficients ◽  
Probing Depth ◽  
Unit Increase ◽  
Multiple Measurements ◽  
Clinical Measurements ◽  
Examiner Agreement

Despite the crucial role of examiner reliability on quality research and practice, there is still limited literature analyzing factors affecting examiner variability of peri-implant clinical measurements. The present study investigated clinical peri-implant parameters to quantify their repeatability and investigate factors that may affect their accuracy. Thirty-three implants were examined by four operators. Peri-implant probing depth (PD), recession (REC) and gingival index (GI) were measured for agreement and included for analysis. Agreement was quantified using intraclass correlation coefficients (ICC; 95% CI); mixed linear and logistic regressions were used to assess additional variables. The overall inter-examiner agreement was comparable between PD (0.80) and REC (0.78), but significantly worse for GI (0.45) (p&lt;0.001). Similarly, the intra-examiner agreement was similar for PD (0.81) and REC (0.80), but significantly worse for GI (0.57) (p&lt;0.05). The magnitude of PD did not influence agreement. In contrast, increasing disagreement was noted for positive REC (OR: 3.0), negative REC (OR: 4.8) and lower GI (OR: 4.4). The incidence of bleeding on probing and severity of GI increased for deeper PD (0.113 unit increase per mm). Negative and positive values of recession and lower GI were associated with increasing disagreement. Radiographic bone loss, restoration contour and implant diameter did not impact PD accuracy within this study. In conclusion, within the limitations of the study, GI measurements presented higher variability than PD and REC. PD and GI were associated with one another and increased after multiple measurements.

scholarly journals How to improve image quality of DWI of the prostate—enema or catheter preparation?

2021 ◽  
Author(s):  
Carolin Reischauer ◽  
Timmy Cancelli ◽  
Sonaz Malekzadeh ◽  
Johannes M. Froehlich ◽  
Harriet C. Thoeny
Keyword(s):  
Image Quality ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Observer Agreement ◽  
Strongly Correlated ◽  
Intraclass Correlation Coefficients ◽  
Single Center Study ◽  
The Impact ◽  
Gas Suction

Abstract Objectives To compare the impact of laxative enema preparation versus air/gas suction through a small catheter on image quality of prostate DWI. Methods In this single-center study, 200 consecutive patients (100 in each arm) with either enema or catheter preparation were retrospectively included. Two blinded readers independently assessed aspects of image quality on 5-point Likert scales. Scores were compared between groups and the influence of confounding factors evaluated using multivariable logistic regression. Prostate diameters were compared on DWI and T2-weighted imaging using intraclass correlation coefficients. Results Image quality was significantly higher in the enema group regarding the severity of susceptibility-related artifacts (reader 1: 0.34 ± 0.77 vs. 1.73 ± 1.34, reader 2: 0.38 ± 0.86 vs. 1.76 ± 1.39), the differentiability of the anatomy (reader 1: 3.36 ± 1.05 vs. 2.08 ± 1.31, reader 2: 3.37 ± 1.05 vs. 2.09 ± 1.35), and the overall image quality (reader 1: 3.66 ± 0.77 vs. 2.26 ± 1.33, Reader 2: 3.59 ± 0.87 vs. 2.23 ± 1.38) with almost perfect inter-observer agreement (κ = 0.92–0.95). In the enema group, rectal distention was significantly lower and strongly correlated with the severity of artifacts (reader 1: ρ = 0.79, reader 2: ρ = 0.73). Furthermore, there were significantly fewer substantial image distortions, with odds ratios of 0.051 and 0.084 for the two readers which coincided with a higher agreement of the prostate diameters in the phase-encoding direction (0.96 vs. 0.89). Conclusions Enema preparation is superior to catheter preparation and yields substantial improvements in image quality. Key Points • Enema preparation is superior to decompression of the rectum using air/gas suction through a small catheter. • Enema preparation markedly improves the image quality of prostate DWI regarding the severity of susceptibility-related artifacts, the differentiability of the anatomy, and the overall image quality and considerably reduces substantial artifacts that may impair a reliable diagnosis.

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