scholarly journals Reliability of Overground Running Measures from 2D Video Analyses in a Field Environment

Sports ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 8 ◽  
Author(s):  
Lauralee Murray ◽  
C. Beaven ◽  
Kim Hébert-Losier
Keyword(s):  
Measurement Errors ◽  
High Speed ◽  
Intraclass Correlation ◽  
Weighted Kappa ◽  
Outdoor Environment ◽  
Two Dimensional ◽  
Running Speed ◽  
Foot Strike ◽  
Absolute Reliability ◽  
Strike Angle

Two-dimensional running analyses are common in research and practice, and have been shown to be reliable when conducted on a treadmill. However, running is typically performed outdoors. Our aim was to determine the intra- and inter-rater reliability of two-dimensional analyses of overground running in an outdoor environment. Two raters independently evaluated 155 high-speed videos (240 Hz) of overground running from recreationally competitive runners on two occasions, seven days apart (test-retest study design). The reliability of foot-strike pattern (rear-foot, mid-foot, and fore-foot), foot-strike angle (°), and running speed (m/s) was assessed using weighted kappa (κ), percentage agreement, intraclass correlation coefficient (ICC), typical error (TE), and coefficient of variation (CV) statistics. Foot-strike pattern (agreement = 99.4%, κ = 0.96) and running speed (ICC = 0.98, TE = 0.09 m/s, CV = 2.1%) demonstrated excellent relative and absolute reliability. Foot-strike angle exhibited high relative reliability (ICC = 0.88), but suboptimal absolute reliability (TE = 2.5°, CV = 17.6%). Two-dimensional analyses of overground running outdoors were reliable for quantifying foot-strike pattern, foot-strike angle, and running speed, although foot-strike angle errors of 2.5° were typical. Foot-strike angle changes of less than 2.5° should be interpreted with caution in clinical settings, as they might simply reflect measurement errors.

scholarly journals Will the Foot Strike Pattern Change at Different Running Speeds with or without Wearing Shoes?

2020 ◽  
Vol 17 (17) ◽  
pp. 6044
Author(s):  
Ying-Jen Lai ◽  
Willy Chou ◽  
I-Hua Chu ◽  
Yu-Lin Wang ◽  
Yi-Jing Lin ◽  
...  
Keyword(s):  
High Speed ◽  
Physical Therapist ◽  
Random Order ◽  
Heel Strike ◽  
Running Speed ◽  
Chi Square ◽  
Significance Level ◽  
Limb Injuries ◽  
Foot Strike ◽  
Chi Square Analysis

Runners strike their feet with three different patterns during running: forefoot, midfoot, and rearfoot. This study aimed to investigate whether runners maintain consistent patterns while running speed and foot condition change. The foot strike patterns of runners when running on a treadmill at paces ranging from slow to fast were recorded from twenty healthy male regular runners, with and without shoes, in random order. A high-speed camera was used to observe the strike patterns, which were then categorized by an experienced physical therapist. Linear-log and Pearson chi-square analysis with a significance level of α = 0.05 was performed to examine the correlation between foot strike pattern, running speed, and shoe conditions. The results suggest that runners strike with different patterns when running with and without shoes (χ2 = 99.07, p < 0.01); runners preferred to adopt heel strike regardless of running speeds when running with shoes. While running barefoot, only 23.8% of landing strikes were rearfoot, and the strike pattern distribution did not change significantly with the running speed (χ2 = 2.26, p = 0.89). In summary, the foot strike preference of runners is correlated with the foot condition (barefoot or shod) rather than running speed. For runners who intend to change their strike patterns for any reason, we recommend that they consider adjusting their footwear, which may naturally help with the foot strike adjustment. Future studies should attempt to use advanced techniques to observe further foot biomechanics in order to discover if changing strike pattern is directly correlated with lower limb injuries.

Psychometric Properties of the Swedish Version of the Self-Transcendence Scale Among Very Old People

2015 ◽  
Vol 23 (1) ◽  
pp. 96-111 ◽  
Author(s):  
Berit Lundman ◽  
Kristofer Årestedt ◽  
Astrid Norberg ◽  
Catharina Norberg ◽  
Regina Santamäki Fischer ◽  
...  
Keyword(s):  
Psychometric Properties ◽  
Intraclass Correlation ◽  
Weighted Kappa ◽  
The Self ◽  
Underlying Structure ◽  
Swedish Version ◽  
Convenience Sample ◽  
Self Transcendence ◽  
Kappa Agreement ◽  
Absolute Reliability

Background and Purpose: This study tested the psychometric properties of a Swedish version of the Self-Transcendence Scale (STS). Methods: Cohen’s weighted kappa, agreement, absolute reliability, relative reliability, and internal consistency were calculated, and the underlying structure of the STS was established by exploratory factor analysis. There were 2 samples available: 1 including 194 people aged 85–103 years and a convenience sample of 60 people aged 21–69 years. Results: Weighted kappa values ranged from .40 to .89. The intraclass correlation coefficient for the original STS was .763, and the least significant change between repeated tests was 6.25 points. Conclusion: The revised STS was found to have satisfactory psychometric properties, and 2 of the 4 underlying dimensions in Reed’s self-transcendence theory were supported.

Load Spectrum Compiling and Fatigue Life Estimation of the Automobile Wheel Hub

2020 ◽  
Vol 13 ◽  
Author(s):  
Xintian Liu ◽  
Yang Qu ◽  
Xiaobing Yang ◽  
Yongfeng Shen
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
Two Dimensional ◽  
Load Spectrum ◽  
One Dimensional ◽  
Life Estimation ◽  
Load Spectra ◽  
Fatigue Life Estimation ◽  
Program Load Spectrum ◽  
Program Load

Background:: In the process of high-speed driving, the wheel hub is constantly subjected to the impact load from the ground. Therefore, it is important to estimate the fatigue life of the hub in the design and production process. Objective:: This paper introduces a method to study the fatigue life of car hub based on the road load collected from test site. Methods:: Based on interval analysis, the distribution characteristics of load spectrum are analyzed. The fatigue life estimation of one - dimensional and two - dimensional load spectra is compared by compiling load spectra. Results:: According to the S-N curve cluster and the one-dimensional program load spectrum, the estimated range fatigue life of the hub is 397,100 km to 529,700 km. For unsymmetrical cyclic loading, each level means and amplitude of load were obtained through the Goodman fatigue empirical formula, and then according to S-N curve clusters in the upper and lower curves and two-dimensional program load spectrum, estimates the fatigue life of wheel hub of the interval is 329900 km to 435200 km, than one-dimensional load spectrum fatigue life was reduced by 16.9% - 17.8%. Conclusion:: This paper lays a foundation for the prediction of fatigue life and the bench test of fatigue durability of auto parts subjected to complex and variable random loads. At the same time, the research method can also be used to estimate the fatigue life of other bearing parts or high-speed moving parts and assemblies.

scholarly journals Comparison of the Mayo Endoscopy Score and the Ulcerative Colitis Endoscopy Index of Severity and the Ulcerative Colitis Colonoscopy Index of Severity

2021 ◽  
Vol 09 (02) ◽  
pp. E130-E136
Author(s):  
María Belvis Jiménez ◽  
Pedro Hergueta-Delgado ◽  
Blas Gómez Rodríguez ◽  
Belén Maldonado Pérez ◽  
Luisa Castro Laria ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Interobserver Variability ◽  
Intraclass Correlation ◽  
Weighted Kappa ◽  
Clinical Situation ◽  
Kappa Index ◽  
Perfect Correlation ◽  
Index Of Severity ◽  
Severity Of The Disease ◽  
Normal Clinical Practice

Abstract Background and study aims: Endoscopy plays an essential role in managing patients with ulcerative colitis (UC), as it allows us to visualize and assess the severity of the disease. As such assessments are not always objective, different scores have been devised to standardize the findings. The main aim of this study was to assess the interobserver variability between the Mayo Endoscopy Score (MES), Ulcerative Colitis Endoscopy Index of Severity (UCEIS) and Ulcerative Colitis Colonoscopy Index of Severity (UCCIS) analyzing the severity of the endoscopic lesions in patients with ulcerative colitis. Patients and methods: This was a single-cohort observational study in which a colonoscopy was carried out on patients with UC, as normal clinical practice, and a video was recorded. The results from the video were classified according to the MES, UCEIS and UCCIS by three endoscopic specialists independently, and they were compared to each other. The Mayo Endoscopy Score (MES) was used to assess the clinical situation of the patient. The therapeutic impact was analyzed after colonoscopy was carried out. Results: Sixty-seven patients were included in the study. The average age was 51 (SD ± 16.7) and the average MES was 3.07 (SD ± 2.54). The weighted Kappa index between endoscopists A and B for the MES was 0.8; between A and C 0.52; and between B and C 0.49. The intraclass correlation coefficient for UCEIS was 0.92 among the three endoscopists (CI 95 %: 0.83–0.96) and 0.96 for UCCIS among the three endoscopists (CI 95 % 0.94–0.97). A change in treatment for 34.3 % of the patients was implemented on seeing the results of the colonoscopy. Conclusions: There was an adequate, but not perfect, correlation between the different endoscopists for MES, UCEIS, UCCIS. This was higher with the last two scores. Thus, there is still some subjectivity to be minimized through special training, on assessing the seriousness of the endoscopic lesions in patients with UC.

scholarly journals Development and Relative Validity of a Semiquantitative Food Frequency Questionnaire to Estimate Dietary Intake among a Multi-Ethnic Population in the Malaysian Cohort Project

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1163
Author(s):  
Suzana Shahar ◽  
Mohd Razif Shahril ◽  
Noraidatulakma Abdullah ◽  
Boekhtiar Borhanuddin ◽  
Mohd Arman Kamaruddin ◽  
...  
Keyword(s):  
Vitamin C ◽  
Correlation Coefficient ◽  
Food Frequency Questionnaire ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Weighted Kappa ◽  
Dietary Intakes ◽  
Food Frequency ◽  
Relative Validity ◽  
Spearman’S Correlation

Measuring dietary intakes in a multi-ethnic and multicultural setting, such as Malaysia, remains a challenge due to its diversity. This study aims to develop and evaluate the relative validity of an interviewer-administered food frequency questionnaire (FFQ) in assessing the habitual dietary exposure of The Malaysian Cohort (TMC) participants. We developed a nutrient database (with 203 items) based on various food consumption tables, and 803 participants were involved in this study. The output of the FFQ was then validated against three-day 24-h dietary recalls (n = 64). We assessed the relative validity and its agreement using various methods, such as Spearman’s correlation, weighed Kappa, intraclass correlation coefficient (ICC), and Bland–Altman analysis. Spearman’s correlation coefficient ranged from 0.24 (vitamin C) to 0.46 (carbohydrate), and almost all nutrients had correlation coefficients above 0.3, except for vitamin C and sodium. Intraclass correlation coefficients ranged from −0.01 (calcium) to 0.59 (carbohydrates), and weighted Kappa exceeded 0.4 for 50% of nutrients. In short, TMC’s FFQ appears to have good relative validity for the assessment of nutrient intake among its participants, as compared to the three-day 24-h dietary recalls. However, estimates for iron, vitamin A, and vitamin C should be interpreted with caution.

Accelerating laser processes with a smart two-dimensional polygon mirror scanner for ultra-fast beam deflection

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Florian Roessler ◽  
André Streek
Keyword(s):  
Energy Distribution ◽  
Real Time ◽  
Laser Processing ◽  
High Speed ◽  
Beam Deflection ◽  
Two Dimensional ◽  
Heat Accumulation ◽  
Field Programmable ◽  
Drill Holes ◽  
Average Laser

Abstract In laser processing, the possible throughput is directly scaling with the available average laser power. To avoid unwanted thermal damage due to high pulse energy or heat accumulation during MHz-repetition rates, energy distribution over the workpiece is required. Polygon mirror scanners enable high deflection speeds and thus, a proper energy distribution within a short processing time. The requirements of laser micro processing with up to 10 kW average laser powers and high scan speeds up to 1000 m/s result in a 30 mm aperture two-dimensional polygon mirror scanner with a patented low-distortion mirror configuration. In combination with a field programmable gate array-based real-time logic, position-true high-accuracy laser switching is enabled for 2D, 2.5D, or 3D laser processing capable to drill holes in multi-pass ablation or engraving. A special developed real-time shifter module within the high-speed logic allows, in combination with external axis, the material processing on the fly and hence, processing of workpieces much larger than the scan field.

Reliability of scapular upward rotation and anterior-posterior tilt measurements using a modified digital inclinometer in patients with subacromial impingement syndrome

2021 ◽  
pp. 1-7
Author(s):  
Da-In An ◽  
Jung-Eun Park ◽  
Chang-Hyung Lee ◽  
Soo-Yong Kim
Keyword(s):  
Intraclass Correlation ◽  
Absolute Measurement ◽  
Impingement Syndrome ◽  
Subacromial Impingement Syndrome ◽  
Subacromial Impingement ◽  
Digital Inclinometer ◽  
Posterior Tilt ◽  
Standard Error Of Measurement ◽  
Absolute Reliability ◽  
Anterior Posterior

BACKGROUD: Reliable scapular upward rotation and anterior-posterior tilt data are required for patients with subacromial impingement syndrome (SIS). Only a few studies have explored the reliability of such measurements derived using a modified inclinometer. OBJECTIVES: To determine the relative and absolute reliability of scapular upward rotation and anterior-posterior tilt measurements derived using a modified digital inclinometer in patients with SIS. METHOD: Seventeen SIS patients were assessed twice within 1 week. We determined the relative and absolute measurement reliability by calculating the intraclass correlation coefficient (ICC), standard error of measurement (SEM), and minimal clinically important difference (MCID). Both intra- and interrater reliability were determined. RESULTS: The intra-rater reliability (both measurements) was high (0.72–0.88), and the interrater ICC was high to excellent (0.72–0.98). Clinically acceptable SEM and MCID values were obtained for scapular upward rotation (SEM: 4.28–9.33∘, MCID: 5.1–11.3∘) and anterior-posterior tilt (SEM: 3.72–7.55∘, MCID: 2.5–10.8∘). CONCLUSIONS: Measurements of scapular upward rotation and anterior-posterior tilt using a modified digital inclinometer reliably reveal scapular position and kinematics in patients with SIS.

scholarly journals Ankle Muscle Activations during Different Foot-Strike Patterns in Running

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3422
Author(s):  
Jian-Zhi Lin ◽  
Wen-Yu Chiu ◽  
Wei-Hsun Tai ◽  
Yu-Xiang Hong ◽  
Chung-Yu Chen
Keyword(s):  
Muscle Activity ◽  
Muscle Activation ◽  
Stance Phase ◽  
Inertial Sensors ◽  
Plantar Flexion ◽  
Intraclass Correlation ◽  
Biceps Femoris ◽  
Ankle Muscle ◽  
Foot Strike ◽  
Muscle Activations

This study analysed the landing performance and muscle activity of athletes in forefoot strike (FFS) and rearfoot strike (RFS) patterns. Ten male college participants were asked to perform two foot strikes patterns, each at a running speed of 6 km/h. Three inertial sensors and five EMG sensors as well as one 24 G accelerometer were synchronised to acquire joint kinematics parameters as well as muscle activation, respectively. In both the FFS and RFS patterns, according to the intraclass correlation coefficient, excellent reliability was found for landing performance and muscle activation. Paired t tests indicated significantly higher ankle plantar flexion in the FFS pattern. Moreover, biceps femoris (BF) and gastrocnemius medialis (GM) activation increased in the pre-stance phase of the FFS compared with that of RFS. The FFS pattern had significantly decreased tibialis anterior (TA) muscle activity compared with the RFS pattern during the pre-stance phase. The results demonstrated that the ankle strategy focused on controlling the foot strike pattern. The influence of the FFS pattern on muscle activity likely indicates that an athlete can increase both BF and GM muscles activity. Altered landing strategy in cases of FFS pattern may contribute both to the running efficiency and muscle activation of the lower extremity. Therefore, neuromuscular training and education are required to enable activation in dynamic running tasks.

Test–Retest Reliability of the Mini-BESTest in People With Mild to Moderate Multiple Sclerosis

2021 ◽  
Author(s):  
A Wallin ◽  
M Kierkegaard ◽  
E Franzén ◽  
S Johansson
Keyword(s):  
Multiple Sclerosis ◽  
Measurement Errors ◽  
Balance Control ◽  
Intraclass Correlation ◽  
Repeated Measurements ◽  
Minimal Detectable Change ◽  
Detectable Change ◽  
Limits Of Agreement ◽  
Retest Reliability ◽  
Test Retest Reliability

Abstract Objective The mini-BESTest is a balance measure for assessment of the underlying physiological systems for balance control in adults. Evaluations of test–retest reliability of the mini-BESTest in larger samples of people with multiple sclerosis (MS) are lacking. The purpose of this study was to investigate test–retest reliability of the mini-BESTest total and section sum scores and individual items in people with mild to moderate overall MS disability. Methods This study used a test–retest design in a movement laboratory setting. Fifty-four people with mild to moderate overall MS disability according to the Expanded Disability Status scale (EDSS) were included, with 28 in the mild subgroup (EDSS 2.0–3.5) and 26 in the moderate subgroup (EDSS 4.0–5.5). Test–retest reliability of the mini-BESTest was evaluated by repeated measurements taken 1 week apart. Reliability and measurement error were analyzed. Results Test–retest reliability for the total scores were considered good to excellent, with intraclass correlation coefficients of .88 for the whole sample, .83 for the mild MS subgroup, and .80 for the moderate MS subgroup. Measurement errors were small, with standard error of measurement and minimal detectable change of 1.3 and 3.5, respectively, in mild MS, and 1.7 and 4.7, respectively, in moderate MS. The limits of agreement were − 3.4 and 4.6. Test–retest reliability for the section scores were fair to good or excellent; weighted kappa values ranged from .62 to .83. All items but 1 showed fair to good or excellent test–retest reliability, and percentage agreement ranged from 61% to 100%. Conclusions The mini-BESTest demonstrated good to excellent test–retest reliability and small measurement errors and is recommended for use in people with mild to moderate MS. Impact Knowledge of limits of agreement and minimal detectable change contribute to interpretability of the mini-BESTest total score. The findings of this study enhance the clinical usefulness of the test for evaluation of balance control and for designing individually customized balance training with high precision and accuracy in people with MS.

An Efficient Match Search Approach Using Two-Dimensional Hash Function in Hardware-Based Dictionary Compression

2019 ◽  
Vol 28 (06) ◽  
pp. 1950106
Author(s):  
Qian Dong ◽  
Bing Li
Keyword(s):  
Compression Ratio ◽  
Hash Function ◽  
High Speed ◽  
Two Dimensional ◽  
Time Data ◽  
Search Result ◽  
Compression Speed ◽  
Real Time Data ◽  
Real Time Data Processing ◽  
Search Approach

The hardware-based dictionary compression is widely adopted for high speed requirement of real-time data processing. Hash function helps to manage large dictionary to improve compression ratio but is prone to collisions, so some phrases in match search result are not true matches. This paper presents a novel match search approach called dual chaining hash refining, which can improve the efficiency of match search. From the experimental results, our method showed obvious advantage in compression speed compared with other approach that utilizes single hash function described in the previous publications.

Sign in / Sign up

Export Citation Format

Share Document