Enhancing the differentiation of walking and standing via the ratio of plantar pressures

2021 ◽  
pp. 095441192110589
Author(s):  
Jing Jin Shen ◽  
Xiao Xiao Jin ◽  
Shu Xing Bao ◽  
Zhen Yu Zhou ◽  
Feng Yu Xu ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Peak Pressure ◽  
Pressure Ratio ◽  
Underlying Mechanism ◽  
Recognition System ◽  
Average Pressure ◽  
Repeated Measures Anova ◽  
Plantar Pressures ◽  
The Monte Carlo Method ◽  
Posture Recognition

Differentiation of standing and walking based on plantar pressures is helpful in developing strategies to reduce health risks in the workplace. In order to improve the differentiation ability, the paper proposes a new metric for posture differentiation, that is, the pressure ratio on the two anatomical plantar regions. The plantar pressures were collected from 30 persons during walking and standing. After verifying the normal distribution of the pressure ratio by the Monte Carlo method, two-way repeated-measures ANOVA was conducted for the pressure ratios. The advantage of the pressure ratio over two conventional pressure metrics (the average pressure and the peak pressure) is demonstrated by its much larger size effect. Furthermore, the pressure ratio permits to establish value ranges corresponding to walking and standing, which are less influenced by specific person factors, thus facilitating the design of a standardized posture recognition system. The underlying mechanism underlying the pressure ratio is discussed from the aspect of biomechanics of movement.

One Size Fits All?

Methodology ◽  
2012 ◽  
Vol 8 (1) ◽  
pp. 23-38 ◽  
Author(s):  
Manuel C. Voelkle ◽  
Patrick E. McKnight
Keyword(s):  
Repeated Measures ◽  
Structural Equation ◽  
Type I Error ◽  
Equation Modeling ◽  
Type I ◽  
Finite Sample ◽  
Traditional Methods ◽  
Repeated Measures Anova ◽  
Special Cases ◽  
Latent Curve

The use of latent curve models (LCMs) has increased almost exponentially during the last decade. Oftentimes, researchers regard LCM as a “new” method to analyze change with little attention paid to the fact that the technique was originally introduced as an “alternative to standard repeated measures ANOVA and first-order auto-regressive methods” (Meredith & Tisak, 1990, p. 107). In the first part of the paper, this close relationship is reviewed, and it is demonstrated how “traditional” methods, such as the repeated measures ANOVA, and MANOVA, can be formulated as LCMs. Given that latent curve modeling is essentially a large-sample technique, compared to “traditional” finite-sample approaches, the second part of the paper addresses the question to what degree the more flexible LCMs can actually replace some of the older tests by means of a Monte-Carlo simulation. In addition, a structural equation modeling alternative to Mauchly’s (1940) test of sphericity is explored. Although “traditional” methods may be expressed as special cases of more general LCMs, we found the equivalence holds only asymptotically. For practical purposes, however, no approach always outperformed the other alternatives in terms of power and type I error, so the best method to be used depends on the situation. We provide detailed recommendations of when to use which method.

Time of imagery’s effect on performance and self-efficacy in college baseball players

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Colton Haight ◽  
Sandra Moritz ◽  
Tanis Walch
Keyword(s):  
Self Efficacy ◽  
Repeated Measures ◽  
Group Interaction ◽  
Physical Effect ◽  
Baseball Players ◽  
Repeated Measures Anova ◽  
Significant Time ◽  
Imagery Group ◽  
College Baseball ◽  
Group 2

AbstractThe relationships among the time of imagery use on performance and self-efficacy in college baseball players during a hitting task was examined. Participants (n=24) were randomly assigned to one of three imagery conditions: (a) before practice, (b) during practice, (c) after practice. A one-shot MG-M imagery intervention was used. Results from a 3 (imagery group) ×2 (pretest and posttest) repeated measures ANOVA showed only a significant time by imagery group interaction for self-efficacy (F (2, 21)=4.67, p<0.05). These findings suggest that imagery had a stronger psychological effect than physical effect.

Effect of Turf Toe on Foot Contact Pressures in Professional American Football Players

2009 ◽  
Vol 30 (5) ◽  
pp. 405-409 ◽  
Author(s):  
Robert H. Brophy ◽  
Seth C. Gamradt ◽  
Scott J. Ellis ◽  
Ronnie P. Barnes ◽  
Scott A. Rodeo ◽  
...  
Keyword(s):  
Body Mass Index ◽  
National Football League ◽  
Peak Pressure ◽  
American Football ◽  
Football Players ◽  
Plantar Pressures ◽  
History Of ◽  
Turf Toe ◽  
The Relationship ◽  
Contact Pressures

Background: The relationship between turf toe and plantar foot pressures has not been extensively studied. Two hypotheses were tested in a cohort of professional American football players: first, that a history of turf toe is associated with increased peak hallucal and first metatarsophalangeal (MTP) plantar pressures; second, that decreased range of motion (ROM) of the first MTP correlates with increased peak hallucal and first MTP plantar pressures. Materials and Methods: Forty-four athletes from one National Football League (NFL) team were screened for a history of turf toe during preseason training. Dorsal passive MTP ROM and dynamic plantar pressures were measured in both feet of each player. Anatomical masking was used to assess peak pressure at the first MTP and hallux. Results: First MTP dorsiflexion was significantly lower in halluces with a history of turf toe (40.6 ± 15.1 degrees versus 48.4 ± 12.8 degrees, p = 0.04). Peak hallucal pressures were higher in athletes with turf toe (535 ± 288 kPa versus 414 ± 202 kPa, p = 0.05) even after normalizing for athlete body mass index ( p = 0.0003). Peak MTP pressure was not significantly different between the two groups tested. First MTP dorsiflexion did not correlate with peak hallucal or first MTP pressures. Conclusion: This study showed that turf toe is associated with decreased MTP motion. In addition, increased peak hallucal pressures were found. Further study is warranted to determine whether these pressures correlate with the severity of symptoms or progression of turf toe to first MTP arthritis.

scholarly journals Differences in Graphomotor Skills by the Writing Medium and Children’s Gender

2021 ◽  
Vol 11 (4) ◽  
pp. 162
Author(s):  
Boram No ◽  
Naya Choi
Keyword(s):  
Preschool Children ◽  
Repeated Measures ◽  
Repeated Measures Anova ◽  
Surface Textures ◽  
Young Learners ◽  
And Gender ◽  
Print Size ◽  
Writing Practice ◽  
Pressure Analysis

Factors of graphomotor skills may serve as indicators to determine a writer’s handwriting proficiency or acclimation to different writing surface textures. This study examines differences in children’s graphomotor skills based on types of writing medium and gender. Participants were 97 six-year-old Korean preschool children who had not received formal writing training prior to the study. Writing tasks were completed on a tablet screen and paper. Writing samples were analyzed using the Eye and Pen software to investigate spatial, temporal, and pressure exertion exhibited during the writing tasks. A repeated measures ANOVA revealed differences in graphomotor skills such as print size, writing speed, and writing pressure. Writing on a tablet screen decreased clarity of writing; print size and speed increased as the stylus slides across the tablet surface with relatively less friction, thereby decreasing the exertion of writing pressure. Analysis of writing differences according to gender indicated that boys generated larger print sizes than girls. Results suggest that while simple writing tasks may be feasible on the tablet screen, providing children with a larger writing medium and encouraging larger print sizes for writing practice, especially for boys, may be beneficial in the development of graphomotor skills among young learners.

Map Width Enhancement Technique for a Turbocharger Compressor

2013 ◽  
Vol 136 (6) ◽  
Author(s):  
Subenuka Sivagnanasundaram ◽  
Stephen Spence ◽  
Juliana Early
Keyword(s):  
Performance Improvement ◽  
Peak Pressure ◽  
Pressure Ratio ◽  
Comparison Study ◽  
Heavy Duty ◽  
Recirculating Flow ◽  
Heavy Duty Diesel ◽  
And Performance ◽  
The Stability ◽  
The Impact

This paper presents an investigation of map width enhancement and the performance improvement of a turbocharger compressor using a series of static vanes in the annular cavity of a classical bleed slot system. The investigation has been carried out using both experimental and numerical analysis. The compressor stage used for this study is from a turbocharger unit used in heavy duty diesel engines of approximately 300 kW. Two types of vanes were designed and added to the annular cavity of the baseline classical bleed slot system. The purpose of the annular cavity vane technique is to remove some of the swirl that can be carried through the bleed slot system, which would influence the pressure ratio. In addition to this, the series of cavity vanes provides a better guidance to the slot recirculating flow before it mixes with the impeller main inlet flow. Better guidance of the flow improves the mixing at the inducer inlet in the circumferential direction. As a consequence, the stability of the compressor is improved at lower flow rates and a wider map can be achieved. The impact of two cavity vane designs on the map width and performance of the compressor was highlighted through a detailed analysis of the impeller flow field. The numerical and experimental study revealed that an effective vane design can improve the map width and pressure ratio characteristic without an efficiency penalty compared to the classical bleed slot system without vanes. The comparison study between the cavity vane and noncavity vane configurations presented in this paper showed that the map width was improved by 14.3% due to a significant reduction in surge flow and the peak pressure ratio was improved by 2.25% with the addition of a series of cavity vanes in the annular cavity of the bleed slot system.

scholarly journals Microhardness evaluation of root dentin after using resin sealer solvents

2021 ◽  
Vol 15 (4) ◽  
pp. 256-261
Author(s):  
Gamze Nalci ◽  
Tayfun Alaçam ◽  
Bülent Altukaynak
Keyword(s):  
Repeated Measures ◽  
Saline Solution ◽  
Prolonged Exposure ◽  
Repeated Measures Anova ◽  
Ultrasonic Agitation ◽  
Gutta Percha ◽  
Before And After ◽  
Root Dentin ◽  
Substantial Decline ◽  
Hardness Values

Background. This study aimed to assess the effects of methyl ethyl ketone (MEK) and ethyl acetate (EA) on dentin microhardness, used as resin sealer solvents. Methods. Eighty halves of single-rooted teeth were randomly divided into four groups to apply MEK, EA, chloroform, or saline solution. Vickers hardness values were measured for three root levels before and after the direct application of solvents for 5 and 15 minutes or a 1-minute application with ultrasonic agitation. The results were analyzed using repeated-measures ANOVA, and adjustments were made for comparisons with Bonferroni tests. Results. The dentin microhardness decreased in all the solvent groups (P<0.05). The changes in microhardness increased with prolonged exposure times, except for the saline solution group. Chloroform exhibited the most significant decrease in value. Furthermore, ultrasonic agitation elicited a more substantial decline in values. Conclusion. MEK and EA might be preferred over chloroform as a solvent for resin sealers because they offer an attenuated decrease in dentin microhardness and do not have gutta-percha-dissolving properties.

scholarly journals Analyzing randomized controlled interventions: Three notes for applied linguists

2015 ◽  
Vol 5 (1) ◽  
pp. 135-152 ◽  
Author(s):  
Jan Vanhove
Keyword(s):  
Repeated Measures ◽  
Intervention Studies ◽  
Mixed Effects ◽  
Analysis Of Covariance ◽  
Cluster Randomization ◽  
Repeated Measures Anova ◽  
Randomized Controlled ◽  
Mixed Effects Modeling ◽  
Statistical Formalism ◽  
Relevant Covariates

I discuss three common practices that obfuscate or invalidate the statistical analysis of randomized controlled interventions in applied linguistics. These are (a) checking whether randomization produced groups that are balanced on a number of possibly relevant covariates, (b) using repeated measures ANOVA to analyze pretest-posttest designs, and (c) using traditional significance tests to analyze interventions in which whole groups were assigned to the conditions (cluster randomization). The first practice is labeled superfluous, and taking full advantage of important covariates regardless of balance is recommended. The second is needlessly complicated, and analysis of covariance is recommended as a more powerful alternative. The third produces dramatic inferential errors, which are largely, though not entirely, avoided when mixed-effects modeling is used. This discussion is geared towards applied linguists who need to design, analyze, or assess intervention studies or other randomized controlled trials. Statistical formalism is kept to a minimum throughout.

scholarly journals Αξιολόγηση της πρώιμης νευροεξελικτικής παρέμβασης στη νευροαναπτυξιακή πορεία πρόωρων νεογνών υψηλού κινδύνου

2012 ◽  
Author(s):  
Μαρία Κυριακίδου
Keyword(s):  
Repeated Measures ◽  
T Test ◽  
Repeated Measures Anova ◽  
Kolmogorov Smirnov ◽  
One Way Anova

Τα ποσοστά θνητότητας των υψηλού κινδύνου πρόωρων νεογνών έχουν σταθεροποιηθεί και συνεπώς η μελέτη των στρατηγικών μείωσης των υψηλών ποσοστών νευροαναπτυξιακών διαταραχών είναι απαραίτητη. Τα υψηλού κινδύνου πρόωρα νεογνά πρέπει να συμμετέχουν σε προγράμματα πρώιμης παρέμβασης από πολύ νωρίς, λόγω της αυξημένης πλαστικότητας του αναπτυσσόμενου εγκεφάλου. Παρόλα αυτά, η αποτελεσματικότητα της παρέμβασης σε όλα τα ΥΚ πρόωρα νεογνά δεν είναι ξεκάθαρη. Έχει αποδειχτεί, ότι οι πρώιμες αναπτυξιακές παρεμβάσεις που ξεκινούν μετά την έξοδο από το νοσοκομείο, βελτιώνουν τη γνωστική ανάπτυξη των νεογνών αλλά το αποτέλεσμα αυτό δε διατηρείται στη σχολική ηλικία. Η απόδειξη των επιδράσεων της πρώιμης παρέμβασης στην κινητική ανάπτυξη είναι ελλιπής. Επομένως, στόχος της παρούσας μελέτης ήταν να αξιολογήσει την επίδραση της πρώιμης παρέμβασης με τη μέθοδο NDT στη γνωστική και κινητική έκβαση ΥΚ πρόωρων νεογνών, μέχρι τη διορθωμένη ηλικία των 18 μηνών αλλά και να συσχετίσει νεογνικούς και περιγεννηρικούς παράγοντες με τη γνωστική και κινητική έκβαση. Στη μελέτη εισήχθησαν νεογνά με ΔΚ≤32 εβδομάδων και ΒΓ≤1500 γραμμαρίων. Αποκλείστηκαν, νεογνά με χρωματοσωμικές ανωμαλίες, μείζονες συγγενείς ανωμαλίες και γενετικά σύνδρομα. Επίσης, αποκλείστηκαν τα νεογνά που στη διορθωμένη ηλικία των 18 μηνών διαγνώστηκαν με εγκεφαλική παράλυση. Συνολικά, 147 νεογνά πληρούσαν τα κριτήρια εισαγωγής και εφαρμόστηκε η δοκιμασία ΤΙΜΡ στη ΔΗ των 38-41 εβδομάδων. Από αυτά, 73 τυχαιοποιήθηκαν στην ομάδα παρέμβασης και 74 στην ομάδα ελέγχου. Η ομάδα παρέμβασης ακολούθησε πρόγραμμα φυσικοθεραπείας με τη μέθοδο NDT με συχνότητα 2 φορές την εβδομάδα, για ένα έτος ενώ η ομάδα ελέγχου εφάρμοσε πρόγραμμα οδηγιών στο σπίτι 2 φορές την εβδομάδα, για ένα έτος. Στη στατιστική ανάλυση χρησιμοποιήθηκε το t-test, η one-way ANOVA, ο έλεγχος χ² κατά Pearson, repeated measures ANOVA και ο έλεγχος κατά Greenhouse-Geisser. Επιπρόσθετα, χρησιμοποιήθηκε ο έλεγχος Kolmogorov-Smirnov. Το ΒΓ και η ΔΚ των νεογνών στις δύο ομάδες ήταν 1325,18 (±368,46) γρ και 30,55 (±1,6) εβδ, αντίστοιχα, στην ομάδα παρέμβασης και 1440,18 (±293,61) και 30,76 (±1,6) στην ομάδα ελέγχου, αντίστοιχα. Η διαφορά δεν ήταν στατιστικά σημαντική. Οι δύο ομάδες ήταν συγκρίσιμες ως προς τους περιγεννητικούς και νεογνικούς παράγοντες . Οι 2 ομάδες αξιολογήθηκαν στη διορθωμένη ηλικία των 3, 6, 12 και 18 μηνών. Οι δύο ομάδες είχαν στατιστικά σημαντική διαφορά στη διορθωμένη ηλικία των 3, 12 και 18 μηνών στη γνωστική και κινητική έκβαση με την ομάδα παρέμβασης να υπερέχει. Στη διορθωμένη ηλικία των 18 μηνών, η ομάδα παρέμβασης σημείωσε μέση βαθμολογία 108,83 (±9,39) στη γνωστική κλίμακα και 109,01 (±10,30) στην κινητική ενώ η ομάδα ελέγχου 99,18 (±7,31) στη γνωστική και 98,81 (±8,91) στην κινητική κλίμακα της δοκιμασίας Bayley III. Η φυσικοθεραπεία (p<0,0001), η IVH (p<0,0001), η πολυδυμία (p=0,008), η ΝΕΚ (p=0,001) και η διάρκεια χορήγησης Ο₂ (p=0,008) επηρέασαν σημαντικά στη βαθμολογία της γνωστικής έκβασης των πρόωρων νεογνών στη διορθωμένη ηλικία των 18 μηνών. Η φυσικοθεραπεία (p<0,0001), ήταν ο μοναδικός παράγοντας που επηρέασε σημαντικά τη βαθμολογία της κινητικής έκβασης των πρόωρων νεογνών στη διορθωμένη ηλικία των 18 μηνών. Τα ΥΚΠΝ επωφελούνται από το πρόγραμμα πρώιμης παρέμβασης με τη μέθοδο NDT, διότι βελτιώνουν την κινητική και γνωστική τους έκβαση μέχρι τη διορθωμένη ηλικία των 18 μηνών. Ως εκ τούτου, συστήνεται η εφαρμογή της μεθόδου κατά τη διάρκεια του 1ου έτους ζωής ως προληπτικό πρόγραμμα θεραπείας στα ΥΚΠΝ. Αδιαμφισβήτητα, μεγαλύτερης διάρκειας μακροχρόνιες παρακολουθήσεις απαιτούνται για να επιβεβαιώσουν ή να απορρίψουν τη διατήρηση των αποτελεσμάτων στην προσχολική ή σχολική ηλικία. Συστήνεται, ο παράγοντας φυσικοθεραπευτική παρέμβαση να συνυπολογίζεται στις πολυπαραγοντικές αναλύσεις διότι οδηγεί σε αξιόπιστη ερμηνεία των αποτελεσμάτων που αφορούν την έκβαση.

scholarly journals Facial attractiveness and lip morphology of Caucasian women

2018 ◽  
Vol 81 (4) ◽  
pp. 404-413 ◽  
Author(s):  
Zdzisław Lewandowski ◽  
Dariusz P. Danel
Keyword(s):  
Empirical Study ◽  
Repeated Measures ◽  
Facial Attractiveness ◽  
Facial Features ◽  
Sexually Dimorphic ◽  
Men And Women ◽  
Repeated Measures Anova ◽  
Adult Men ◽  
Caucasian Women

Abstract Human lips are one of the most sexually dimorphic facial features. Although lip morphology is considered particularly important for female facial attractiveness no systematic empirical study has been conducted in this respect. This study aimed to investigate a relationship between female Caucasian facial attractiveness and their lip morphology. Two series of morphologically average composite portraits with digitally increased and decreased lip width and height measurements were assessed by adult men and women. Results were analysed using repeated measures ANOVA. When compared to the average lip shape both a decrease and an increase in lip width were associated with lower female facial attractiveness. A systematic increase in lip height from the lowest values to the highest, was associated with an increase in attractiveness scores. Attractiveness assessments of men and women did not differ significantly. The results show that perception of lip attractiveness may be intersexually congruent and that a variation in lip morphology may significantly affect female facial attractiveness.

Sign in / Sign up

Export Citation Format

Share Document