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COMPARISON OF SPRINT STRIDE KINEMATICS BETWEEN THREE DIFFERENT CARBON SPIKES – A CASE STUDY
Get PDFThe aim of this study was to compare the effect of three different carbon spikes that have different carbon plate and foam placement upon stride-by-stride kinematics during short and long sprints. An international leveled 400m (52.60 s) master athlete performed several 50 and 200m sprints, while wearing three different carbon spikes types in which stride kinematics and angular foot velocity were measured. The main findings were that in the 50m sprints with Puma spikes peak velocity and step frequency were lower with longer contact times than with the other spikes and during the 200m Saucony had a shorter average step length than Adidas. The largest changes in kinematics were found in the angular foot velocities in both sprints thereby it was concluded that placement of carbon plate can influence step kinematics particularly during the short sprint for this athlete
BIOMECHANICAL GUIDELINE VALUES TO SUPPORT GYMNASTS LEARNING OF HANDSPRING AND DOUBLE SALTO FORWARD TUCKED ON VAULT
Get PDFThe vault handspring and double salto forward tucked was already studied biomechanically several times performed 20 or more years ago. However, this vault is still important today. Our aim is to check the validity of the published results under current apparatus conditions using 24 vaults from 24 gymnasts selected via the minimum execution-score (≥ 9.0) from high level competitions. For this purpose, 14 parameters are evaluated using a 2-dimensional analysis. Compared to published data the results show an increase of the velocity during the flight to the vaulting board. There is no notable change in the maximum height of the body center of mass in the post flight. Our new results are the basis for a comparison of one example national gymnast in an infographic, in which strengths and weaknesses are recognizable and should support the coach in his work
CONCURRENT VALIDITY AND RELIABILITY OF IN-LAB MARKERLESS MOTION CAPTURE IN ESTIMATING JOINT KINEMATICS IN BASEBALL PITCHING
Get PDFMarkerless motion capture systems allow for the estimation of 3D segmental pose of human movement without the encumbrance of makers. Therefore, the aim of this study is to measure the concurrent validity and reliability of baseball pitching kinematics estimated by an in-lab markerless motion capture system. This analysis is based of 100 pitches thrown by 18 collegiate baseball pitchers. Discrete kinematic variables varied in their equivalence and reliability between systems. Kinematic variables in the sagittal plane had more agreement between systems than variables in the transverse plane. Segment lengths were also comparable between systems. Although markerless technology provides ease of collecting biomechanical data in a baseball setting, inter-system differences do still exist between marker-based systems and markerless systems
INFLUENCE OF KINETIC FACTORS ON JAVELIN THROW PERFORMANCE
Get PDFThe purpose of the study was to find out the relationship of Javelin throw performance on peak vertical Ground Reaction Force (GRFv) at last third step, at penultimate step and at delivery step and release velocity at the instant of release. Twelve national level male javelin throwers performed six trials of javelin throw with adequate rest between trials. The Qualisys 3D mocap system were synchronized with four force plates to capture the delivery phase. The data were analyzed using Pearson product moment correlation followed by multiple linear regression. The javelin throw performance had a significant positive linear correlation with peak vertical GRF at last third step, at penultimate step, at delivery step and release velocity at delivery phase. The multiple linear regression revealed that peak GRFv at last third step was the predictor of javelin throw performance
COMPARISON OF WRIST ANGLES BETWEEN TWO ESTABLISHED BIOMECHANICAL MODELS
Get PDFThe purpose of this study was to identify differences between two established methods for wrist angle calculation (U.L.E.M.A. by Jaspers et al. & model by Metcalf et al.) during range of motion (ROM) movement tasks. Reflective markers, representing both hand models, were placed on anatomical landmarks of 10 healthy participants. Sagittal plane ROM of the wrist was analysed during open and closed hand wrist flexion/extension. Differences in ROM of the wrist flexion/extension were found for both tasks over the entire movement cycle (closed hand=12.4° (±10.1), open hand=10.3° (÷7.0°)). In particular, differences in extension are noticeable during wrist movement with open hand, though, an offset correction in neutral position might influence this outcome. Potential reasons for these variances are identified and should be taken into account when utilizing the hand model
THIS NOW WHICH IS TO SAY YOU
No full textThe following manuscript is a hybrid artifact; a book-length poem-essay and visual artwork. The driving movement propelling the piece forward is that of an imagined (or enacted) epistolary correspondence between myself and my undergraduate mentor, Monica Berlin—who passed away in November of 2022. The manuscript is set up in the form of call and response. Each of the sections beginning with, “Dear Lauren,” quote directly from a letter Berlin wrote to me in 2018 as a response to my undergraduate writing portfolio. Each of the sections beginning, “Dear Monica,” are made up of my response back (re-contextualized through my interaction with the letter now, as opposed to when I first received it). The ensuing conversation that unfolds over these pages is a meditation on grief as well as the closeness, tensions, and distances that exist within our most intimate and meaningful relationships. It is an attempt to speak to (and through) the dead as well as the living
Drug Treatments for Post-Traumatic Stress Disorder in a Mouse Model
No full textPost-traumatic stress disorder (PTSD) is a trauma- and stressor-related disorder caused by exposure to a traumatic or distressing event. Symptoms related to this disorder are known to be detrimental to one’s quality of life, affecting aspects of behavior, cognition, and mood. Furthermore, PTSD has been found to have high rates of comorbidity with other psychological disorders such as generalized anxiety disorder (GAD). Current pharmacological treatments for PTSD have been insufficient, with fewer than 50% of patients reporting full remission from the disorder following treatment. Both ketamine, a dissociative anesthetic, and fluoxetine (FLX), a selective serotonin reuptake inhibitor (SSRI), have shown promise in their ability to treat stress-related disorders. The aim of this study was to determine the efficacy of R-S ketamine and FLX, alone and in combination, in reducing the onset of symptoms associated with PTSD and GAD. A fear conditioning (FC) paradigm in which mice were exposed to an aversive stimulus paired with a neutral stimulus was used. Treatments began 4 hours post-FC, and fear response behaviors such as freezing and aggression were recorded 24 hours and 2 weeks post-FC. 2-weeks after FC, mice were placed in an open-field apparatus and assessed for behaviors indicative of anxiety, such as percent time spent in the center of the open field and escape behaviors. Results indicated that the combination ketamine/FLX treatment most effectively reduced PTSD-related behaviors, while FLX alone was most effective for GAD-related behaviors
Plumbing the Depths of the Shallow End: Exploring Persistent Homology Using Small Data
Get PDFPersistent homology is a prominent tool in topological data analysis. This thesis is designed to be an introduction and guide to a beginner in persistent homology. This comprehensive overview discusses the math used behind it, the code needed to apply it, and its current place in the field. We explain and demonstrate the algebraic topology which fuels persistent homology. Homotopies inspire homology groups, which are able to determine how many holes a shape has. By visualizing data as a shape, persistent homology determines what type of holes are present.
We demonstrate this by using the package TDA in the manipulation software R on controlled datasets. A kernel density estimate diagram presents the results. We showcase applying TDA to an external, uncontrolled dataset. The limits on memory allowed us to process no more than four columns of data at a time. To more thoroughly explore the dataset, we analyzed several four-column subsets, but found no special features aside from a base level of closeness
EVALUATING EMBRYO SURVIVAL OF SURROGATE FISH SPECIES USING MULTIPLE INCUBATORS: CONTINUING EFFORTS TOWARDS REINTRODUCING ARCTIC GRAYLING (THYMALLUS ARCTICUS) INTO LOWER MICHIGAN STREAMS
Get PDFArctic Grayling Thymallus arcticus have been successfully reintroduced to the Upper Missouri River Basin of Montana using Remote Site Incubators (RSI). Widespread use of RSIs as part of reintroduction efforts in Michigan is challenged by low gradient streams, which limit deployment success. In this study, I evaluated the utility of an alternative instream rearing device, the Floating Basket Incubator (FBI), by directly comparing the survival of Rainbow Trout Oncorhynchus mykiss, Brook Trout Salvelinus fontinalis, and Walleye Sander vitreus (as Arctic Grayling surrogates) between RSI and FBI in stream and hatchery environments. In addition, I assessed how abiotic and biotic factors influenced survival for rainbow trout within FBIs among three natural streams. Overall, I found that mean survival of rainbow trout was higher than that of brook trout and walleye. My results suggested that FBIs performed similarly to RSIs in most experiments. Linear mixed effect model results suggested that survival of surrogate species was best explained by incubator type and stream location. The proportion of variation explained by the incubator type was low, relative to the random effect of stream location. My results suggest that although surrogates of Arctic Grayling sometimes had lower survival in FBI, the magnitude of this difference was small enough that FBIs should be considered as a tool when reintroducing Arctic Grayling
