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FATIGUE-RELATED CHANGES OF MUSCLE COORDINATION DURING A MAXIMAL 100-M BUTTERFLY STROKE SWIMMING: A CASE STUDY
Get PDFThis study investigated the fatigue-related changes in muscle coordination during a maximal 100-m butterfly stroke swimming in an international level male swimmer. Four muscle synergies were extracted from the electromyography (EMG) data during the butterfly stroke in 1st-3rd laps, while five muscle synergies were extracted from the data in 4th lap. The muscle combinations and activation times in the synergy #1, #2, #3 and #4 were similar between each lap. The synergy #5 in 4th lap had a high contribution from the trapezius and rectus femoris muscles and was active in the catch phase. These results suggest that the muscle synergies during a maximal 100-m butterfly stroke swimming are not largely altered between each lap in this swimmer, although the additional neural control appeared to be related to fatigue
IMPACT OF FEMORAL MORPHOLOGY ON MUSCLE FORCES AND JOINT LOADS DURING HIGH-LOAD SQUATS IN ELITE POWERLIFTERS - A PRELIMINARY INVESTIGATION
Get PDFThis study investigated the effects of femoral morphology on musculoskeletal loading during high-load squats. Three Austrian top-ranked powerlifters executed competition-style squats at 90% of their 1-repetition-maximum, captured with a 3D motion capture system. Femoral anteversion (AVA) and neck-shaft angles were quantified from magnetic resonance images. For each athlete, two musculoskeletal models were created: 1) generic and 2) athlete-specific femoral geometry. Muscle forces and joint contact forces were estimated using static optimisation and normalized to bodyweight (BW). Results show increases in hip and knee muscle work (2-14 J/BW) and hip and knee joint contact forces (0.5-2.3 BW) when comparing generic with athlete-specific models, particularly in athletes with low AVA. Findings suggest that low AVA leads to increased musculoskeletal loading during high-load squats
PHYSICAL CHARACTERISTICS ASSOCIATED WITH LUMBAR BONE STRESS INJURY RELATED TECHNIQUE IN MALE FAST BOWLERS
Get PDFThe purpose of this study was to determine whether physical characteristics were associated with cricket fast bowling technique previously associated with lumbar bone stress injury, rear hip flexion at back foot contact and lumbopelvic extension at front foot contact (FFC). Forty-one elite male cricket fast bowlers underwent 3D biomechanical analysis of their bowling technique and movement competency of the lower limbs and lumbopelvic region. Further, participants completed range of motion, lumbopelvic stability, core endurance and lower body power tests. Moderate-strong significant correlations were found between lumbopelvic extension at FFC with back bowling hip dynamic leg swing extension and front bowling hip external rotation range. Physical competencies including hip flexibility or lumbopelvic control may influence injurious bowling techniques
Resting-state Functional Connectivity Correlates of Inhibitory Control over Emotional Stimuli
Get PDFInhibitory control is defined as the stopping or overriding of a mental process with or without intention. It is known as a motor process in which executive control suppresses an automated motor response. Currently, there is no existing research discussing the neural mechanisms of an emotional anti-saccade task, therefore with the use of resting-state functional magnetic resonance imaging (fMRI) and an emotional anti-saccade task, this study aims to identify the neural correlates of inhibitory control over emotional stimuli. The anti-saccade task is known as an effective measure of inhibitory control since it requires inhibiting a reflexive response and re-orienting attention while emotional faces are presented. Given the nature of the anti-saccade, where it requires the top-down inhibition of an automatic pro-saccade response, investigating the neural correlates could serve as an important tool to evaluate deficits in response inhibition in clinical populations. Previous research was confirmed by demonstrating significant effects for the anti-saccade task. ROI-to-ROI analyses showed overlap in the salience and frontoparietal networks in relation to response inhibition. Seed-to-voxel analysis revealed significant connectivity between numerous seed networks in relation to response inhibition. Anti-saccade trials showed stronger functional connectivity between seeds (i.e. salience, default mode network, frontoparietal, and amygdala) compared to pro-saccade trials
The Fuel of Social Change: Native Activism in the 1960s and 1970s and the Development of Native American Studies
Get PDFDuring the 1960s and 1970s, the United States experienced a rise in social activism which subsequently sparked progressive political movements. In the midst of this social atmosphere, the Native American community advocated for rights and visibility for the Indigenous populations and were active participants in many other social movements of the time. This paper uses Northern Michigan University’s archives to explore how the influx of progressive social movements created an atmosphere for Native American activism to grow and henceforth contributed to the development of Native American Studies programs as an academic pursuit across the country. Archival research reveals how the engagement of students influenced social change across America, and by specifically focusing on sources from NMU, this paper explores how the local area reveals the larger progressive movements and changes taking place all around the United States during this time. Since the emergence of the Native American Studies program at NMU during the 1970s, the program has continued to grow and develop
PERCEPTIONS OF TRAUMA-INFORMED EDUCATIONAL PRACTICES IN WASHTENAW COUNTY, MICHIGAN
Get PDFSchools at the middle level embrace students through a transformative time of life. This time of transition and transformation can be challenging for any student. However, for students who have experienced childhood trauma, this season of life can prove even more difficult. Schools have an obligation to individually support students as they grow; this includes moments of dysregulation and problematic behaviors. Through implementation of trauma-informed practices, schools can begin to positively impact students through shaping behavior that promotes growth and learning rather than applying punitive consequences that lead to an ongoing cycle of trauma and removal.
This qualitative study sought to understand the experiences of principals in Washtenaw County, Michigan as they implemented trauma-informed practices at the middle level. It was conducted through semi-structured interviews with five local middle school principals. Using phenomenology as a methodology and compassion fatigue theory as a theoretical framework, the interviews were reviewed, coded, and analyzed for themes. The study explored how the nuances of trauma-informed practices shifted staff attitudes and impacted student behavior and discipline. The following themes emerged from the data: initial resistance to gradual acceptance, increased empathy towards students, improving student behavior and changing disciplinary practices, and challenges in implementation
EFFECT OF RESISTED SLED SPRINT TRAINING ON SPRINTING ABILITIES OF JUNIOR HIGH SCHOOL STUDENTS
Get PDFThis study aimed to clarify the effects of different resisted sled sprint (RSS) loads on the sprinting abilities of junior high school students. Thirty-two junior high school students completed five RSS sessions in a physical education class. Each used a 12-, 14.5-, or 17-kg sled for the RSS training. According to the ratio of sled weight to body mass (%BM), the students were divided into light (25.75 ± 2.57%BM) and heavy (34.46 ± 2.96%BM) groups. Students completed a 50-m run before and after the session, and their running time, running velocity, step frequency, and step length at 50 m and 5 m were calculated. No significant changes were observed in any of the measurements for the 50- and 5-m run for either group. Therefore, the five RSS sessions did not affect performance regardless of load
SPRING-MASS MODEL SYMMETRY CHARACTERISTICS IN DISTANCE RUNNERS ACROSS A COMPETITIVE SEASON
Get PDFThis study aimed to apply characteristics of the spring-mass model (SMM) to distance running over a competitive season by measuring changes in landing-takeoff and rebound asymmetries. Thirteen runners from the same university team underwent 3D biomechanical gait analyses at the start and end of a 7-week competitive season. Paired-sample t-tests compared landing-take-off asymmetry [effective contact time (tce) to aerial time (tae)], rebound asymmetry [positive work time (tpush), to negative work time (tbrake), and average vertical ground reaction force (vGRF). Rebound asymmetry increased by 4%, but was not significant, t(12)=-1.239, p=0.239. Landing-take-off asymmetry decreased by 1%, but was not significant, t(12)=0.232, p=0.82. vGRF did not change, t(12)=-0.074, p=0.942. It appears only minor SMM improvements may occur over a season in distance runners
ANKLE KINEMATICS AND PLANTAR FASCIITIS IN RUNNERS: A ONE-YEAR PROSPECTIVE 4HAIE STUDY
Get PDFThe aim of this prospective study was to compare ankle kinematics between runners with and without plantar fasciitis (PF). We biomechanically analysed 719 runners (17 PF and 702 non-PF) using a 3-D motion capture system during overground running at their self-preferred speed. An independent t-test was performed to assess ankle kinematics during the stance phase of running (at initial contact, at maximum and range of motion). Runners with PF displayed abduction ankle angle approximately 3o lower than the non-injured runners at maximal adduction (P = 0.006; d = 0.68). In conclusion, it appears that a higher ankle abduction (external rotation of the foot) may be a protective factor for PF. This information appears to be valuable for assessing running technique and may be beneficial to clinicians, coaches and runners who are afflicted with PF
THE INFLUENCE OF DIFFERENT IMPLEMENTS ON KINEMATICS AND KINETICS COMPARED TO MENS JAVELIN THROW
Get PDFThe aim of the study was to investigate the influence of different throwing devices on the kinematics and kinetics of the throwing arm. Therefore, six experienced athletes threw six different implements (five balls, one javelin) with different masses. Retroreflective marker data were captured using a 12-camera infrared system. The results show significant differences between the implements, where lighter implements achieve higher release speeds. Furthermore, differences in the shoulder external rotation angle, the angular velocities of shoulder internal rotation and elbow extension, as well as the moments at the shoulder and elbow could be shown. It can be concluded that balls of different masses have similar kinematics and kinetics and can therefore be used to train speed and strength aspects of the javelin throw while using lower run-up speeds