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MALE FOOTBALL PLAYERS WITH HIP-RELATED PAIN DEMONSTRATE DIFFERENT SAGITTAL PLANE KINETICS DURING RUNNING WHEN COMPARED TO HEALTHY CONTROL PARTICIPANTS
Get PDFThe purpose of this study was to evaluate the differences in sagittal and frontal plane hip kinematics and kinetics between male football players with and without hip-related pain (HRP). A total of 10 men with HRP and 10 control participants were recruited from larger longitudinal cohort studies. During stance, football players with HRP demonstrated a significantly larger peak external hip flexion moment and impulse compared to healthy control participants. Football players with HRP appear to adopt a movement strategy during running that imparts greater loads on the hip joint; however, the cross-sectional nature of the study cannot determine a causal relationship. This preliminary finding indicates that further investigation of running biomechanics in a larger sample of football players with HRP is warranted
THE FREE MOMENT IN CUTTING MANEUVERS – AN UNDERESTIMATED CONTRIBUTOR TO THE MOVEMENT?
Get PDFThe purpose of this study was to identify the relationship between different movement strategies during 90° cutting maneuvers and the free (reaction) moment. It is observed that the orientation of either a positive or negative free moment is generated by different orientations of the foot segment at initial touch down. These finding impacted the rotational moment that is transferred to the knee joint: A higher internal reaction moment is observed when athletes are exposed to a positive free reaction moment, which potentially increases load on the ACL. The most important finding was that it is possible to generate differently orientated reaction moments during the same movement, which highlights the importance of investigating movement strategies in order to understand potential injury risk factors
COMPARISON OF SIMPLE GRAVITY BASED ACCELEROMETER CALIBRATION PROCEDURES
Get PDFAccelerometers are commonly used, yet the process of calibrating them and the influence this has on recorded accelerations is rarely reported. The aim of this study was to compare the accuracy of three simple gravity based calibration methods of accelerometers. Using a custom made rig, 16 Delsys Trigno sensors were simultaneously calibrated by positioning the sensors in 9 positions throughout the full range of orientations across three axes. Three calibration methods were used spanning a range of 1g (1G), 2g (2G), and 2g with optimisation (2Gopt). Errors were greatest in 1G (RMSD=3.1%) and equally as good for the 2G and 2Gopt (2.1%). Gravity based calibration of accelerometers can be achieved quickly, and calibration over a larger range provides more accurate results. This work provides recommendations of accelerometer use which help the applied practitioner to collect more reliable and valid data. Further investigation of factors, including those affecting the frequency of calibration, is required
KINETIC ANALYSIS OF LANDING A GRAND JETÉ BETWEEN BAREFOOT AND POINTE SHOE FOOTWEAR FOR DOMINANT AND NON-DOMINANT LEGS
No full textThe purpose of this study was to examine the vertical ground reaction force in the skill of a Grand Jeté between barefoot and pointe shoes for both dominant and non-dominant legs. Seven female college dancers participated in the the study, and the results showed that there were no statistically significant differences between the landing legs or footwear conditions. However, there was an observable difference between the landing forces of the dominant and non-dominant legs, indicating that the dancers may be able to dissipate landing forces more effectively when landing on their dominant leg. This study provides a preliminary understanding on the effects of footwear between dominant and non-dominant legs. Future studies are warranted to evaluate the kinematics of lower body extremity to acquire a comprehensive understanding on the skill of Grand Jeté
Disrupting Notions and Challenging Stereotypes through Young Adult Literature: Research and Teaching to Enact Social Change
No full textEFFECTIVE USE OF ANGULAR MOMENTUM FOR ROTATIONS ABOUT THE LONGITUDINAL AXIS - EXAMPLES OF QUADRUPLE JUMPS IN FIGURE SKATING
Get PDFQuadruple jumps (QJ) have conquered the competitions in figure skating. In men\u27s competitions three or four different QJ is standard for top skaters. The key task of the study with 17 excellently executed QJ was to investigate the influence of the angle between the principal axis of inertia (PAI) and the vector of the angular momentum (AM) on the effective use of the angular momentum for a high angular velocity in the flight. The smallest possible angle between PAI and AM results in the most effective use of the angular momentum and a stable axis of rotation. It is of great interest for sports practice to find out which options can compensate larger angles between PAI and AM. The study shows that QJ can excellently performed even with an angle of 20 to 30 degrees between the PAI and AM. In this case, a larger angular momentum and a longer flight time are required
Behavioral and Psychophysiological Effects of Near-Miss Outcomes in a Game of War
Get PDFWithin the gambling literature, the misidentification of outcomes has been shown to affect gambling behaviors in players. A notably salient stimulus frequently cited as leading to the misidentification of wins is near-misses. Near-misses occur when the outcome of an event closely resembles a winning outcome, even though it is a loss. The current study intended to further investigate the effects of near-misses relative to wins and losses on player’s inter-trial latencies and the presence of the feedback-related negativity (FRN) and P300 event related potentials (ERPs) in a game of war card game. FRN is a negative fronto-central ERP component occurring 200 and 300 ms post-feedback, and P300 is positive centro-parietal ERP component occurring 300 to 600 ms post-feedback. The results of this study revealed decreased amplitudes for FRN and an unanticipated ERP component, N1, following winning outcomes than near-miss or loss outcomes. No differences were observed in latency to resume playing, average bet amount placed on the following round, or the amplitude of an additional unanticipated ERP component, P2. The P300 ERP component was not observed following feedback presentation onset. Near-misses and losses showed no differences across any of the measures included in the current study, indicating the lack of an observed near-miss effect when measuring from feedback presentation. Further studies are needed in order to assess the presence of any possible near-miss effects when measuring from card presentation onset rather than feedback presentation
The role of muons in semiconductor research (Ch 5)
No full textThe aim of this chapter is to provide an introduction and overview of using muons to study defects in semiconductors for an audience with a background in material science. First is a general tutorial to relevant models and discussion of the muon-based techniques that have been important to the semiconductor field. The latter portion of this chapter highlights results from selected studies on semiconductors to demonstrate and describe some contributions that muon spin research (SR) techniques have made to the semiconductor community in recent years
THE ROLE OF SKELETAL MUSCLE SYNTHESIZED BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) ON THE HEALTH AND MAINTENANCE OF THE MURINE MOTOR UNIT
No full textSkeletal muscle is a cytokine-producing organ capable of expressing various myokines, including tumor necrosis factor alpha, IL-6, IL-8, IL-15, IL-17, and brain-derived neurotrophic factor (BDNF) (Pederson, 2011, So et al., 2014, Schnyder and Handschin, 2015). BDNF is a small neurotrophic protein, that regulates neuron differentiation, maturation, and survival, and modulates central nervous system neurotransmitters (Oppenheim, 1991; Acheson et al., 1995; Binder and Scharfman, 2004; Reichardt, 2006). However, the role of BDNF in skeletal muscle health and maintenance is not well understood. To investigate this, we used a mouse model with Cre/Lox targeted gene deletion driven by the human alpha skeletal actin promoter, resulting in experimental animals with reduced or absent muscle-derived BDNF (MuscleBDNF+/-, MuscleBDNF-/-). We examined gastrocnemius and soleus muscles across multiple age groups (30, 90, 120, 180, and 210 days), assessing myofiber health in the absence or reduction of skeletal-derived BDNF. Significant pathology was observed in gastrocnemius tissues of both young and young-adult transgenic mice lacking endogenous BDNF, including mispositioned nuclei, split fibers, and fewer total myofibers, further histological analysis showed that fast-twitch myofibers were disproportionally affected. We next assessed the structure of gastrocnemius associated neuromuscular junctions of 120d mice and found that there is a presynaptic decrease of vesicle acetylcholine transporter and an increased probability of junction fragmentation in muscle BDNF knockout mice. Taken altogether these findings suggest that muscle-synthesized BDNF plays a role in the maintenance of muscle fibers and retrogradely affects innervating gastrocnemius associated motorneurons at the neuromuscular junction