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GROUND REACTION FORCES DURING TATTA ADAVU OF BHARATANATYAM
Get PDFThe purpose of the study was to establish the normative values for vertical ground reaction forces during the most basic step of Bharatanatyam dance. Bharatanatyam involves rthymic tapping of the feet with varying trunk, upper extremity, and hand movements. These dancers are prone to lower extremity injuries. However, there is very little insight into the physical demands of the dance form. Seven experienced Bharatanatyam dancers performed the tatta adavu by tapping their feet repeatedly on a force plate at 2 speeds. Peak ground reaction force was found to be 4 to 5 times the body weight. These high forces repeatedly experienced by the lower extremities could contribute to the higher incidence of lower extremity injuries. Further biomechanical analysis of these dance movements must be undertaken to understand the complexities of the dance form
COMPARISON OF THROWING ARM MECHANICS DURING LONG-TOSS THROWING AND PITCHING IN PROFESSIONAL BASEBALL PLAYERS
Get PDFThe purpose of this study was to quantify long-toss throwing mechanics of professional baseball pitchers and compare biomechanics of mound pitching to long-toss throwing. Kinematic and kinetic data from 19 professional baseball pitchers throwing from 18-m to 91-m, along with fastball pitches were analyzed using marker-based motion analysis and linear mixed models. Throwing approach and arc were not restricted for long-toss throws. Linear associations were found between the long-toss throwing distances and biomechanical metrics. While elbow and shoulder kinetics increased with distance, they were lower than pitching kinetics at shorter distances and did not significantly exceed the average pitching kinetics at the maximum distance. This is the first study to quantify long-toss throwing mechanics without restriction of throwing style
A LARGE-SCALE NUMERICAL ANALYSIS OF UNIMODAL AND BIMODAL FEATURES IN FORCE PLATE DATA MEASURED DURING VERTICAL COUNTERMOVEMENT JUMPING
Get PDFThis study presents a novel algorithm for automatically analyzing modality patterns in countermovement jump (CMJ) force-time curves. Bimodal peaks (Fz1, Fz3) are identified using a minimum threshold (Ttrough_drop) for their relative drop to the intermediate trough value (Fz2). In a large sample of athletes (n = 214), 75% of jumps were technically bimodal (Ttrough_drop \u3e 0%) but this decreased to 17% (Ttrough_drop \u3e 5%) and 0% (Ttrough_drop \u3e 20%) using alternative definitions. This suggests that conflicting findings in other studies may be explained by a lack of standardized criteria for classifying modality. The drop from Fz1 to Fz2 in bimodal jumps was also largely correlated (r = 0.75) to the force at zero velocity and braking acceleration (r = 0.63). These findings highlight the potential value of extracting new quantitative features related to curve modality for CMJ research and interpretation
ANALYSIS OF SPRINT START TRANSITION PHASES AND THEIR ASSOCIATIONS WITH PERFORMANCE
Get PDFThe sprint start consists of three transitions defined by the instants the hands, rear leg and front leg leave the ground, which delimit three phases. Ground reaction forces produced by 57 sprinters during the block phase were analysed to investigate the performance (average horizontal external power) implications of transition timing and the force production and centre of mass (CM) displacements between them. Better sprint starters exhibited higher horizontal (r = 0.47 for phase two), but lower vertical (r = -0.40), CM displacement across shorter time periods. Additionally, more horizontally-orientated force vectors to reduce CM projection angle at each transition were favourable (r range = -0.62 to -0.45). Coaches should encourage high anteroposterior bilateral force production even though this may compromise (r = -0.41) subsequent front block force production
Improving Procedural Fidelity and Treatment Outcome in Natural Environment Training Using Peer Feedback
Get PDFProcedural fidelity as it relates to client outcomes is a topic of growing interest in applied behavior analysis. Behavior analytic treatments are implemented by Registered Behavior Technicians (RBTs). The current requirements for the RBT credential is a forty hour training and a 75 question examination. However, research has shown that immediately following training, procedural fidelity decreases. Many methods have been tried to improve procedural fidelity following training, including performance feedback. The present study evaluated the effect of peer feedback immediately following a natural environment training (NET) session and peer feedback immediately preceding the next opportunity. For all three of the participants, procedural fidelity scores increased following peer feedback. For both of the two participants who completed the study, peer feedback immediately preceding a session produced higher levels of procedural fidelity
Assessment of sex differences and amphetamine on schedule-induced polydipsia
Get PDFAmphetamine (AMPH) is one of the most common psychotropic drugs abused in the United States. Its major pharmacological effect is to increase synaptic dopamine levels in the mesolimbic reward pathway, which in turn causes behavioral effects in animals, and subjective effects in humans. These reinforcing properties of AMPH trigger very strong levels of craving the drug, and eventually result in patterns of compulsive use of AMPH. Regarding psychostimulant action, female rats have been reported to be more vulnerable to the reinforcing effects of psychostimulants. In the current study, schedule-induced polydipsia (SIP), an animal model of compulsive behavior, was applied for the further study of sex differences in the behavioral effects of AMPH. SIP is a phenomenon whereby food-restricted rats exhibit exaggerated polydipsic behavior when presented with food pellets under an intermittent schedule of reinforcement. This behavior appears to be mediated by the neurotransmitter dopamine in the brain’s limbic system, and this neurotransmitter and system is also affected by psychostimulant drugs. During the SIP training sessions, it was found that female rats needed more sessions to develop stable schedule-induced polydipsic behavior. In line with previous studies, AMPH dose-dependently decreased total water intake and licks during a SIP task. Significant differences were found on their total number of lever presses and reinforcers earned
Native American Boarding Schools: Understanding an Issue from the Past and Remixing It for the Present
Get PDFAntecedents of Workplace Deviance
Get PDFWorkplace deviance occurs in organizations everywhere and has been found to produce detrimental effects to companies such as serious financial loss and higher rates of employee turnover. There has been substantial research conducted investigating different factors that add to the likelihood of employees engaging in deviant behavior. Some of these factors include situational and personality influences, emotions, perceptions, and motivation. By gaining more knowledge of the antecedents of workplace deviance, managers can gain a better understanding of how to both manage and prevent these behaviors. It is important for organizations to find ways to meet the needs of their employees while also motivating them to work hard and in a productive manner. Research has suggested that the behaviors of employees have a large impact on the success of an organization and thus should be prudently evaluated and managed
ASSOCIATIONS BETWEEN GLENOHUMERAL ROTATION STRENGTH AND SELECT KINETIC PARAMETERS DURING THE BASEBALL PITCH IN ADOLESCENT BASEBALL PITCHERS
Get PDFThe purpose of this study was to examine the associations between isometric glenohumeral rotation strength and select biomechanical parameters during the pitching motion in adolescent baseball pitchers. Glenohumeral (GH) rotation strength and pitching kinetic data were assessed in 28 (14.2 ±0.94 yrs; 66.5 ±11.7 kg; 175 ±10.8 cm) adolescent baseball pitchers. Spearman’s rank correlations were used to assess relationships between GH rotation strength and upper extremity torques during the pitching motion. Peak GH internal rotation torque during the pitch was negatively correlated with the ratio of throwing arm external rotation strength to non-throwing arm external rotation strength (r= -0.552, p \u3c 0.05). These results provide evidence for a potential mechanism behind the increased injury risk seen in pitchers who exhibit GH external rotation weakness
THE EFFECTS OF FATIGUE ON SOFTBALL PITCHER FROM PITCHING MULTIPLE GAMES
Get PDFThe purpose of this study was to examine the effects of fatigue on softball pitching from pitching back to back games. Players were asked to throw 15 balls in each inning for seven innings and for a total of two games. The results showed fastball’s velocity in the first inning of the first game (25.4 ± 2.5 m/s) had significantly decreased after a game and a half (24.3 ± 2.7 m/s; p = 0.00). Hence, this study suggests that the pitchers started to show signs of fatigue after this amount of pitches (165 pitches), so softball coaches may take this into consideration and make necessary pitching change. Given the established relationship between fatigue and injury in pitchers, the Amateur Softball Association may use this information to implement a pitch count to protect softball pitchers from overuse injur