Latin-Americans have become major contributors in Major League Baseball, but face many challenges acculturating to living and playing in the United States. This research examined the acculturative support provided to Latin-American players by teams in the South Atlantic League of Minor League Baseball and whether or not people involved think that support was effective. Semi-structured interviews were conducted with front-office members and Latin-American former players, and transcriptions were analyzed for emerging themes using QDA Miner content analysis software. Three main themes emerged from the interviews: the language barrier, interaction between Latin-American and Anglo-American teammates, and the youth of Latin-American prospects. These themes were identified both as presenting the biggest challenges to the acculturation of players and also areas where assistance should be focused in order to be of the most benefit. All interview subjects believed the support currently provided for Latin-American players was effective, but that there are still areas where improvements can be made. Future research should explore acculturation from current players‟ perspectives, instead of taking a front-office approach, and would not only provide information on the player‟s opinions of current acculturative practices, but also their attitudes and beliefs about acculturation and whether they view it as a positive or negative experience.

Thesis (Ph. D.)--Ohio State University, 1994. / Includes bibliographical references (leaves 148-156). Available online via OhioLINK's ETD Center.

Perception of effort, defined as “the conscious sensation of hard, heavy and strenuous exercise”, is known to regulate endurance performance and human behaviour. Perception of effort has recently been shown to be exacerbated by mental exertion and is also known to be a main feature of fatigue. However, to date, not only its neurophysiology but also how manipulations of perceived exertion might impact endurance performance remain poorly understood. The main aim of this thesis was to investigate how manipulations of perceived exertion might impact endurance performance. This thesis is divided in two parts: central and peripheral manipulations of perceived exertion. In each part, three experimental chapters aimed to get a better insight in the neurophysiology of perceived exertion and its impact on endurance performance. In the first part (central manipulations), we firstly investigated the impact of exacerbating perceived exertion via mental exertion involving the response inhibition process on self-paced running endurance performance. This study demonstrated that as with time to exhaustion tests, time trial performance is impaired following mental exertion leading to mental fatigue. Secondly, we investigated whether mental exertion leading to mental fatigue could alter the rate of central fatigue development during constant load whole-body exercise. This study demonstrated that the exacerbated perception of effort in presence of mental fatigue does not reflect an altered rate of central fatigue development, but is likely to be due to i) an impaired central motor command and/or ii) an alteration of the central processing of the corollary discharge. Thirdly, we investigated whether mental exertion could impact the repeatability of maximal voluntary contraction of the knee extensors. We found that contrary to submaximal exercise, force production capacity is not altered by mental exertion. Finally, these three studies demonstrated that i) mental exertion negatively impacts submaximal exercise but not maximal exercise and that ii) mental fatigue differs from central fatigue. In the second part (peripheral manipulation), we firstly developed and tested the reliability of a new endurance exercise model non-limited by the cardiorespiratory system (one leg dynamic exercise), which will be of benefits for future researches aiming to manipulate feedback from group III-IV muscle afferents. Secondly, we described neuromuscular alterations induced by this exercise and tested a new methodology to indirectly measure feedback from group III-IV muscle afferents. This study demonstrated that one leg dynamic exercise induced central and peripheral fatigue and also a decrease in spinal excitability associated with an increase in cortical excitability. Furthermore, this study also suggests that monitoring cardiovascular responses during muscle occlusion might be a suitable tool to indirectly measure feedback from group III-IV muscle afferents. Thirdly, we tested the corollary discharge and afferent feedback model of perceived exertion with electromyostimulation. This study demonstrated for the first time that for the same force output, perception of effort generation is independent of muscle afferents and reflects the magnitude of the central motor command (manipulated by electromyostimulation). All together, these findings provide further evidence in support of the corollary discharge model of perceived exertion, and provide a new exercise model to investigate and manipulate perception of effort. This thesis, when integrating both experimental parts, provides new insight on how perception of effort regulates endurance performance. Specifically, it demonstrates how muscle fatigue is a contributor of the continuous increase in perception of effort during endurance exercise, but also that other contributors play a role in this increase in perception of effort. Indeed, we demonstrated for the first time that i) perception of effort alterations in the presence of mental fatigue is independent of any alterations of the neuromuscular system, and ii) muscle afferents does not directly impact perception of effort, but may influence it indirectly via their role in motor control.

The aim of this study was to investigate the effect of visual skills training on the visual ability of elite rugby players. This study utilized a quantitative approach; and it employed a true experimental study design, in particular a pre-test-post-test randomized-group design. A total number of 26 participants (that met the specified criteria) were selected from the Eastern Province Rugby Academy squad. Those that met the criteria were then divided randomly into two groups (13 per group), which comprised the experimental and control groups, respectively. The control and experimental groups were tested on six visual skills, namely: accommodation, saccadic eye movements, speed of recognition, hand-eye co-ordination, visual memory and peripheral awareness. An optometric assessment was also conducted as a pre-test to ensure that the participant had “normal vision”, followed by a six week intervention (visual skills-training). The sessions were performed for thirty minutes three times per week for six weeks, followed by a post-test. Descriptive statistics were employed, both numerically, such as the mean standard deviation, and graphically by means of histograms. Inferential statistics were also used in the form of t-tests and Cohen’s d calculations to determine the statistical and practical significance of the mean score differences between the experimental and control groups. The pre- to post-test results indicated both statistical and practical significant differences in each of the visual skills tested among the experimental group; accommodation (hart near far rock test, p<.0005, d=2.34), saccadic eye movements (saccadic eye movement test, p<.0005, d=2.08), hand-eye coordination and peripheral awareness (accumulator test, p<.0005, d=2.20), speed of recognition (evasion test, p<.0005, d=1.14) and visual memory (flash program test, p<.0005, d=1.20). However, there were no statistically significant differences (p>.05) found when comparing the pre- and post-tests for the control group. It was concluded that the visual skills training program used had a significant positive impact on the visual performance of the Eastern Province rugby academy players.

INTRODUCTION: The knee joint is one of the most frequently injured structures in the game of golf. The loads experienced by the knee during the golf swing are typically greater than those experienced during walking. In particular, a heightened lead limb peak external knee adduction moment has been linked to the progression of medial compartment knee osteoarthritis (OA). Altering movement patterns is a common strategy that can be used to reduce loading on the knee joint but has received little attention during the golf swing. Also, while such manipulations may be beneficial from an injury prevention perspective, they may have implications on golf performance. The purpose of this study was to analyze the effects altering stance has on the peak knee adduction moment and swing speed during the golf swing. METHODS: Twenty healthy subjects were recruited for a 3-dimensional biomechanical analysis wherein participants hit three golf shots using different stance positions in which either foot angle or stance width was altered. The following stance conditions were used: self-selected, 0º foot angle (perpendicular to target line), 30º foot angle (externally rotated), wide stance width, and narrow stance width RESULTS: Both the 30º foot angle and the wide stance width significantly decreased (p < 0.001) the lead limb peak external knee adduction moment compared to the self-selected golf stance. In contrast, the narrow stance width significantly increased (p = 0.023) the peak knee adduction moment when compared to the self-selected stance. No significant differences were found in the peak knee adduction moment between the 0º foot angle and self-selected stance. Lastly, no significant differences (p = 0.109) were found in swing speed between any of the stance conditions. CONCLUSION: The externally rotated foot position and wider stance width decreased the lead limb peak knee adduction moment without hindering performance. Considering the prevalence of injury to the lead limb knee joint, modifying a golfer’s stance could potentially be used to increase the longevity of their playing career.

PURPOSE: To quantify squat jump and isometric mid-thigh pull performance characteristics of an international level male weightlifter relative to a group of male weightlifters at an Olympic training site. METHODS: An 85kg international level male weightlifter (22.0y, 81.63kg, 168.5cm) representing the USA was recruited for this study and compared to a group of male weightlifters (n=41, 24.2±4.6y, 93.14±21.10kg, 173.8±8.6cm). Data was collected as part of an on-going athlete monitoring program and athletes were familiar with all tests performed. Unloaded squat jumps and isometric mid-thigh pulls were performed on force plates sampling at 1000Hz and analyzed with LabView software. Variables analyzed included squat jump height (JH) and allometrically scaled peak power (PPa), isometric mid-thigh pull allometrically scaled peak force (IPFa) and rate of force development at 200ms (RFD200). Standardized (z) scores were calculated for the athlete on each testing variable. RESULTS: Testing results for the athlete and group were as follows: JH=47.0 vs. 33.9±6.1cm (z=2.13), PPa=309.14 vs 278.68±81.76W·kg0.67 (z=0.37), IPFa=263.78 vs 270.31±48.27N·kg0.67 (z= -0.14), RFD200=4701.93 vs 10241.4±5422.6N·s-1 (z= -1.02). CONCLUSION: Despite having the highest absolute (total=326kg) and relative (Sinclair=389.54) weightlifting total, the only variable that corresponded with the athlete’s competition success was JH. These findings suggest that coaches and sport scientists can use squat jumps to predict competition success and identify talent in male weightlifters.

Abstract available in the 9th Annual Coaches and Sport Science College.

No description available.

Abstract available in the The Journal of Strength and Conditioning Research.

The split jerk and power jerk are two commonly used lifts among strength and conditioning coaches, as well as lifts included in the sport of Olympic weightlifting. However, it is unknown which of these jerk techniques exhibit more advantageous barbell kinematics. PURPOSE: To compare the barbell kinematics between a power jerk and a split jerk at a constant load. METHODS: Twelve men were recruited for this study (height = 1.8 ± 0.1 m; mass = 85.3 ± 10.2 kg; age = 23.4 ± 2.4 years). All subjects had been completing the jerk for a minimum of six months, and reported their split jerk 1 repetition maximum (1-RM: 105.3 ± 19.1 kg). Subjects completed 3 repetitions of each jerk technique, at 85% of their split jerk 1-RM. The data were collected using 6 3D video cameras, with a sampling rate of 200Hz and were analyzed using Vicon software. A multivariate paired t-test was used to determine the effect of jerk technique on all kinematic variables. Paired samples t-tests were used as post hoc analyses when necessary. An alpha level of (p<0.05) was used for all inferential statistics. RESULTS: No significant differences were found between the two techniques for starting barbell position, lowest barbell position and maximum concentric velocity. Peak barbell height, range and displacement were all found to be significantly greater in the power jerk when compared to the split jerk (p<0.05). CONCLUSIONS: Results suggest that more work is done on the barbell, and greater range of motion, occur during the power jerk. The results suggest that more work may be done on the body during the split jerk due to the technique of dropping quickly under the bar for the catch. Less work done on the barbell could result in higher absolute loads, making the split jerk the superior technique for populations such as weightlifting athletes.