The aim of this study was to review the available literature on the epidemiology of injuries in professional rugby, and then to collect data on previous injuries and the influence of external factors on rugby injuries. Secondly, the incidence, nature and circumstances surrounding injuries in a cohort of professional South African provincial rugby players were documented. The data collected was compared with available data in order to determine trends of injuries that, if taken into consideration, could possibly lead to the prevention of injuries to future rugby players. No study has been done on injury rate and frequency in the Currie Cup competition. Being the cornerstone of providing players for competitions like the Super 12 and Tri-nations, it is certainly appropriate to record the incidence and nature of injuries in the Currie Cup competition. This study attempted to identify factors associated with injury, to direct further analytical research and suggest measures to reduce injury rate. It also drew a comparison between results obtained through this study, and results obtained by other relevant studies in other competitions. The epidemiological data used in this study were collected from two professional rugby teams that competed in the 2002 Currie Cup Rugby Competition. This competition is held annually in South Africa and includes provincial teams from 14 regions in South Africa.

The study was undertaken to identify and evaluate variables that contribute to wildlife tourist satisfaction. Clark et al. (1999) argue that the hospitality and tourism industries are still relatively under researched. Therefore, this research is particularly important because it focuses on wildlife tourist satisfaction as opposed to customer satisfaction in general. According to Teye and Leclerc (1998), satisfaction is vital for ensuring sustainability of the tourism industry. Similarly, Bramwell (1998) argues that tourist destinations should offer exceptional and satisfying products and services in order to retain and attract more tourists. The study was conducted at the Chobe National Park (CNP), Botswanaâs largest and most popular national park. CNP is popular for its abundant and diverse wild species. Following the arguments on the importance of wildlife tourist satisfaction the study sought to establish how wildlife touristsâ experiences impact on their overall satisfaction. The study also assessed the extent to which Chobe National Park contributes to wildlife tourist satisfaction in relation to the identified variables. The convenience sampling method was applied and the success of the pilot study indicated the usability of the research instrument. The research utilised the SERV-PERVAL scale (Petrick 2000). The scale was developed to assess service quality and perceived value. SERV-PERVAL measures quality as a measure of the supplierâs performance. The measurement of quality is crucial because quality is argued to be the best predictor of perceived value. Data was collected by the use of a structured self-completion questionnaire. The questionnaire was divided into three sections: demographic data, the SERV-PERVAL scale to assess questions on service quality, perceived value and satisfaction. The third section was a combination of a Likert scale and open-ended questions gathering information on expectations and motivations. The descriptive method of analysis, with tables and figures, was applied. The level of significance between variables was determined through the use of the correlation analysis, and the multiple regression model was utilised to investigate the contribution of variables to wildlife tourist satisfaction. The conclusion derived from the literature reviewed is that the concept satisfaction is core in the wildlife tourism industry because it involves feelings of wildlife tourists after experiencing wildlife tourism services. The literature has positively associated and it emphasised the importance of several concepts to wildlife tourist satisfaction. These concepts are: service quality, price and value for money, tourist experience and expectations. While the results of the survey condoned the significance of service quality, price, value for money and tourist experience to wildlife tourist satisfaction, they also indicated and emphasised the importance of wildlife-related variables. These are: safety measures from attack by wild animals, availability and diversity of wild species, condition of vegetation in the wildlife area and accessibility. It is through the use of these variables that wildlife tourists evaluate their experiences and rate their satisfaction levels. Some of the results are, however, in conflict with two arguments found in the literature. Firstly the results contradicted the argument that wildlife tourists assess their satisfaction on the basis of whether or not their initial expectations were met. Some tourists indicated they had a satisfactory experience and yet they did not have prior expectations before they travelled to CNP. As a result, touristsâ expectations were found not to be one of the critical variables that contribute to wildlife tourist satisfaction. Secondly, despite the argument that one benefit of tourist satisfaction is the revisits by satisfied tourists, satisfied wildlife tourists in this study indicated they were satisfied with their experience but would not re-visit CNP, mainly because they had other commitments.

All adults involved in childrenâs sport affect the nature of the sporting experience, and to a large extent determine whether or not it is a positive experience for children. Of all adults involved, the parents are perhaps the most important and play the most significant role in childrenâs sport. The purpose of this study was to examine how a group of competitive and professionally trained adolescent swimmers perceived parental involvement and how it affected their total sport experience. Participants in the study were 93 (45 male and 48 female) competitive adolescent swimmers between the ages of 13 and 22 years, who received professional coaching for 1 to 15 years, and trained for 5 to 11 months per annum. Respondents completed the parental involvement in sport questionnaire (PISQ). The questionnaire consists of three multi-item scales. The three scales measured Directive behaviour (DB), Active involvement (AI), and Praise and understanding (PU). A single item of Pressure (P) was included as a dependent variable. The questionnaire was designed to elicit responses about the behaviour of parents with regard to their childrenâs swimming activities. Respondents identified the frequency with which certain behaviours were (a) exhibited by, and (b) desired of their parents. Discrepancies between exhibited and desired behaviour indicated the extent of respondentsâ satisfaction with these behaviours. Single sample t-tests showed that respondents perceived insufficient levels of DB, and satisfactory levels of PU, AI and P from their mothers. The results revealed that swimmers perceived satisfactory levels of pressure from their mothers, which leads to the conclusion that they find the amount of pressure acceptable. Single sample t-tests to determine the behaviour of fathers, showed satisfactory levels of DB, which suggests that fathers exhibit an appropriate level of directing or controlling of their childrenâs sporting experience. This is in contrast with the excessive levels of PU, AI and P that the respondents perceive from their fathers. Respondents may feel pressured by disproportionate praise as this might be accompanied by efforts to take control to an unacceptable degree. A second questionnaire was distributed to assess participantsâ enjoyment of their swimming. This questionnaire consists of three questions measuring the enjoyment of sport. The data revealed that the majority of the respondents (92%) were very satisfied with their swimming experience in general and indicated that they enjoyed it to a large extent. The data suggests that the current level of pressure the swimmers experienced did not have any affect on their level of enjoyment. The study indicates that parents who express satisfaction with childrenâs sport performance, who interact positively with them, and who are generally positively involved and supportive in the childrenâs sport experience may enhance the enjoyment they derive from their sport participation. Optimal parental involvement in sport could be achieved by having well-organised, well-run programmes, and by providing parents with an opportunity to receive some education about the sport programmes in which their children are involved. A proposed document, âPractical Guidelines for Swimmersâ Parentsâ, was prepared in order to provide parents with a course of action to maximise their involvement. It is recommended that the above-mentioned document be distributed to the parents of the participants in this study.

No description available.

Twisting movements are categorised into three mechanical types, named as DIRECT, COUNTER-ROTATION and TILT TWIST. Twisting techniques are studied using mathematical models. A mathematical inertia model is constructed to enable the determination of segmental inertia parameters from anthropometric measurements. A film analysis program is developed so that the angles, which specify the orientation and configuration of the body, may be derived from digitised film data. A computer simulation model, comprising 11 segments and 17 degrees of freedom, is constructed to represent the human body in free fall. The combined use of the three computer programs results in maximum errors of 3% for somersault and 9% for twist in ten filmed movements. The mechanics of twisting techniques are explained using simple mathematical models. An analysis of rigid body motions shows that there are two distinct modes of motion, named as the ROD MODE and the DISC MODE. It is shown that it is possible to change from one mode to the other by varying the angle of pike and this permits the twist to be increased or stopped or even reversed. The capacities of twisting techniques are determined using simulations. For twists from a piked position, delaying the extension from the pike can increase the twist rate although this does depend upon the particular technique used and the initial direction of somersault. The contributions of twisting techniques used in the filmed movements are determined using simulations based upon modifications of the film data. It is found that counter-rotation techniques made small contributions and that aerial techniques, which increased the angle of tilt, were the major contributors, even in movements where the twist was apparent at take off. Using the simulation model it is shown that the build up of twist in the unstable double layout somersault may be controlled by means of small asymmetrical arm movements during flight.

Thesis (PhD )--Stellenbosch University, 1978. / ENGLISH ABSTRACT: no abstract available / AFRIKAANSE OPSOMMING: geen opsomming

No description available.

Thesis (MMBK.)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: The purpose of this study was to investigate the influence of a six-week lateral movement training programme on selected physiological variables in netball players. Calf and thigh girth measurements, mass, body fat percentage, lateral agility, lateral flexibility, dynamic balance, heart rate and isokinetic concentric and eccentric quadriceps, hamstring, abductor and adductor muscle strength, were measured. A pre-recorded, six-week slide board training programme was followed in order to: increase calf and thigh girth measurements, decrease mass, decrease body fat percentage, increase lateral agility, increase lateral flexibility, better dynamic balance, meet the prescribed guidelines in terms of heart rate and increase the isokinetic muscle strength. The subjects (n=23) were between the ages of 18-23 years. They either played netball for the 1st or 2nd netball teams of the Maties Netball Club, or for the 1st or 2nd netball teams of the residence Nerina. They entered the study voluntarily. All of the subjects participated in the pre- and posttests. Fourteen subjects completed the six-week lateral movement training programme. Various significant differences (p < 0.05) were found between the pre- and post-test measurements: a significant decrease in body fat percentage, an increase in lateral agility, a decrease in mass, an increase in dynamic balance, an increase in concentric and eccentric abductor and adductor muscle strength, as well as an appropriate aerobic heart rate response. It was concluded that the lateral movement training programme proved to be beneficial to netball players at any level of fitness and participation. The programme provided an excellent aerobic workout, with either improvement or maintenance of the selected variables. / AFRIKAANSE OPSOMMING: Die doel van die studie was om ondersoek in te stel na die invloed van In ses-weeklange laterale bewegingsoefenprogram op geselekteerde fisiologiese veranderlikes in netbal speelsters. Kuit- en bobeenomtrekmates, massa, liggaamsvetpersentasie, laterale ratsheid, laterale lenigheid, dinamiese balans, harttempo en isokinetiese konsentriese en eksentriese quadriceps-, hampeus-, abduktor- en adduktorspierkrag, is gemeet. In Vooraf opgestelde, ses-weeklange laterale oefenprogram is gevolg om: die kuit- en bobeenomtrekmates te vergroot, die massa te verminder, die liggaamsvetpersentasie te verlaag, die verbetering van laterale ratsheid, laterale lenigheid en dinamiese balans te bewerkstellig, die voorgestelde riglyne in terme van harttempo te handhaaf en om isokinetiese spierkrag te vermeerder. Die proefpersone (n=23) was tussen 18-23 jaar oud. Die proefpersone het óf vir die 1ste of 2de netbalspanne van die Maties Netbalklub gespeel, óf vir die 1ste of 2de netbal spanne van die koshuis Nerina. Hulle deelname was volkome vrywillig. Al die proefpersone het aan die pre- en post-toetse deelgeneem. Veertien proefpersone het die ses-weeklange laterale bewegingsoefenprogram voltooi. Verskeie beduidende verskille (p < 0.05) tussen die pre- en post-toetse is gevind: 'n beduidende afname in liggaamsvetpersentasie, In toename in laterale ratsheid, In afname in massa, In toename in dinamiese balans, In toename in konsentriese en eksentriese abduktor- en adduktorspierkrag, asook In ooreenstemmende harttempo reaksie. Daar is tot die gevolgtrekking gekom dat die laterale bewegingsoefenprogram tot voordeel strek van netbalspeelsters op enige vlak van fiksheid en deelname. Die program bied In goeie aërobiese komponent met óf die verbetering, óf die handhawing van die geselekteerde veranderlikes.

Research in robotics has recently broadened its traditional focus on industrial applications to include natural, human-like systems. The human musculoskeletal system has over 600 muscles and 200 joint degrees-of-freedom that provide extraordinary flexibility in tailoring its overall configuration and dynamics to the demands of different tasks. The importance of understanding human movement has spurred efforts to build systems with similar capabilities and has led to the construction of actuators, such as pneumatic artificial muscles, that have properties similar to those of human muscles. However, muscles are far more complex than these robotic actuators and will require new control perspectives. Specifying how to encode high degree-of-freedom muscle functions in order to recreate such movements in anthropomorphic robotic systems is an imposing challenge. This dissertation attempts to advance our understanding by modeling the workings of human muscles in a way that explains how the low temporal bandwidth control of the human brain could direct the high temporal bandwidth requirements of the human movement system. We extend the motor primitives model, a popular strategy for human motor control, by coding a fixed library of movements such that their temporal codes are pre-computed and can be looked up and combined on demand. In this dissertation we develop primitives that lead to various smooth, natural human movements and obtain a sparse-code representation for muscle fiber length changes by applying Matching Pursuit on a parameterized representation of such movements. We employ accurate three-dimensional musculoskeletal models to simulate the lower body muscle fiber length changes for multiple repeatable movements captured from human subjects. We recreate the length changes and show that the signal can be economically encoded in terms of discrete movement elements. Each movement can thus be visualized as a sequence of coefficients for temporally displaced motor primitives. The primary research contribution of describing movements as a compact code develops a clear hierarchy between the spinal cord and higher brain areas. The code has several other advantages. First, it provides an overview of how the elaborate computations in abstract motor control could be ‘parcellated’ into the brain’s primary subsystems. Second, its parametric description could be used in the extension of learned movements to similar movements with different goals. Thirdly, the sensitivity of the parameters can allow the differentiation of very subtle variations in movement. This research lays the groundwork for understanding and developing further human motor control strategies and provides a mathematical framework for experimental research. / text

Rings is one of six disciplines in Men's Artistic Gymnastics. Judging criteria stipulate that a routine must incorporate two swinging elements completed in a motionless handstand. Performing backward and forward longswings in a routine fulfils this requirement. During both types of longswing, gymnasts typically use large angle changes at their hip and shoulder joints and move their arms laterally. Previous studies have ignored these three-dimensional arm movements, possibly neglecting a crucial aspect of technique. Using a computer simulation model this study investigated the contributions of hip and shoulder elevation angle changes and lateral arm movements to the performance of backward and forward longswings. A three-dimensional video and cable tension analysis of several backward and forward longswings performed by two elite gymnasts was conducted. The data provided accurate three-dimensional descriptions of backward and forward longswing techniques and the forces experienced by the gymnasts. In addition, data describing deformations of the rings frame and the extension of the gymnast were determined. A simulation model representing the three-dimensional movements of the rings cables and arms of a gymnast was developed. The model represented the right side of the gymnast and rings apparatus and comprised five segments: rings cable, arm, torso with head, thigh, and shank with foot. Damped linear springs represented the elasticity of the apparatus and gymnast. The model was evaluated against actual backward and forward longswing performances of two elite gymnasts. Actual joint angle time histories describing the gymnasts' techniques, together with subject specific inertia parameters, were used for this procedure. The RMS differences between values estimated by the model and actual values for the orientation of the gymnast and rings cable, the cable tension and the body extension were 4.3°, 2.1°,161N and 0.1 m respectively. The evaluated model was used to determine the contributions of each aspect of technique to the performance of longswings. Hip and shoulder elevation angle changes are important in producing the required rotation of the gymnast in both types of longswing. Without these components of technique the gymnast generated up to 113° less rotation. Lateral arm movements performed during backward longswings resulted in 40% less shoulder elevation torque required to complete the element and a 0.8 bodyweights decrease in peak force experienced at the shoulder joints. When lateral arm movements were omitted during forward longswings the gymnast produced 49° less rotation, and failed to reach the final handstand. This study shows that lateral arm movements make an important contribution to the performance of longswings on rings.