Doctoral Degrees (Exercise, Sport and Lifestyle Medicine)

Permanent URI for this collection

https://scholar.sun.ac.za/handle/10019.1/105282

Browse

Now showing 1 - 20 of 53

The acute : chronic workload ratio and injury occurrence among South African PSL soccer players
(Stellenbosch : Stellenbosch University, 2019-07) White, Ryan Colin; Grobbelaar, Heinrich Wilhelm; De Waal, Simon Jake; Swart, Jeroen; Stellenbosch University. Faculty of Medicine and Health Science. Dept. of Sport Science.
ENGLISH ABSTRACT: Purpose: Soft-tissue, non-contact injuries (STNCI) are the most prevalent injuries in professional soccer. Considerable research has focussed on injury prevention and training load (TL) monitoring, however, the multifactorial nature of injury occurrence is often neglected. As such, both internal and external TL were examined in this study with the intention of enhancing current understanding of the mechanisms behind STNCI. The acute:chronic workload ratio (ACWR) was used to model the internally and externally derived workloads, providing a dynamic representation of preparedness and subsequent injury risk. This study aimed to identify and describe the association of both internal and external workload variables and injury risk in the subsequent week using the ACWR among professional South African Premier Soccer League (PSL) players. Article one: Article one examined the association between internally-derived TL (session rating of perceived exertion [sRPE]) and injury risk in the subsequent week utilising the ACWR and 1-, 2-, 3- and 4-weekly cumulative TL. TL data was collected from 41 professional male soccer players over one and a half seasons. In total, 85 STNCIs were recorded. Only the ACWR was significantly associated (p<0.05) with injury in the subsequent week. The workload-injury relationship was sigmoidal (s-shaped) in nature. An increased injury risk in the subsequent week was found at moderate-low (0.77-0.89; OR: 1.67, 95% CI: 1.23-2.27) and high (>1.14; OR: 1.26, 95% CI: 1.06-1.50) ACWR zones, while a low (<0.77; OR: 0.29, 95% CI: 0.14-0.61) ACWR zone exhibited a most likely beneficial effect compared to a moderate-high ACWR zone. Article two: Article two investigated the association between externally-derived (global positioning systems [GPS] and accelerometer-derived mechanical load indicators) and injury likelihood in the subsequent week utilising the ACWR. Total distance (TD), high intensity speed (HIS), high intensity acceleration (HIA) and high intensity deceleration (HID) data, was collected from 37 professional male soccer players over one and a half seasons. The workload-injury relationship was sigmoidal (s-shaped) and quadratic (u-shaped) in nature. Increased injury likelihood for the subsequent week was identified at high {(TD; >1.30, OR: 1.78, 95% CI: 0.72-4.38)(HIS; >1.41, OR: 1.74, 95% CI: 0.80-3.77)(HIA; >1.41, OR: 1.80, 95% CI 1.00-3.24)}, moderate-high (HID; >1.37, OR: 0.80, 95% CI 0.39- 2.76) and low (HIA; <0.77, OR: 1.29, 95% CI 1.00-1,66) ACWR zones, when compared to a moderate ACWR (~0.91 to ~1.20) zone. Conclusion: The workload-injury relationship was sigmoidal in nature and players exposed to acute de-loads and spikes in TL experienced an increased risk of subsequent injury. A moderate ACWR of between ~0.91 to ~1.20 represents the most realistic, optimal TL index to maintain or improve fitness and/or preparedness, while limiting injury likelihood. The similar sigmoidal nature of injury risk between internally and externally derived TL implies that sRPE may be a useful alternative to costly GPS systems in the world of injury prevention for soccer players - which is of significant importance in a South African context. Key words: Acute:chronic workload ratio, session rating of perceived exertion, global positioning systems, training load monitoring, team sport.
An adapted rehabilitation programme for a cross section of South African chronic obstructive pulmonary disease patients
(Stellenbosch : Stellenbosch University, 2008-03) De Klerk, Danelle Ria; Barnard, J. G.; Joubert, J. R.; Stellenbosch University. Faculty of Education. Dept. of Sport Science.
The benefits of exercise training for patients with chronic obstructive pulmonary disease (COPD) are well-documented. In South Africa, exercise programmes for COPD patients are limited and often expensive and inaccessible to the broader community. The purpose of this study was to assess the responses of COPD patients to an exercise programme and to determine if the same results can be obtained through a less costly programme. In the primary programme of the study, 22 subjects were subjected to 12 weeks of exercise training. Each subject underwent comprehensive pre- and post-intervention assessments, which included the measurement of overall health status by a physician, level of dyspnoea, forced expiratory lung function, exercise capacity, body mass index and health-related quality of life. Exercise sessions included aerobic and strength training exercises and involved three, hour-long exercise sessions a week. In the modified programme, 18 subjects were randomly divided into an experimental and control group. Eleven subjects were included in the experimental group and seven subjects in the control group. Subjects had to complete 32, hour-long exercise sessions in a 10-week period. The experimental group’s exercise programme was adapted so that no specialised equipment was used, while the control group exercised in a well-equipped exercise- and rehabilitation centre.
An analysis of tactical thinking in tennis
(Stellenbosch : University of Stellenbosch, 2011-03) Thomas, Brendan Nigel; Bressan, E. S.; University of Stellenbosch. Faculty of Education. Dept. of Sport Science.
ENGLISH ABSTRACT: The purpose of this study was to explore the knowledge of tennis tactics of a group of South African tennis coaches. A secondary purpose was to gather their perceptions about where they believe they learned about tactics. A mixed methodology approach was used. The first was a quantitative knowledge test administered to 37 coaches. The second was a qualitative semi-structured interview with five coaches. The results of the study showed that there was a significant difference in the choices of tactical options in 43 game scenarios between the less experienced and the more experienced coaches. No differences were found between coaches who were coaching at the top level compared to the lower levels. No differences were found between coaches who had been top tennis players and those who had not. The majority of the coaches in this study reported that they had learned tactics through trial and error. Problems facing the development of top level tennis coaches in South Africa are discussed in relation to their knowledge of tactics and the priorities for the development of mass participation supported by national sport policy.
Behavioural lifestyle factors, physical health-related fitness and cardiometabolic disease risk in women from a low socio-economic urban community in Stellenbosch (Western Cape)
(Stellenbosch : Stellenbosch University, 2020-03) Dickie, Kasha Elizabeth; Terblanche, Elmarie; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Sport Science.
ENGLISH ABSTRACT: Non-communicable diseases (NCDs), such as cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM), represent an ever-rising threat to the effective management of national health in South Africa. This especially among low versus high socio-economic urban communities as evidenced almost a decade ago. The results of which are likely to lead to an even higher demand for chronic public health care provision, and thus put immediate economic strain on the imminent South African (SA) National Health Insurance fund soon to be launched in 2026. However, one could argue that the evidence needed to reformulate the existing SA health policies, especially those directed at NCD-risk management and inclusive of modifiable behavioural/lifestyle factors, is either: i) not implemented and no action is taken; or ii) implemented, yet ineffective; or iii) limited and thus unable to detect a clinically significant effect to date. Thus, the primary aim of this study was to characterise behavioural/lifestyle factors namely physical activity (PA) and sedentary behaviour, as well as physical health-related fitness and cardiometabolic disease risk profiles for CVD and T2DM in a group of urban women from an under-resourced Western Cape community. In addition, to determine whether physical inactivity, sedentarism and poor health-related fitness levels are important predictors of obesity and other cardiometabolic disease risk outcomes associated with CVD and T2DM. Fifty-one (N=51) apparently healthy women (42 ± 13 yrs) underwent the following measurements: physical activity (PA) and sedentary time (ST), anthropometric, cardiovascular and physical-health related fitness (cardiorespiratory fitness [CRF] and muscular strength). Results from the study showed that less than a third of the women met the World Health Organisation (WHO) Global Health Recommendations for moderate to vigorous-intensity PA (MVPA) using accelerometry. Although overweight, women who accumulated ≥ 30-min of MVPA per day presented with more favourable body composition and regional body fat measures, compared to those who did not. In addition, women who were sufficiently active presented with reduced cardiometabolic disease risk. Although the associations between PA (intensities and volume) and CRF were not statistically significant, all were positive and showed clinically important associations. Independent of steps/day, higher CRF was associated with women who were younger and with reduced measures of total and central adiposity (p < 0.001). Whereas higher physical health-related fitness as opposed to ST and MVPA, was independently associated with reduced cardiometabolic risk but potentially mediated by adiposity. In an attempt to combat cardiometabolic disease risk for CVD and T2DM among low socio-economic community urban-dwelling women, public health interventions should target domains in which time is already spent physically active. Such as walking briskly for travel- and/or occupational-related activities, while also aiming to increase public awareness of the health-enhancing benefits associated with meeting MVPA recommendations. Furthermore, intervention strategies also aimed at reducing cardiometabolic risk should target physical health-related fitness while also reducing ST especially among women who are already sarcopenic. Although the success of which will only be met once we understand the community’s specific barriers to PA and healthy dietary habits.
Bridging the gap from inpatient rehabilitation to sustainable health and wellness in spinal cord injured individuals
(Stellenbosch : Stellenbosch University, 2016-12) Vermaak, Candace; Ferreira, Suzanne; Terblanche, Elmarie; Stellenbosch University. Faculty of Education. Dept. of Sport Science
ENGLISH ABSTRACT : Background: A spinal cord injury is a devastating and life changing neurological event that present multiple challenges throughout the life of the affected individual. One of the challenges is being physically active and more specifically healthy living. Physical activity has many benefits and plays an essential role in community reintegration, which is considered the final outcome of the rehabilitation process. In South Africa this outcome is seldom achieved due to the lack of physical activity opportunities. Without regular physical activity the physical gains that were achieved in hospital are easily diminished or lost and this is a major concern as it ultimately affects health and wellness. Objective: To determine the barriers and facilitators to physical activity and whether an intervention designed to reduce the barriers can be successful in promoting health and wellness in people with a spinal cord injury. Design: An experimental research design incorporating both quantitative and qualitative methodologies was used to execute the study. Methods: A self-developed research questionnaire was distributed to people with a spinal cord injury in the Western Cape, South Africa in order to identify the barriers to physical activity. The results from the research questionnaire were used to design a 16 week intervention which was implemented in two different environments (formal exercise setting and community based setting) and its success was measured by physical tests, the reintegration to normal living index questionnaire and the research questionnaire. Subjects: Fifty seven people with a spinal cord injury completed the research questionnaire and 16 participants partook in the intervention. Results: In the beginning (pre-intervention) the most important barriers were the environmental barriers and included problems with accessibility and lack of facilities, lack of transport, and the weather. The most reported facilitators were personal, which included a desire to be active, to improve self esteem and because physical activity made them feel good. Based on the results from the research questionnaire the intervention was implemented and showed that the participants from both groups improved their physical abilities (strength, endurance and functional abilities) and their satisfaction with community participation. The barriers that were identified prior to the intervention were also considerably reduced, especially in the community based group. The participants also agreed that physical activity was beneficial and important and that they would like to stay physically active post-intervention. Discussion and Conclusion: People with a spinal cord injury face many barriers in being physically active, however, by reducing the barriers a community based physical activity program can be successful in introducing people with a spinal cord injury to a life of healthy living and wellness. Although some of the environmental and program barriers remained, the personal facilitators that were identified were enough to ensure physical activity adherence.
Characterisation of running specific prostheses and its effect on sprinting performance
(Stellenbosch : Stellenbosch University, 2015-12) Grobler, Lara; Terblanche, Elmarie; Ferreira, Suzanne; Stellenbosch University. Faculty of Education. Dept. of Sport Science.
ENGLISH ABSTRACT: The development of the running specific prosthetic (RSP) has allowed athletes with lower limb amputations to participate at a high level in sports such as sprinting. Literature regarding mechanical properties of RSPs and their influence on the athlete’s performance, on the other hand, is limited. This makes prosthetic selection a difficult task. The aim of this study was to assess the biomechanical and physiological effects of the mechanical characteristics of different RSPs on an athlete’s sprinting performance. The sprint performances of athletes with lower limb amputations were described in a retrospective analysis of Olympic and Paralympic times between 1992 and 2012, in an attempt to assess whether the technological advances in RSPs is evident. A 14 – 26% performance improvement was found for the T42 and T44 classes of the 100 and 200 m during this time in comparison to 2.2 – 2.8% for the Olympic athlete performances. These results were further supported by the lower competition density found in the amputee groups (Olympic 23.90 and 9.29 competitors.s-1; T42 4.53 and 1.93 competitors.s-1). It was therefore proposed that technology played a significant role in the performance progression of these athletes over the last 20 years. Differences in the characteristics of two RSP models (model E and X) were investigated. This was achieved by athlete independent mechanical testing during which the RSPs were dropped from a height of 30 cm and left to bounce on a force platform. The results revealed differences in the peak ground reaction force (GRFpeak) (model E > model X; p < 0.05) and maximal RSP compression (ΔL) (model X > model E; p < 0.05). This indicated that the RSP model E is more stiffness than the model X. These stiffness characteristics related to discrepancies in sprinting economy of an athlete completing four maximal anaerobic running tests (MART) using different RSPs. Two RSP stiffness categories of each model (Ecat4, Ecat6, Xcat4, Xcat6) were used for this testing and was randomly allocated to each testing session. It was found that the running speed at which the athlete attained a blood lactate concentration of 10 mmol.l-1 was the highest with the stiffest RSP (Ecat6), whereas it was the lowest in the softest RSP (Xcat4). Accordingly the lowest functional muscular fatigue as measured by a decrease in the pre and post-test counter movement jump height was found in this condition (Ecat6 7.35% vs. Xcat4 24.43%). From these investigations it was clear that technology is an important factor in the performances of amputee sprint athletes. Therefore prosthetic selection is of the utmost importance. Differences in the mechanical characteristics of the RSPs influence the sprint physiology and biomechanics and should therefore be taken into consideration when selecting a RSP.
A community-based lifestyle intervention program for adults with type 2 diabetes mellitus in a low socio-economic status community
(Stellenbosch : Stellenbosch University, 2016-03) Fryer, Bradley James; Terblanche, Elmarie; Stellenbosch University. Faculty of Education. Dept. of Sport Science
ENGLISH ABSTRACT : The prevalence, and associated burden of type-two diabetes mellitus (T2DM), is rapidly increasing globally, and in South Africa, with men and women of all ages being affected. While there has been an extensive research into the pathophysiological mechanisms, and to some extent, the management of T2DM, healthcare systems are still not able to adequately deal with the increasing number of patients being diagnosed with the disease. Professional- and community-led lifestyle interventions have recently showed the most promise in combating T2DM. There is however, a paucity of data on comprehensive lifestyle interventions in communities of low socio-economic status (SES), where the incidence of T2DM and its related complications is high. The primary aim of this study was to determine the effectiveness of a community-based, 10-week lifestyle intervention on physiological, psychological and health-related outcomes in adults suffering with T2DM in a low SES community. Forty-three participants completed the study (age 59.5 ± 12.2 years, 25 Women; 18 Men), of which 23 made up the experimental group (EXP; BMI: 33.8 ± 7.5; HbA1c: 8.8 ± 2.1) and 20 made up the control group (CON; BMI: 34.4 ± 9.7; HbA1c: 9.4 ± 2.3). The control group completed a pre- and post-testing session, while experimental completed an additional post-testing retention session. The experimental group participated in a 10-week comprehensive lifestyle intervention. A number of anthropometric, cardiovascular and functional measurements were carried out, and questionnaires related to health-related quality of life (HRQoL), social support, dietary habits and lifestyle behaviours, as well as health professional usage were also administered. Following the 10-week comprehensive lifestyle intervention, there was a positive change in the outcome variables measured. There was a statistically significant decrease (p < 0.05) in body fat percentage, diastolic blood pressure and HbA1c, with a statistically significant increase in the total distance walked during the six-minute walk test (6MWT) (p < 0.05). Furthermore, there was a statistically significant improvement (p < 0.05) in all but three of the HRQoL domains. Dietary habits and lifestyle behaviours improved significantly (p < 0.05), with the exception of eating times where there was no change. The frequency at which the participants actively sought professional assistance with the management of their T2DM did not change significantly (p > 0.05). The results from the retention period, obtained 10-weeks after the conclusion of the intervention, suggest that the changes as a result of the program were maintained, however, it is uncertain if those results can be attributed to the use of the post-intervention guide. The findings of this study indicate that a 10-week comprehensive lifestyle intervention is effective in improving physiological, psychological and health-related outcomes in adults with T2DM living in a low SES community. The use of a post-intervention guide as an assistive device to maintain these improvements requires further investigation and revision. Furthermore, this study reveals the opportunity for community-based interventions to assist the primary healthcare sector in the management and prevention of T2DM.
A comparison of coping strategies of ethnically diverse football players
(Stellenbosch : University of Stellenbosch, 2006-12) Plaatjie, Mzwandile Ronald; Potgieter, Justus; University of Stellenbosch. Faculty of Education. Dept. of Sport Science.
Stress and coping are complex phenomena that are not always fully understood. They are psychological factors that impinge on individuals and people’s responses in dealing with them are described and interpreted in various ways. This study compared the coping strategies used by football players from ethnically diverse backgrounds. The aim was to explore the role that the environment, ethnicity and culture play in players' responses to stressful situations. A sample of 33 players was drawn from a professional club in the Professional Premier Soccer League in the Western Cape, Republic of South Africa. Subjects were representative in terms of race, age, years of experience and playing positions. Eleven black, coloured and white players for each group were selected for individual interviews. Their ages ranged between 15 and 32 years. An interpretive-qualitative research methodology was employed. Semistructured interviews and a biographical questionnaire were used as tools to gather information. The data were analyzed using interpretive analysis or the immersion crystallization method. The results revealed that football players were exposed to stress and there were differences and similarities in the way they conducted themselves. The similarities were recorded on matters related to match situations e.g., pressure to perform, inclusion in a starting line-up, and unruly behavior of supporters. Differences were cited on issues related to language, culture, financial matters, poor playing conditions, negative evaluation of the team by others, losing matches, referees' decisions and being away from home. These differences were found both between and within ethnic groups. Players' perceptions of stress showed that black players were experiencing more stress than the other two ethnic groups and white players were experiencing far less stress than the other two groups. Despite this finding, the majority of players reported to have been in control of stressful situations. The perception of lack of control was reported by black and coloured players only. It appeared that background experience of stressful events was producing greater psychosocial consequences for non-white players than white players. The football players used multiple strategies to cope with their sport challenges and there were both differences and similarities within and between the ethnic groups in the use of these strategies. Subjects used problem-focused coping, emotion-focused coping, passive coping, and avoidance coping in stressful situations. Problem-focused coping and emotion-focused coping were the dominant strategies employed by all three groups. Passive coping and avoidance coping were the lesser-used strategies and were employed by the three groups in situations where players felt that they could not exert control e.g., playing conditions or dubious referees' decisions. Self-criticism, not blaming others, adopting a negative approach, substance use/abuse and turning to religion were the strategies that appeared only in specific groups. This finding supports the hypothesis of differences in strategies related to differences in ethnic backgrounds. It was also revealed that football players were responding differently to stressful challenges that were presented at the different stages of the match. The dominant strategies used at the pre-match stage by the nonwhite group were: planning and preparation, relaxation, praying, focusing and concentration. At the same stage, white players used mostly focusing, concentration and planning. There were strong similarities between the groups in the use of these strategies. During the match stage, non-white players used active coping, positive approach, suppression of competitive activities, focusing and concentration. White players used similar strategies including emotional expression and mental disengagement. Different strategies were employed by players during the match stage, most of them being problem-focused strategies. In the post-match stage players used less-dominant coping strategies. Some strategies were used by players in all three ethnic groups and others appeared in specific groups only, e.g., substance use (coloured group) and passive thinking (white group). The study further revealed that coping strategies could be classified either as sport or non-sport related. A variety of sport-related strategies were found mostly during the pre-match and match stages. The nonsport related strategies appeared mostly during the post-match stage and were used mostly by non-white players. Concerning the processes involved in the selection of strategies, the study revealed that thought-out processes, automatic processes, influence of experience and a combination of processes were used to identify and select coping strategies. Processing of information was a preferred option used by the three groups of players to identify strategies and very few players used automatic processes. Between-group differences were found in the relationship between environmental background and previous experience and the players' selection of coping strategies. For black and coloured players this influence related mostly from factors outside their home environment. For white players it came from within their home situations. The study showed that factors that affected the players in selecting coping strategies, were both intrinsic and extrinsic. Intrinsic factors included personal safety and protection, performance, self-control and personal experience. Extrinsic factors included stress, influence of others, institutional influences, social background, pleasing others, family obligation, opponents and research. White players used intrinsic and extrinsic factors with equal frequency. Non-white players on the other hand, used fewer intrinsic factors than extrinsic factors. The results also showed that relatively less-experienced players were inclined to use achievement motivation as a determining factor. Black players were influenced by one other factor that did not appear in the other groups, that is, family obligations. Finally, exhaustion, cultural differences, language, absence of a family support structure, peer pressure, home circumstances, communication, diet, substance use/abuse, being in a new environment, personality differences and high expectations were identified as factors that restrict the use of coping strategy. Exhaustion and cultural differences appeared across all three groups. Group differences were however observed in language, absence of a family support structure, peer pressure, home circumstances, high expectations, and absence of compliments. These restrictive factors were experienced differently within and between the three ethnic groups and originated from exposure, challenges, and experiences that players encounter in their daily life situations.
A configurational evaluation of elite sport policy in South Africa: a realist perspective
(Stellenbosch : Stellenbosch University, 2019-12) Jacobs, Shaundre Dwaylynn; Venter, Ranel; De Bosscher, Veerle; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Sport Science.
ENGLISH ABSTRACT: Over the years, the attainment of international sporting success has become a critical important focus of the South African government. In this regard, specific elite sport policies have been introduced by policymakers in order to ensure that sport persons can perform internationally. Elite sport policies and the implementation thereof have been identified to be quite complex in reality, and differ considerably from one country to another. The overall aim of the current study was to assess what facilitates and/or inhibits the elite sport policies of South Africa through the configurational lens of a ‘realist perspective’, in the case of the Western Cape Province. In this regard, a configuration of several approaches was utilised in the ‘realist evaluation’. The current study made use of a multi-method research design by involving primary sport stakeholders, namely: athletes; coaches; administrators; expert sport management academics; and government partners. Data was collected and analysed in terms of the ‘realist perspective’ configurational elements, which comprise the components of context and mechanism in order to provide a basis for the outcome elements. The influence of various macro-level contextual factors was examined through the lens of systems theory. This was executed to determine how and to what extent contextual factors may or may not influence an elite sporting system in a nation characterised as an "emerging country". Furthermore, the effectiveness of the elite sport policies was measured using a multidimensional approach (input-throughput-output and feedback cycles). Furthermore, the emerging issues concerning the inter-organisational relationships between government stakeholders were explored by means of juxtaposing two theoretical frameworks, specifically the resource dependency theory and the inter-organisational theory. Research on inter-organisational relationships aided in the understanding on why dyadic government partnerships are formed, how they are managed, what the outcomes are, and how financial resources play a role in the dynamics of these relationships in the current study. The current study on elite South African sport policies produced the following results: (1) the organisation of sport in the country is quite complex; (2) ineffectiveness was established for the sporting performance (output), input and throughput cycles in the Western Cape Province; (3) the nation-specific context was identified to influence the elite sporting system quite extensively; and (4) the inter-organisational relationships between government stakeholders were reported to be challenging due to the variety of barriers that were identified. Firstly, the Stellenbosch University https://scholar.sun.ac.za 10 | P a g e current study implemented a configurational assessment of the elite sport policies of South Africa, specifically in the Western Cape Province, herewith advancing the field of sport management by adding to the limited number of available studies on elite sport policies of ‘emerging’ countries. Secondly, this study should provide empirical evidence for when policymakers review the (elite) sport policies of South Africa.
Coordination of place kicking in Rugby Union
(Stellenbosch : Stellenbosch University, 2020-03) Mathewson, Elizabeth; Venter, Ranel; Cockcroft, John; Preatoni, Ezio; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Sport Science.
ENGLISH ABSTRACT: Place kicking is a crucial skill in rugby as more than 40 per cent of the points scored in professional rugby matches are achieved by means of place kicks. Research in rugby kicking has mainly focussed on isolated segment position or movement, with limited literature on segments moving relative to each other. The aim of this study was to identify characteristics of place kicking technique from a coordination and coordination variability perspective. Ten male kickers performed five trials from three different distances (40 m, 32 m, and 22 m) in a range that proficient kickers should convert successfully 80 per cent of the time. An optoelectronic motion capture system consisting of ten cameras were used for capturing total body kinematic data. Data collection took place outdoor, on a rugby field. Data reductions included normalisation of kicking phases, extracting discrete kinematic variables, joint angles, joint and segment coordination patterns (hip-knee, knee-ankle, and pelvis-torso), and coordination variability measures. ANOVA comparisons were made on discrete data, while statistical parametric mapping repeated measures ANOVA analysis was used for continuous variables to determine differences groups differences. Coordination patterns were determined by means of vector coding technique. A bivariate method of calculating the area of the ellipse at each time point was used to determine the coordination variability. A hierarchal cluster analysis was performed on sagittal plane angles at kicking events to determine different technique profiles. Parameters such as greater hip extension and external rotation during the backswing (p=0.001, p=0.015) as well as increased pelvic external rotation (p=0.015) in the 40 m kicks compared to the 22 m and 32 m kicks are related to the formation of the tension arc in attempt to increase foot speed by means of the stretch-shortening cycle. The 40 m kicks had increase knee flexion (p<0.001), increasing the pre-stretch in the thigh muscles. Both factors allow greater force to be applied to kicking foot over greater distance during forward swing. During the forward swing a period of in-phase is reported as both the hip and the knee were flexing, creating a whip-like action. During the backswing the pelvis and thorax worked together to create a tension arc, while during the forward swing, the anti-phase with pelvis dominancy was seen. The pelvis was main mover for tension arc release, while the thorax stays more stable. Even though absolute changes in joint angles were seen, no changes were reported for the coordination patterns when kicking at different distances (22 m, 32 m, 40 m). An investigation into coordination variability found no differences between groups, indicating no change in movement strategy when kicking at different intensities. The cluster analysis revealed three clusters of sagittal plane kinematics describing a knee-dominant, hip-dominant as well as a combination technique. Stemming from the above, place kick training can benefit by coaching cues and drills focussing attention on tension arc formation, and the rhythm of movements. These results impart the knowledge that different distances require similar movement coordination strategies.
The effect of a movement programme on selected psychological variables among adolescent girls from previously disadvantaged communities
(Stellenbosch : Stellenbosch University, 2002-12) Alexander, Leonieke Franziska; Potgieter, J. R.; Stellenbosch University. Faculty of Education. Dept. of Sport Science.
ENGLISH ABSTRACT: The purpose of this study was to determine if the participation in a movement programme, utilising 21 life skill development strategies would make a significant contribution to adolescent girls' self-esteem. The adolescent girls participating in the programme were from a previously disadvantaged community in the Western Cape, South Africa, and considered to be at-risk youth. The movement divisions through which the life skill strategies of the five and one half month programme were presented to the experimental group, were designed by the investigator, and included: modern dance, swimming, self-defence and an individual session of team building. Harter's (1985) Self-perception Profile for Children was used to measure the six subscales of self-competence/esteem of a control group (n = 8) and an experimental group (n = 13) of girls between ages 13 - 16. The six dimensions of self-esteem measured, included: global self-worth; scholastic competence; social acceptance; athletic competence; physical appearance, and; behavioural conduct. On completion of the movement intervention programme by the experimental group, all the girls (N = 21) were post tested, using the same quantitative measurement instrument. The experimental group completed an additional open-ended Life Skill Questionnaire, designed by the investigator, to see if there had been a cognitive transferral of the life skills used in the movement programme from the movement experience to everyday life activities. Following the comparison between the pre- and post-test data of Harter's (1985) Se/fperception Profile for Children, it was concluded that participation in the movement programme had an overall positive and significant affect on the six sub-scales of the girls' self-esteem. On analysis of the girls' responses to the Life Skill Questionnaire it was found that they had been able to utilise all 21 life skills in the various movement components offered in the programme, and that cognitive transferral of the skills had taken place to their everyday environment. Conceming the movement division, the statements revolving around the utilisation of the skills predominantly revolved around ii Stellenbosch University http://scholar.sun.ac.za the swimming, followed by dance and lastly self-defence. The life skills that were most widely used in their everyday environment were highlighted by the themes of perseverance, commitment and academics.
The effect of active brain-breaks on in-school physical activity, fundamental movement skills and executive functioning in grade one children
(2021-03) Van Stryp, Odelia; Africa, Eileen Katherine; Duncan, Michael J.; Faculty of Medicine and Health Sciences. Dept. of Sport Science.
Thesis (PhD Sport Sc)--Stellenbosch University, 2021.
The effect of law changes on the match profile of international and national rugby union between 2007 and 2013
(Stellenbosch : Stellenbosch University, 2015-12) Kraak, Wilbur Julio; Venter, Ranel; Coetzee, Frederik; Stellenbosch University. Faculty of Education. Dept. of Sport Science.
ENGLISH ABSTRACT: Rugby union has changed continually since the inception of professionalism in 1995. For example, to increase the appeal, continuity and safety of the game several law changes were introduced after the 2007 Rugby World Cup. The primary aim of this study was to determine the impact of these law changes on selected performance indicators on the match profile of international rugby union between 2007 and 2013 and national rugby union between 2008 and 2013. To this end, three specific objectives were set. The first was to compare the scoring profile of international rugby between 2007 and 2013. The second was to compare the changes in the general match profile of international rugby and the third was to compare the scoring and general match profile of Super Rugby between 2008 and 2013. The study followed a mixed-method study design for data collection. A total of 248 international and 646 national matches were recorded by the Fika Coding Centre and analyzed by the researcher using the Fairplay video analysis software package. Semi-structured interviews were conducted with 30 international- and national-level coaches, referees, specialist coaches and players.The year 2007 was used as baseline for international matches and 2008 for national matches in order to compare and track the changes over the different years. Results indicate that law changes over the years have indeed had an influence on the profile of international and national rugby. The scoring profile of international rugby revealed a significant increase in the number of penalty kicks (p<0.01). With regard to the origin of tries, there was a decrease in the number of tries from structured play (47 to 43%) and an increase from turnover possession (27 to 43%). The duration of the international matches increased owing to the increase in the number of stoppages, mainly as a result of greater use being made of the Television Match Official (TMO), substitutions and on-field concussion tests. There was a small practical significant increase in total match time (d=0.34), and a moderate increase in ball-in-play time (d=0.87). Results of the study show that the profile of international rugby has changed to a more continuous game dynamic with a moderate practical significant increase in the number of passes (d=0.73), large ball carries (d=1.22) and tackle breaks (d=2.03), and a very large increase in line breaks (d=3.00), which has led to a moderate increase in the number of tackles (d=0.65). The number of rucks (d=0.86), mauls (d=0.90) and scrums (d=1.03), scrum resets (d=0.74) and line-outs (d=0.61) showed a moderate practical significant decrease. Both penalty kicks (d=0.98) and free kicks (d=1.22) decreased significantly. The scoring profile of national rugby indicated fewer tries (p<0.01), conversion kicks (p<0.01) and significantly more penalty kicks (p<0.01). The duration of national matches decreased due to fewer stoppages, mainly thanks to the improved skill level of the players. There was a small practical significant decrease in total match time (d=0.41). The ball-in-play time (d=0.91) showed a moderate practical significant decrease. Results of the study show that the profile of national rugby has changed to a game with more contact situations, with a small practical significant increase in the number of passes (d=0.43), a large practical significant increase in the number of ball carries (d=1.34), tackle breaks (d=1.59) and line breaks (d=2.40), and has led to a moderate practical significant increase in the number of tackles (d=0.63). A large practical significant decrease in the number of rucks (d=1.73) and scrum resets (d=1.36) was found. A moderate practical significant increase in penalty kicks (d=2.04) and a moderate practical significant decrease in free kicks (d=4.53) between 2008 and 2013 were observed. By analyzing the scoring and match profile of international and national rugby, coaches and trainers could be better informed in order to develop training programmes that are specific to the technical, tactical and physical demands of modern rugby. Based on the findings of this study, coaches and trainers should develop individual and team performance profiles to better understand the demands experienced by the players and teams. This type of information could assist with implementing more specific periodization models, strategic planning, drill design, recovery strategies and planning of training loads.
The effect of sensory-motor training on brain activation and functional recovery in chronic stroke survivors
(2018-10) Zastron, Tania; Welman, Karen Estelle; Reer, Rudiger; Hollander, Karsten; Stellenbosch University. Faculty of Medicine and Health Sciences.
ENGLISH ABSTRACT: Introduction: Functional loss is greatly determined by postural control impairment in chronic stroke survivors causing reduced ability to execute activities of daily living, impaired mobility and increases the risk of falling. It is known that the basal ganglia network play an important role in postural control, however the effect of sensory-manipulated balance training on structural connectivity in chronic stroke survivors remains unknown. Objective: To assess the influence of sensory-manipulated balance training, i.e. sensory-motor training (SMT), on structural connectivity and functional recovery in chronic stroke survivors. Study design: Double-blind randomised controlled trial. Methods: Twenty-two individuals with chronic stroke (≥6 months post-stroke) were randomly divided into two groups, namely the sensory-motor training (SMT; n = 12) and attention-matched control group (CON; n = 10). The SMT group participated in task-specific balance training, which focused on manipulating the visual, vestibular and somatosensory systems, three times a week for 45 to 60-minute sessions, over an eight-week period. The CON group attended educational talks regarding various lifestyle topics for the same duration as the SMT group. Both interventions were delivered by experienced clinical exercise therapists and were executed in a group setting. Primary outcome measures included changes in structural connectivity strength (diffusion tensor magnetic resonance imaging (MRI) scan), postural sway and sensory dependency (modified Clinical Test for Sensory Interaction and Balance (m-CTSIB), as well as functional mobility (Timed-Up and Go (TUG). Structural connectivity strength was specifically investigated between the twosubcortical basal ganglia nuclei, caudate and lentiform nucleus, with other regions of interest. Furthermore, the m-CTSIB and TUG tests were executed with APDM’s Mobility LabTMbody-worn inertial sensors. Secondary outcome measures were health-related quality of life (Short Form Health Survey (SF-36)) and fall efficacy (Fall Efficacy Scale - International (FES-I)). Participants were tested pre- and post-intervention. Results: Diffusion tensor MRI results showed interaction effects for increased connectivity strength between the basal ganglia and sensory-motorfronto-parietal areas in the SMT group (n = 5; p<0.05), where as the CON group (n = 4 ) presented increased structural connectivity in the higher cognitive orbitotemporal and frontal lobe areas (p<0.05). For the behavioural outcome measures, interaction effects were found for turning performance(p = 0.02), perceived physical functioning (p = 0.005) and fall efficacy (p= 0.03). Moreover, the SMT group (n = 12) showed improved postural sway when standing on a foam pad with eyes open (p = 0.04, ES = 0.61M, 95% CI= -0.27 to 1.36), reduced somatosensory dependence (p = 0.02, ES = 0.63M,95% CI = -0.24 to 1.40), improved turning performance (p≤0.05) as well as improvements in perceived physical (p = 0.01, ES = 0.52M, 95% CI = -0.33to 1.29) and social functioning (p = 0.02, ES = 1.03L, 95% CI = 0.11 to 1.80)after participating in the SMT programme. Lastly, a group difference wasobserved for perceived physical (p = 0.003, ES = 0.90L, 95% CI = -0.05 to1.70) and social functioning (p = 0.02, ES = 1.01L, 95% CI = 0.04 to 1.81) at post-intervention. Conclusions: This study highlights postural control-related improvements induced by SMT, which may be associated with structural connectivity changes in chronic stroke survivors. Therefore, the preliminary results support the notion that the human brain has the ability to undergo activity-dependent neuroplasticity.
Effects of a barefoot intervention programme on the landing kinetics and kinematics of netball players
(2018-12) Jaiyesimi, Boluwaji Gbenga; Venter, Ranel; Cockcroft, John; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Sport Science.
ENGLISH ABSTRACT: Effective landings, as a component of movement tasks in many sports, have a significant role during ground contact and subsequent kinetic chain intersegmental interactions. Landings are frequently performed tasks in sports to manipulate skills, maximise mechanical functions of the body and to possibly avoid injury. The rationale of biomechanical studies on landing in netball focuses on the reduction of risk of lower extremity injuries and enhance performance. The trauma of injury to a female athlete ranges from immobility, disengagement from the team to psychophysiological stress and physical deterioration. The primary aim of the study was to determine the acute differences in landing kinetics and kinematics between barefoot and shod conditions in netball players. The secondary aim was to determine effect of a six-week barefoot training intervention on landing biomechanics in netball players. The experimental design adopted for the study was a pretest-posttest randomized groups design. Thirty netball players were recruited for the study and randomly allocated into an experimental (EXP) (n = 15) or a control group (CON) (n = 15). The players performed jump-landing tasks (single-leg drop landing right and left) (SLR and SLL), a drop vertical jump (DVJ) and a stop-jump performance task (SJPT) in barefoot (BF), and shod (SH) conditions. The intervention for the study spanned a 6-week period with 18 training sessions over this period. Ground reaction forces, time to peak ground reaction forces and shock attenuation were considered for kinetic variables while impact peak acceleration, initial contact angles, peak angles and range of motion were considered for kinematic variables. A 3D force plate (sampled at 1000 Hz) was used to capture force data while a wireless inertial motion capture system (sampled at 200 Hz, filtered with Butterworth 60 Hz low-pass), was used to capture kinematic data. The Subjective evaluation of the Landing Error Scoring System (LESS), Modified Lower Limb Comfort Index (mLLCI) and barefoot activity experience was adopted for qualitative assessment of the study. Mean, standard deviation, standard error of mean, and percentage differences were used in the descriptive analysis while Chi-square, independent t-tests and a mixed model ANOVA were used in the inferential analysis. The results showed a non-significant reduction in peak resultant force and vertical ground reaction forces for the jump-landing tasks in SH condition. The mediolateral ground reaction force was significantly lower in BF condition for some of the jump-landing tasks (SLL p = 0.02; DVJ p = 0.03). It was further shown that sagittal plane kinematics increased at initial contact in BF condition but decreased at peak angle. The frontal plane kinematics increased in BF more than SH conditions at initial contact but decreased at peak angle. The EXP (p = 0.00) and CON groups (p = 0.00) had significant changes in knee shock attenuation after the intervention. However, the CON group had more shock attenuation at the knee and ankle during the jump-landing tasks. The feedback of subjective experience of barefoot activities after the intervention showed that the negative experience of injury risks and significant others did not outweigh the positive perception of neuromuscular benefits and other related factors. In conclusion, BF training could form part of training modalities implemented to enhance safe and effective landings. Coaches need to be educated on the implementation of an injury prevention programme, including emphasis on effective landings, to possibly reduce the incidence of lower limb injuries in netball. Keywords: Barefoot, kinetics, kinematics, shock attenuation, impact peak acceleration
The effects of an eight-week customised endurance-training programme on running kinematics and impact associated with fatigue in recreational runners
(Stellenbosch : Stellenbosch University, 2019-04) Sackey, Saint Andrews; Venter, Ranel; Schutte, Kurt H.; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Sport Science.
ENGLISH ABSTRACT: Background: The unrestrained and easily accessible nature of running has led to an exponential increase in participation in running. However, the incidence rate of injuries is a concern. Loading and fatigability have been linked as underlying injury risk factors. It has been proposed that runners would automatically fine-tune their kinematics after exposure to training to be more efficient for better performance and reduce the occurrence of injuries. However, there is no evidence to support this hypothesis under fatigued conditions. Aim: The current study investigated the “self-optimisation hypothesis” under fatigued conditions. I again determined the influence of fatigue on novel running parameters that have previously been associated with running injury to provide foundational information on interventions for injury prevention and better performance. Methods: A pre-post interventional approach was deployed for the current study. Recreational runners (n = 40) were recruited from the Stellenbosch Boland community for the study. The study was carried out in two phases. In the phase I, the participants were subjected to a running fatigue protocol which involved running at incremental speed to volitional exhaustion on a motorised treadmill. Running impact variables at the tibia, lower back and upper back were assessed using tri-axial accelerometers whereas spatio-temporal, and upper extremity kinematic parameters were collected with an Opto-Gait photoelectric system and 2D video analysis respectively before and after the run. In the phase II, the runners were randomly assigned to either an intervention group or a control group. The intervention group underwent eight-weeks of endurance training while the control group continued with their normal running routine. After the eight-weeks, all the participants were subjected to the same running fatigue protocol and measurements as in the phase I. Results: Running induced fatigue resulted in significant increases in contact times, forward trunk lean, and body load (p ˂ 0.05). Running impact magnitude at the tibia, external distribution of impact, stride angle, step length, flight times, and arm carriage remained unchanged after fatigue (p ˃ 0.05). The eight weeks of endurance training caused reductions in step length, forward trunk lean, and contact times. Step frequency on the other hand increased after the eight weeks of endurance training. There were no significant differences in body load, and running impact variables. The changes in the running kinematics under fatigued conditions after the intervention was accompanied with a significant reduction in the oxygen cost of transport. Conclusions: Running-induced fatigue resulted in changes in some running kinematic parameters. Such changes are accompanied with increases in the oxygen cost of transport. An exposure to eight weeks of endurance training resulted in significant alterations in the kinematic parameters for better efficiency under fatigued conditions with a corresponding decrease in the oxygen cost of transport.
The effects of participation in movement programs on the movement competence, self-esteem and resiliency of adolescent girls
(Stellenbosch : University of Stellenbosch, 2008-03) Jonathan, Bronwyn Bock; Bressan, E. S.; Newmark, R. E.; University of Stellenbosch. Faculty of Education. Dept. of Sport Science.
The purpose of this study was to examine the effects of two different types of movement programs on movement competence, self-esteem and resiliency in adolescent girls from a low-socio economic environment. A non-equivalentcontrol-group design was followed. A total of N=63 girls from similar socioeconomic environments between the ages of 13-14 participated in the study. The subjects were divided into three groups. The pre-tests and post-tests were administered to all groups. Four motor fitness/motor ability tests were selected to gather data about movement competence. The Self-Perception Profile for Children (Harter, 1985) was used to measure self-esteem and the Connor-Davidson Resilience Scale (Connor & Davidson, 2003) was used to measure resiliency. Only two of the groups received intervention programs. One group received 20 sessions in an expressive dance movement program called Biodanza and the other intervention group received 20 sessions in self-defence.
Die effek van sportsielkundige opleiding op die prestasie van sportlui met spesifieke verwysing na baanatlete
(Stellenbosch : Stellenbosch University, 2004-04) Pieterse, Johannes Jacobus; Potgieter, J. R.; Stellenbosch University. Faculty of Education. Dept. of Sport Science.
ENGLISH ABSTRACT: This study investigated the effects of a relaxation, self-talk, goal-setting, imagery, and concentration training package on the performance of six athletes in the 1500- meter event. Subjects were four female and two male high school middle distance athletes. The dependent measure was time taken to complete the 1500-meter nm in competition settings. A mental skills training package was developed, implemented and evaluated using a single subject, multiple baseline design. Performance scores were plotted for each 1500-meter nm and subjects' graphs were assessed for intervention-related change against mean performance change and established split-middle analysis criteria. Visual inspection of plotted values was supplemented by quantitive analysis using repeated measures analysis of variance (RANOV A). This study also included procedural reliability checks to ensure that the athletes did in filet utilize the mental skills they received training in. Visual analysis indicated the mental skills package to be effective in enhancing performance times (1500-meter) in the case of four of the athletes. Overall, repeated measures analysis of variance revealed significant improvement in 1500- meter performance times for subjects across phases. However, a split-middle analysis of within subject variation indicated that a significant intervention effect was not observed in two of the six subjects. The social validity assessment by athletes and their two coaches provided further confirmation of the overall effectiveness of the intervention. Social validation checks indicated all participants to have perceived the intervention to be successful and all were satisfied with the delivery and content of the training package. The results support the usefulness of single-subject research designs for assessing the impact of mental training. The present study demonstrated that a mental skills training package combining relaxation, self-ta1k, goal setting, imagery, and concentration skills was effective in enhancing athletic performance.
The evaluation of an accreditation programme for quality improvement in private physiotherapy practice in South Africa
(Stellenbosch : Stellenbosch University, 2001-11) Bowman, Winifred Edna; Kapp, C. A.; Van der Merwe, T. D.; Stellenbosch University. Faculty of Education. Dept. of Sport Science.
ENGLISH ABSTRACT: "Quality" has different meanings to different people. Even quality experts do not agree on a single definition: Juran's definition of quality revolves around his concept of "fitness for use", Crosby defines quality in terms of performance that produces "zero defects" and Deming defines quality as a "never ending cycle of continuous improvement". One element, however, that is common to all three approaches is that management must accept and demonstrate leadership if quality is to be achieved. Quality is rarely thought of as others perceive it. What is apparent is that if providers of care wish to maintain leadership in defining quality, they need to - Actively participate in the public debate about quality. Review the way in which they have been defining quality. Question whether their definitions are aligned with what the purchasers of health care define as being important. Develop meaningful measures of quality and data collection systems that will allow them to demonstrate quality and value. - Willingly share data not only on outcomes, and also measures that are specific to individual procedures and service providers. The PhysioFocus practice accreditation programme attempted to achieve the above factors. By realising the goal of the research this was determined. The goal of the research was to evaluate the PhysioFocus practice accreditation programme and to make recommendations on the educational programme for accreditation in private physiotherapy practices. This goal was realised by means of an exploratory and descriptive research design with a qualitative orientation. The evaluation of the PhysioFocus practice accreditation programme was performed by means of a validated evaluation instrument. The group interview revealed components of the PhysioFocus practice accreditation programme that require remediation. Recommendations included professional-ethical issues, business management and legislative issues. The recommendations will be implemented by the PhysioFocus practice accreditation committee. The PhysioFocus practice accreditation learning programme was evaluated by means of a semi-structured questionnaire, containing eleven questions and a section for comments. The general consensus was that the PhysioFocus practice accreditation programme is essential in private physiotherapy practice in South Africa. The implementation of the PhysioFocus practice accreditation programme resulted in the facilitation of quality physiotherapy; professional and personal development; monitoring of quality improvement processes; and the evaluation and remediation of these processes. This supported the central theoretical assumption of the research. Concerns were voiced about the lack of standards, lack of quality improvement skills, the public image of the physiotherapy profession and the lack of basic business management training. The researcher concluded that the implementation of the PhysioFocus practice accreditation programme is essential in private physiotherapy practice in South Africa. At present the current PhysioFocus practice accreditation programme does not address all the needs of private physiotherapy practices. Recommendations based on the research included remediation of the current PhysioFocus practice accreditation programme, formal education included business management, professional-ethical-Iegal issues, standards and scientific methods to analyse process variation and the development of improvement strategies in quality improvement. Other recommendations include informal education, physiotherapy management and structured quality improvement activities. The issue of the image of the professional physiotherapist was also addressed. Topics for future research were identified. The uniqueness of the research lies in the fact that this is the only physiotherapy practice accreditation programme implemented in South Africa. It is also the only physiotherapy practice accreditation programme in South Africa that has been evaluated.
The evolution of major games
(Stellenbosch : Stellenbosch University, 1978-12) Craven, Daniel Hartman,1910-1993; Thiart, B. F.; Stellenbosch University. Faculty of Education . Dept. of Sport Science.
ENGLISH ABSTRACT: no abstract available

Browse

Browsing Doctoral Degrees (Exercise, Sport and Lifestyle Medicine) by Title

Results Per Page

Sort Options