Masters Degrees (Exercise and Sport Sciences)
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Browsing Masters Degrees (Exercise and Sport Sciences) by Author "Coetzee, F. F."
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Item Open Access Analysis of tries scored during the 2018 and 2019 super rugby tournaments(University of the Free State, 2021-11) Greef, Gabriel Pieter; Coetzee, F. F.; Kraak, W. J.Introduction: The last few years, the professional rugby union defensive system improved and lead to teams scoring fewer tries. The growth of professionalism in sport has aided this with many teams now having a performance analysis staff to support the coaching process. Part of their job is to analyse performances of their teams and conduct analysis on opposition teams to then share this information with the management and support team. Analysing and understanding the performance indicators pertaining to tries can assist coaching staff with information to develop and rethink attacking strategies. Aim of the study: The primary aim of the study is to analyse the try scoring profile of the 2018 and 2019 Super Rugby competition. Methods: The current study included all the Super Rugby matches that was played during the 2018 and 2019 seasons. Video footage of all Super Rugby matches were supplied by the South African Rugby Union technical department. All videos was then analysed according to set performance indicators using Nacsport Scout+ video analysis software. All data was captured using data Microsoft Excel software. Results: The current study revealed that tries were responsible for most of the modes of scoring and points for both the 2018 and 2019 rugby seasons. The results indicated that during 2018 the percentage points contribution of tries was 65% (4,570 out of 7,069) and during 2019 it was 46% (811 out of 1,779). When looking at zonal locations where the tries orginated from the results revealed that 75% of the tries for the 2018 and 2019 seasons originated from the attacking half of the field (Zone A & B) and 64% Channel 1. Lineouts were the set piece origin for 37% and 39% of the tries for 2018 and 2019. Turnovers won were the general play origin for 22% of the tries for both the 2018 and 2019 seasons. Conclusions: In summary, tries were scored originating from all over the field, but more tries were scored in Zone A and B. Tries originated from several different possession platforms, where set pieces: lineouts and general play: turnovers won were the main ones platforms in both 2018 and 2019 seasons. Fundamentally, coaches and specialist attacking coaches will be able to use these try scoring profiles to improve technical and tactical skills and develop a framework to plan and execute effective plays and tactics in training to score more tries and concede less tries in matches. The results found in this study can be used to guide further research around this topip. Future studies should compare the findings with that of other professional rugby tournaments for the example the United Rugby Championships, Top14 and the newly formed Super Rugby tournament. Lastly, research should focus on the try scoring profile in women’s rugby to see if similar trends are evident.Item Open Access Attitudes and insights of Free State Swimming coaches towards scientific coaching principles(University of the Free State, 2013-02) Jones, Colleen Jo-Ann; Bloemhoff, H. J.; Coetzee, F. F.English: Objectives: The aim of this study is to determine the attitudes and insights of swimming coaches in the Free State Aquatics region towards scientific coaching principles. A comparison between performance coaches and participant coaches’ scientific coaching principles to improve performance or participation levels in swimming were recorded. Methods: This study was done by sampling data via quantitative research (i.e. a questionnaire). All swimming coaches who were at least 18 years old, regardless of their level of qualification, affiliated or not with Free State Aquatics, were invited to participate in the study. A questionnaire was compiled using data from various research sources. All coaches were categorised into a participant or performance coach. The researcher captured data from the data forms to Microsoft Excel. A statistician conducted further analysis using SAS Version 9.1.3. Frequencies and percentages were calculated for categorical data. For numerical data, where data were evenly distributed, means and standard deviations were calculated. Medians and percentiles were calculated where data were not normally distributed. The Student’s T-test was used to compare mean values between the two groups, whereas the Kruskal-Wallis test was used to compare median values. The appropriate p-values and/or confidence intervals were reported. For the dependent data, the mean or median differences were calculated within the groups. The Student’s T-test, or Wilcoxon signed rank test, was used to test for significant median differences. A Fischer Exact test was used to test for significant frequency differences. A significance level of p ≤ 0.05 was used throughout the research study. Results: Seventy one percent of the participant coaches and 29% of the performance coaches participated in the research study. Out of a total of 42 participants (coaches), 21% were male and 79% were female. An alarming result was that 36% of coaches had no qualifications in swimming coaching whatsoever, but are currently involved in coaching. Almost half (46.7%) of the participants have no swimming coaching qualification, while 41.7% of the performance coaches only have a ‘Learn to Swim’ qualification. Only 23.8% of all coaches (participant and performance coaches) are registered with SSA, which is compulsory. Therefore, 76.2% of all coaches are not compliant with SSA rules and regulations pertaining to a coach. As expected, performance coaches rated professional knowledge (50%) and interpersonal knowledge (58.4%) as very important. This differs from participant coaches who indicated that professional knowledge (50%) was important to them. Performance coaches preferred learning methods through internal learning (75%) and unmediated learning (58.4%). Participant coaches reported that internal learning (56.7%) and mediated learning (40%) were their preferred learning methods. Differences between performance and participant coaches’ characteristics are passion and enthusiasm and love for the sport, as demonstrated by performance coaches. This is contradictory to the main goal of participant coaches who would like to instil an element of fun in swimming, in order for the swimmers to gain passion and enthusiasm and ideally love for the sport so that they continue with swimming. In comparison, a participant coach’s role as a friend differed significantly from performance coaches (p = 0.0437). This coincides with their strategy of integrating professional and personal life while coaching. There was no significant difference between participant and performance coaches with regard to the multi-disciplinary involvement in performance improvement. Conclusions: It is alarming that almost half of the current swimming coaches have no qualifications at all. SSA and FSA must enforce stricter rules and regulations regarding coaching, so that all coaches have the minimum qualification in relation to their level of coaching. Various learning methods must be employed to develop numerous knowledge components to achieve optimal scientific coaching.Item Open Access Biomechanical analysis of foot contact in junior sprinters(University of the Free State, 2011) Hugo, Elmie; Coetzee, F. F.; Opperman, M. C.English: The purpose of this study was to determine the effects of different foot types (normal, flat and high arch) with regards to speed, roll-over and impact forces, thus attempting to indicate if a specific foot type is dominant amongst sprinters. The different foot types of ten junior sprint athletes and ten nonsprinters were determined by walking over a pressure platform (RSscan International’s Footscan® 7.x plate system). The effects of foot roll-over and peak pressures during sprinting were determined for left and right feet respectively. The subjects ran barefoot at their top speed (sprinted) over 20 meters, crossing a pressure platform (RSscan International’s Footscan® 7.x plate system) comprising the last two meters of the 20 meter distance. The initial contact, final contact, time to peak pressure and the duration of contact of the different sub-areas of the foot were measured. The results of the sprinters’ trials were averaged and compared to the non-sprinters’ averaged trials by performing a statistical T-test. The control group (non-sprinters) dominantly has a high arch foot type for both feet. In the sprinter group, the different foot types are all represented almost equally with regards to right feet, whereas the left feet are dominantly normal type, followed by high arch and then flat foot types. There was a significant difference (p < 0.05) during the Foot flat phase (FFP) between the sprinter group (mean left: 4.04ms, mean right: 4.34ms) and control group (mean left: 26.40ms, mean right: 24.46ms), left: p=0.007; right: p=0.022. This indicates that the FFP time is significantly faster for the sprinter group than for the control group. The control group spent a higher percentage of time on the rear foot than the sprinters did (left: p=0.0057, right: p=0.0268). The control group’s peak plantar pressures were predominantly on the sub-areas of the heel (mean:HL=Left: 327.69, right: 351.44; mean HM= Left: 434.08, right: 423.19) and M1, M2, M3, whereas the sprinters’ peak plantar pressures are predominantly on the subareas of the M1, M2, M3, mid-foot and T1, meaning that sprinters predominantly have peak pressures on forefoot contact whereas the nonsprinters predominantly have peak pressures on heel contact. The results of this study therefore indicate that in general, sprinters dominantly have a normal foot type whereas the non-sprinters have a high arch foot type, and sprinters predominantly have peak pressures on forefoot contact whereas the non-sprinters predominantly have peak pressures on heel contact during sprints.Item Open Access Factors associated with injuries sustained by players during a Currie Cup rugby competition(University of the Free State, 2004-10) Le Roux, Douglas Leonard; Holtzhausen, L. J.; Coetzee, F. F.English: 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.Item Open Access The motor proficiency of obese 8-11 year old children(University of the Free State, 2005) Potgieter, Carolina Frederika; Botes, S. L.; Coetzee, F. F.English: A rapid increase in the prevalence of obesity in children has been seen around the world. There was a 60% increase in the prevalence of being overweight and a 70% increase in the prevalence of obesity between 1989 and 1998 (Ogden et al., 1997:1, Reilly et al., 1999:1039, Martorell et al., 2000:959). What’s more, motor abilities can be influenced by excess weight from a very early age. Groups of normal weight and obese babies were compared, and a delayed gross motor development was found in the obese. A significant correlation was found between excessive weight and gross motor delay. Over the following year, both weight and motor development reverted to normal in the majority of infants (Jaffe & Kosakov, 1982:619). Parizkova (1996) found that the potential deteriorating effect of excess fat on dynamic performance increases with age and the longer the duration of obesity. This researcher discovered that in preschool children, the effect of increased weight and body mass index is only apparent in some areas, such as broad jump and the 20 meter dash, and much less so in other measured variables. The significant effect of increased weight and fat is most marked during puberty. From the above mentioned statistics and research, the question is raised on whether obesity has an influence on the motor proficiency of 8-11 year old children. The first goal of the study was to identify 30 children with obesity (age 8-11) and 30 non-obese children (age 8-11) to form the control group. Body mass index was used as criterium to determine obesity. Boys with a body mass index of 18- 21kg/m2 and girls with a body mass index of 18-22 kg/m2 were identified as obese, while the control group all had a body mass index of less than 18kg/m2. Fat percentage was determined using the Heath and Carter method (skinfolds of the triceps, sub-scapula, para-umbilicus, supra-iliac, medial thigh and medial calf) (Heath and Carter, 1969:57). Furthermore, somatotyping has been used for the estimation of body composition. Somatotyping of an individual is expressed by a three digit evaluation comprising three consecutive numbers (rated from lowest to highest, 1-7) and always listed in the same order. Each number represents the evaluation of a basic component, endomorphy (relating to relative adipose), mesomorphy (relating to skeletal muscle development), and ectomorphy (relating to the relative linearity of the body). There after, the obese (n=30) and non-obese (n=30) children, age 8-11, were evaluated with the Bruininks-Oseretsky test (Bruininks, 1978) to determine their motor proficiency. The Bruiniks-Oseretsky Test of Motor Proficiency is an individually administered test that assesses the motor functioning of children from 4½ to 14½ years of age. The complete battery – eight subtests (Running Speed and Agility, Balance, Bilateral Coordination, Strength, Upper Limb Speed, Response Speed, Visual Motor Control and Upper Limb Coordination and Dexterity) comprised of 46 separate items – provides a comprehensive index of motor proficiency as well as separate measures of both gross and fine motor skills. The Short Form – 14 items from the Complete Battery – provides a brief survey of general motor proficiency (Bruininks, 1978:11). The data was analyzed by means of the t-test. This test was used because it is the most commonly used method to evaluate the differences in means between two groups. The study revealed that there was no significant difference in any age group (8, 9, 10 or 11) between the motor proficiency of obese versus non-obese children. This is in contrast with the hypothesis that states that there will be a significant difference between the motor proficiency of obese versus non-obese children. Although the study can conclude that there was no major difference between the two groups, obesity remains a concern. The prevalence of this epidemic is rising year after year and it is therefore recommended that obesity should be prevented as far as possible and that those who suffer from obesity should be treated as soon as they are diagnosed with obesity. Treatment of obesity is most successful if realistic goals are set; a balanced diet is emphasized; a safe rate of weight loss of about 0.5 kg a week is achieved through moderate reduction of energy intake (about 20-25% decrease); increased physical activity is emphasized as much as diet; parental support is strong and behavior therapy is provided to help both child and parents achieve the diet, exercise and behavior goals (Frühbeck, 2000:328). Another concern is that the motor proficiency of children between 8 and 11 years is not what it is suppose to be. Both the obese and non-obese group had a low score of motor proficiency, which means that they were probably never exposed to appropriate motor development in their early childhood years. It is therefore recommended that more attention be given to early motor development to help children improve their motor proficiency which is essential for the performance of specialized movements in later childhood and adolescence. Motor development programs may be implemented in pre-school and primary schools as part of the curriculum.Item Open Access Performance indicators in (ATP) tournaments(University of the Free State, 2021-11) Carlisle, Jason; Coetzee, F. F.Introduction: Key performance indicators (KPI’s) are vitally important in the context of sport. Being able to analyse and adapt accordingly to the KPI’s, would be of great benefit to the athletes as well as the coaches. Aim: To differentiate between the KPI’s of winning and losing players of matches played and the surface types and their influence on the outcome of matches. (Player height and age, number of aces hit, 1st and 2nd serve accuracy, points won off the 1st and 2nd serves, number of breakpoints faced, and number of breakpoints saved.) Methods: The current study was conducted in a retrospective manner as a quantitative design. The data was collected from a public domain, GitHub, and consisted of the 2018 ATP Tour. The data collected varied across three surfaces played on, namely Clay, Grass, and Hard Courts. The outcome of the current study was to determine the effects of the KPI’s on the final result of the tennis matches. Results: The current study found significant differences between the winning and losing players with regards to Aces, Service Points, 1st Serves Won, 2nd Serves Won, Breakpoints Faced, as well as Breakpoints Saved, however, no significant difference was found between the 1st Serves In (p=1.368). The current study also find a significant difference with regards to Aces struck (p=0.0006) between Hard and Clay Courts. No other significant differences (p<0.05) were reported across the KPI’s. Conclusion: It is important for coaches and players to note that age and height do not discriminate between winner and losers in men’s tennis as well as 1st Serves. However, all the other KPI’s show significant differences between winner and losers. This information may assist players and coaches in preparing themselves or their athletes to achieve success.Item Open Access Physical activity and lifestyle aspects of female students at a tertiary institution(University of the Free State, 2013-07) Losper, T'Neil Sarelle; Opperman, M. M.; Coetzee, F. F.; Bloemhoff, H. J.English: BACKGROUND AND RATIONALE: It is generally believed that a sharp rise in chronic diseases and unhealthy living has occurred. Researchers believe that the modern lifestyle and a lack in physical activity (PA) are the main reasons for this problem (McGinnis, 1992:S196). Chronic diseases and obesity are factors that can be prevented or reduced with physical activity and a healthy way of living. The way in which physical activity can have an indirect influence on conserving health can be explained in two ways: Firstly physical activity can be used as trigger mechanism to change other destructive lifestyle habits (Weinstein, 1987:8; Eddy & Beltz, 1989: 168). Secondly, participation in PA can have an indirect effect on the reduction of coronary diseases because of its reducing effect on depression, anxiety and tension, to name a few (Willis & Campbell, 1992:47). According to Bray and Born, (2004:181) there is an increasing need for physical activity among young adults. Young adults attending universities gain increased control over their lifestyles. However, they may not necessarily develop positive behaviors like regular PA. The lifestyle that students live is questionable. Whether their activity levels are adequate and whether they generally lead to healthy lifestyles is unknown as little research is available on this matter, especially in South Africa. Keating, Guan, Pinero and Bridges (2005:116) stated that it is well known that students' PA as a research topic has been seriously neglected. Young adulthood is considered to be an important phase of life, as many lifelong health behaviour patterns are established during this phase (Timperio, Salmon & Ball, 2004:20). OBJECTIVES: The purpose of the study is twofold: 1. To identify PA levels of undergraduate female students indifferent ethnic groups on a South African university campus, and 2. To establish the lifestyle profile and body composition of female students in different ethnic groups in a South African university campus. RESEARCH METHODS: The sample constituted of female students at the University of the Free State in their 1st, 2nd and 3rd year+ of study residing on the campus. The sample consisted of 244 students (78 1st years, 98 2nd years, 68 3rd years-: 139 black, 21 coloured and 84 white students). The following three research instruments were used: • International Physical Activity Questionnaire (IPAQ) (2012) • Belloc and Breslow's 7 lifestyle habits questionnaire • The Heath and Carter anthropometrical assessment. RESULTS AND DISCUSSION: By comparing the 1st, 2nd and 3rd year groups it is evident that 40.16% of the group as a whole (all ethnic groups) did take part in some form of physical activity. Fifty five point one percent (55.13%) of 1st year female students, 42.86% of the 2nd year and 44.12% of the 3rd year female students participated in PA. The White female students had the highest physical activity participation rate (67.86%), followed by the coloured students (38.10%). The black students' physical activity participation (35.97%) was the lowest. An average of 4 out of the 7 lifestyle habits being followed by the majority of the participants. The majority of participants eat breakfast daily (51.64%) but they do not eat 3 meals per day. Eighty seven present (87.70%) of the sample are nonsmokers, with 77.05% of the respondents consuming little to no alcohol, and at least 66.80% of the group maintains a healthy body weight. Unfortunately their eating, sleeping and exercise habits are not optimal. It is evident that the lifestyle habits of the students decrease from the 1st to the s= year, but that by the time they progress to the 3rd year-, they start trying to change their lifestyles habits to a certain extent. The ethnic groups do not show a significant difference among their lifestyle habits but white female students do have a more positive profile.Item Open Access Randomised observer-blind controlled clinical trial of the effect of static stretching versus static stretching with self-myofascial release on hamstring flexibility(University of the Free State, 2021-11) Vos, Madeline; Coetzee, F. F.; Schall, R.; Sinclair, C.Introduction: Flexibility is an important component in everyday life, especially for athletes. Flexibility is related to improved quality of life, better performance and reduced risk of injuries, and better functionality are associated with improved ROM. Static stretching (SS) is one of the most frequently used mechanisms with self-myofascial release (SMR) being a newly implemented mechanism. Both these interventions are seen as an effective way of flexibility improvements, each with their own set of downfalls. Objectives: The purpose of this study was to compare the effects of SS alone versus SMR + SS on hamstring flexibility. To assess the difference, SS alone and SMR + SS were evaluated over a 4-week period.Methods: This was a randomized control study. Fifty-six (56) male high-performance athletes from the University of the Free State were recruited and were randomly assigned into the two intervention groups, 28 participants in group one who represented SS and 28 participants in group two who represented SMR + SS. Data collection took place over a period of one month, with three data collections taking place. Outcome measures for this study were hamstring flexibility, which was assessed with an active knee extension (AKE) test and a straight-leg raise test (SLR). The two groups received three sets of one-minute stretching and/or foam rolling with 30-second rests for at least 3 days out of a 7-day week. Results: Both groups showed improvement in both AKE and SLR when comparing Week 0 to Week 4. However, the improvement seen when comparing SS alone versus SMR + SS was the same; the only exception was the pace at which improvement was seen at Week 2 and Week 4. Improvement at Week 2 was at a faster pace for both interventions than that of Week 4. When comparing the sport codes with one another, all showed improvements with both interventions; one intervention was not superior to another. Conclusion: The results of this study show that the addition of SMR before SS does not show a significant improvement in hamstring flexibility than that of SS alone. Actually, SMR + SS improved hamstring flexibility quicker than SS only when analysing Week 2 versus Week 4.Item Open Access The relationship between core stability and athletic performance among female university athletes(University of the Free State, 2020-07) De Bruin, Marizanne; Coetzee, F. F.; Opperman, M.Introduction: Literature on the effect of core stability on athletic performance in different sport codes is limited. Questions remain as to whether core stability should be considered as a component in itself or as different components, as well as the assessment thereof, and if a relationship exists with athletic performance in different sport codes. Objective: The primary objectives of this research study were to establish an anthropometric profile of female university hockey, netball, running, soccer and tennis athletes and to determine if a relationship exists between core stability and athletic performance. Population: Data were collected from 83 female athletes from the University of the Free State participating in hockey, netball, middle- and long-distance running (400 m, 800 m, 1 500 m and 3 000 m), soccer and tennis in the 2018/2019 sport season. Methods: This was a quantitative, cross-sectional study. Core stability was assessed using the isometric back extension (IBE) test, lateral flexion (LF) test and the abdominal flexion (AF) test to assess core strength (in Newton) and core endurance (in seconds), respectively, and the core stability grading system using a pressure biofeedback unit to assess core motor control. Athletic performance was assessed using the forty-metre sprint, T-test, vertical jump and the medicine ball chest throw. All athletes executed three trials of each test in a randomised order and the best value of each test was used for analysis. Correlations between each of the seven core stability tests and the four athletic performance tests were determined, overall, and separately by sport. Furthermore, the effect of core stability on athletic performance assessments was assessed using ANCOVA, fitting the factor of sport, and the covariates age, height, weight, body fat percentage and BMI of the athletes, as well as various interaction terms. Results: This study depicted the anthropometric profiles of female university athletes and found that runners have the greatest height and netball the greatest body weight, body fat percentage and BMI compared to the other sport codes. Overall, there is a statistically significant difference with respect to age, body weight, body fat percentage and BMI, but height difference is not statistically significant between sports. The highest mean value for core strength was observed in hockey, whilst tennis showed the lowest, as measured by the IBE, LF and AF characteristics. The highest mean value of core endurance was observed in runners, and the lowest in tennis, as measured by the same characteristics as core strength, only for time. The highest value of core motor control was noted in runners (grade 5) and the lowest in netball (grade 1). The highest average percentage of female university athletes obtained a grade 3. Overall, there is a statistically significant difference in sports with respect to all three characteristics of core strength and core endurance as well as the core motor control component. When considering the correlations between core stability and athletic performance for all sport codes, all correlations of core strength, core endurance and core motor control with athletic performance were weak (r<0.2) and moderately weak (r=0.2-0.5). However, when the different core tests were considered separately, the correlations for the LF characteristic of core strength was moderately strong (r=0.5-0.8) for the medicine ball chest throw and strong (r=0.8-1.0) for the vertical jump. When considered for the different sport codes separately, moderately strong correlations (r=0.2-0.5) were found in all sport codes only- for core strength with certain athletic performance tests. Overall, there is a statistically significant difference between sports with respect to all four athletic performance characteristics. Conclusion: Correlations were found between core stability and athletic performance, even though some correlations were weak and moderately weak. It can also be concluded that different sport codes require different components of core stability, and have different sets of skills based on the position played and event. Therefore, core stability can be considered as an important modality to improve athletic performance, however, it should not be the main focus in exercise training programmes.Item Open Access Stretching tecniques on hamstring flexibility in female adolescents(University of the Free State, 2010) Janse van Rensburg, Lizl; Coetzee, F. F.This study compared the eflicacy of 4 ditlerent hamstring-stretching techniques. Flexibility can be achieved by a variety of stretching techniques, yet little research has been performed on the most effective method. The four most basic stretches includes: Static stretching where the limb is held stationary at and endpoint for a certain time period; Dynamic stretching, an active stretch where the limb is slowly moved from the neutral position to the endpoint; PNF hold-relax- and PNF contract-relax stretching which is also referred to as active stretches because of the concentric and isometric contractions throughout the stretch (Prentice) 2010: Ill). This study’s aim was to determine which type of stretching technique IS most effective in improving hamstring length. One hundred female subjects between the ages of 13 and 17 years were enrolled in the study. The 90°/90° hamstring length measure was used for all measurements to measure knee extension angle. Alii 00 subjects were included in a randomized controlled trial of 5 different groups comparing different hamstring-stretching techniques. Outcorne measure (hamstring length) was recorded on all subjects initially, at 3 weeks and at 6 weeks. After 3 weeks of stretching, there was a statistically significant improvement in hamstring length (p<0.0001) using all stretches when compared to the control group. From weeks 3 through 6, hamstring length for all groups again showed statistically significant improvement when compared to the control group. No significant difference was found comparing the intervention groups after 3 weeks or after 6 weeks of stretching. After both 3 weeks and 6 weeks of stretching the straight-leg-raise (static stretching) group had the greatest improvement in hamstring length, although the difference was not statistically significant.Item Open Access Time motion analysis of elite under 19 female netball players using GPS technology(University of the Free State, 2018-01) Shaw, Michael-Louis; Coetzee, F. F.; Kraak, W. J.Introduction: Netball is a high intensity team sport characterized by short bursts of movements coupled with less intense recovery periods. Understanding the physiological demands of the sport is essential for constructing sport-specific conditioning programmes. Objectives: The purpose of this study was to profile the physical characteristics and physiological demands on elite u/19 female netball players during netball matches, in an attempt to assess the differences in those characteristics and demands for the various playing positions in netball. Methods: Global Positioning System (GPS) data on a total of forty-four (44) elite junior netball players (u/19A) were collected and a total of sixteen netball matches were analysed for the study. Therefore, a total of hundred and forty (140) GPS data sets (player games) were analysed (equivalent to 560 (140 x 4) player quarters out of a total of 731 player quarters that were recorded). Minimax X4 Catapult GPS units as well as a Polar HR monitors and chest straps were used to determine the physiological demands of netball players. The following variables were recorded: Distances covered, player load, the maximal velocity during the match; and heart rate (HR) response. The various HR and GPS data variables were analysed using a linear mixed model with Playing Position as fixed effect, and the random effects Game, Team, Game x, Team interaction term, and Player. Fitting these random effects allowed for correlation between the observations in question due to multiple observations from the same game, team, and player. Based on this linear mixed model, the mean values of the variable for each playing position were estimated, together with their standard errors. Furthermore, the pairwise mean differences between playing positions were estimated, together with 95% confidence intervals (CIs) for the mean differences and P-values associated with the null-hypothesis of zero mean difference between the pair of playing positions in question. Results: The body weight, body fat percentage and height of u/19 female netball players vary according to playing position. The Goal Shooter (GS) (186 b/min) recorded significantly (p<0.05) lower mean maximum HR than all the other positions. The mean HR of the GS (162 b/min) and the Goal Defence (GD) (170 b/min) was significantly lower than the Centre (C),Goal Attack (GA) (180 b/min) and WA (178 b/min). The C presented with the highest mean maximum velocity (5.23m.s-1) whereas the GS recorded the lowest mean maximal velocity of 4.05m.s-1. The C also covered significantly (p<0.05) more distance and presented with significantly (p<0.05) higher Player load (PL) than all the other positions, whereas the GS and the Goal Keeper (GK) presented with significantly (p<0.05) lower distance covered and PL. However, the GS and GK had a significantly higher PL per meter. The C covered 44% of its total distance between 0.2 – 3.6 m.s-1 whereas the GK and GS covered 77% of their total distance between 0.2 – 3.6 m.s-1. The GS and GK covered significantly (p<0.005) more distance in velocity band 1 than the C, GA, GD and Wing Attack (WA) and the Wing Defence (WD) travelled significantly (p=0.007) further than the C in velocity band 1. However, the GK and GS covered significantly (p<0.05) less distance than all the other positions in velocity band 2. The C travelled significantly (p<0.05) further than all the other positions in velocity band 3 and 4 and the GK travelled significantly (p<0.05) less in velocity band 4 than the other positions. Conclusions: The study revealed the differences in physical profile and physical demands of u/19 female netball players between the seven playing positions. These findings emphasize the difference in physical demand between the different positions as well as the different type of load placed on the different positions. Coaches and conditioning coaches must implement the findings of the study to develop sport-specific, and more importantly, position-specific conditioning programs.Item Open Access Time motion analysis of international rugby(University of the Free State, 2010-11) Schoeman, Riaan; Coetzee, F. F.English: This study examined the relationship between the Distance covered, High Intensity Distance covered, and the Percentage Work Rate at High Intensity and how it correlates to the score and result of each match. This paper attempted to address deficiencies in the game of rugby and provide a meaningful body of data to determine winning and losing components that jeopardize matches at senior international level. Eighteen matches (Test and Super 14) were used to gather data through the Pro zone time motion analysis program. Calculating the frequency, mean duration and total time spent in activities is fundamental in time motion analysis (McLean, 1992:285-96). The extent of these changes has, however, never been quantified. What is even more important is that their impact on playing the game has not been evaluated. Teams losing the away games, even though they won all components, can be due to home team support, playing conditions, the magnitude of the game, law variations, competition structure and the team structure played. Time motion analysis is an effective method of quantifying the demands of rugby and provides a conceptual framework for the specific physical preparation of players. The results of this study showed no significant difference (p < 0.05) between the variables (distance covered, high intensity distance covered and percentage work rate at high intensity) in the winning and losing team. The correlation between all the variables (distance covered, r = 0.67 , high intensity distance covered, r = 0.62 and percentage work rate at high intensity, r = 0.54) and winning have practical implications. The information obtained from these analyses allows coaches to structure training programmes specific to the requirements of the game, and facilitates more effective training and improved performance.