Masters Degrees (Exercise and Sport Sciences)

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Open Access
Analysis of performance indicators in IPL Twenty20 Cricket from 2015 to 2017
(University of the Free State, 2020-01) Sloane, Surita; Schoeman, Riaan
Introduction: Cricket teams practice various batting and bowling strategies when preparing for matches or tournaments. Within the IPLT20 tournament these performance variables are considered as vital due to these variables discriminating between winning and losing teams. All teams participating in the IPLT20 seek a competitive advantage therefore an analysis of performance variables such as boundaries hit by batsmen and runs scored during the power play can be used to predict future success or failure of a cricket team based on the match outcome. Objectives: The purpose of this study was to identify which batting and bowling performance variables correlate with winning and losing teams in the IPLT20 Cricket tournament from 2015-2017. Furthermore, this study is aimed to supply coaches and players with performance outcomes that most significantly influence the winning and losing of an IPLT20 cricket match. Methods: A total of 150 IPLT20 cricket matches between 2015 and 2017 were captured. Six teams were selected for the purpose of this study, namely Delhi Daredevils, Kings XI Punjab, Kolkata Knight Riders, Mumbai Indians, Royal Challengers Bangalore and Sunrisers Hyderabad. These teams all participated in all three season from 2015 to 2017. This will result in 150 matches over the 3 seasons. Measuring Instruments: Retrospective data from the 2015, 2016 and 2017 Indian Premier League Tournament was collected from ESPN Cricinfo website. Data Analysis: A reliable data source for this research was found in Statsguru. Statsguru is ESPN Cricinfo’s cricket statistics maintenance database. The data was then analysed using the SAS Statistical Software (SAS, 2017). Data were analysed separately for the team batting first and for the team batting second. The outcome of the match is a binary variable (win/lose) since drawn matches were excluded from the analysis. The association of the potential predictor variables with the match outcome was analysed using univariate logistic regression, fitting each predictor variable, one at a time. The statistical significance of each predictor variable was tested using an exact test (exact conditional logistic regression); the exact P-value is reported. The analysis was carried out using SAS procedure LOGISTIC (see SAS, 2017). Results: Variables that predict success in T20 cricket differed for teams batting first and second, respectively. The significant predictors of winning an IPLT20 cricket match when batting first were: total runs scored in a match (p=0.0001), total wickets lost in a match (p=<0.0001), and wickets taken in a match (p=<0.0001). The significant predictors of winning an IPLT20 cricket match when batting second were: wickets taken in a match (p=<.0001) and wickets lost in a match (p=<.0001). Conclusions: The results of this study concludes that there are various performance variables such as the influence of a higher total runs scored, wickets taken in a match and wickets lost in a match correlates positively with success in Indian Premier League T20 cricket between teams batting first and second and can be used as success performance predictors. In contrast to other studies, this study focusses on variables in T20 cricket that reflect the performance of the entire team. From this study it can be concluded that batting first has a higher success rate although bowling data such as wickets taken and wickets lost for teams batting second are the most important predictors of winning.
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.
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.
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.
Open Access
Body composition and blood measurements of elite senior South African body builders during a competitive season
(University of the Free State, 2012-01) Barnard, Riaan; Holtzhausen, L. J.
A dearth of literature exists surrounding the sport of Body Building. Anecdotally, when preparing for a competition, most elite body builders in South Africa will go through two totally different phases of training and dieting. The first phase is the bulking- or weight-gaining phase. During this phase, a structured diet with high carbohydrate component and moderate to high fat content will be followed for several months. During the weight-gaining phase, Androgenic-Anabolic Steroid (AAS) substances are used in moderately high doses compared to the pre-contest period. The second phase of training and dieting, is called the pre-contest preparation phase. This is a very intense phase of high volume training that usually starts about 16-13 weeks from the time of the competition. During this phase, extremely strict, structured diets are followed, with each meal being weighed. During the pre-contest phase, a multitude of chemical substances are used to enhance the desired physique – this strategy of using combinations of different classes of drugs, is called “stacking”. This will be the period with the highest AAS substance milligram usage per week. Very little current information on the profile of these athletes is available to the South African Medical Community, especially the Sports Medicine Community. There exists only a small body of knowledge in the literature on the dosing protocols abused by these athletes and the side effects they incur. Little is known of the usage of high dose AAS amongst the elite, competitive South African Body Building population and the possible side effects. A rare opportunity was presented to the author to study a group of elite level body builders during the 2010 competitive season. Obtaining participants for this cohort was difficult as these athletes form part of a very secluded group of sportsmen. Though the present cohort was disadvantaged in small cohort size, the opportunity to study such a group in depth will not be readily repeated. This is a novice study – to present, no similar study has been conducted in South Africa. All the athletes registered with the International Federation of Body Building South Africa were invited to participate in the study. Interested volunteers were asked to contact the researcher. More than 200 invitations were sent out to the existing database – only 19 athletes conveyed their interest in participation. Eventually, only 14 athletes partook in the full protocol. Blood assays were performed on each athlete on 3 different occasions, while anthropometric measurements and blood pressure readings were taken on 4 different occasions over the length of the competitive season. Each individual athlete recorded his AAS abuse, while some athletes provided sample diets as well. Data was captured on Excel spread sheets and forwarded to Department of Biostatistics, University of the Free State, South Africa. Along with the concomitant abuse of high doses of AAS over extended periods, the present study also found: - Minimal changes in blood pressure - Initial decrease in lean mass, followed by rapid increase in lean mass in just one week and failure to maintain that gain over the following weeks - Disturbed carbohydrate metabolism with increased risk for pre-diabetic status - Lipid profile changes, with decreased HDL, unchanged Total Cholesterol and decreased LDL - Liver enzyme changes highly suggestive of AAS-driven adverse effects - Hypogonadotrophic hypogonadism status - Very high Androgen Status for the cohort with mean total AAS abuse per week measuring 1638,3 mg, with average AAS cycle lengths of 17.43 weeks. In conclusion, it should be noted that the present study’s cohort differed vastly from cohorts from other studies in the literature, as none of the latter observed cohorts under full pre-contest preparation conditions. It should also furthermore be understood that body builders under full pre-contest preparation will respond differently to the use of special diets, different training strategies and different types of AAS abused, than compared to when they train under normal out-of season conditions. The author recommends that sports physicians should continuously target their efforts at counselling adolescents and other athletes about the potential long-term harms of AAS abuse, as well as regularly and prudently follow-up on the potential adverse effects that may develop in current AAS abusers. The author further recommends that, if an opportunity to study such a secluded group of body builders would present itself again, it should be immediately fully utilised.
Open Access
The development of a measuring instrument to determine the knowledge and attitudes of elite adolescent athletes about ergogenic aids and banned substances
(University of the Free State, 2016-02-09) Welthagen, Amanda; Holtzhausen, L.; Van der Merwe, P.
The use of sports supplements and banned substances amongst adolescent athletes is high. The literature review reveals that supplement and banned substance use is a complex health and social issue. Athletes use supplements in the belief that it improves performance in various ways, although there is a lack of scientific evidence of the efficacy and safety of nutritional supplements. Health risks exist with regard to using supplements due to lack of quality control and contamination with banned or dangerous substances. Contamination can cause inadvertent doping offences. A continuum from supplement use to banned substance and recreational drug use was identified. The use of banned substances have pronounced health, psychological and socio-ethical risks. The risk of getting ostracised for a doping offence is probably limited to elite sports. Banned substance use is driven by the belief that others are using it and not following suit reduces the chances of athletic success. Especially adolescents are vulnerable to controlling influences from significant others. Athletes with an external locus of control are more prone to use supplements and banned substances. Moral disengagement has been associated with the use of banned substances. The zero tolerance (ZT) approach to doping by the World Anti-Doping Agency (WADA) has not reduced the prevalence of doping. The harm reduction (HR) approach accepts the reality of widespread doping in sports and approaches the problem with the social drivers of doping in mind. Many athletes are willing to use substances to achieve their goals even at the expense of their health and wellbeing. It is therefore important to not only evaluate the prevalence of use in the adolescent athlete population, but to develop effective preventative interventions. Understanding adolescents’ knowledge, their preferred sources of information, attitudes and beliefs about sports supplements and banned substances are required in this regard. Therefore, the aim of this study was to develop a reliable measuring instrument (questionnaire) to be used in South Africa to assess the knowledge and attitudes of adolescent athletes about ergogenic aids and banned substances. The study was done in two phases. A mixed method research model was used to gather both quantitative and qualitative data. In the first phase of the study a questionnaire was developed and the relevancy and validity of the questionnaire ensured by means of qualitative research methods. In the second phase, the questionnaire was tested with a cohort of elite adolescent athletes of the University of the Free State Athletics Club, where both quantitative data (closed-ended questions) and qualitative data (open-ended questions) about the habits and knowledge of the cohort were gathered and analysed. The questionnaire was assessed as functional and user friendly. The majority of the athletes in the test population (90%) reported the use of sports supplements in the previous six months; however, all the participants (100%) claimed that they would refuse the use of banned substances even if its use was encouraged by a coach or trainer. The main reasons for using sports supplements were reported as “to increase energy” (65%), “aiding recovery” (45%), “to improve endurance” (35%), “to improve strength” (20%) and “to improve sporting performance” (15%). Thirty-five percent (35%) of the participants indicated that they were not aware of any dangers of sports supplements. Supplement information was obtained from the internet (35%), coaches (30%) and friends (30%). This complex social and health issue requires in-depth analysis and intervention, including holistic educational programmes. If these factors are addressed and their effects monitored, a positive contribution could be made to the knowledge and attitudes of adolescent athletes about ergogenic aids and banned substances in South Africa.
Open Access
The effect of gross motor stimulation on gross motor proficiency of Grade R learners in a low-resourced environment
(University of the Free State, 2021-11) Mathews, Chante Elizabeth; De Waal, E.
Introduction: Motor development has been reported as a crucial part of learners’s overall development and is interweaved into many different fascist of the growing child. In addition, the growth and development of young learners can be influenced by many factors, with nutrition and the surrounding environment being highlighted as major contributing factors. Grade R learners in South Africa are typically five – six years of age and are expected to perform certain tasks and skills as set out by the National Curriculums and Assessment Policy Statement (CAPS). In the CAPS, specific motor skill tasks are identified which needs to be mastered by the Grade R learner. The development of Grade R learners’ motor skill ability will influence the motor skill foundation they start Grade 1 with. Exploring Grade R learners’s motor proficiency levels and growth status in low resourced environments will enable the identification of possible delays, and consequently provide direction for future interventions. Aims: This study aims to answer three questions. Firstly, what is the gross motor proficiency of Grade R learners in a low-resourced environment? Secondly, using the anthropometric profile of the participants, does stunting influence gross motor proficiency? Lastly, will a gross motor stimulation program have an impact on the gross motor proficiency of Grade R learners in a low-resourced environment? Methodology: This study was conducted in a low resourced town in the Southern Free State in South Africa. The participant group included Grade R learners (four to six years old). The study consisted of a pre-test, intervention and post-test. During the pre-test 57 learners with a mean age of 5.2 years (SD=0.33) were evaluated, of which 36 were girls (62.1%) and 21 were boys (37.9%). Motor proficiency was evaluated using the Bruininks-Oseretsky Test of Motor Proficiency, second edition. Anthropometric data collected consisted of height, weight, body mass index (BMI) and upper-arm circumference. After concluding the pre-test, the experimental group (n=18) participated in an 18 week gross motor intervention, specifically designed by the researcher to aid in the gross motor development of Grade R learners. Teachers were equipped to present the gross motor intervention in a set out free-play period. After the intervention concluded a post-testing was conducted. The motor proficiency of 49 participants was again measured. Results: The anthropometric profile of the participants indicated a mean average height of 107.3 cm, weight of 17.3 kg, BMI of 15.03 kg/m² and upper arm circumference of 15.6 cm. These measurements were slightly lower than the indicated norms by the World Health Organization. When the anthropometric profiles were compared to the norms of malnutrition, two (3.5%) out of the 57 participants were underweight and nine (15.5%) were stunted. The motor proficiency results identified upper-limb coordination (17.5%) and running speed and agility (15.7%) as gross motor skills that participants struggled with. In regards to balancing skills, 50.8% of the participants scored mainly on or above standard. No statistically significant gender differences were found with regard to motor proficiency. When comparing the pre- and post-test data of the experimental and control group, no statistically significant differences were found. Small increases were noted in the running speed and agility (control = 14.9 vs 17.9; experimental = 15.1 vs 16.9) and upper-limb coordination (control = 15.96 vs 17.1; experimental = 15.5 vs 17.8) subtests’ standard mean scores. Conclusion: Grade R learners in low resourced environments portray anthropometric measurements below standard norms, and although their balance skills were adequate, below average upper-limb coordination, and running speed and agility were noted. Although the gross motor intervention program did not yield any statistical significant improvements, a need was identified to better equip teachers to be able to deliver meaningful gross motor stimulation.
Open Access
Establishing norms for kinesthetic coordination tasks in 6-year-olds in the Mangaung, Motheo District
(University of the Free State, 2021-11) Bonafede, Carmen; De Waal, Elna
Background: A well-functioning proprioceptive system and overall kinesthetic coordination is foundational to six-year-old children’s movement coordination abilities. The age of six is a crucial time in children’s developmental years, and in South Africa this is the age when they enter the formal school setting. Intact proprioception and kinesthetic coordination are therefore essential for the six-year-old South African. Several intrinsic and extrinsic factors such as gender, hand dominance and socio-economic status (SES) can influence the kinesthetic coordination abilities of six-year-old children. Norms for kinesthetic coordination testing is not available and testing is either inaccessible to everyone and/or very costly from this the main aim of the study was formed. Aims: The first aim of this study is to establish norms for kinesthetic coordination tasks in six-year-old children in the Mangaung, Motheo district and, secondly to establish if kinesthetic coordination differences occur in six-year-olds regarding school quintiles, gender and hand dominance. Setting: The participant group consisted of N=193 six-year-old children of which 97 were boys and 96 were girls, with an average age of 6.46 years (0.27). Participants forming part of this dissertation’s study population were from different quintile schools (one to five) in the Mangaung, Motheo district. Methods: Five kinesthetic coordination tasks (Angels-in-the-snow, Rhomberg, finger-to-nose, shoulder-level-arm raise and force perception) were identified and used to establish norms. Using these norms associated with the five identified kinesthetic coordination tasks differences in school quintiles, gender and hand dominance were studied. Analysis of the study was largely descriptive of nature and norms were calculated using frequencies and percentages. Differences between school quintiles were calculated using the Cochran-Mantel-Haenszel (correlation) chi-square test, and gender and hand dominance differences were calculated using the nonparametric Wilcoxon Two-sample test. Cohens d effect sizes were used to calculate practical significance where applicable. Results: Norms were successfully established for the five kinesthetic coordination tasks. Angels-in-the-snow norms was set at six to ten successful repetitions, Rhomberg norms at 22 – 30 seconds of balance, norms for finger-to-nose for the left and right hand was set at two to three successful repetitions. Norms for shoulder-level-arm-raise for the preferred arm and both arms were set at two to four successful repetitions and for the non-preferred arm at one to four successful repetitions, and lastly for force perception the norm was seen as being able to correctly identify in which hand the heavier weight was placed. Using these norms, it was evident that children in higher SES schools outperformed children in lower SES schools in most of the tasks, except for the Rhomberg task. No significant gender differences in kinesthetic coordination abilities were observed; however, girls mainly outperform boys, with the exception of the shoulder-level-arm-raise task. No practical significance was seen in the Angels-in-the-Snow and Rhomberg tasks regarding gender and preferred arm, although a practical significance was seen for finger-to-nose regarding the left hand and none for gender. For shoulder-level-arm-raise a small practical effect was seen regarding the right hand and again none for gender. No calculations were done for force perception. Conclusions and recommendations: Norms for kinesthetic coordination tasks in six-year-old children were successfully established. Kinesthetic coordination abilities are to an extent influenced by school quintile statuses, gender and hand dominance, as differences occurred. It is recommended that Kinderkineticists in practice use the established norms of the five kinesthetic coordination tasks to identify children with possible proprioceptive functioning or kinesthetic coordination backlogs. This can be followed by the implementation of a programme that is specifically tailored to each child’s individual kinesthetic coordination backlogs. Future research on a larger sample size, in different provinces of South Africa, and on children of different age ranges is advised. It is also recommended that the reliability and validity of the five task items be established in future research.
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.
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.
Open Access
'n Ondersoek na die behoefte en deelname aan sport en fisieke rekreasie van technikonstudente met spesiale verwysing na die Orange-Vrystaat
(University of the Free State, 1987-06) Venter, Everhardus Johannes; Cruywagen, F. M.
Afrikaans: Hierdie verhandeling het eerstens ten doelom die toeretiese grondslae met betrekking tot bewegingskundige studies van vryetyd en vryetydsbesteding na te gaan ten einde 'n teoretiese verwysingsraamwerk vir die empiriese gedeelte van die studie te bepaal. Die klem val hier op die tyd en ruimtelike aspek van menslike beweging, waar tyd in besonder na vryetyd verwys, ruimte na die natuurlike- en geskepte omgewing wat die mens aanwend vir die benutting van sy vryetyd * en beweging na daardie aktiwiteite wat in hoofsaak tydens vrye tyd * beoefen word. In plaas van 'n holistiese, segmentalistiese of pluralistiese benadering volg die navorser 'n fenomenologiese benadering vir die beskrywing van vryetyd. In navolging van die beskrywende paradigma van Immorlica val die fokus in die studie op dieveelheid van dimensies van vryetyd. Vryetyd is ingevolge hierdie benadering in verskeie dimensies verdeel. Vir die dimensionele kategorisering van vryetyd is slegs die sentrale idee gebruik wat in die verskillende definisies oor vryetyd vervat is. Hiervolgens is vryetyd verdeel in universele, unieke, supraorganiese, organiese, dinamiese en statiese dimensies, as synde algemene dimensies en kwantitatiewe, ruimtelike, kwalitatiewe, funksionele, kognitiewe, konfigurale, idiële, reële en gekonstrueerde dimensies, as synde besondere dimensies daarvan. Wat die verhouding tussen vryetyd, rekreasie, spel en sport betref, is in teenstelling met die integrasionistiese, segmentalistiese en molekulêre benadering, 'n kwalitatiewe benadering in die studie gevolg. Rekreasie, spel en sport is as die konkrete onderbou van die kwalitatiewe dimensie van vryetyd beskou. Binne die bestek van die kwalitatiewe benadering is die empiriese, normatiewe en psigologiese paradigmas met betrekking tot vryetyd, spel, rekreasie en sport geakkomodeer. Die belangrikheid van vryetyd en die sinvolle benutting daarvan is by wyse van 'n omvangryke literatuurstudie ondersoek. 'n Omvattende studie is gemaak van spel, rekreasie en sport as synde die kwalitatiewe onderbou van vryetyd. Uit die literatuur blyk dit dat spel oor 'n intrinsieke beloning beskik en derhalwe hoofsaaklik proses-georiënteerd is. Rekreasie is dus weer 'n emosionele ervaring en aktiwiteit en is dus proses- sowel as produkgeoriënteerd. Beide verteenwoordig positiewe komponente van vryetyd. Sport daarenteen is in hoofsaak produk-georiënteerd. Vryetyd is 'n belangrike komponent van die daaglikse lewe van die student. Die student is inderwaarheid nie alleen "homo faber" - mens die werker nie, maar ook "homo ludens" - mens die speler. Voortreflike en produktiewe akademiese arbeid is daarom net so noodsaaklik vir die student as positiewe produktiewe vryetyd en dit setel in 'n besonder rekreatiewe sportervaring. Daarom moet spel steeds die grondslag van die rekreasie- en sporthandeling bly. Daarsonder word beide aktiwiteite gestroop van hul kwalitatiewe inhoud, word die kwalitatiewe waarde daarvan gereduseer tot die momentele en is dit nie meer 'n ryke lewenservaring nie. Wat die praktiese ondersoek betref, is 'n opname gemaak van die behoeftes- en deelnamepatrone ten opsigte van sport en fisieke rekreasie van die studentekorps aan die Technikon O.V.S. In die verband is ondersoek, ingestel na die invloed van veranderlikes soos geslag, ouderdom, kursus en woonplek op die sport- en fisieke rekreasie behoeftes- en deelnamepatrone. Die ondersoek toon dat die genoemde veranderlikes 'n beduidende invloed op die deelnamepatroon van die technikonstudent wat sport en rekreasie betref uitoefen. Oor die algemeen dui die studentegemeenskap se aktiewe deelname aan sport en rekreasie op 'n gunstige syfer van bykans 70%. Wat die 30% fisiek onaktiewe studente betref, behoort stappe geneem te word om die groep tot deelname, veral wat fisieke rekreasie betref, aan te moedig. Die oorgrote meerderheid van die damestudente is sterk ten gunste van massadeelname, terwyl die manstudente voorkeur gee aan daardie aktiwiteite met 'n oorheersende kompetisie-element. Aangesien die studentegemeenskap se voorkeure met betrekking tot sport en rekreasie na hul toetrede tot die technikon wegbeweeg van die tradisionele sportsoorte wat op skoolvlak beoefen is, kan die geleentheid benut word om veral die manstudente aan te spoor om in 'n groter mate aktiwiteite te beoefen waar die intrinsieke beloning sterker figureer.
Open Access
Parental involvement in sport: perceptions of competitive adolescent swimmers
(University of the Free State, 2006-11) Stroebel, Leoni Catherine Emilie; Bloemhoff, H. J.; Walker, S.
English: All adults involved in children’s sport affect the nature of the sporting experience, and to a large extent determine whether or not it is a positive experience for children. Of all adults involved, the parents are perhaps the most important and play the most significant role in children’s sport. The purpose of this study was to examine how a group of competitive and professionally trained adolescent swimmers perceived parental involvement and how it affected their total sport experience. Participants in the study were 93 (45 male and 48 female) competitive adolescent swimmers between the ages of 13 and 22 years, who received professional coaching for 1 to 15 years, and trained for 5 to 11 months per annum. Respondents completed the parental involvement in sport questionnaire (PISQ). The questionnaire consists of three multi-item scales. The three scales measured Directive behaviour (DB), Active involvement (AI), and Praise and understanding (PU). A single item of Pressure (P) was included as a dependent variable. The questionnaire was designed to elicit responses about the behaviour of parents with regard to their children’s swimming activities. Respondents identified the frequency with which certain behaviours were (a) exhibited by, and (b) desired of their parents. Discrepancies between exhibited and desired behaviour indicated the extent of respondents’ satisfaction with these behaviours. Single sample t-tests showed that respondents perceived insufficient levels of DB, and satisfactory levels of PU, AI and P from their mothers. The results revealed that swimmers perceived satisfactory levels of pressure from their mothers, which leads to the conclusion that they find the amount of pressure acceptable. Single sample t-tests to determine the behaviour of fathers, showed satisfactory levels of DB, which suggests that fathers exhibit an appropriate level of directing or controlling of their children’s sporting experience. This is in contrast with the excessive levels of PU, AI and P that the respondents perceive from their fathers. Respondents may feel pressured by disproportionate praise as this might be accompanied by efforts to take control to an unacceptable degree. A second questionnaire was distributed to assess participants’ enjoyment of their swimming. This questionnaire consists of three questions measuring the enjoyment of sport. The data revealed that the majority of the respondents (92%) were very satisfied with their swimming experience in general and indicated that they enjoyed it to a large extent. The data suggests that the current level of pressure the swimmers experienced did not have any affect on their level of enjoyment. The study indicates that parents who express satisfaction with children’s sport performance, who interact positively with them, and who are generally positively involved and supportive in the children’s sport experience may enhance the enjoyment they derive from their sport participation. Optimal parental involvement in sport could be achieved by having well-organised, well-run programmes, and by providing parents with an opportunity to receive some education about the sport programmes in which their children are involved. A proposed document, “Practical Guidelines for Swimmers’ Parents”, was prepared in order to provide parents with a course of action to maximise their involvement. It is recommended that the above-mentioned document be distributed to the parents of the participants in this study.
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.
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.
Open Access
Physical activity demands of golf
(University of the Free State, 2018-12) Brink, Tania Kristel; Schoeman, Riaan
Introduction: Golf is quite challenging in terms of the physical demands that it places on the body throughout a round of golf, and even more so during a golf tournament, due to the repetitive action. Understanding the fitness characteristics inherent in playing golf can supply prosperous advantages to golf players, including a better and more productive swing as well as improved body mechanics. Objectives: The purpose of the study is to quantify the demands and load being placed on golf players, especially during tournaments, and therefore to assist them with a better construction of their conditioning programmes during golf practice. The study also aimed to determine the distance covered, work to rest ratios, and frequency of movements in golf. Methods: GPS data on a total of twelve (12) amateur golf players were collected and a total of forty rounds of golf (18 holes) were analysed for the study. Therefore, a total of forty (40) GPS data sets (player rounds) were analysed (equivalent to 720 holes were recorded). Minimax X4 Catapult GPS units as well as a Polar HR monitors and chest straps was used to determine the physiological demands on golf players. The variables recorded are distances covered, player load, the maximal velocity during the round, and heart rate (HR) response. Players were categorised according to their handicap - handicap<0, handicap=0 and handicap>0. The handicap categories were compared with respect to selected activity variables using a linear mixed model with handicap category (3 levels) as fixed effect, and player as random effect. Fitting player as random effect accommodated potential correlation of the data collected from the same player. Based on this linear mixed model, the mean values (of the activity variable) for each handicap category were estimated, together with their standard errors. Furthermore, the pairwise mean differences between handicap categories 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 handicap categories in question. Results: The mean value for players with a handicap below zero has the lowest playing duration (<0: = 4.32 hours) in relation to the players with the handicap equal to zero (=0: = 4.71 hours) with a handicap above zero (>0: = 4.88 hours). The total distance covered by players with the handicap below zero (<0: = 10.82km) was the furthest, compared to players with a handicap equal to zero (=0: = 10.52km) as well as player with a handicap above zero (>0: = 10.42km). Total player load was the highest for players with a below zero handicap (<0: = 606.67) followed by those with an above zero handicap (>0: = 587.05) and players with handicaps equal to zero (=0: = 583.56). Results also show that players with a handicap above zero (>0: = 2.02) has the lowest player load per minute value. Player load per kilometre was highest amongst players with a handicap below zero (<0: = 56.32) followed by players with handicaps above zero (>0: = 55.61). Below zero handicap (<0: = 42.52) players covered the longest distance per minute of all players. Players with a handicap below zero (<0: = 3.24) had the highest maximum velocity compared to players with handicaps equal to zero (=0: = 2.87), followed by players with handicaps above zero (>0: = 2.73). Significant differences between the players with a handicap below zero and players with a handicap above zero for total duration (p=0.0194) and meters per minute (p=0.021) can be observed. Conclusions: The study reveals the physical profile of and physical demands on amateur golf players and indicates differences between the various handicaps of golf players. These findings emphasise the differences in amateur players regarding handicaps for the load, duration, and distance placed on the players. Coaches and conditioning coaches must implement the findings of the study to develop sport-specific, and more importantly, handicap-specific conditioning programmes.
Open Access
Randomised crossover trial of m. gluteus maximus and m. gluteus medius activation during rehabilitation exercises in female hockey players
(University of the Free State, 2020) Coetzee, Daretha; Coetzee, Frederik; Sinclair, Colleen
Introduction: Various researchers have focused on the activation capabilities of the gluteal muscles during different commonly used rehabilitation exercises. However, there is currently a lack of research in examining body weight rehabilitation exercises that elicit the highest percentage maximal voluntary isometric contraction (%MVIC) for both the m. gluteus maximus (mGmax) and m. gluteus medius (mGmed) in a high-performance athletic population. Field hockey predominantly requires maintaining a forward flexed posture, which places excessive stress on the lumbar spine of the players. Hence, it is necessary to assess the muscles that support the lumbar spine, especially the muscles that surround the hip, in order to prescribe strengthening exercises for this population. Knowledge of the percentage activation of the mGmax and mGmed elicited during body weight rehabilitation exercises may result in more specific exercise programme prescription during prehabilitation and the later stages of rehabilitation for high-performance female field hockey players. Objectives: The aim of the study was first to establish which commonly prescribed body weight rehabilitation exercises from previous studies produced greater than 61%MVIC for both the mGmax and mGmed. Hereafter, the study examined the exercises that fall into this category to determine which exercise will elicit the highest %MVIC, defined as the peak normalised sEMG signal amplitude, in high-performance female field hockey players of the University of the Free State (UFS). Methods: Surface electromyography (sEMG) was used to record the muscle activation of the mGmax and mGmed of four (4) body weight rehabilitation exercises on twenty-six (26) highperformance female field hockey players of the UFS. The %MVIC activation data of both the mGmax and mGmed were analysed using a three-way ANOVA, with ‘participant’, ‘period’ and ‘exercise’ as categorical variables in the model. Point estimates for the mean %MVIC for each exercise were reported, as well as point estimates, 95% confidence intervals (CIs) and p-values for the pairwise differences in peak %MVIC between the four body weight rehabilitation exercises. For each variable analysed, the overall F-test for the four body weight rehabilitation exercises is reported, as well as the partial effect size measure for ANOVA. Results: The mean age of the participants was 20.15±1.59 years, the mean height was 164±0.07cm, mean body mass was 64.72±10.21kg, and mean BMI was 23.87±2.92kg.m². Side-plank hip abduction with dominant leg on bottom generated a 124.61±7.94%MVIC of the mGmax and a 126.07±14.16%MVIC of the mGmed. Side-plank hip abduction with dominant leg on top generated a 124.33±8.63%MVIC of the mGmax and a 124.52±11.37%MVIC of the mGmed. The single-leg squat generated a 125.65±10.13%MVIC of the mGmax and a 126.30±12.89%MVIC of the mGmed. Plank with hip extension generated a 122.73±9.37%MVIC of the mGmax and a 125.04±13.14%MVIC of the mGmed. Concerning the mGmax, there was no significant difference found in activation when sideplank hip abduction with dominant leg on bottom was compared to side-plank hip abduction with dominant leg on top (p=0.8475, d=0.28), the single-leg squat (p=0.4807, d=-1.03) and plank with hip extension (p=0.2000, d=1.88). Furthermore, no significant difference was found when side-plank hip abduction with dominant leg on top was compared to the singleleg squat (p=0.3685, d=-1.31) and plank with hip extension (p=0.2770, d=1.60). However, there was a significant difference between the single-leg squat and plank with hip extension (p=0.0487, d=2.91). Concerning the mGmed, there was no significant difference in activation when side-plank hip abduction with dominant leg on bottom was compared to the side-plank hip abduction with dominant leg on top (p=0.3272, d=1.54), the single-leg squat (p=0.8837, d=-0.23) and plank with hip extension (p=0.5134, d=1.03). Furthermore, no significant difference was found when side-plank hip abduction with dominant leg on top was compared to the single-leg squat (p=0.2606, d=-1.77) and plank with hip extension (p=0.7437, d=-0.52) or between the single-leg squat and plank with hip extension (p=0.4240, d=1.26). When the exercise effect is combined, the four body weight rehabilitation exercises did not significantly affect either mGmax (p=0.2558) or mGmed (p=0.6285) activation. Conclusion: The four body weight rehabilitation exercises examined by the study generated very similar %MVIC activation of the mGmax and mGmed in high-performance female field hockey players. This research enables practitioners to apply evidence-based practice into programme prescription. Implementation of the findings of the current study could result in significant benefits during prehabilitation, injury prevention programmes and the later stages of rehabilitation for high-performance female field hockey players. The conditioning coach stands to benefit, especially given that these exercises can be executed on the playing pitch as part of a warm-up without the need for any equipment.
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.
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.
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.
Open Access
Time Motion Analysis in the South African Premier Soccer League using GPS technology
(University of the Free State, 2020-01) Melesi, Kopano Zabulon; Coetzee, Frederik F.; Schoeman, Riaan
Introduction: The game of soccer is an intermittent sport characterised by aerobic and anaerobic periods. TMA research on soccer in South Africa is lacking when compared with international counterparts, even though scientific-based soccer research can equip Strength and Conditioning Coaches in soccer with the precise knowledge to aid the development of individualised conditioning programmes for soccer players. Objectives: The purpose of this study was to quantify the physical demands of different positions in the Premier Soccer League (PSL) in South Africa. Methods: GPS data on 26 players were collected, 46 matches and 459 observations and entries were analysed for the study. Minimax X4 Catapult GPS units were used to determine the physical and physiological demands made on soccer players. The following variables were recorded: Distances covered runs, run distance; number of runs, sprints, sprint distance and number of sprints in a match play. The quantitative variables were compared between playing positions using a mixed linear model, fitting playing position as fixed effect and match and (individual) player as random effect. Fitting the random effects allowed for the correlation of data within matches and for a given player. For each variable analysed, the overall F-test for playing position and the associated P-value are reported. Furthermore, the pairwise mean differences between playing positions, 95% confidence intervals for the mean differences, and associated P-values are reported. A so-called “lines” display is used to indicate which pairwise differences between the various playing positions are statistically significant. Results: All playing positions combined covered a mean total distance of 8494m (7197m-9200m) during a match which is notably lower than total distances reported from international soccer leagues which range from 10.180m- 11.680m. The CAM covered the highest total distance (9200.63m), closely followed by the WB (8724m) and CM (8621m). The ST, in contrast, covered the lowest total distance (7197m), closely followed by CB (7741m) and WA (8301m). The same positions made the greatest number of runs CAM (78m) and WB (72m). The WA covered the highest sprinting distance (299m), narrowly followed by the WB (278m). The lowest sprint distance was registered by CM (99m) and CB (101m). The WA performed a greater number of sprints (19) closely followed by the WB with a total of (17). CM and CB listed the lowest number of sprints in a match (7). Conclusions: In order to optimise soccer performance and to construct appropriate conditioning programmes, it is critical to have an understanding of the physiological demands placed on PSL players during a match. Our findings emphasise the differences in physical demand between the playing positions in soccer. Coaches can apply the findings of this study to develop position-specific strength and conditioning programmes for PSL players. For example, programmes for the CAM, should pay attention on improving aerobic capacity (extensive continuous low intensities) and aerobic power (intensive high intensity training, 2v2). The total distance covered by the W positions suggests that the W should have a balanced programme that switches between aerobic and anaerobic intensities. WA covers the highest sprinting distance among all positions; training regimens should focus on improving the W’s anaerobic capacity and anaerobic power ability. The WB training would consist of anaerobic modalities to help prepare the WB for the high intensity of speed endurance demands associated with the position. However, the WA must concentrate on anaerobic power as the sprints in this position consist of lower distances, so speed endurance production is essential in this position. To perform at high intensity throughout the duration of the match, soccer players should improve both aerobic and anaerobic endurance using high-intensity training modalities. This study can also help aspiring soccer players from club level to understand the physiological demands to play at PSL level and the physical demands at International level.