Physical fitness profile of primary schoolchildren from lower socio-economic communities in Port Elizabeth
- Authors: Smith, Danielle
- Date: 2018
- Subjects: Physical fitness , Exercise -- Physiological aspects Sports -- Psychological aspects Malnutrition -- Physiological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/35491 , vital:33740
- Description: The aim of this study was to measure the physical fitness status of primary schoolchildren from lower socio-economic areas in Port Elizabeth, South Africa. A total of 915 schoolchildren (n=462 boys and n=453 girls), aged 8-to-11-years from eight government schools participated in this study. These included four schools from the Northern Areas (previously reserved for Coloured individuals) and four schools from the Township Areas (previously reserved for Black African individuals). Measurements included weight, height, skinfolds, sit-and-reach, grip strength, standing broad jump and the 20 m shuttle run test. Results showed that girls had higher body fat percentage values than boys (p<.0005). Children of Black African ethnicity were taller and heavier (p<.0005), with higher body fat percentages and body mass index results (p<.0005) than Coloured children (excluding the 8-year-old age group). Children attending Northern Areas schools presented with higher frequencies of underweight, stunting and thinness (p<.0005), than children from Township Area schools who presented with a higher prevalence of overweight and obesity (p<.0005). In relation to physical fitness, boys presented with higher values (p<.0005) for all components, except for flexibility; in which girls performed better (p<.0005). The composite fitness score revealed that boys, Black African children and children from Township Area schools performed better (p<.0005) than Coloured children and children attending Northern Area schools, respectively. Furthermore, children categorised as overweight and obese presented with lower VO2max values than their thin and normal weight peers. Overall, findings revealed that the physical fitness status of children from these disadvantaged areas were not satisfactory. In addition, distinct geographical and ethnic differences were identified.
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- Date Issued: 2018
Changes in muscle recruitment, functional strength and ratings of perceived effort during an 8-over bowling spell: impact on performance
- Authors: Barford, Gareth Charles
- Date: 2013
- Subjects: Cricket -- Bowling , Sports -- Physiological aspects , Muscles -- Wounds and injuries , Fatigue , Physical fitness , Cricket injuries
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5102 , http://hdl.handle.net/10962/d1003926 , Cricket -- Bowling , Sports -- Physiological aspects , Muscles -- Wounds and injuries , Fatigue , Physical fitness , Cricket injuries
- Description: Background: The musculoskeletal demands placed on the lower limb musculature of fast bowlers over time have not received much attention. In particular, measures of muscle recruitment changes have, to the author’s knowledge, not been considered. Objective: The present study, therefore sought to establish any associations between an eight over, simulated fast bowling spell, and muscle activation patterns, power output, perceptual demands, and changes in performance. This will enable improvements in the development of training programmes. Methods: Players’ were required to attend two sessions in total. The purpose of the initial session was to collect specific demographic, anthropometric and physiological data and injury history information from each player. In addition, this first session allowed for habituation with the treadmill, the jump meter and all other equipment involved in experimentation. The second testing session involved electrode attachment sites being identified on player’s dominant leg. The areas were then shaved, wiped with an alcohol swab and left to dry, to ensure good connectivity. Pre- and post- measures of muscle activity and functional strength of the lower limbs were recorded in the Department of Human Kinetics and Ergonomics. The protocol took place at the Kingswood High Performance Centre, which is in close proximity to the initial testing site. The protocol involved players bowling eight overs (48 balls). During the protocol, accuracy, ball release speed and perceptual measures were recorded at the end of each over. After the protocol, players were driven back to the Human Kinetics and Ergonomics Department where post-testing measures were completed. The dependable variables of interest were muscle activation, functional strength of the lower limbs, ‘local’ ratings of perceived exertion (RPE), body discomfort, accuracy, and ball release speed. Results: For all muscles it was shown that, as the speed increased so did the muscle activity in players’ lower limbs. There were no significant changes in muscle activity preversus post-protocol. There was however, a general trend of decreasing muscle activity post protocol at higher testing speeds. There were significant (p<0.05) decreases in peak power following the simulated eight over bowling spell. ‘Local’ RPE displayed a significant (P<0.05) increase with each additional over and were observed to reach the ‘heavy’ category. The players’ highest discomfort area was in the lower back, with 13 players perceiving discomfort in this region following the eight over spell. The shoulder and chest were another two areas player’s indicated discomfort with eight players selecting the dominant shoulder. Seven players complained of the dominant side pectoral muscle, leading foot and dominant latissimus dorsi muscle being uncomfortable. Interestingly, the dominant pectoral showed the highest body discomfort ratings amongst players. There were no significant changes in accuracy between overs although there were large interindividual differences in accuracy points between players. The decrease in ball release speed observed during over seven was shown to be significantly (p<0.05) lower than overs one to four. Conclusion: The power output and perceived strain results of the players, appears to indicate the presence of fatigue in players. However, the results are not conclusive, as the fatigue was not shown in muscle recruitment patterns, as well as the body discomfort ratings. There was a non-significant trend observed in the lower limb muscle activation decreasing at higher speeds. Players were able to maintain accuracy. However, the significantly lower ball release speed observed during over seven showed players performance decreasing.
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- Date Issued: 2013
Obesity prevalence and associated physical activity levels of children aged seven to ten years in quintile five primary schools in the Nelson Mandela Metropolitan Municipality
- Authors: McKersie, Joanna Mary
- Date: 2013
- Subjects: Obesity in children -- South Africa -- Nelson Mandela Metropolitan Municipality , Overweight children -- South Africa -- Nelson Mandela Metropolitan Municipality , Physical fitness
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10115 , http://hdl.handle.net/10948/d1021086
- Description: Background: Obesity is a chronic and complex metabolic disease with associated comorbidities. The prevalence of excess body weight has risen substantially in both affluent developed countries and in developing countries worldwide. In 2008 it was estimated that 43 million children under the age of five were overweight, with developing countries accounting for 75 percent of these rates. Furthermore, with 75 percent of these children developing adulthood obesity, mortality rates due to obesity will continue to increase unless preventative interventions are implemented. Objective: To identify the prevalence of obesity and overweight among urban seven to 10 years old children in Quintile five English-medium schools in the Nelson Mandela Metropolitan municipality in the Eastern Cape, South Africa. Design and Methods: A quantitative descriptive one-way cross-sectional research design utilising random sampling was used. A total of 713 children participated in the study. A onceoff survey consisted of anthropometrical assessment of height, weight and waist circumference. To classify children into weight categories, the International Obesity Task Force cut-off values were used. A validated physical activity – related behaviour questionnaire was completed to explore and identify the daily level of physical activity expressed in MET values. Using one-way ANOVA’s and Chi-squared tests, significance between variables was analysed. Results: Overweight prevalence was 20.9 percent and obesity prevalence was 9.8 percent. A significant relationship was found between obesity and overweight levels for gender, age, ethnicity and culture. No significant relationship was found for obesity and overweight prevalence and physical activity. Conclusion: Results highlight the rising prevalence of obesity and overweight amongst urban children from affluent primary schools and the necessity for further research to explore sociocultural factors that impact on obesogenic behaviour in South African youth.
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- Date Issued: 2013
Effects of a gymnasium-based resistance training programme on selected physical fitness components in sub-elite martial artists
- Authors: Von der Marwitz, Reiner Keith
- Date: 2012
- Subjects: Martial arts , Training , Physical fitness
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10110 , http://hdl.handle.net/10948/d1020822
- Description: The aim of the study was to explore, describe and compare the impact of a 12-week intervention on selected physical fitness variables in sub-elite martial artists. The experimental group (expG) participated in a combination of alternating dojo and gymnasium-based resistance training, each bi-weekly, with the comparison group (comG) exclusively undergoing four conventional dojo training sessions weekly. The variables measured included; anthropometric measures (height, body mass and percentage body fat); functional core muscular endurance; hamstring flexibility; upper body muscular strength and endurance; lower body muscle strength; and static balance. A quasi-experimental research design was employed, with pre - and post - test assessments after a 12 week intervention period. Purposive and snowball sampling techniques were employed from existing dojo’s in Port Elizabeth, with a randomised allocation of participants into two groups. The gymnasium-based training programme was designed according to the national conditioning and strength association (NCSA) principles of resistance training. The identified variables were tested at a 95% level of probability (p < 0.05). Similar trends in performance improvement were evident for both the expG and compG in of the majority of the selected physical fitness variables. One-way, two-sample and independent t-tests analysis found no statistical significant intra- group or inter-group differences in any of the selected dependant variables for both groups. Thus, the supplemental resistance training programme was not superior to that of the conventional dojo training programme in improving aforementioned variables. Despite the lack of statistical significance, these results indicate that a structured and supervised resistance training programme in a gymnasium may serve as an alternative method of intervention for improving physical fitness in sub-elite mixed martial artists. The resistance training programme should be specifically adapted according to the individual practitioner’s strengths and weaknesses, as well as to the type of martial art being practised.
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- Date Issued: 2012
The isolation of muscle activity and ground reaction force patterns associated with postural control in four load manipulation tasks
- Authors: Pettengell, Clare Louise
- Date: 2010
- Subjects: Physical fitness , Exercise , Materials handling , Manual work , Lifting and carrying
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5125 , http://hdl.handle.net/10962/d1005203 , Physical fitness , Exercise , Materials handling , Manual work , Lifting and carrying
- Description: Although much effort has been placed into the reduction of risks associated with manual materials handling, risk of musculoskeletal disorder development remains high. This may be due to the additional muscle activity necessary for the maintenance of postural equilibrium during work tasks. This research proposes that postural control and subsequent additional muscle activity is influenced by the magnitude of the external load and the degree of body movement. The objective of this research was to identify whether performing tasks with increased external load and with a greater degree of trunk motion places additional strain on the musculoskeletal system in excess of that imposed by task demands. Twenty-four male and twenty-four female subjects performed four load manipulation tasks under three loading conditions (0.8kg, 1.6kg, and 4kg). Each task comprised of a static and dynamic condition. For the static condition, subjects maintained a stipulated posture for ten seconds. The dynamic condition required subjects to move and replace a box once every three seconds, such that a complete lift and lower cycle was performed in six seconds. Throughout task completion, muscle activity of six pairs of trunk muscles were analysed using surface electromyography. This was accompanied by data regarding ground reaction forces obtained through the use of a force platform. After the completion of each condition subjects were required to identify and rate body discomfort. Differential analysis was used to isolate the muscle activity and ground reaction forces attributed to increased external load and increased trunk movement. It was found that the heaviest loading conditions (4kg) resulted in significantly greater (p<0.05) muscle activation in the majority of muscles during all tasks investigated. The trend of muscle activity attributed to load was similar in all significantly altered muscles and activation was greatest in the heaviest loading condition. A degree of movement efficiency occurred in some muscles when manipulating loads of 0.8kg and 1.6kg. At greater loads, this did not occur suggesting that heavier loading conditions result in additional strain on the body in excess of that imposed by task demands. In manipulated data, trend of vertical ground reaction forces increased with increased load in all tasks. Sagittal movement of the centre of pressure attributed to load was significantly affected in manipulated data in the second movement phase of the “hip shoulder” task and the second movement phase of the “hip twist” task. The “hip reach” task was most affected by increased load magnitude as muscle activity attributed to load was significantly different (p<0.05) under increased loading conditions in both movement phases in all muscles. Further, a significant interactional effect (p<0.05) between condition and data point was found in all muscles with the exception of the right and left lumbar erector spinae during the second movement phase of the “hip reach” task. Muscle activity associated with increased trunk motion resulted in additional strain on the trunk muscles in the “hip shoulder” and “hip reach” tasks as muscle activity associated with the static component of each of the above tasks was greater than that of the dynamic tasks. Trend of ground reaction forces attributed to increased trunk motion generally increased under increased loading conditions. Additionally, a significant interactional effect (p<0.05) between load and muscle activity pattern was found in all muscles during all tasks, with the exception of the right rectus abdominis in the first movement phase of the “hip shoulder’ task, the left rectus abdominis in the second movement phase of the “hip knee” task and the right latissimus dorsi during the first movement phase of the “hip twist” task. This was accompanied by a significant interactional effect (p<0.05) between load and sagittal centre of pressure movement attributed to load, in both movement phases of all tasks investigated. From this research it can be proposed that guidelines may underestimate risk and subsequently under predict the strain in tasks performed with greater external loads as well as tasks which require a greater degree of trunk motion. Therefore, this study illustrates the importance of the consideration of the muscle activity necessary to maintain postural equilibrium in overall load analyses.
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- Date Issued: 2010