Human Movement and Biokinetic Sports Science
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Browsing Human Movement and Biokinetic Sports Science by Author "Coetsee, M.F."
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- ItemThe application of prophylactic knee bracing in relation to selected proprioceptive and fitness and skill parameters in first league South African rugby players(2001) Kruger, Theodore Hendrik; Coetsee, M.F.; Davies, S.E.H.In rugby and other sports involving rapid change in direction and physical contact, there has been a high incidence of knee injuries in match situations as well as in training sessions. Ample literature is available on the effect of braces for the prevention and recurrence of injuries. However, due to different research fields/subjects (American football, soccer and baseball) and methodologies, results are not always applicable to rugby union. The primary focus of the present study was to evaluate selected parameters important in modem rugby, and the effect of prophylactic knee bracing on speed, agility, strength, proprioception and economy of running. These parameters all play an important role in performance on the rugby field. The questions addressed are: are any of these parameters affected by wearing a prophylactic knee brace, and could forwards and backs be affected differently. Thirty subjects aged 21 - 30 with the mean age of 24,33 ± 4,98 years volunteered to participate in this study. Subjects were evaluated with respect to their anthropometric, proprioceptive, fitness and skill responses. The data were statistically analyzed by a one way ANOVA for significant differences in the following: braced and non-braced conditions for the combined group, backs and forwards separately. An independent t-test was employed to analyse the difference between backs and forwards. Both, p<0.05 and p<0.01 level of probability are indicated, although p<0.05 was the criteria for refuting the null hypothesis. Anthropometric results illustrated that forwards and backs were significantly (p<0.01) different in their stature, mass, bodyfat, upper thigh girths and significantly (p<0.05) different in their above knee and calf girth and the mid thigh calf ratios (MTCR). Fitness and skill responses indicated that speed was insignificantly (p>0.05) influenced with prophylactic bracing for combined subjects, forwards and backs. However, speed was slower with bracing, but the difference was insignificant (p>0.05). Forwards' speed results were slower than results of the backs but-the speed difference between forwards and backs illustrated an insignificant (p>0.05) difference for both variables (braced and non-braced conditions). Agility performance was insignificantly (p>0.05) decreased with brace application for the combined group, forwards and the backs. Forwards' agility performance was significantly (p<0.05) worse than backline players' performance in both variables, braced and non-braced conditions. Proprioception responses indicate that proprioceptive ability improved significantly (p<0.01) with prophylactic bracing for combined subjects and backs, however the forwards' performance also increased with bracing, but the increase was only significant at (p<0.05). Forwards' proprioceptive results in both conditions were worse than results of the backs, and the difference illustrated to be significant (p<0.01) for both variables. For strength, prophylactic bracing illustrated no significant influence on flexion and extension of the knee (p>0.05) for the combined group, backs or forwards. However, a significant (p<0.01) difference was found between backs and forwards in peak strength (Nm) but not in relative strength (Nm ■ kg"1). Economy of running performance for the combined subjects was not significantly (p>0.05) influenced for levels 1-8, but was significantly (p<0.05) influenced in level 9. Backline players illustrated an significant difference from levels 5-9 and the forwards only a significant difference (p<0.05) at level 9 with brace application. In conclusion the major two questions of the present study is to investigate if rugby players should use prophylactic knee bracing to prevent or reduce injuries to the knee, and will the brace affect forwards differently from backline players. From the results one could conclude in saying that bracing would not hamper performance on the rugby field significantly. But one should remember that each rugby player has a unique morphological composition and therefore one would suggest that rugby players evaluate or compare the involving factors, and experiment with prophylactic braces. The individual should, after reading the arguments, be in a better position to make an informed decision whether to use prophylactic braces or not.
- ItemThe effects of a supplementary high intensity muscle endurance resistance training programme on Comrades Marathon performance(2007) Ellapen, Terry Jeremy.; Coetsee, M.F.In this study, the aim was to determine the effects of a high intensity muscle endurance resistance intervention programme as a supplement to normal running training for Comrades Marathoners. A sample voluntary population of 115 subjects were initially distributed at random into two groups of approximately equal size, namely the control (CT) group and the experimental (RST) group. Originally, the CT group constituted 57 subjects, whilst the RST group constituted 58 subjects. However, four subjects from the CT and one subject from the RST group failed to complete the pre-intervention test battery, thereby eliminating themselves from the study. The sample size was therefore reduced to 110 subjects, resulting in 53 subjects in the CT group and 57 in the RST group. Subjects were males between the ages of 25 to 50 years who had successfully completed a minimum of five Comrades Marathons (at least three up runs and two down runs). All subjects completed a PAR-Q as well as an informed consent form prior to participating in the pre-intervention test battery. The pre-and post-intervention test batteries comprised of physical characteristics measurements (age, body mass, height, body fat percentage and percentage of fat-free mass) and physical performance measurements (10km run, 400m-sprint, Wingate anaerobic cycle test, one-minute sit-up test, one-minute press-up test and lower back-leg dynamic strength test). The pre-intervention test battery results indicated comparable, non-significant (p> 0.05) differences between the control and experimental groups' physical characteristics and physical performance parameters. The statistical analyses of the control and experimental groups' previous Comrades Marathon completion times proved to be non-significantly (p> 0.05) different and therefore comparable. Subsequent to the pre-intervention test battery, the experimental group was subjected to the intervention programme for 34 weeks. The experimental group completed the intervention programme twice a week in addition to their normal marathon running training, whilst the control group continued with their normal Comrades Marathon running training. Thereafter both .the groups underwent the post-intervention test battery. The control group's post-intervention physical characteristics and physical performance parameters remained relatively similar, with non-significant (p> 0.05) differences. The control group's average 10km run time was non-significantly (p> 0.05) reduced by 2.1%. The experimental group experienced significant (p< 0.05) changes to both their physical characteristics and physical performance parameters. These changes included: a post-intervention decrease of percentage of body fat by 22.6%; an increase of percentage of fat-free mass by 4.8%; a reduction of 10km run time by 12.1%; a reduction of 400m-sprint time by 28.5%; an increase in Wingate anaerobic cycle test results by 16.3%; an improvement in one-minute sit-up test results by 27.8%; an improvement in one-minute press-up test results by 32.4%; an increase of lower body dynamic strength by 28.9%; and, most importantly, a reduction in their Comrades Marathon completion times by 9.2%. In addition to this, the intervention programme helped the experimental group to reduce their 21.1km and 42.2km completion times. The intervention programme increased the structural/musculoskeleta! joint integrity and stability of the members of the experimental group. It is proposed that the increased structural/musculoskeletal joint integrity and stability reduced the total incidence of overuse injury experienced by the experimental group by 43.3% as compared to the control group. In conclusion, the study demonstrated that the high intensity muscle endurance resistance programme that was used to supplement the primary running training of Comrades Marathon runners (experimental group) did help improve their Comrades Marathon completion times.
- ItemThe effects of differentiated physical activity programmes on the motor proficiency of children with learning disabilities(2002) Scheepers, Glynis Kay; Coetsee, M.F.With this study, the researcher investigated the effect of specially designed physical education programmes on the motor proficiency of learners with learning disabilities. The subjects (N=60) were aJ! learners from the Zululand Remedial School in Empangent, Kwa Zulu/Natal. Two experimental groups participated in a twelve week Perceptual Motor (N=20) or a Sensory Motor (N=20) intervention programme, while a Control group (N=20) was tested on all test variables, but did not participate in a intervention programme. Using a repeated measures with matched pairs design, the Bruininks Oseretsky Test of Motor proficiency (long format) was used during the pre, post and post post testing periods. An ANOVA calculation revealed that the Perceptual Motor group achieved a significant improvement in their motor proficiency (p < 0.01). The Sensory group improved significantly on their motor proficiency score. The Control group showed no significant changes on their scores. * The results displayed enough evidence to prove that a specially designed physical education programme (to suit the special needs of learners with learning disabilities ) is of the utmost importance. Additional data was gathered to establish whether there was any relationship between motor proficiency and body composition profiles, self- concept and classroom behaviour. A very low correlation was found on each of these variables. This raises questions about the nature of the relationship between motor proficiency and these variables and indicates that further substantial studies are required.
- ItemEnergy expenditure and working efficiency of South African sugarcane cutters(2005) Muller, Marie de Lanoy; Coetsee, M.F.; Davies, S.E.HThis study sought to examine the physiological demands as well as selected measures for working efficiency in the manual harvesting of burnt and unburnt sugarcane, along with the effects of using a short handle curved blade knife and a long handle curved blade knife on energy expenditure and working efficiency. The effect of subject observation and unobtrusive observation interaction on the cane cutters' performance was also investigated. A total of fifteen professional male cane cutters participated with written informed consent. Only cane cutters with five or more years' working experience were randomly selected to participate in this study. Research in the field of sugarcane cutters in South Africa has been restricted to estimates of energy expenditure only. Evidence shows that heart rate and oxygen uptake during an actual activity differ from measurements in the laboratory at equal workloads. With this in mind, oxygen uptake and energy expenditure were measured directly by means of indirect calorimetry, during the performance of work. The metabolic measures were measured by means of the portable MetaMax 1 Ergospirometry System. Heart rate was measured telemetrically by means of the Polar Accurex Plus™ wrist receiver and its Polar Pacer transmitter. After data collection, heart rate data were downloaded via a Polar Interface Plus with Training Advisor Software onto a computer, and analysed. For the effects of unobtrusive observation interaction on the cane cutters' performance average heart rate during cane harvesting was related to the oxygen consumption, measured by the MetaMax I, using the corresponding heart rate. From this, the energy expenditure was estimated. Burnt and unburnt sugarcane Findings indicated significant differences (p<0.05) between harvesting burnt and unburnt sugarcane with regard to the following physiological parameters: absolute oxygen consumption (p<0.01) and relative oxygen consumption as well as absolute and relative energy expenditure. The mean and peak heart rates during work were not significant (p>0.05), indicative of similar levels of exertion for harvesting burnt and unburnt cane. Ratings of perceived exertion (RPE) did not differ significantly (p>0.05), suggesting that the subjective perception of exertion of harvesting burnt and unburnt cane was similar. The selected measures for working efficiency were as follow: Rate of productivity harvesting burnt cane was significantly higher (p<0.01) than that for unburnt cane. Significantly less energy was required to cut one kilogram of burnt cane than that for unburnt cane. The amount of burnt cane cut per litre of oxygen consumed was also significantly higher (p<0.01) than in harvesting unburnt cane. The number of cane cutting strokes per minute to cut the stalks of burnt cane was significantly higher (p<0.05) than that for unburnt cane while the number of stalks cut per stroke for burnt cane was significantly lower (p<0.05) than that for unburnt cane. Despite the last two measures of working efficiency being in favour of unburnt cane, the results in general lend credence to the fact that harvesting burnt cane was more economical with regard to physiological parameters and selected measures of the working efficiency of the cane cutters. Manual sugarcane harvesting implements No significant differences (p>0.05) were demonstrated for the comparison between the short handle curved blade knife and the long handle curved blade knife in burnt cane in any of the measured variables for the physiological parameters, except for the cane cutters' ratings of perceived exertion (RPE). This suggests that the cane cutters' subjective perception of strain experienced harvesting burnt cane with the short handle curved blade knife was more strenuous than using the long handle curved blade knife. Though the selected measures for working efficiency for the comparison of the short handle curved blade knife with the long handle curved blade knife did not significantly differ (p>0.05), the following measures were all in favour of using the long handle curved blade knife: Rate of productivity, energy required to cut one kilogram of burnt cane, similar amounts of cane were cut per litre of oxygen consumed, number of cane cutting strokes per minute to cut the stalks, and number of stalks cut per stroke. Subject observation and unobtrusive observation interaction The effect of observation and unobtrusive observation interaction on the cane cutters' physiological system during cane harvesting revealed significant differences (p<0.05) in corrected measures for relative oxygen consumption and relative energy expenditure. Mean heart rate responses were also significantly higher during subject observation interaction. AH remaining physiological parameters were statistically insignificant (p>0.05). The rate of productivity of the cane cutters recorded during observation interaction was significantly higher (p<0.05). Other selected measures for the working efficiency, though not statistically different (p>0.05) were also higher during subject observation compared with the experimental condition of unobtrusive observation interaction. These results show that subject observation interaction leads to increases in the performance of the cane cutter.
- ItemThe influence a 10-week Zulu stick fighting intervention programme has on motor proficiency and health-related physical fitness of prepubescent Zulu males(University of Zululand, 2010) Nxumalo, Sabelo Abednego; Coetsee, M.F.; Semple, S.J.; Longhurst, G.K.The aim of this study was to investigate the effect of a 10-week stick fighting intervention programme on anthropometrical measures, motor proficiency and healthrelated physical fitness parameters such as body composition, cardiovascular fitness, flexibility, muscular endurance and muscular strength. Twenty two prepubescent Zulu males (mean age = 9.80 ± 0.64 years, range 8.60-11.10) formed the experimental group and twenty three other Zulu males (mean age = 10.09 ± 0.73, range 8.43-11.70) formed the control group. The experimental group underwent a 10 week stick fighting intervention programme facilitated by two professional stick fighters whilst for the same period, the control group did not receive any intervention programme rather continued with their daily activities. For motor proficiency, data was collected at three intervals: pre, post and post-post intervention. The Bruininks-Oseretsky Test of Motor Proficiency (BOTMP) was used to assess motor proficiency: fine and gross motor skills. For anthropometrical measures and health-related physical fitness, data was collected at two intervals: pre- and postintervention. The five health-related components of physical fitness were measured by the following: body composition, flexibility, muscular endurance, muscular strength and cardiovascular fitness. The experimental group showed significant improvements (p < 0.05) in the postintervention motor proficiency composite mean scores for balance and upper limb dexterity subtests whereas the control group did not exhibit significant improvements in any of their post-intervention composite mean scores. The experimental group also experienced an 11.62% significant improvement (p < 0.05) in their motor proficiency mean scores relative to the control group when the pre-intervention and the post-post intervention scores were compared. The low internal consistency and inter-item correlation of the Bruininks-Oseretsky Test of Motor Proficiency suggests that there are challenges with the reliability of the results. Thus, the results should be interpreted with viii caution. The experimental group also recorded significant improvements (p < 0.05) in the body composition, cardiovascular fitness and flexibility after a 10-week Zulu stick fighting intervention programme when post-intervention mean scores are compared adjusted for pre-intervention mean scores whereas no significant improvement in the post-intervention mean scores was recorded for the control group. It appears that the levels of motor proficiency and health-related physical fitness can be positively influenced through participating in traditional Zulu games such as Zulu stick fighting. It would seem the benefits derived from engaging in Zulu stick fighting may be the same as the one derived from doing any king of physical activity. It must be said though that the results of the motor proficiency in the current study can not be declared as useful data.
- ItemThe role of a biokinetics rehabilitation programme in alleviating anterior knee pain in adolescents(2007) Phillips, Jacqueline; Coetsee, M.F.Anterior knee pain is a common condition prevalent within the adolescent population and frequently interferes with sporting and routine activities. The condition is often self-limiting, but can take up to two years to resolve- Surgical intervention is not recommended in this population group, and often there is no demonstrable anatomical abnormality. Conservative treatment should always be the first approach. A questionnaire designed to determine the incidence of anterior knee pain among adolescents was distributed to various local schools, and was completed under the guidance of either a researcher or the parents. Results from the questionnaires indicate that 27.4% of adolescents who participated in the study had experienced non-traumatic anterior knee pain at some time between the ages of 10 and 17 years. Of this group, 42.9% was male and 57.1% was female. Subjects in the intervention section of the study followed a Biokinetics rehabilitation programme which aimed at stabilising the knee joint by stretching and strengthening the involved musculature and improving proprioception and dynamic stability of the lower limb. The programme resulted in significantly reduced subjective ratings of pain and disability in the experimental group (N=18) compared to the control group (N=12). This improvement in condition can be attributed to the increase in strength, flexibility, proprioception and dynamic balance components tested. The decrease in pain as indicated on a Visual Analogue Scale was in the range of 35.3 to 43.0% at the post- and post-post testing in comparison with the initial pain ratings (p<0.01). There was also significant improvement in the ability to perform activities indicated by individual subjects on the Patient-Specific Functional Scale (p<0.01). All subjects in the experimental group indicated improvement in their condition at the post-test. Most of the group reported that their condition was at least as good or better at the post-post test compared with the post-test. There was an increase of between 9.0 and 17.5% in muscle strength in both the quadriceps and hamstring muscle groups at the post- and post-post testing of the experimental group (p<0.01). There was a small but significant improvement of between 2.2 and 4.4% in quadriceps, hamstring and gastrocnemius flexibility of the experimental group at the post- and post-post testing (rxO.Ol). There was also a large significant improvement in both proprioception and dynamic balance of the experimental group at the post- and post-post testing (p<0.01), which is indicative of improved stability of the knee joint complex. Proprioception as measured on a wobbleboard improved by between 49.5 and 50.8%, and dynamic stability scores improved by 37.5 to 53.2% at the post and post-post testing (p<0.01). These variables improved as a consequence of the Biokinetics rehabilitation programme and were maintained or improved further at the one month follow up. In the context of South African health care, a structured Biokinetics rehabilitation programme based on sound clinical and scientific principles has the potential to endear positive outcomes in the treatment of anterior knee pain.