Thesis (MScSportSc)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: Postural deformities are a commonly encountered problem among children. Most of the aches and pains of adults are the result, not of injuries, but of the long-term effects of distortions in posture or alignment that have their origins in childhood or adolescence. Television, video entertainment, motorized transportation, fast food and lack of regular physical activity contribute to the poor physical condition of children. School screening for scoliosis is mandated in schools in 26 states of the United States (US) for children between 10 and 16 years of age. Previous studies conducted in the US found that 160 out of 1000 people suffer from scoliosis. This means that scoliosis is as prevalent as hypertension or diabetes mellitus (Boachie-Adjei & Lonner, 1996). Identification of postural deformities at an early stage makes early treatment possible, which may, in future, prevent serious postural abnormalities. The American Academy of Orthopedic Surgeons approved the implementation of screening programs in schools in 1974 (Lonstein, 1988). Few studies have included the entire musculoskeletal system. The purpose of this study was to determine the prevalence of postural deformities among children aged 11 to 13 years in selected primary schools in the Western Cape. The study also proposes to investigate factors that may influence the prevalence rate of postural deformities. These factors included age, gender, school district, weight, height, BMI (Body Mass Index), fat%, waist-hip ratio, and physical activity. Letters were sent to 15 primary schools within a 30km radius of Stellenbosch. This region included Stellenbosch, Strand, and Kuilsrivier. Four schools replied, giving permission to conduct the study at their schools. The sample (N=288, mean age=12.36, SD=0.92) consisted of 78 scholars from grade five; 104 scholars form grade six; and 106 scholars from grade seven. Of the total number of scholars examined (288), 154 were boys, and 134 were girls. Only children with parental consent were allowed to participate in the study. Anthropometric measures included stature, mass, skinfoids (two-site skinfoid), waist- and hip circumferences and trochanterion leg length. Level of physical activity and family history of deformities were obtained by means of a questionnaire. The New York Posture Test was used for postural evaluation (Bloomfield et aI., 1994:320; Reedeo Inc., 2001. This Posture Test was designed for the screening of 13 categories of deformities. Using a "see-through" posture grid, lateral and posterior examinations were performed. The "Adam's position" (forward bending) was used for further scoliosis evaluation. Quantitative data was analyzed, using Statistica (Statsoft, 2001) and classification tree methodology (Breiman et aI., 1993). The anthropometric results indicated that the subjects had a mean stature of 1.54m, mass of 47.48kg, BMI of 19.75, waist-hip ratio of 0.79 and fat% (Lohman, 1987) of 21.35%. The prevalence of postural deformities was as follows: Lordosis, 70%; Kyphosis, 57%; Uneven shoulders, 55%; Inclined trunk, 43%; Winged scapulae, 42%; Pronated feet, 30%; Flat feet, 30%; Flat chest, 29%; Forward head, 28%; Protruding abdomen, 28%; Uneven hips, 11%; Scoliosis, 10%; and Twisted head, 1%. Uneven hips, scoliosis and twisted head were not considered for statistical purposes, because of their low incidence compared to the other deformities. The factors that influenced the prevalence rate of deformities the most were BMI and fat%. A higher BMI and fat% resulted in a higher prevalence rate in most deformities. The prevalence rate of postural deformities in this study was considerably high. Sedentary lifestyles of children (watching television, computer games, junk food and physical inactivity) were a contributing factor in the high prevalence rate of postural deformities. It is known that overweight and sedentary behavior of children is increasing and this could pose an alarming concern to the health of a child. Also, if a significant correlation does exist between the prevalence of postural deformities and conditions such as back pain, the high prevalence rate reported in this study is a matter of concern. / AFRIKAANSE OPSOMMING: Postuurafwykings is "n algemene probleem wat dikwels onder kinders voorkom. Baie van die skete en pyne by volwassenes spruit nie uit beserings nie, maar vanuit langtermyn gevolge van swak postuur wat huloorsprong uit die kinderjare het. Televisie, videospeletjies, vervoer per motor, kitskos en gebrek aan fisieke aktiwiteit dra by tot die swak fisieke kondisie van kinders. Evalueringsprogramme in skole word in 26 state in die Verenigde State van Amerika (VSA) toegepas vir kinders tussen die ouderdomme van 10 en 16 jaar. Vorige studies in die VSA het getoon dat 160 uit 1000 mense skoliose het (Boachie-Adjei & Lonner, 1996). Dit beteken dat skoliose net so veel voorkom soos hipertensie of diabetes mellitus. Identifikasie van postuurafwykings op "n vroeë stadium maak vroeë behandeling moontlik, wat in die toekoms ernstige postuurafwykings kan voorkom. Die "American Academy of Orthopedie Surgeons" het reeds in 1974 die implementering van assesseringsprogramme goedgekeur (Lonstein, 1988). Volgens navorsing het slegs "n beperkte aantal studies die hele spierskeletale stelsel geëvalueer. Die doel van hierdie studie was om die voorkoms van postuurafwykings by kinders tussen die ouderdomme van 11 en 13 jaar in geselekteerde Wes-Kaapse skole te bepaal. Die studie het ook faktore wat "n invloed op die voorkoms van postuurafwykings kan hê, ingesluit. Hierdie faktore het onder andere ouderdom, geslag, skool, gewig, lengte, LMI (Liggaamsmassa-indeks), vet%, middel-heup-ratio en fisieke aktiwiteit ingesluit. Uitnodigingsbriewe is na 15 laerskole binne "n 30km radius vanaf Stellenbosch gestuur. Dit het ingesluit Stellenbosch, Strand, en Kuilsrivier. Vier skole het toestemming verleen om die studie by die betrokke skole te loods. Die steekproef (N=288, gemiddelde ouderdom = 12.36, SD=0.92) het bestaan uit 78 leerlinge uit graad vyf; 104 leerlinge uit graad ses en 106 leerlinge uit graad sewe. Uit die totale aantal leerlinge wat geëvalueer is, was daar 154 seuns en 134 dogters. Antropometriese metings het die volgende ingesluit: lengte, gewig, velvoue (twee-velvou meting), middel- en heupomtrekke en trochanterion beenlengte. Fisieke aktiwiteitsvlak en familiegeskiedenis van postuurafwykings is bepaal met behulp van "n vraelys. Die "New York Posture Tesf' is gebruik vir postuurevaluasie (Bloomfield et al., 1994:320; Reedco Inc., 2001). Hierdie toets is ontwerp vir die evaluering van 13 deformiteite. Die kinders is vanuit 'n posterior en anterior aansig ge-evalueer met behulp van 'n "deurskynende" postuurruitnet (grid). Die "Adam's-" toets (vooroorbuig-toets) is gebruik vir verdere evaluering van skoliose. Statistica (StatSoft, 2001) en klassifikasieboom-metodologie (Breiman et al., 1993) is gebruik vir statistiese ontleding. Die proefpersone het 'n gemiddelde lengte van 1.54m, gewig van 47.48kg, LMI van 19.75, middel-heup-ratio van 0.79 en vet% (Lohman, 1987) van 21.35% gehad. Die voorkoms van die onderskeie postuurafwykings was as volg: Lordose,70%; Kifose, 57%; Ongelyke skouers, 55%; Romp na posterior gebuig, 43%; Gevleuelde skapulas, 42%; Voetpronasie, 30%; Plat voete, 30%; Plat bors, 29%; Protraksie: skedel, 28%; Uitstaan buik, 28%; Ongelyke heupe, 11%; Skoliose, 10%; en Gekantelde hoof, 1%. Ongelyke heupe, skoliose en gekantelde hoof het minder voorgekom in vergelyking met die ander deformiteite, daarom is die deformiteite nie vir statistiese analise in aammerking gebring nie. LMI en vet% was die faktore wat die voorkoms van postuurafwykings die meeste beïnvloed het. 'n Hoër LMI en vet% het 'n toenemende voorkoms in meeste deformiteite veroorsaak. Die voorkoms van postuurafwyking in hierdie studie was hoog. Sedentêre leefwyses van kinders (TV, rekenaarspeletjies, gemorskos, en fisieke onaktiwiteit) het bygedra tot die hoë voorkoms. Die voorkoms van oorgewig en sedentêre leefwyses is besig om te verhoog by kinders en kan ernstige gevolge vir die gesondheid van die kind inhou. Indien daar 'n betekenisvolle korrelasie tussen die voorkoms van postuurafwykings en kondisies soos rugpyn is, dan blyk die hoë voorkoms, wat in hierdie studie gevind is, 'n bron van bekommernis te wees. Postuurevalueringsprogramme is 'n effektiewe metode vir die vroeë identifikasie van postuurafwykings, aangesien dit vroeë identifikasie en konserwatiewe behandeling moontlik maak.

Thesis (MScSportSc)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Physical activity is an integral part of children's lives. It makes an essential contribution to their physical, psychological and social well-being. Often, it is through movement and active play that children learn to discover themselves. This movement and play sometimes serves as a medium for communication. Unfortunately, various research studies show that children are not active enough and lead ever increasing sedentary lifestyles and these lifestyles lead to various types of hypo-kinetic diseases. Technology, as well as the phasing out of structured physical education in schools, are aspects that are responsible for the decrease in activity levels of children. The primary aim of this study was to determine if present-day children's (Grades 1 - 3) physical abilities have improved or worsened over the years. Movement tests from Katzenellenbogen (1976) were used to test movement abilities of these children. Adapted questionnaires from Van Deventer (1999) were used to construct the lifestyle patterns of learners and to get information concerning movement programmes from teachers at schools. The sample population (N=372) was selected from four schools (two previously disadvantaged and two former Model C schools) in the Stellenbosch area. The tests evaluated, inter alia the following, velocity, velocity and power, power, velocity and accuracy, accuracy and precision. Children from the previously disadvantaged and former Model C schools, as well as age and sex were compared. A comparison with the 1976 study of Katzenellebogen was also done. The latter study only involved girls and was undertaken only at White schools. The coding of the variable data was done in a computer format, coded and statistically analysed. Averages are compared through the Analyses of Variance (ANOVA). From the results of the study, it can be concluded that children at the former Model C schools fared better in most of the tests and it is evident that boys generally are more active than girls. As far as the comparison with the 1976 study is concerned, present-day girls fared worse in almost all the tests. The weight of the 9 year old girls increased by as much as 7.2 kg. This study can therefore be a starting point for further study attempting to combat the tendency of inactivity amongst the youth of today. / AFRIKAANSE OPSOMMING: Fisieke aktiwiteit is 'n integrale deel van kinders se lewens. Dit maak 'n essensiële bydrae tot hul fisieke, psigologiese en sosiale welstand. Dit is dikwels deur beweging en aktiewe spel wat kinders leer om hulself te ontdek. Hierdie beweging en spel dien ook soms as 'n medium vir kommunikasie. Ongelukkig toon verskeie navorsing dat kinders nie aktief genoeg is nie en al hoe meer sedentêre leefstyle handhaaf, wat lei tot allerhande hipokinetiese siektetoestande. Tegnologie, asook die uitfassering van gestruktureerde Liggaamlike Opvoeding in skole is aspekte wat verantwoordelik gehou word vir die afname in aktiwiteitsvlakke van kinders. Die primêre doel van hierdie studie was om te bepaal of hedendaagse kinders (Graad 1 tot 3) se bewegingsvermoëns oor die jare heen verbeter of verswak het. Bewegingstoetse uit Katzenellenbogen (1976) is gebruik om bewegingsvermoëns van die kinders te toets. Aangepaste vraelyste uit Van Deventer (1999) is gebruik om die leefstylpatrone van leerders vas te stel en om inligting aangaande bewegingsprogramme in die skole by onderwysers te bekom. Die proefpersone (N=372) is uit vier skole (twee voorheenbenadeelde [VB]- en twee voormalige Model-C [VMC]-skole) in die Stellenbosch omgewing geselekteer. Die toetse het die volgende veranderlikes gemeet: snelheid; snelheid en dryfkrag; dryfkrag; snelheid en akkuraatheid; akkuraatheid en presiesheid; getoets. Kinders van VB- en VMC-skole, ouderdomme en geslagte is met mekaar vergelyk. Daar is ook 'n vergelyking met die 1976-studie van Katzenellenbogen getref. Die 1976-studie van Katzenellenbogen het slegs dogters ingesluit en is slegs by Blanke skole onderneem. Die veranderlikes se datametings is in rekenaarformaat gekodeer en statisties verwerk. Gemiddeldes is vergelyk deur middel van analise van variansie (ANOVA). Uit die resultate van die studie kan tot die gevolgtrekking gekom word dat kinders by die VMC-skole beter in meeste van die toetse gevaar het en dit blyk ook dat seuns oor die algemeen meer aktief is as dogters. Wat die vergelyking met die 1976-studie betref, het hedendaagse dogters swakker gevaar in byna al die toetse. Die 9-jarige dogters het ook met soveel as 7.2 kg in gewig vermeerder. Hierdie studie kan dus as 'n beginpunt dien vir verdere studie in 'n poging om die tendens van onaktiwiteit onder vandag se jongmense te bekamp.

Dissertation (PhD)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: The present study was undertaken with the aim of developing and implementing a model for the rehabilitation of sports injuries. Injury is, without a doubt, one of the most significant obstacles to athletic performance. Very few, if any, athletes escape injury and it seems that regardless of experience and ability, all physically active individuals are prone to injury at some stage of their careers. The ability to resist injury and to rehabilitate well when injury does occur is fundamental to longevity in sport. Previous injury rehabilitation interventions commonly addressed only the physiological dimensions of injury, excluding the psychological dimensions. Only very recently has there been a shift in focus to include psychological principles in the treatment procedures, with Heil (1993) and Pargman (1993a) some of the first authors to publish works on the subject. A comprehensive literature review was done. In the first chapter attention was paid to the role of personality in injury occurrence and rehabilitation outcome, with special emphasis on the model of stress and athletic injury of Andersen and Williams (1993). An extension to this model, taking into account the role of personality, coping resources, cognitions, interventions and other injury and treatment related factors in the rehabilitation process was added by Grove (1993). The next chapter was devoted to the causes and stresses of sports injuries. Topics that were covered include the over-training syndrome, understanding injuries from the athlete's, physician's and psychologist's points of view and a study of what exactly the stresses involved in athletic injury are. Special attention was paid to the concept of pain and all its dimensions, the social well-being of the injured athlete and the impact of injury on the athlete's self-concept and identity. In the following chapter psychological adjustment to athletic injury was discussed. The concepts of loss and grief and applicability of grief response models in particular were discussed. In response to grief response models, cognitive appraisal models (Brewer, 1994) and an integrated model by Wiese-Bjomstal et al. (1998) were also discussed. Attention was given to the factors associated with rehabilitation adherence with particular remarks on malingering athletes. Peer modelling as a coping strategy in injury rehabilitation also came under scrutiny, as did the role and effect of social support. The next chapter focused on the development of the service-provider model for sports injury rehabilitation. From the initial literature review it was clear that of all the treatment providers involved with injured athletes, physiotherapists and biokineticians (athletic trainers) are probably those who spend the most time with them. In the development of the model for injury rehabilitation, special emphasis was therefore placed on the role of the physiotherapist and biokineticians. As a basis for developing the model, the traditional medical model was used, but it was adapted to incorporate psychological principles. A computer program was written to assist physiotherapists and biokineticians in treating injured athletes through the use of psychological principles. This program was constructed using psychological instruments that already exist, but they were adapted to be used as non-pen and paper tests. The tests used were the Emotional Responses of Athletes to Injury Questionnaire (ERAIQ), the Incredibly Short POMS (ISP), a Pain Drawing Instrument, a Visual Analogue Scale and the Affective subscale of the McGill Pain Questionnaire. Provision was made for handouts to be included in the program which can then be given to patients after each therapy session. To be able to determine whether the program was successful in assisting physiotherapists and biokineticians in their treatment of injured athletes, the program was evaluated in the next chapter. Feedback from both patients, physiotherapists and biokineticians using the program were received. Two short questionnaires were used for this purpose. Finally, conclusions were drawn from the information received from the program and recommendations based on these conclusions were made. Key words: Sports injuries, injury rehabilitation. / AFRIKAANSE OPSOMMING: Die doel van die huidige studie was die ontwikkeling en implementering van 'n model vir die rehabilitasie van sportbeserings. Beserings is, sonder twyfel, van die belangrikste struikelblokke in die weg van sportprestasie. Baie min, indien enige, atlete spring beserings vry. Dit wil ook voorkom of alle fisiek aktiewe individue, ongeag hulle ondervinding en vermoë, op een of ander stadium van hulle loopbane 'n besering opdoen. Fundamenteel aan volgehoue deelname aan sport, is die vermoë om beserings te vermy en om atlete suksesvol te rehabiliteer indien 'n besering welopgedoen word. In die verlede het rehabilitasie-intervensies hoofsaaklik die fisieke dimensies van beserings aangespreek sonder inagname van die sielkundige dimensies. Slegs on1angs het daar 'n klemverskuiwing begin plaasvind deurdat daar begin is om sielkundige beginsels in te sluit in behandelingsprosedures. Heil (1993) en Pargman (1993a) was van die eerste skrywers wat werke oor hierdie onderwerp gepubliseer het. 'n Uitgebreide literatuuroorsig is onderneem. In die eerste hoofstuk was aandag geskenk aan die rol wat persoon1ikheid speel in die voorkoms van beserings en die suksesvolle rehabilitasie daarvan, met spesiale klem op Andersen en Williams (1993) se model van stres en sportbeserings. Hierdie model is deur Grove (1993) uitgebrei deur inagname van die rol van persoon1ikheid, hanteringsvaardighede, kognisies, intervensies en ander beserings- en behandeling-verwante faktore in die rehabilitasieproses. Die volgende hoofstuk was gewy aan die oorsake van, en die stres verbonde aan, beserings. Onderwerpe wat aangespreek is, het ingesluit die ooroefeningsindroom, begrip van beserings soos gesien vanuit die atleet, medikus en sielkundige se oogpunte, asook presies watter faktore stres tydens beserings veroorsaak. Spesiale aandag is aan die konsep van pyn en al sy dimensies, die sosiale welstand van die beseerde atleet en die impak van beserings op die selfkonsep en identiteit van die atleet geskenk. In die volgende hoofstuk is die sielkundige aanpassing by beserings bespreek. Die konsepte van "verlies" en ''rou'' en die toepaslikheid van rouresponsmodelle in besonder, is bespreek. In antwoord op rou responsmodelle is kognitiewe waarderingsmodelle (Brewer, 1994) en die geïntegreerde model van Wiese-Bjornstal et al. (1998) bespreek. Aandag is ook geskenk aan faktore wat 'n rol in volgehoue deelname aan rehabilitasieprosedures speel, met klem op atlete met skynsiektes. Navolging van voorbeelde deur eweknieë as 'n hanteringsvaardigheid is ondersoek, asook die rol en effek van sosiale ondersteuning. Die volgende hoofstuk het gefokus op die ontwikkeling van die diensleweraar-model vir sportbeseringrehabilitasie. Vanuit die aanvanklike literatuuroorsig het dit geblyk dat van al die persone betrokke by die behandeling van beseerde atlete, dit waarskynlik fisioterapeute en biokinetici is wat die langste by hulle betrokke is. Tydens die ontwikkeling van die model vir rehabilitasie van beserings, is as basis die tradisionele mediese model gebruik, maar met sekere aanpassings om sielkundige beginsels in te sluit. 'n Rekenaarprogram is geskryf om fisioterapeute en biokinetici te ondersteun in die behandeling van beseerde atlete. Die program het gebruik gemaak van bestaande psigometriese toetse, maar dit was aangepas om as nie-potlood-en-papiertoetse gebruik te kan word. Die toetse wat gebruik is, is die Emotional Responses of Athletes to Injury Questionnaire (ERAIQ), die Incredibly Short POMS (ISP), 'n pyntekeninginstrument, 'n visueelanaloogskaal en die affektiewe subskaal van die McGill Pain Questionnaire. Voorsiening is gemaak na afloop van elke behandelingsessie om uitdeelstukke aan pasiënte beskikbaar te stel. Om te bepaal of die program suksesvol was om fisioterapeute en biokinetici tydens behandeling van beseerde atlete te ondersteun, is die program in die volgende hoofstuk kortliks geëvalueer. Terugvoer vanaf beide die pasiënte, fisioterapeute en biokinetici wat die program gebruik het, is verkry. Twee kort vraelyste is vir dié doel gebruik. Laastens is gevolgtrekkings op grond van die terugvoer gemaak en aanbevelings vir aanpassings is gedoen. Sleutelwoorde: Sportbeserings, rehabilitasie

The tibialis anterior (TA) muscle plays a vital role in human movement such as walking and running. Overuse of TA during these movements leads to an increased susceptibility of injuries e.g. chronic exertional compartment syndrome. TA activation has been shown to be affected by increases in exercise, age, and the external environment (i.e. incline and footwear). Because activation parameters of TA change with condition, it leads to the interpretation that force changes occur too. However,activation is only an approximate indicator of force output of a muscle. Therefore, the overall aim of this thesis was to investigate the parameters affecting accurate measure of TA force, leading to development of a subject-specific EMG-driven model, which takes into consideration specific methodological issues. The first study investigated the reasons why the tendon excursion and geometric method differ so vastly in terms of estimation of TA moment arm. Tendon length changes during the tendon excursion method, and location of the TA line of action and irregularities between talus and foot rotations during the geometric method, were found to affect the accuracy of TA moment arm measurement. A novel, more valid, method was proposed. The second study investigated the errors associated with methods used to account for plantar flexor antagonist co-contraction. A new approach was presented and shown to be, at worse, equivalent to current methods, but allows for accounting throughout the complete range of motion. The final study utilised the outputs from studies one and two to directly measure TA force in vivo. This was used to develop, and validate, an EMG-driven TA force model. Less error was found in the accuracy of estimating TA force when the contractile component length changes were modelled using the ankle, as opposed to the muscle. Overall, these findings increase our understanding of not only the mechanics associated with TA and the ankle, but also improves our ability to accurately monitor these.

Thesis (PhD (Sport Sc)) -- University of Stellenbosch, 2004. / ENGLISH ABSTRACT: This study investigated the effects of a relaxation, self-talk, goal-setting, imagery, and concentration training package on the performance of six athletes in the 1500- meter event. Subjects were four female and two male high school middle distance athletes. The dependent measure was time taken to complete the 1500-meter nm in competition settings. A mental skills training package was developed, implemented and evaluated using a single subject, multiple baseline design. Performance scores were plotted for each 1500-meter nm and subjects' graphs were assessed for intervention-related change against mean performance change and established split-middle analysis criteria. Visual inspection of plotted values was supplemented by quantitive analysis using repeated measures analysis of variance (RANOV A). This study also included procedural reliability checks to ensure that the athletes did in filet utilize the mental skills they received training in. Visual analysis indicated the mental skills package to be effective in enhancing performance times (1500-meter) in the case of four of the athletes. Overall, repeated measures analysis of variance revealed significant improvement in 1500- meter performance times for subjects across phases. However, a split-middle analysis of within subject variation indicated that a significant intervention effect was not observed in two of the six subjects. The social validity assessment by athletes and their two coaches provided further confirmation of the overall effectiveness of the intervention. Social validation checks indicated all participants to have perceived the intervention to be successful and all were satisfied with the delivery and content of the training package. The results support the usefulness of single-subject research designs for assessing the impact of mental training. The present study demonstrated that a mental skills training package combining relaxation, self-ta1k, goal setting, imagery, and concentration skills was effective in enhancing athletic performance. / AFRIKAANSE OPSOMMING: Die effek van "n sportsielkundige opleidingspakket, bestaande uit ontspanningsvaardighede, effektiewe selfspraak, doelwitstelling, beelding en konsentrasievaardighede op die prestasie van sportlui in die 1500-meter wedloop, is in die onderhawige navorsing ondersoek. Die proefpersone wat aan die navorsingprojek deelgeneem het, was vier vroulike en twee manlike hoërskool middelafstand-atlete. Die afhanklike veranderlike is gedefinieer as die tyd wat dit elke proefpersoon neem om die 1500-meter wedloop in kompetisie-situasies te voltooi. 'n Sportsielkundige opleidingspakket is ontwikkel, geïmplementeer en die effek daarvan op prestasietyd is geëvalueer deur gebruik te maak van "n enkelproefpersoon-, meervoudige basislynontwerp oor individue. Wedlooptyd in die 1500- meter is graftes ten opsigte van elke proefpersoon voorgestel en volgens kriteria vir visuele inspeksie en die "split-middle" -tegniek geanaliseer. Visuele analise van die data is deur middel van kwantitatiewe herhaalde waameming;analise van die variansie uitgebrei. Die ondersoek het ook kontrole vir prosedurelebetroubaarheid ingesluit om te verseker dat die betrokke sportsielkundige vaardighede waarin proefpersone opgelei is, inderdaad deur hul gebruik word Visuele analise van die navorsingdata het aangedui dat die sportsielkundige opleidingsprogram wel effektiefwas om presf.asietyd (l500-meter) by vier van die ses atlete te verbeter. Die herhaalde waamemingsanalise van die variansie het oor die algemeen beduidende verbetering in presf.asietyd in die 1500-meter vir proefpersone vanaf die basislyn:fase na die intervensiefase aangetoon. "n "Split-miádle" analise van intra-proefpersoon variasie het egter aangedui dat "n beduidende intervensie-effek nie by twee van die ses proefpersone waargeneem kon word nie. 'n Gunstige sosiale validering is van die betrokke proefpersone en hul afrigters ontvang wat verdere bevestiging bied vir die effektiwiteit van die intervensie oor die algemeen. Resultate met betrekking tot die sosiale validering het aangedui dat al die deelnemers by die navorsingprojek die intervensie as suksesvol beskou het en tevrede was met die toepassing en inhoud van die opleidingspakket. In die onderhawige ondersoek is aangedui dat "n sportsielkundige opleidingsprogram wat ontspanningsvaardighede, selfspraak, doelwitstelling, beelding en konsentrasievaardighede kombineer, weloor die algemeen effektief was om sportlui se prestasie te verbeter.

The majority of previous research investigating the role of vision in controlling adaptive gait has predominantly focused on over-ground walking or obstacle negotiation. Thus there is a paucity of literature investigating visuomotor control of step descent. This thesis addressed the importance of the lower visual field (lvf) in regulating step descent landing control, and determined when visual feedback is typically used in regulating landing control prior to/during step descent. When step descents were completed from a stationary starting position, with the lvf occluded or degraded, participants adapted their stepping strategy in a manner consistent with being uncertain regarding the precise location of the foot/lower leg relative to the floor. However, these changes in landing control under conditions of lvf occlusion were made without fundamentally altering stepping strategy. This suggests that participants were able to plan the general stepping strategy when only upper visual field cues were available. When lvf was occluded from either 2 or 1 step(s) prior to descending a step during on-going gait, stepping strategy was only affected when the lvf was occluded in the penultimate step. Findings suggest that lvf cues are acquired in the penultimate step/few seconds prior to descent and provide exproprioceptive information of the foot/lower leg relative to the floor which ensures landing is regulated with increased certainty. Findings also highlight the subtle role of online vision used in the latter portion of step descent to 'fine tune' landing control.

This thesis addresses the hypothesis that a single, waist-mounted triaxial accelerometer (TA) can be used to monitor human movement patterns in unsupervised, freeliving subjects over extended periods, and that it can be used to quantitatively measure parameters that can provide clinical insight into the health status of the subject. A rigorous theoretical and experimental understanding of the signals obtained from a TA is developed. The effect of the placement of the TA device on the waist is explored and a model relating device position to TA signal is developed for a range of postures and activities. A classification framework for movement identification using the signals from a waist-mounted TA is presented. This framework is based on a hierarchical binary processing tree and is designed for real time use. An implementation of this framework for monitoring housebound patients is presented. Algorithms for detecting falls, distinguishing between activity and rest, classifiying transitions between different postural orientations, and for identifying periods of standing, sitting, lying and walking are developed. In evaluation studies performed in controlled laboratory conditions, every algorithm performed with better than 90% accuracy. Once movements are identified, movement-specific parameters sensitive to changes in functional status are extracted from the signal. A two stage methodology for employing the accelerometry system in monitoring free-living subjects is introduced. The first stage involved monitoring specific movements through a directed routine. The second stage involved monitoring of free movement. Signals obtained from the directed routine are used to extract clinically relevant, movement-specific parameters. Signals obtained from the period of free movement are monitored for falls and other abnormal events. General parameters of movement, including energy expenditure, are also measured. The system was evaluated in a series of field studies in laboratory and home environments, in supervised and unsupervised settings, using cohorts of healthy subjects. A pilot trial was conducted in which six healthy elderly subjects wore the TA device for a period of up to three months. The technical performance and useability of the system were evaluated. Clinically significant parameters were measured and the effects of age and health status on the measured parameters were evaluated.

The desire to age well is a common goal among the human population. How to do so is therefore, a popular question. One theory of ageing involves the accumulation of damage to mitochondrial protein and the subsequent loss of function the damage causes. Increasing the rate of mitochondrial protein synthesis, a variable that declines with advancing age, is one way to improve quality of life in the twilight years. A review of literature lead to a multi-level approach, with measurements of protein synthesis made at the whole body, muscle, and molecular levels. An acute bout of aerobic exercise, followed by feeding, two factors which have a positive effect on the rate of mitochondrial protein synthesis, was used. Adaptations to a period of exercise training are mediated by the accumulation of proteins due to each acute exercise bout, and so an acute intervention was postulated to be indicative of changes expected over the long term. A stable isotope infusion combined with sampling of breath, blood, and muscle was used to determine the rate of whole body protein synthesis in 12 older adults. Intracellular signalling for mitochondrial and whole body protein synthesis was examined using RT-quantitative PCR and Western blotting in eleven young adults. The rate of post-exercise whole body protein synthesis was 19% greater over the first four hours of post-exercise recovery, in subjects receiving a protein-plus-carbohydrate drink immediately after a bout of cycling than in those receiving a carbohydrate-only drink (p = 0.001). The same trend was revealed in signalling for whole body protein synthesis and the abundance of cytochrome c, a mitochondrial protein, although these results were not statistically significant (p = 0.2). In contrast there was a strong, albeit also statistically insignificant, tendency for signalling for mitochondrial protein synthesis to be higher in the skeletal muscle of subjects receiving a carbohydrate-only drink after a bout of cycling (p = 0.06). The exercise and feeding intervention described in this thesis may provide a means to enhance the rate of mitochondrial protein synthesis in older individuals and, in so doing, improve the quality of their old age.

No description available.

The desire to age well is a common goal among the human population. How to do so is therefore, a popular question. One theory of ageing involves the accumulation of damage to mitochondrial protein and the subsequent loss of function the damage causes. Increasing the rate of mitochondrial protein synthesis, a variable that declines with advancing age, is one way to improve quality of life in the twilight years. A review of literature lead to a multi-level approach, with measurements of protein synthesis made at the whole body, muscle, and molecular levels. An acute bout of aerobic exercise, followed by feeding, two factors which have a positive effect on the rate of mitochondrial protein synthesis, was used. Adaptations to a period of exercise training are mediated by the accumulation of proteins due to each acute exercise bout, and so an acute intervention was postulated to be indicative of changes expected over the long term. A stable isotope infusion combined with sampling of breath, blood, and muscle was used to determine the rate of whole body protein synthesis in 12 older adults. Intracellular signalling for mitochondrial and whole body protein synthesis was examined using RT-quantitative PCR and Western blotting in eleven young adults. The rate of post-exercise whole body protein synthesis was 19% greater over the first four hours of post-exercise recovery, in subjects receiving a protein-plus-carbohydrate drink immediately after a bout of cycling than in those receiving a carbohydrate-only drink (p = 0.001). The same trend was revealed in signalling for whole body protein synthesis and the abundance of cytochrome c, a mitochondrial protein, although these results were not statistically significant (p = 0.2). In contrast there was a strong, albeit also statistically insignificant, tendency for signalling for mitochondrial protein synthesis to be higher in the skeletal muscle of subjects receiving a carbohydrate-only drink after a bout of cycling (p = 0.06). The exercise and feeding intervention described in this thesis may provide a means to enhance the rate of mitochondrial protein synthesis in older individuals and, in so doing, improve the quality of their old age.