Thesis (MA)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: In 1994 the Durban College of Education, that used to be an all white Afrikaans-medium institution, changed to a multicultural institution with Afrikaans and English as medium of instruction. The author, other lecturers and teachers of all races have not been educated to teach from a multicultural perspective and due to stereotyping and prejudices which were still dormant, a great need arose to address the cultural diversity of the college. This diversity lead to differences in culture, which lead to conflicts and may even have been responsible for poor academic achievements. As a lecturer at the Durban College of Education, the author became interested in whether selected initiative and cultural activities could foster a positive self-concept and a positive attitude towards other students of the same ethnic group, as well as towards students of other ethnic groups. The author agreed with De Klerk and Labuschagne (1995) that cultural differences have a great impact on the life, personal development and academic achievements of the students at a multicultural institution of higher education. The author also believes that students should be guided (Wasserman, 1997) in how to perceive themselves and other students of all ethnic groups. This will assist them. to achieve a successful academic career (Greyling, 1997) without wrong perceptions, stereotyping and prejudices (Van der Walt, 1991). The subjects for this study (N=127) were all first year students at the Durban College of Education. The group was comprised of black students (n=24); white English speaking students (n=58); white Afrikaans-speaking students (n=34) and Indian students (n=11) (see table 3 page 43). A pre-test was administered to determine the initial status of the subjects. An intervention programme followed and a post-test was administered directly after the intervention programme (see chapter 4). A follow-up test was administered three months later to determine the influence of the daily college routine on the self-concept and attitude towards ethnicity of the subjects. A control group (N=30) also completed the three questionnaires. The control group did not follow the intervention programme. Adolescent Sport Self-concept Scale of Smith (in Paterson 1991) and an ethnic attitude scale, was administered. The ethnic attitude scale was based on the ethnic attitude scales used by Paterson (1991) and Pretorius (1978). This ethnic attitude scale was adapted to adhere to the needs of this study. The data were computerised; at-test statistic and a Duncan's multiple range test were applied to determine if there were significant differences. By comparing the results of the experimental group with that of the control group, it was evident that after the intervention programme, there was a significant positive change (p<O.01) not only in the self-concept of the first year students, but also in the attitude of these students towards students of the same ethnic group, as well as towards students of other ethnic groups. The same results were evident after the three-month period in which no special treatment had been administered. To ensure similar positive effects in the future, a follow-up programme, similar to the intervention programme, would be necessary. The intervention programme accordingly served its purpose as part of the orientation programme well. There are, however, many changes to be made to suit the needs and requirements of other institutions that would wish to use similar programmes. The dynamic interaction of energetic facilitators is essential. If possible, the facilitators should come from the student body to create more interaction within the student community. / AFRIKAANSE OPSOMMING: Die Durbanse Onderwyskollege wat voorheen 'n inrigting vir Afrikaanssprekende blankes was, het in 1994 na 'n multikulturele inrigting verander met beide Afrikaans en Engels as voertale. Die skrywer, baie ander dosente en onderwysers van alle rasse is tans nog nie geskool om vanuit multikulturele perspektiewe te onderrig nie. 'n Groot behoefte het ontstaan om die kulturele diversiteit van die kollege aan te spreek aangesien stereotipering en vooroordele nog steeds onder die studente voorgekom het. As 'n dosent aan die Durbanse Onderwyskollege, het die skrywer gewonder of uitgesoekte inisiatiewe en kulturele aktiwiteite 'n positiewe verandering in die houding van die eerstejaarstudente teenoor die self, teenoor studente van dieselfde etniese groep, sowel as studente van ander etniese groepe sal hê. Die skrywer stem saam met De Klerk en Labuschagne (1995) dat kulturele verskille 'n groot uitwerking op die lewe, persoonlike ontwikkeling en akademiese prestasie van studente het. Hy glo ook dat studente gelei moet word (Wasserman, 1997) in hul beskouing van hulself en studente van alle rasse, sodat hul akademiese loopbaan nie skade moet lei onder verkeerde persepsies, stereotipering en vooroordele nie. Hierdie verskille kan ly tot swak akamiese prestasies (Greyling, 1997) en kulturele konflik (Van der Walt, 1991). 'n Voortoets is afgeneem om die aanvanklike houding van die proefpersone te bepaal. Die proefpersone van die eksperimentele groep het onmiddellik na die voortoets 'n intervensieprogram gevolg. Direk na die intervensieprogram is In natoets afgeneem om die invloed van die intervensieprogram te bepaal. 'n Verdere opvolgtoets is drie maande na die intervensieprogram afgeneem om te bepaal hoe blywend die veranderde houding van die proefpersone was. Die - proefpersone (N=127) was almal eerstejaarstudente aan die Durbanse Onderwyskollege en het bestaan uit; swart studente (n=24), blanke (Engelssprekende) studente (n=58), blanke (Afrikaanssprekende) studente (n=34) en Indiër studente (n=11). 'n Kontrole groep (N=30) het ook die drie toetse afgelê. Hulle het nie die intervensieprogram gevolg nie. Die toetse was in die vorm van 'n vraelys wat gebaseer is op die Selfkonsepskaal van Coopersmith (1967) asook die Adolesente Sport-selfkonsepskaal van Smit (in Paterson, 1991). Die vraelys het ook 'n aangepaste etniese houdingskaal ingesluit wat op die vraelyste van Paterson (1991) en Pretorius (1978) gebaseer is. Hierdie houdingskaal is spesiaal aangepas om aan die spesifieke behoeftes van hierdie studie te voldoen. Die data is deur 'n rekenaar verwerk. 'n T-toets en Duncan se veelvuldige omvangtoets is aangewend om enige beduidende verskille te bepaal. Deur die resultate van die eksperimentele met die resultate van die kontrole groep te vergelyk, het aan die lig gekom dat daar 'n beduidende (p<O.01) positiewe verandering in die selfkonsep, en in die houding teenoor etnisiteit van die proefpersone in die eksperimentele groep was. Die positiewe verandering was na die drie-maandetydperk na die intervensieprogram nog steeds sigbaar. Na aanleiding van die resultate van hierdie studie, het die program sy doel as deel van die oriëntasieprogram van die eerstejaarstudente aan die Durbanse Onderwyserskollege gedien. Daar behoort egter baie veranderinge aangebring te word ten einde die program te verbeter, sou enige ander inrigtings soortgelyke programme wil gebruik. Eie inisiatiewe en kulturele aktiwiteite moet gebruik word om aan hulle spesifieke behoeftes te voldoen. Die sukses van so 'n program sal van die dinamiese en energieke aanbieding van die fasiliteerders afhang. Die fasiliteerders moet verkieslik vanuit die studente leierskorps kom om sodoende die verhouding in die studentegemeenskap te versterk.

Thesis (PhD (Education )--University of Stellenbosch, 2003. / 355 leaves printed on single pages, preliminary pages i- xxiii and numbered pages 1-330. Includes bibliography and list of tables. Digitized at 600 dpi grayscale to pdf format (OCR), using a Bizhub 250 Konica Minolta Scanner. / ENGLISH ABSTRACT: The sporting environment in South Africa started changing drastically when professional sport increasingly became a reality after years of sporting isolation. As a result of these changes new career opportunities opened up because professionals were required to manage professional sport. These new professional sporting organisations are modelled on economically active businesses that require managers at all levels. Training institutions soon started offering programmes to train these so-called sports managers. Although there are specialists working in the sporting environment, the generic term "sports manager" is used to identify these individuals. The appropriate and sustainable training of sports managers forms the nucleus of the research in this study. Training programmes for sports managers are mostly offered at departments of human movement studies or sports science. This tended to create the impression that these training programmes are merely adapted human movement studies programmes that do not necessarily make provision for the professional sports management industry. The main purpose of this study was to design a curriculum framework for sport management training that is not only practice-oriented, but that also ensures sustainable programmes. To realise this, both an international and a national historical perspective on sport management training were researched. A description of a theoretical curriculum model with specific reference to current trends in education in South Africa was given. Furthermore it endeavoured to establish, from within the sporting industry, the knowledge and skills that are required for a career in sports management. From this information an attempt was made to suggest a curriculum framework so that appropriate and sustainable sports management training programmes can be offered. From a historical survey it became evident that sports management training programmes are in a relatively early development phase. An analysis of international programmes revealed that these programmes focus mainly on the economic and management activities in sports management organisations. Few instances were found where human movement studies constituted a prominent part of the contents of the programmes. However, the opposite was found to be true when South African programmes were reviewed. The majority of these programmes include components of human movement studies/sport science in their contents. Some of the programmes focus specifically on human movement studies/sport science and merely offer introductory modules on aspects of sports management. This study indicates the necessity for sports management training programmes in higher education to fit into specific structures in the South African education framework. New developments centred around the South African Qualifications Authority, the Higher Education Board and more specifically the National Qualifications Framework have been researched and applied to sports management training programmes. To place this study within the perspective of curriculum development, various models and methods of curriculum evaluation were explored. As a result of this a synoptic list was compiled to which sports management programmes may be required to comply. As part of the study a questionnaire review was conducted to indicate sports managers' knowledge and skills requirements in three levels of management. Guidelines were derived from this for generic contents of sports management programmes. It was also indicated that specialist functions exist within the sports management industry and that this phenomenon cannot merely be ignored by academic institutions when curricula are designed. These findings were used to suggest a possible framework for sports management curricula. In the light of a changing environment in South Africa and the development of the professional sports management industry, it is necessary that this framework should continuously be supplemented in a dynamic sporting environment. / AFRIKAANSE OPSOMMING: Die sportbedryf het in Suid-Afrika drasties begin verander toe beroepsport na jare van sportisolasie toenemend 'n werklikheid geword het. Uit hierdie veranderinge het daar nuwe beroepsmoontlikhede ontstaan deurdat professionele persone nodig was om professionele sport te bestuur. Hierdie nuwe professionele sportorganisasies is op die lees van ekonomies-aktiewe besighede geskoei wat beteken dat bestuurders op aile vlakke benodig is. Opleidingsinstellings het spoedig begin om programme aan te bied vir die opleiding van hierdie sogenaamde sportbestuurders. Alhoewel daar 'n verskeidenheid spesialiste in die sportomgewing werk, word die generiese term "sportbestuurder" gebruik om hierdie persone te identifiseer. Die toepaslike en volhoubare opleiding van sportbestuurders vorm die kern van ondersoek in hierdie studie. Opleidingsprogramme vir sportbestuuropleiding word meestal in departemente van menslike bewegingskunde of sportwetenskap aangebied, wat die vermoede laat ontstaan het dat hierdie programme slegs aangepaste menslike bewegingskundeprogramme is en nie noodwendig vir die volle spektrum van behoeftes van die professionele sportbestuurbedryf voorsiening maak nie. Die hoofdoel van hierdie studie was die daarstelling van 'n kurrikulumraamwerk vir sportbestuuropleiding wat nie net praktykgerig is nie, maar ook die volhoubaarheid van hierdie programme verseker. Om dit te verwesenlik, is daar gepoog om 'n internasionale en nasionale historiese perspektief oor sportbestuuropleiding daar te stel. 'n Teoretiese kurrikulummodel is beskryf met spesifieke verwysing na huidige onderwystendense in Suid-Afrika. Vervolgens is gepoog om vanuit die sportbedryf te bepaal wat die kennis- en vaardigheidsvereistes is wat die sportbestuurberoep aan individue stel. Uit hierdie gegewens is gepoog om 'n kurrikulumraamwerk te ontwerp ten einde 'n bydrae te maak tot die volhoubare en toepaslike voorsiening van sportbestuuropleiding. Uit 'n historiese oorsig het dit geblyk dat sportbestuuropleidingsprogramme in 'n relatief vroeë ontwikkelingsfase verkeer. Wat uit die ontleding van internasionale programme duidelik geblyk het, is dat hierdie programme veral op die ekonomiese en bestuursaktiwiteite van sportbestuurorganisasies gefokus is. Min gevalle is aangetref waar menslike bewegingskunde 'n prominente deel van die programinhoud uitmaak. Daar is egter bevind dat die teendeel grootliks waar is van programme in Suid-Afrika. Die meerderheid van die programme het wel komponente van menslike bewegingskunde/sportwetenskap as deel van die inhoud. Sommige programme fokus spesifiek op menslike bewegingskunde/sportwetenskap en bied sportbestuuraspekte slegs as inleidende modules aan. Die studie toon aan dat dit noodsaaklik is om sportbestuuropleidingsprogramme in hoër onderwys binne spesifieke strukture in die Suid-Afrikaanse opvoedingsraamwerk in te pas. Ontwikkelinge rondom die Suid-Afrikaanse Kwalifikasie-owerheid, die Hoër Onderwysraad en meer spesifiek die Nasionale Kwalifikasieraamwerk is ondersoek in die lig van moontlike toepassings op sportbestuurprogramme. Om die studie binne die perspektief van kurrikulumontwikkeling te plaas, is ondersoek ingestel na verskillende modelle en metodes van kurrikulumevaluering. Hieruit is 'n oorsiglys waaraan sportbestuurprogramme moontlik beoordeel kan word, saamgestel. 'n Vraelysondersoek is benut ten einde kennis- en vaardigheidsvereistes van sportbestuurders op drie bestuursvlakke aan te toon. Riglyne ten opsigte van generiese inhoude vir sportbestuurprogramme is hieruit verkry. Daar is ook aangetoon dat spesialisfunksies binne die sportbestuurbedryf bestaan en dat hierdie verskynsel tydens kurrikulumontwerp nie sonder meer deur akademiese instellings geignoreer kan word nie. Hierdie bevindinge is gebruik om 'n moontlike raamwerk vir sportbestuurkurrikula voor te stel. In die lig van 'n veranderende samelewing in Suid-Afrika en die ontwikkeling van die professionele sportbestuurbedryf is dit noodsaaklik dat hierdie raamwerk in 'n dinamiese sportomgewing voortdurend aangevul word.

The aim of this graduation thesis was to find out the level of motor skills in younger school age children, namely in the group of 7-10 years, using the standardized test battery MABC-2 (Movement Assessment Battery for Children-2nd Edition) at our chosen primary school. 62 children participated in the testing, of which 34 were girls and 28 were boys. We tested three components - gross motor skills, fine motor skills and balance. After evaluating all three components, we compared both sexes with each other. The results showed that all 62 children (100%) did not show any motor difficulties and ranked in the 1st zone. However, in a more detailed examination of the sub-components, we encountered problems with aiming & catching (coarse motoring). There were six children who were diagnosed with the risk of developing motor problems with recommendations for further monitoring (2nd band). In the same component, there were even 9 children who had significant motor difficulties with recommendation for specialized examinations (3rd band).

Made available in DSpace on 2016-04-28T20:56:38Z (GMT). No. of bitstreams: 1 Marcia de Oliveira Pasetto Lebkuchen.pdf: 950362 bytes, checksum: ac61498a91567adff4f38923284ba3dd (MD5) Previous issue date: 2013-06-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The general purpose of this research is to comprehend how the student s body is meant by the teachers from the public network in São Paulo. To do so, the paper found theoretical basement in the Socio-Historical assumptions in which recommend an analysis and interpretation processes must overcome appearances and in a dialectic way, under the light of information about life history, institutional and social conditions of the subject, broadening the discussion and understanding the phenomena genesis. The main matter directs itself to make the individual, from its social environment, becomes human. The main papers on the area, concerning the project, are the research based on Lev S. Vigotski and his followers, who defend the idea of a continuous interaction between social and historical, which is mutable, and the relation with the biological basis of the human behavior. Starting from the body, elementary organic structure and depending on the social experiences to which the individual is exposed, complex mental functions appear, the so-called higher mental functions. Although there is a series of publications and papers in the Socio-Historical area, there are few researches on Education about the significance of the teacher concerning the student s body. This research tried to fill in the gap, supported by the Socio-Historical approach, broadening the debates about the importance of the body during the learning process. Besides the Socio-Historical assumptions, the project was also based on the Human Movement Science. There are many papers concerning Movement and Corporality, such as the ones presented by Sérgio (1994), Kolyniak (2001), Negrão (2008) and Melani (2006). In spite of this, only Carlini s work (1993) focused on the problem of teacher formation to constitute body conception to students, as proposed here. Thus, the project tried to make an original contribution to the study of constitutive aspects in the professional teacher formation and the educational practice in school, broadening Carlini s proposal (1993) and adding Human Movement studies. The main question proposed by the research were the following: (1) How does the teacher plan the given activities considering the student s body? And some specifics questions are: (2) What is the space available in the school environment to develop body activities? (3) Is the school environment appropriate for the development of Human Movement? It is expected that this paper contributed for Educational Psychology by showing results that indicated that the student s body is not meant effectively and considered an important learning language. The paper still presents and discusses the limitations of the research and possible future studies, besides suggestions of pedagogical approaches of its results / O objetivo geral desta pesquisa foi o de compreender como o corpo do aluno é significado pelos docentes da Rede Pública na cidade de São Paulo. Para tanto, o trabalho encontrou suporte teórico nos pressupostos da linha Sócio-Histórica por preconizar um processo de análise e interpretação dialético e profundo considerando a história de vida e as condições institucionais e sociais do sujeito de modo a ampliar a discussão e compreensão da gênese do fenômeno. Particularmente, o trabalho fundamentou-se na área de pesquisa que se estrutura por meio de uma abordagem Sócio-Histórica Aguiar (2006). A questão central dessa área se dá por entendermos que o indivíduo se tornar humano a partir do social em que está inserido, ou seja, dele se humanizar. Os trabalhos centrais da área, com relevância para o projeto, são as pesquisas baseadas em Lev S. Vigotski e seus seguidores por defenderem a ideia de contínua interação entre social e histórico, que é mutável, e a relação com a base biológica do comportamento humano. Partindo do corpo, estrutura orgânica elementar e dependendo das experiências sociais a que é exposto se formam complexas funções mentais, as chamadas funções mentais superiores. Embora haja uma série de publicações e trabalhos na área Sócio-Histórica, há poucas pesquisas em Educação sobre as significações do docente em relação ao corpo de seus alunos. Esta pesquisa buscou atender essa demanda na medida em que, apoiada na abordagem Sócio-Histórica, objetivou ampliar os debates sobre a importância do corpo no momento de aprendizagem. Além desses pressupostos, o projeto fundamentou-se na Motricidade Humana. Há vários trabalhos que lidam com a questão da Motricidade e Corporalidade, tais como os apresentados por Sérgio (1994), Kolyniak (2001), Negrão (2008) e Melani (2006). Entretanto, apenas o trabalho de Carlini (1993) enfocou o problema da formação dos educadores para constituir a concepção do corpo dos educandos, conforme proposto aqui. Dessa forma, acreditamos que este projeto tenha contribuído com os estudos sobre os aspectos constitutivos da formação profissional docente e a prática educativa do cotidiano escolar, na medida em que amplia a proposta de Carlini (1993) e acrescenta os estudos de Motricidade Humana. Nossas questões de pesquisa foram concebidas em geral e as questões específicas, são elas: A questão geral é: (1) Como o corpo do aluno é percebido no cotidiano escolar? As questões específicas são: (2) Como o professor planeja ou não as atividades realizadas com o aluno considerando seu Corpo? (3) O ambiente escolar é adequado ou não ao desenvolvimento mediado pela Motricidade Humana considerando o espaço educativo? Os dados coletados revelaram que a Corporalidade do discente não é significada de maneira efetiva pelo docente quando, nem mesmo quando esse planeja as atividades que fará com seu aluno e, ainda, que ela não é considerada como uma linguagem importante à aprendizagem. No momento de nosso trabalho não encontramos nenhum trabalho nessa área desse modo e esperamos que nosso trabalho seja uma contribuição útil è reprodução de novos estudos no futuro que superem as limitações que encontramos nesta pesquisa

The aim of this study was to measure the degree of dehydration experienced during surf practice and examine the effect this might have on surfing performance, cognitive function and muscular endurance of elite surfers. Twelve male national and international level surfers volunteered to take part in the study. Their mean (± SD) age, body mass, height and surfing experience were 27.0 ± 3.3 years, 73.2 ± 7.1 kg, 1.7 ± 0.05 m and 21.0 ± 3.1 years, respectively. The participants were randomly assigned to one of two trials: no fluid ingestion (NF) or fluid ingestion (FI) during 100 min of surf practice in a steamer wetsuit. The experiment was designed to emulate not only the physical and cognitive demands of surfing but also the ambient environment in which it takes place. Before and immediately after surf practice, the participants had their hydration status measured, completed a cognitive test battery and upper and lower-body muscular endurance tests. Surfing performance was assessed during the first and last 20 min of practice. At the conclusion of the NF trial, participants showed a 3.9 ± 0.7% body mass (BM) loss, this was significantly greater (P < 0.05) than the 1.6 ± 0.7% BM loss seen at the end of the FI trial. In the NF trial, surfing performance decreased by 20.3 ± 7.1%, but showed a slight improvement in the FI trial (1.9 ± 10.2%). Of the six cognitive domains assessed (short-term memory, information processing speed, working memory, attention, visuomotor skill and visual acuity) all were significantly impaired when at a 3.9 ± 0.7% BM loss (P < 0.05) yet were unaffected at a 1.6 ± 0.7% BM loss. Information processing speed and working memory were the most strongly correlated to surfing performance (r = 0.74; P < 0.05). At the conclusion of the NF trial upper and lower-body muscular endurance were diminished by 21.2 ± 5.5% and 4.4 ± 5.8%, respectively. At the conclusion of the FI trial upper-body muscular endurance was reduced by 17.0 ± 4.1% while lower-body muscular endurance was marginally better (1 ± 3%). There was a significant difference in muscular endurance capacity between trials yet no significant correlation was observed between muscular endurance and surfing performance. The findings of this study suggest that surf practice for 100 min in a steamer wetsuit results in BM loss severe enough to significantly impair surfing performance, cognitive function and muscular endurance. Yet, when water is consumed during surf practice, surfing performance, cognitive function and lower body (but not upper-body) muscular endurance is maintained. Keywords: fluid ingestion, surf training, steamer wetsuit, hypohydration.

Motion planning and control synthesis are challenging problems for underactuated mechanical systems due to the presence of passive (non-actuated) degrees of freedom. For those systems that are additionally not feedback linearizable and with unstable internal dynamics there are no generic methods for planning trajectories and their feedback stabilization. For fully actuated mechanical systems, on the other hand, there are standard tools that provide a tractable solution. Still, the problem of generating efficient and optimal trajectories is nontrivial due to actuator limitations and motion-dependent velocity and acceleration constraints that are typically present. It is especially challenging for manipulators with kinematic redundancy. A generic approach for solving the above-mentioned problems is described in this work. We explicitly use the geometry of the state space of the mechanical system so that a synchronization of the generalized coordinates can be found in terms of geometric relations along the target motion with respect to a path coordinate. Hence, the time evolution of the state variables that corresponds to the target motion is determined by the system dynamics constrained to these geometrical relations, known as virtual holonomic constraints. Following such a reduction for underactuated mechanical systems, we arrive at integrable second-order dynamics associated with the passive degrees of freedom. Solutions of this reduced dynamics, together with the geometric relations, can be interpreted as a motion generator for the full system. For fully actuated mechanical systems the virtually constrained dynamics provides a tractable way of shaping admissible trajectories. Once a feasible target motion is found and the corresponding virtual holonomic constraints are known, we can describe dynamics transversal to the orbit in the state space and analytically compute a transverse linearization. This results in a linear time-varying control system that allows us to use linear control theory for achieving orbital stabilization of the nonlinear mechanical system as well as to conduct system analysis in the vicinity of the motion. The approach is applicable to continuous-time and impulsive mechanical systems irrespective of the degree of underactuation. The main contributions of this thesis are analysis of human movement regarding a nominal behavior for repetitive tasks, gait synthesis and stabilization for dynamic walking robots, and description of a numerical procedure for generating and stabilizing efficient trajectories for kinematically redundant manipulators.

BACKGROUND and OBJECTIVES: Low-back overexertion injuries represent a large proportion of fireground “strains, sprains and muscular pains” and are a leading cause of disability and early retirement in firefighters. Given the inherently hazardous and unpredictable nature of many fireground activities, it is often infeasible to implement “task-focused” ergonomic controls and there are limited options to accommodate injured firefighters. Accordingly, effective and practical “worker-focused” injury prevention approaches are needed. Toward this end, four studies were conducted to address the following global thesis objectives: 1) Examine the possible role that firefighters’ personal movement strategies could have on their occupational low-back loading demands and injury potential; and 2) Compare the effects of two different exercise approaches on firefighters’ occupational low-back loading demands and injury potential. STUDY 1: Low-Back Loading Demands during Simulated Firefighting Tasks – Inter-Subject Variation and the Impact of Fatigue and Gender. Background: Non-modifiable fireground duties are considered hazardous for low-back health, but personal movement strategies could modulate low-back loading demands and injury potential. Study objectives were to quantify low-back loading demands during simulated firefighting tasks and to examine the impact of fatigue and gender on the peak loading response. Methods: Ten men and 10 women performed a battery of laboratory-simulated firefighting tasks before and following repeated bouts of a fatiguing stair-climbing protocol. An EMG-assisted three-dimensional dynamic biomechanical model was used to compute peak L4/L5 joint forces during task performance. Results: Peak low-back loading demands varied considerably between subjects and tasks, but 70% of all loading variables examined were of greater magnitudes in male subjects and 40% of all loading variables were of lower magnitudes in both males and females after stair-climbing. Some inter-subject variation in low-back loading was attributed to body size differences, but between- and within-subject differences in movement strategies also contributed to low-back loading variability between subjects and over time. Conclusions: Results of this study suggest that characteristics of individuals, tasks performed, and physical fatigue may influence peak low-back loading demands and injury potential in firefighters. Despite considerable inter-subject variation in the internal low-back loading response to fixed external task and environmental constraints, opportunities to attenuate low-back loading demands through movement behaviour adaptations alone may be limited to only a subset of fireground activities. STUDY 2: Ankle Immobilization alters Lifting Kinematics and Kinetics – Occupational Low-Back Loading Demands and Potential for Injury. Background: Firefighters with lingering lower extremity functional impairments could be forced to move in ways that increase their potential for sustaining occupational low-back lifting injuries. The study objective was to examine the impact of unilateral ankle immobilization on lifting kinematics and kinetics. Methods: With and without their right ankle immobilized, 10 male volunteers performed laboratory-simulated occupational lifting tasks. Together with force platform data, three-dimensional kinematics of the lumbar spine, pelvis, and lower extremities were collected, and a three-dimensional dynamic biomechanical model was used to calculate peak low-back compression and shear loading demands. Results: In comparison to the unaffected conditions, ankle immobilization resulted in less knee (p-values between 0.0004 and 0.0697) and greater lumbar spine (p-values between 0.0006 and 0.3491) sagittal motion when lifting. Associated with this compensatory movement strategy were greater L4/L5 anterior/posterior reaction shear forces (p-values between 0.0009 and 0.2450). However, in a few cases where individual compensatory movement strategies differed from the “group” response (i.e., subjects increased their sagittal knee and hip motion on the affected side), peak L4/L5 joint compressive loads increased while the peak L4/L5 anterior-posterior shear did not change. Conclusions: Distal lower extremity joint dysfunction can alter the way in which individuals move and load their low-backs when lifting. The specific ways in which individuals compensate for personal movement constraints could alter the potential site and mechanism of occupational low-back injury. STUDY 3: FMS™ Scores and Occupational Low-Back Loading Demands – Whole-Body Movement Screening as an Ergonomic Tool? Background: Results of Study 1 suggested that a whole-body movement screen could be used to identify personal characteristics that constrain movement behaviour in ways that impact occupational low-back loading demands and injury potential. The purpose of this study was to examine if Functional Movement Screen™ (FMS) scores could be used to project the low-back loading response to lifting. Methods: Sagittally symmetric and asymmetric laboratory-based lifting tasks were performed by 15 firefighters who scored greater than 14 on the FMS (high-scorers) and 15 size-matched low-scorers (FMS < 14). A three-dimensional dynamic biomechanical model was used to calculate low-back loading demands, and lumbar spine posture was recorded when peak low-back compression was imposed. Results: Regardless of the task performed, there were no differences in peak L4/L5 joint compression (p ≥ 0.4157), anterior/posterior reaction shear (p ≥ 0.5645), or medial/lateral reaction shear (p ≥ 0.2581) loading demands between high- and low-scorers. At the instant when peak compression force was detected, lumbar spine deviation was not different between high- and low-scorers about the lateral bend (p ≥ 0.4215), axial twist (p ≥ 0.2734), or flexion/extension (p ≥ 0.1354) axes. Conclusions: Using the previously established musculoskeletal injury prediction threshold value of 14, the composite FMS score did not project the low-back loading response to lifting. Future attempts to modify or reinterpret FMS scoring are warranted given that several previous studies have revealed links between composite FMS scores and musculoskeletal complaints. STUDY 4: Movement- vs. Fitness-Centric Exercise – Firefighter Fitness, Whole-Body Movement Qualities, and Occupational Low-Back Loading Outcomes. Background: The impact of exercise on firefighter job performance and cardiorespiratory fitness has been studied extensively, but its effect on musculoskeletal loading remains less understood. The aim of this study was to compare various physical fitness, general movement quality, and low-back loading outcomes between groups of firefighters who completed fitness- or movement-centric exercise. Methods: Fifty-four firefighters participated and were assigned to a control (CON), fitness-centric exercise (FIT), or movement-centric exercise (MOV) group. Before and after 12 weeks of exercise, subjects performed a physical fitness test battery, the Functional Movement Screen™ (FMS), and laboratory-simulated firefighting tasks during which low-back loading demands were quantified. Results: FIT and MOV subjects exhibited statistically significant improvements in nearly all measures of physical fitness (i.e., body composition, cardiorespiratory capacity, muscular strength, power, endurance, and flexibility), but FMS scores and occupational low-back loading demands were not impacted in a consistent way across individuals. Conclusions: Improving physical fitness can enhance job performance and prevent cardiac events in firefighters, but it was not clear that 12 weeks of exercise would alter their occupational low-back loading demands. Given variability in individual responses, the short study duration, and limited number and nature of tasks examined, more research incorporating alternative biomechanical and statistical analyses is needed to better understand how individuals adapt to chronic exercise and what impact these adaptations have on occupational movement behaviours, low-back loading demands, and low-back loading capacity. SUMMARY and CONCLUSIONS: Results confirmed that fireground activities are potentially hazardous for low-back health, as simulated occupational low-back loading demands routinely exceeded recommended exposure limits in the studies performed. However, results also indicated that personal movement strategies – possibly influenced by body size, preference, gender, physical fatigue, or distal lower extremity joint dysfunction – could alter occupational low-back loading demands and injury potential. It could not be concluded that occupational low-back loading demands and injury potential would be consistently affected by short-term improvements in physical fitness, nor could the low-back loading response to lifting be projected by scoring above or below 14 on the Functional Movement Screen™. Future research is warranted to examine the low-back loading demands associated with performing non-fireground duties, as opportunities may exist to implement ergonomic strategies to control cumulative low-back loading exposures. Particular attention should be paid to the exercise and training practices of firefighters, as musculoskeletal injuries sustained during these activities are potentially avoidable and could reduce the capacity of the musculoskeletal system to withstand demands imposed during non-modifiable fireground operations.

Although research has highlighted the importance of decisions when learning and performing motor actions, few studies have focused on individuals’ ability to choose between potential motor actions. To help bridge this gap, this thesis presents a series of studies that investigate the behaviour of able-bodied individuals when attempting to choose movements based on a speed-accuracy tradeoff. In the first study, a two-alternative forced-choice task was used to determine whether people are consistent with Fitts’s law when choosing the movement they perceive to require the least movement duration. Participants performed almost perfectly when clear visual cues were available—when one of the targets was closer, wider, or both. Contrary to Fitts’s law, however, participants showed a preference for closer targets when visual cues were not informative—when one of the targets was closer and narrower. This study demonstrates that motor decisions are not always optimal, especially when participants are naïve at the task. To determine the basis of individuals’ preference for closer targets, a pair of studies explored the relation between motor decisions, imagined movements, and visual perception. Participants showed a similar deviation from Fitts’s law when imagining movements—believing that movement duration increased with distance within the same index of difficulty. Participants did not behave similarly, however, in a perceptual version of the decision task. These results suggest that imagined movements and motor decisions are linked, but they are not always based on veridical representations of actual movement. To further probe the origin of individuals’ erroneous belief about movement duration, the final study of this thesis measured movement duration for movements made at speeds other than ‘as fast as possible’. Movements made at more natural movement speeds shared important similarities with decisions and imagined movements. This study suggests that the biases seen in naïve motor decisions might originate from participants considering movements for which they have more experience, such as target-directed movements made at a naturally-selected pace. Together, the findings presented in this thesis may help to identify the ways that motor decisions can deviate from optimal, suggesting how those decisions must change with practice to better accomplish a task.

Although research has highlighted the importance of decisions when learning and performing motor actions, few studies have focused on individuals’ ability to choose between potential motor actions. To help bridge this gap, this thesis presents a series of studies that investigate the behaviour of able-bodied individuals when attempting to choose movements based on a speed-accuracy tradeoff. In the first study, a two-alternative forced-choice task was used to determine whether people are consistent with Fitts’s law when choosing the movement they perceive to require the least movement duration. Participants performed almost perfectly when clear visual cues were available—when one of the targets was closer, wider, or both. Contrary to Fitts’s law, however, participants showed a preference for closer targets when visual cues were not informative—when one of the targets was closer and narrower. This study demonstrates that motor decisions are not always optimal, especially when participants are naïve at the task. To determine the basis of individuals’ preference for closer targets, a pair of studies explored the relation between motor decisions, imagined movements, and visual perception. Participants showed a similar deviation from Fitts’s law when imagining movements—believing that movement duration increased with distance within the same index of difficulty. Participants did not behave similarly, however, in a perceptual version of the decision task. These results suggest that imagined movements and motor decisions are linked, but they are not always based on veridical representations of actual movement. To further probe the origin of individuals’ erroneous belief about movement duration, the final study of this thesis measured movement duration for movements made at speeds other than ‘as fast as possible’. Movements made at more natural movement speeds shared important similarities with decisions and imagined movements. This study suggests that the biases seen in naïve motor decisions might originate from participants considering movements for which they have more experience, such as target-directed movements made at a naturally-selected pace. Together, the findings presented in this thesis may help to identify the ways that motor decisions can deviate from optimal, suggesting how those decisions must change with practice to better accomplish a task.

BACKGROUND and OBJECTIVES: Low-back overexertion injuries represent a large proportion of fireground “strains, sprains and muscular pains” and are a leading cause of disability and early retirement in firefighters. Given the inherently hazardous and unpredictable nature of many fireground activities, it is often infeasible to implement “task-focused” ergonomic controls and there are limited options to accommodate injured firefighters. Accordingly, effective and practical “worker-focused” injury prevention approaches are needed. Toward this end, four studies were conducted to address the following global thesis objectives: 1) Examine the possible role that firefighters’ personal movement strategies could have on their occupational low-back loading demands and injury potential; and 2) Compare the effects of two different exercise approaches on firefighters’ occupational low-back loading demands and injury potential. STUDY 1: Low-Back Loading Demands during Simulated Firefighting Tasks – Inter-Subject Variation and the Impact of Fatigue and Gender. Background: Non-modifiable fireground duties are considered hazardous for low-back health, but personal movement strategies could modulate low-back loading demands and injury potential. Study objectives were to quantify low-back loading demands during simulated firefighting tasks and to examine the impact of fatigue and gender on the peak loading response. Methods: Ten men and 10 women performed a battery of laboratory-simulated firefighting tasks before and following repeated bouts of a fatiguing stair-climbing protocol. An EMG-assisted three-dimensional dynamic biomechanical model was used to compute peak L4/L5 joint forces during task performance. Results: Peak low-back loading demands varied considerably between subjects and tasks, but 70% of all loading variables examined were of greater magnitudes in male subjects and 40% of all loading variables were of lower magnitudes in both males and females after stair-climbing. Some inter-subject variation in low-back loading was attributed to body size differences, but between- and within-subject differences in movement strategies also contributed to low-back loading variability between subjects and over time. Conclusions: Results of this study suggest that characteristics of individuals, tasks performed, and physical fatigue may influence peak low-back loading demands and injury potential in firefighters. Despite considerable inter-subject variation in the internal low-back loading response to fixed external task and environmental constraints, opportunities to attenuate low-back loading demands through movement behaviour adaptations alone may be limited to only a subset of fireground activities. STUDY 2: Ankle Immobilization alters Lifting Kinematics and Kinetics – Occupational Low-Back Loading Demands and Potential for Injury. Background: Firefighters with lingering lower extremity functional impairments could be forced to move in ways that increase their potential for sustaining occupational low-back lifting injuries. The study objective was to examine the impact of unilateral ankle immobilization on lifting kinematics and kinetics. Methods: With and without their right ankle immobilized, 10 male volunteers performed laboratory-simulated occupational lifting tasks. Together with force platform data, three-dimensional kinematics of the lumbar spine, pelvis, and lower extremities were collected, and a three-dimensional dynamic biomechanical model was used to calculate peak low-back compression and shear loading demands. Results: In comparison to the unaffected conditions, ankle immobilization resulted in less knee (p-values between 0.0004 and 0.0697) and greater lumbar spine (p-values between 0.0006 and 0.3491) sagittal motion when lifting. Associated with this compensatory movement strategy were greater L4/L5 anterior/posterior reaction shear forces (p-values between 0.0009 and 0.2450). However, in a few cases where individual compensatory movement strategies differed from the “group” response (i.e., subjects increased their sagittal knee and hip motion on the affected side), peak L4/L5 joint compressive loads increased while the peak L4/L5 anterior-posterior shear did not change. Conclusions: Distal lower extremity joint dysfunction can alter the way in which individuals move and load their low-backs when lifting. The specific ways in which individuals compensate for personal movement constraints could alter the potential site and mechanism of occupational low-back injury. STUDY 3: FMS™ Scores and Occupational Low-Back Loading Demands – Whole-Body Movement Screening as an Ergonomic Tool? Background: Results of Study 1 suggested that a whole-body movement screen could be used to identify personal characteristics that constrain movement behaviour in ways that impact occupational low-back loading demands and injury potential. The purpose of this study was to examine if Functional Movement Screen™ (FMS) scores could be used to project the low-back loading response to lifting. Methods: Sagittally symmetric and asymmetric laboratory-based lifting tasks were performed by 15 firefighters who scored greater than 14 on the FMS (high-scorers) and 15 size-matched low-scorers (FMS < 14). A three-dimensional dynamic biomechanical model was used to calculate low-back loading demands, and lumbar spine posture was recorded when peak low-back compression was imposed. Results: Regardless of the task performed, there were no differences in peak L4/L5 joint compression (p ≥ 0.4157), anterior/posterior reaction shear (p ≥ 0.5645), or medial/lateral reaction shear (p ≥ 0.2581) loading demands between high- and low-scorers. At the instant when peak compression force was detected, lumbar spine deviation was not different between high- and low-scorers about the lateral bend (p ≥ 0.4215), axial twist (p ≥ 0.2734), or flexion/extension (p ≥ 0.1354) axes. Conclusions: Using the previously established musculoskeletal injury prediction threshold value of 14, the composite FMS score did not project the low-back loading response to lifting. Future attempts to modify or reinterpret FMS scoring are warranted given that several previous studies have revealed links between composite FMS scores and musculoskeletal complaints. STUDY 4: Movement- vs. Fitness-Centric Exercise – Firefighter Fitness, Whole-Body Movement Qualities, and Occupational Low-Back Loading Outcomes. Background: The impact of exercise on firefighter job performance and cardiorespiratory fitness has been studied extensively, but its effect on musculoskeletal loading remains less understood. The aim of this study was to compare various physical fitness, general movement quality, and low-back loading outcomes between groups of firefighters who completed fitness- or movement-centric exercise. Methods: Fifty-four firefighters participated and were assigned to a control (CON), fitness-centric exercise (FIT), or movement-centric exercise (MOV) group. Before and after 12 weeks of exercise, subjects performed a physical fitness test battery, the Functional Movement Screen™ (FMS), and laboratory-simulated firefighting tasks during which low-back loading demands were quantified. Results: FIT and MOV subjects exhibited statistically significant improvements in nearly all measures of physical fitness (i.e., body composition, cardiorespiratory capacity, muscular strength, power, endurance, and flexibility), but FMS scores and occupational low-back loading demands were not impacted in a consistent way across individuals. Conclusions: Improving physical fitness can enhance job performance and prevent cardiac events in firefighters, but it was not clear that 12 weeks of exercise would alter their occupational low-back loading demands. Given variability in individual responses, the short study duration, and limited number and nature of tasks examined, more research incorporating alternative biomechanical and statistical analyses is needed to better understand how individuals adapt to chronic exercise and what impact these adaptations have on occupational movement behaviours, low-back loading demands, and low-back loading capacity. SUMMARY and CONCLUSIONS: Results confirmed that fireground activities are potentially hazardous for low-back health, as simulated occupational low-back loading demands routinely exceeded recommended exposure limits in the studies performed. However, results also indicated that personal movement strategies – possibly influenced by body size, preference, gender, physical fatigue, or distal lower extremity joint dysfunction – could alter occupational low-back loading demands and injury potential. It could not be concluded that occupational low-back loading demands and injury potential would be consistently affected by short-term improvements in physical fitness, nor could the low-back loading response to lifting be projected by scoring above or below 14 on the Functional Movement Screen™. Future research is warranted to examine the low-back loading demands associated with performing non-fireground duties, as opportunities may exist to implement ergonomic strategies to control cumulative low-back loading exposures. Particular attention should be paid to the exercise and training practices of firefighters, as musculoskeletal injuries sustained during these activities are potentially avoidable and could reduce the capacity of the musculoskeletal system to withstand demands imposed during non-modifiable fireground operations.