Orientador: Elenice Aparecida de Moraes Ferrari / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-17T13:20:19Z (GMT). No. of bitstreams: 1 Sousa_GrazielleAurelinaFragade_M.pdf: 2482319 bytes, checksum: 98003776bf4be1025c31d965be705e09 (MD5) Previous issue date: 2010 / Resumo: Este estudo investigou se o desempenho de estudantes universitários, em testes de memória episódica e operacional, varia em função do horário e do intervalo de tempo em que são realizados os testes de evocação. Na Fase 1, o Questionário Cronotipo foi utilizado para classificar o tipo cronobiológico. Dos 396 alunos avaliados, 59% foram classificados como intermediários, 35% como vespertinos e 6% como matutinos. Na Fase 2, foi avaliada uma amostra de 43 alunos, de ambos os sexos, classificados como intermediários, com 20,12 ± 2,18 anos de idade, falantes nativos de Português, sem histórico de distúrbios do sono ou uso de drogas psicoativas. Foram constituídos quatro grupos de acordo com os horários das sessões de treino/teste imediato e teste tardio: GMN - treino pela manhã e teste à noite, após 12horas; GMM - treino pela manhã e teste pela manhã, após 24 horas; GNM - treino à noite e teste pela manhã, após 12 horas; GNN - treino à noite e teste à noite, após 24 horas. Para avaliação da memória episódica e operacional foram utilizados: Teste de Aprendizagem Auditivo Verbal de Rey (TAAVR), Teste de Memória Lógica (TML), Teste de Extensão de Dígitos e Teste dos Blocos de Corsi. O Diário de Sono foi usado para avaliar o ciclo vigília-sono e o uso de termistor e de actímetro permitiu avaliar os ritmos de temperatura de punho e atividade motora. Questionários específicos foram utilizados para avaliação da percepção de estresse, ansiedade e estado de humor. Os dados do TAAVR e TML em três diferentes momentos de avaliação (imediato, após 30 minutos e tardio - após 12 ou 24horas) não indicaram efeito do horário ou do intervalo entre os testes de evocação (ANOVA; p > 0,05); no entanto, foi observada uma redução significativa dos escores ao longo dos momentos de avaliação (ANOVA; p < 0,05). Os escores médios obtidos no teste 30 minutos e no teste tardio do TAAVR correlacionaram-se positivamente com a média de duração do sono global (Teste de Spearman, p < 0,05). A média de duração do sono anterior à sessão de teste imediato apresentou correlação positiva com o escore médio do teste tardio do TML (Teste de Spearman, p < 0,05). Não houve efeito de horário ou de sessão sobre os índices do Teste de Extensão de Dígitos, Teste dos Blocos de Corsi e fatores de avaliação do humor (ANOVA; p > 0,05). Os grupos não diferiram quanto ao índice de estresse percebido e características de traço e estado de ansiedade (ANOVA, p > 0,05). O ritmo da temperatura de punho e o ritmo da atividade motora apresentaram relações de fase adequadas para a maioria dos sujeitos avaliados. A distribuição dos cronotipos na população avaliada concorda com os dados descritos para a população brasileira. Os dados indicaram a ausência de efeito do horário sobre o desempenho de indivíduos com cronotipo intermediário e sugerem uma relação entre a duração do sono e a memória episódica verbal. Estas evidências contribuem para o conhecimento sobre a variação do desempenho cognitivo durante a fase de vigília / Abstract: The aim of this study was to investigate if the performance of undergraduate students in episodic and working memory tests is influenced by the time-of-day and the interval between the retrieval tests. In Phase 1, the Morningness-Eveningness Questionnaire was used for assessment of the chonotype in a sample of students. Of 396 students assessed, 59% were classified as intermediate-type, 35% evening-type and 6% morning-type. The Phase 2 was conducted with 43 students classified as intermediatetype, both genders, with 20.12 ± 2.18 years old, native Portuguese speakers, without history of sleep disorders or use of drugs known to influence sleep and memory. These students were allocated in four groups according to the time-of-day of the training and the tests: GMN - trained in the morning (7:30 a.m.) and tested at same day, at night (6:30 p.m.); GMM - trained in the morning (7:30 a.m.) and tested after 24 hours (7:30 a.m.); GNM - trained at night (6:30 p.m.) and tested in the morning of the next day (7:30 a.m.); and the GNN - trained at night (6:30 p.m.) and tested after 24 hours (6:30 p.m.). The Rey Auditory Learning Test (RAVLT), Logical Memory Test (LMT), Corsi Block- Tapping Test and Digit Span Test were used to assess episodic and working memories. The sleep-wake cycle was assessed by sleep-logs and the wrist temperature and motor activity rhythmics was evaluated by thermistor and actigraphy. The levels of perceived stress, state of anxiety and mood were also evaluated. There was no time-of-day effect or interval effect on the retrieval of the RAVLT and LMT in the immediate test, 30 minutes test and delayed test - after 12 or 24 hours (ANOVA, p > 0.05). However, the scores showed a significant decrease across these three assessments (ANOVA p < 0.05). Positive correlation was observed between the mean sleep duration and the mean scores of the RAVLT after 30 minutes and in the delayed test (Spearman Test, p < 0.05). The mean of sleep duration before the immediate test was positively correlated with the LMT score during the delayed test (Spearman Test, p < 0.05). There was no effect of the time-of-day on Digit Span Test, Corsi Block-Tapping Test and mood assessment (ANOVA, p > 0.05). No between-group differences occurred in the level of perceived stress and trait-state anxiety (p > 0.05). The rhythm of wrist temperature and the rhythm of motor activity showed appropriate phase relations for the most part of evaluated subjects. The data indicate absence of time-of-day effect on the performance of intermediate-type individuals and suggest a relationship between memory and the sleep duration. Such evidence contributes to our understanding of the variation in cognitive performance during the wake period / Mestrado / Fisiologia / Mestre em Biologia Funcional e Molecular

Orientador: Miguel Arcanjo Areas / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-15T12:08:35Z (GMT). No. of bitstreams: 1 Santos_GustavoBarbosados_M.pdf: 1865766 bytes, checksum: 33bc98691c7f175ef683408a35219198 (MD5) Previous issue date: 2010 / Resumo: Esteróides androgênicos anabolizantes (EAA) são indicados clinicamente para promover aumento da síntese protéica após queimaduras, cirurgias, radioterapia, no tratamento contraceptivo, no hipogonadismo, na osteoporose, na sarcopenia relacionada à idade e à pacientes portadores de HIV. Por outro lado, o uso indiscriminado dos EAA, com intuito de aumentar o desenvolvimento muscular, o desempenho físico, a capacidade aeróbia, a tolerância ao treinamento de alta intensidade e até mesmo para fins estéticos, é crescente entre atletas e esportistas recreacionais. O uso abusivo de EAA está relacionado à toxicidade cardíaca e hepática em consequência do aumento do estresse oxidativo. Por outro lado, estudos apontam a melatonina como substância com significativa ação antioxidante, apresentando efeitos benéficos no tratamento de doenças cardíacas. Este trabalho teve por objetivo avaliar os efeitos da melatonina sobre biomarcadores do estresse oxidativo e parâmetros cardiovasculares e hepáticos em ratos adultos sedentários ou treinados com natação e tratados com estanozolol. Os ratos foram distribuídos nos seguintes grupos: sedentário (S), sedentário+estanozolol (SE), sedentário+estanozolol+melatonina (SEM), treinado (T), treinado+estanozolol (TE) e treinado+estanozolol+melatonina (TEM). Realizou-se avaliação eletrocardiográfica no início e ao final do período experimental (6 semanas), sendo, então, determinada a pressão arterial, atividade de enzimas antioxidantes e da fosfatase alcalina e histologia do coração e do fígado. Os resultados mostraram que o estanozolol provocou bradicardia, queda do peso relativo do fígado e aumento da atividade das enzimas superóxido dismutase cardíaca e hepática, catalase cardíaca e fostatase alcalina hepática. Quando associado ao treinamento, estanozolol aumentou a pressão arterial sistólica e diastólica, o peso relativo do coração, desviou o eixo elétrico cardíaco para esquerda e provocou alterações hepatotóxicas. A administração da melatonina nos ratos tratados com EST, por sua vez, impediu o aumento da pressão arterial sistólica e diastólica e da atividade das enzimas catalase cardíaca, fostatase alcalina hepática além de impedir o desvio do eixo elétrico cardíaco causado pela hipertrofia ventricular esquerda induzida pelo estanozolol. Além disso, melatonina reduziu as alterações nos hepatócitos induzidas pelo estanozolol. Concluímos que, em nossas condições experimentais, a melatonina atenuou os efeitos adversos ao sistema cardiovascular e ao fígado causados pelo uso de doses suprafisiológicas de estanozolol / Abstract: Anabolic androgenic steroids (AAS) are nominated for clinical use to promote protein synthesis after burns, surgery, radiotherapy, on contraceptive treatment, osteoporosis, hypogonadism, age-related sarcopenia and HIV patients. However, the indiscriminate use of ASS aiming to stimulate muscular development, physical performance, aerobic capacity, tolerance to high-intensity training and with aesthetic purpose is increasing among athletes and recreational sportsmen. The abusive use of ASS is related to oxidative stress-induced cardiac and hepatic toxicity. Nonetheless, many studies point to melatonin as a substance with antioxidant properties, with beneficial effects on cardiovascular diseases treatment. The purpose of this study was to assess melatonin's effects on oxidative stress biomarkers, cardiovascular and liver parameters in stanozolol-treated trained rats. Rats were divided into the following groups: sedentary (S), sedentary+stanozolol (SS), sedentary+stanozolol+melatonin (SSM), trained (T), trained+stanozolol (TS) and trained+stanozolol+melatonin (TSM). Electrocardiography assessment were performed at the beginning and at the end of experimental period, and then, blood pressure, antioxidant enzymes and phosphatase alkaline activities, heart and liver histology were determined. Stanozolol induced bradycardia, relative liver weight decreased and increased cardiac and liver superoxide dismutase, cardiac catalase and liver phosphatase alkaline activities. Stanazolol plus training induced increased systolic and diastolic blood pressure, relative heart weight, left cardiac axis deviation and toxic liver damage. Melatonin induced decreased systolic and diastolic blood pressure, cardiac catalase and liver phosphatase alkaline activities, and prevented stanazolol-induced left cardiac axis deviation. Furthermore, melatonin decreased stanozolol-induced liver damage. In conclusion, under our experimental conditions, the side effects of supraphysiology doses of stanozolol on liver and cardiovascular system are mitigated by melatonin / Mestrado / Fisiologia / Mestre em Biologia Funcional e Molecular

Orientador: Maria Cristina Cintra Gomes Marcondes / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-12T11:27:11Z (GMT). No. of bitstreams: 1 Cruz_BreadLeandroGomesda_M.pdf: 401647 bytes, checksum: bd87e2b677303756744ab1ef75ad2316 (MD5) Previous issue date: 2007 / Resumo: Câncer acomete, aproximadamente, uma entre 3000 gravidezes e causa um terço de mortes maternas. A leucina é usada experimentalmente para minimizar as alterações do metabolismo protéico durante o crescimento tumoral. Este trabalho investigou os efeitos do crescimento tumoral sobre o metabolismo protéico e estresse oxidativo nos fetos provenientes de ratas alimentadas com dieta suplementada com leucina. Os grupos de fêmeas prenhes foram divididos da seguinte forma: controle (C), controle com dieta suplementada com leucina (L), tumor (W), tumor com dieta suplementada com leucina (WL), dieta pareada á ingestão diária das ratas do grupo W (Cp), dieta suplementada com leucina e pareada á ingestão diária das ratas do grupo WL (Lp). Após 20 dias de prenhes os músculos fetais foram analisados. Os resultados mostraram que a síntese protéica fetal foi reduzida no grupo W quando comparados aos outros grupos. Houve significativa recuperação da síntese protéica no músculo dos fetos WL sugerindo efeito positivo do uso de aminoácido de cadeia ramificada nessa situação. Ocorreu aumento significativo da degradação protéica nos fetos W. Essa perda protéica foi amenizada pelo uso da dieta suplementada com leucina indicando efeito benéfico sobre a degradação protéica no grupo WL que obteve valores similares ao observado no grupo C. A atividade da enzima glutationa-S-transferase ficou elevada no músculo de fetos WL em comparação com o grupo W. Também houve aumento na atividade da enzima fosfatase alcalina no grupo WL indicando maior atividade celular nesse grupo quando comparado ao grupo W. A presença de MDA (Malondialdeído) no músculo fetal também ficou reduzida nos fetos WL. Com a análise desses parâmetros conclui-se que a dieta suplementada com leucina pode alterar o metabolismo muscular fetal aumentando a síntese protéica e reduzindo o efeito danoso do estresse oxidativo. / Abstract: Cancer occurs in approximately 1 per 3.000 pregnancies and accounts for one-third of maternal deaths. Leucine has been used experimentally to minimize the protein metabolism changes during tumor growth. The present work investigated the effects of tumor growth on muscle protein metabolism and oxidative stress in fetus pregnant rats fed a leucine-rich diet. Fetal groups from pregnant Wistar rats were: control (C), control fed leucine-rich diet (L), tumor-bearing (W), tumor-bearing fed leucine-rich diet (WL), Pair-fed control (P) and Pair-fed Leucine (PL). After 20 days the fetal muscles were analyzed. The results showed that fetal protein synthesis was decreased in W group, when compared to the other groups. The significantly recover on muscle protein synthesis in fetus of WL group suggested a positive effect of this branched-chain amino acid. There was a significant increase on protein degradation in W fetus and a protective effect of the leucine-rich diet on muscle protein waste in WL group, since it was similar to C group. The muscle enzyme glutathione-S-transferase activity was increased in WL fetus in comparison to W group. The muscle alkaline phosphatase activity increased in WL group. The malondialdehyde content (MDA) in fetal muscle was decreased in WL fetus. The leucine supplemented diet can alter the fetal muscle protein metabolism, improving the fetal muscle protein synthesis and reducing the oxidative stress. / Mestrado / Fisiologia / Mestre em Biologia Funcional e Molecular

Ph.D. / It has become an accepted fact that Coronary Heart Disease is an epidemic of modern civilisation. Coronary Heart Disease is responsible for approximately a third of all deaths in the Western world (Fullard, 1990) and South Africa is no exception. Several risk factors contributing to the development of heart disease have been identified but the extent and exact nature of their contribution is not fully understood. Traditionally accepted risk factors that play a role in the development of Coronary Heart Disease include diet, hypertension, hypercholestrolaemia, smoking, physical inactivity, age, sex and genetic disposition. However the strongest combination of these factors has been unable to predict the majority of heart disease cases. In this regard psychological factors are steadily gaining acceptance as risk factors, one of the most important of these being the Type A behaviour pattern. The far reaching consequences of Coronary Heart Disease have necessitated investigations into methods of decreasing contact with risk factors, particularly psychological ones. The substantial success of the Recurrent Coronary Prevention Project (Friedman et al), coupled with the promising results from other intervention studies, suggests that behaviour change is a viable goal in the prevention of heart disease. Following on from the Recurrent Coronary Prevention Project, Venter (1993) and Viljoen (1993) adapted it for the South African population. Although relatively successful, it did have its flaws. Thus the motivation for redesigning this intervention addressing its shortcomings The revised intervention was administered to a group of 25 Coronary Heart Disease patients. A second group of 22 patients were subjected to the intervention utilised in the original South African Recurrent Coronary Prevention Project. A third group of 18 patients served as a waiting list control group. The results indicated that although the revised intervention produced larger changes in Type A behaviour than the original South African Recurrent Prevention Project intervention, these differences were not significant. Possible reasons for this were the measures utilised, the sample sizes and the nature of the groups themselves. However, the revised version of the SARCPP was found to be more effective in the reduction of the hostility and anger components of the behaviour pattern than the original version. In conclusion it was found that before any further research in this area be conducted, the measures utilised should be modified and the mechanisms of treatment effect be examined.

M.A. / Leadership has been defined as the competencies and processes required to enable and empower ordinary people to do extraordinary things in the face of adversity. It is also the ability to constantly turn in superior performance to the benefit of oneself and the organisation (Bennis & Nanus, 1985; Charlton, 1993; Kelly, 1986; Senge, 1991). This definition includes being skilled in emotional competencies. Emotional competence results in being attuned to those one is dealing with, as well as being self-aware. This study focusses on the emotional intelligence factors considered to be characteristic of effective leaders. The link between the management of emotions and leadership ability is gaining increasing interest in business. People who are unable to maintain a degree of control over their emotional life, fight inner battles that sabotage the ability for focussed work and clear thoughts (Goleman, 1995). Unclear thinking and a lack of focus may in turn, contribute to decreased productivity and an overall decline in organisational success. Emotionally intelligent leaders with the ability to think clearly whilst being in tune with self and others, would thus be required to lead an emotionally intelligent organisation (Cooper & Sawaf, 1997). Leaders may not necessarily occupy positions of authority in the organisation, yet even at lower organisational levels they lead others by example. Otto (1995) refers to such leaders as "little leaders". It is the purpose of this study, to identify specific emotional competencies that may be characteristic of successful "little leaders". The question to be addressed, is: Is their a statistically significant difference in factors of emotional intelligence, between a group of identified "little leaders" and a group of nonleaders at the same level in an organisational context? A leadership questionnaire (The Multifactor Leadership Questionnaire (MLQ), (Bass & Avolio, 1990b)) consisting of 45 items was administered to managers of a large financial institution. They were asked to rate their subordinates using this scale as it identifies the presence of transformational and transactional leadership behaviour (Bass, 1985). Only the transformational leadership scores were used to identify two groups. Based on the transformational leadership scores of the MLQ, rated employees were grouped into leader and non-leader groups. Of the 220 (N=220) rating forms returned, 31 subjects fell into the leader group and 31 fell into the non-leader group based on the cutoff scores provided by the authors of the questionnaire. The middle ratings were not utilised for the present study. No participant in the study was made aware of the grouping procedure. The employee group was all English speaking, with a minimum educational level of matric. They occupied similar positions within the hierarchy and were all of non-managerial status. All 220 employees were asked to complete the Emotional Quotient Inventory (EQ-i) inorder to ensure privacy regarding the group ratings (Bar-On, 1996a). The EQ-i assesses 15 factors said to be important indicators of emotional intelligence. These include; problem solving ability, social responsibility, happiness, independence, stress tolerance, self-actualisation, assertiveness, reality testing, interpersonal relationship, self regard, impulse control, flexibility, self awareness, empathy and optimism. Two additional factors, namely, positive and negative impression provide assistance in score validation. Comparative statistics (Wilks' coefficient lambda and Students t-test) were used to analyse the data. A stepwise discriminant analysis was also conducted. A comparison of EQ-i scores between the leader group and the non-leader group indicates that the factors of optimism and self-actualisation are significantly higher for the leader group than for the non-leader group. The non-leader group had significantly higher scores on the positive impression scale, indicating a possible skewing of results for that group. A total of four variables was extracted following the stepwise discriminant analysis namely, positive impression, self-actualisation, self-regard and optimism. Generally, the research data appear to support the fundamental postulates of transformational leadership theory. Transformational leaders are able to raise awareness in both self and others regarding issues of consequence (Bass, 1997). This heightening of awareness requires a leader with vision, self-confidence, and inner strength to argue successfully for what he or she sees as right or good (Bass, 1997; Charlton, 1993; Senge, 1991). The factors of self-actualisation and optimism indicate an awareness of self and an ability to influence others (Seligman, 1990). The research findings indicate that the application of emotional intelligence theory to leadership identification may assist those in the fields of recruitment, selection and training and development. Future empirical research within the same empirical framework as this investigation, may benefit from greater standardisation and broader application of the assessment instrument used, the use of larger experimental populations and a possible replication of the findings of the present investigation. A comprehensive exploration of the interaction of Emotional Intelligence factors and the contribution of other possible factors to emotional intelligence in leadership may also contribute to the accuracy of future identification of potential leaders.

Disruptive behaviour disorders (DBDs) in children are among the most common referrals to mental health services and can lead to adverse psychosocial outcomes. There is consistent evidence that dysfunctional parenting, which has been associated with parental psychopathology, is a risk factor for the onset of these disorders. Yet, few studies have explored a wide range of parental pathology and parenting behaviours as well as perceptions of mental health and parenting of the parents of children with DBDs. This study, which took the form of a multiple case study, aimed to explore and describe the mental health and parenting of parents of pre-adolescent and adolescent children with DBDs. It also aimed to explore and describe parental perceptions of their own mental health and parenting and how (or if) they perceive their mental health as influencing their parenting. Purposive sampling was used to select participants and the sample size was determined through data saturation. Data was collected via the Millon Clinical Multiaxial Inventory and a semi-structured interview. Thematic content analysis and cross-case synthesis were used to analyse the data. The participants’ personality profiles indicated the presence of moderate to severe pathology including personality disorders and clinical disorders. Parenting themes that emerged included a number of dysfunctional parenting behaviours. The parents showed an awareness of their mental health and perceived it as influencing their parenting. This study emphasised the importance of exploring mental health and parenting interventions for parents of children with DBDs. The biggest limitations of this study was the small sample size.

The aim of this study was to generate useful isokinetic normative data for various cervical musculature strength, range of motion and ratio variables based on different positional categories in a sample of senior elite South African rugby players. Normative data was generated for the following variables: peak torque, power generated at 0.2 of a second, active and passive range of motion, the ratio of peak torque flexion to peak torque extension (PTF/PTE), the ratio of peak torque lateral flexion left to peak torque lateral flexion right (PTL/PTR), the ratios of peak torque to body weight (PT/BW) and the ratios of peak torque to lean body mass (PT/LBM). Furthermore, the data gathered from the senior elite players was compared to similar data obtained from a sample of schoolboy rugby forwards to detect statistically significant differences (p < .05). A normative survey design was used in which 189 subjects from eight provincial unions participated in a one off evaluation session. The evaluation session comprised of various anthropometrical measurements and an isokinetic cervical musculature assessment. The normative data, displayed in Stanine tables, was generated for four positional categories: the front row (# 1-3), the second row (# 4-5), the back row (# 6-8) and the backline (# 9 -15). The second row positional category performed the best on the peak flexion torque variable (44.04 Nm). The front row positional category achieved the largest average peak extension torque (65.6 Nm). The second row positional category achieved the largest average peak lateral flexion right torque (69.42 Nm). A similar result was observed with the measurement of peak lateral flexion left torque, with the second row positional category achieving the largest average peak lateral flexion left torque (66.31 Nm). The backline positional category achieved the lowest averages on all the abovementioned peak torque variables. The front row positional category performed the best on the flexion power generated at 0.2 of a second variable (160.92 W). The front row positional category again achieved the largest extension power generated at 0.2 of a second average (237.02 W). The second row positional category achieved the largest lateral flexion right power generated at 0.2 of a second average (269.81 W). Similar results were observed with the measurement of lateral flexion left power generated at 0.2 of a second. The second row positional category achieved the largest lateral flexion left power generated at 0.2 of a second average (259.62 W). Again the backline players achieved the smallest power generated at 0.2 of a second averages for all the above-mentioned power variables. The measurement of passive (PROMFE) and active (AROMFE) range of motion for flexion to extension revealed that the second row had the largest average PROMFE (125.44°). The measurement of AROMFE revealed a similar result. The second row again had the largest average AROMFE (108.45°). The measurement of passive (PROMLF) and active (PROMFE) range of motion for lateral flexion left to right revealed smaller and different results to those found for PROMFE and AROMFE. For the variable of PROMLF the backline players had the largest average PROMLF (119.44°). Conversely, the second row had the largest average AROMLF (106.96°). The calculation of the various ratios revealed great variation between the positional categories. This can be attributed to the functional requirements the players have to adhere to, to be successful in their position. Various other statistical calculations were performed to draw the average force distance graphs for the positional categories for the peak torque variables. Furthermore the force distance graphs were assessed to determine the players’ ability to maintain 80% of peak torque. All the senior elite positional categories proved to be significantly (p < .05) older and heavier than the schoolboy forwards. The senior elite forward positional categories were also significantly (p < .05) taller than the schoolboy forward. There however proved to be no significant difference (p > .05) in stature between the backline and schoolboy forwards. All the positional categories proved to have significantly thicker (p < .05) necks, but significantly shorter (p < .05) cervical spines than the schoolboy forwards. The forward positional categories demonstrated to be significantly stronger (p < .05), on all peak torque measures, than the schoolboy forwards. The same was observed between the backline and schoolboy forwards, however no statistically significant difference (p > .05) was observed between the respective sample groups for the measure of peak lateral flexion left torque. For all the measures of power generated at 0.2 of a second, the senior forward positional categories proved to be significantly more powerful (p < .05) than the schoolboy forwards. The senior backline, although significantly more powerful (p < .05) in the flexion movement pattern, proved to be significantly less powerful (p < .05) than the schoolboy forwards in the lateral flexion right movement pattern. No statistically significant differences (p < .05) were found to exist between the senior backline and schoolboy forwards for the extension and lateral flexion left power generated at 0.2 of a second variables. All positional categories proved to have significantly smaller (p < .05) active and passive ranges of motion compared to the schoolboy forwards. Conversely, the senior elite players had significantly larger (p < .05) ratios (PTF/PTE, PTL/PTR, PT/BW and PT/LBM) than the schoolboy forwards. Literature has identified schoolboy rugby as having a much higher incidence of cervical spinal injuries than senior rugby. It can thus be inferred from the above information that the variables of peak torque and power generated at 0.2 of a second play a important role in safeguarding a player from injury on the field of play. Furthermore, calculated ratios show that senior players, especially the forwards, have undergone adaptive changes in cervical musculature strength to meet the requirements of the position they play in, thereby safeguarding themselves from cervical spinal injury. Proper cervical musculature conditioning has been cited in the literature as being an effective but neglected method of preventing cervical spinal injuries. The generation of normative data, concerning cervical musculature performance, can thus be used to prevent the occurrence of cervical injuries and re-injury of the cervical spine by providing a standard of musculature strength for safe participation in rugby, and possibly other collision type sports, and a quantified guide for successful patient rehabilitation respectively.

Muscle strength has been identified as an important contributor to athletic performance. Little attention however, has been paid to the specific relationship between peak isokinetic muscle strength and sprint starting performance. The aim of this study was to determine the influence of an adapted front knee angle, as determined by isokinetic assessment (the angle of peak torque production), on starting performance. Sixteen track sprinters, of elite-national or competitive-regional standard, were asked to perform eight sprints over 50m using four separate starting techniques. Technique 1 featured the athlete’s usual starting preferences while Techniques 2, 3 and 4 featured a standardised set of starting preferences with experimental modifications of the front knee angle in the “set” position. Isokinetic muscle strength was measured at slow (60°/s) and fast (240°/s) test speeds in order to determine the angle of peak torque production for concentric knee extension of each subject’s lead leg. Using one-way analysis of variance (ANOVA) and Post Hoc analysis (LSD), no significant differences (p>0.05) were observed between the experimental techniques for: block time, force-time measures during block time, sprint times, sprint velocity and acceleratio n measures at intervals up to 50m. Significant differences (p<0.05) were however observed between reaction times for the experimental techniques. Slower reaction times are most likely due to increased upper body pretension, resulting from the increased hip elevation seen for these techniques. The results indicate that increased hip elevation may have delayed the initiation of the relevant motor response required to affect an optimal sprint start. Technique 1 resulted in the shortest reaction times, shortest block times, fastest sprint times and greatest sprint velocities for all four techniques. This result was possibly due to the athlete’s experience with, and repeated use of, this technique. The experimental techniques therefore provided no added advantage over the subject’s preferred starting technique and did not significantly optimise sprint starting performance. The results show that modification of the front knee angle had no significant influence on sprint starting performance and sprint running ve locity or acceleration patterns up to 50m. Using Pearson’s Correlation Coefficient to determine the strongest correlations between isokinetic knee strength and sprint starting performance, analysis revealed that the strongest relationships were found between sprint starting performance expressed as acceleration and isokinetic knee strength expressed as relative peak torque and absolute peak torque. For Technique 1 the strongest correlation was found between acceleration (30m - 40m) and relative peak torque as measured at a test speed of 240°/s (r = 0.62). For the remaining experimental techniques, the strongest correlation was found between acceleration (10m - 20m) and relative peak torque as measured at a test speed of 60°/s (r = 0.53) for Technique 2, between acceleration (40m - 50m) and peak torque measured at a test speed of 60°/s (r = 0.72) for Technique 3, and between acceleration (0m - 5m) and peak torque as measured at a test speed of 240°/s (r = 0.71) for Technique 4. These results suggest that isokinetic muscle strength does not correlate strongly with sprint starting performance and that additional factors, such as neuromuscular organisation and muscle fibre typing, possibly make a greater contribution to optimal sprint starting performance.

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The present study sought to investigate the effects of changes in gradient, under apparently optimal combinations of speed and load, on selected physiological, psychophysical and biophysical responses of military personnel. Subjects (n = 32) were required to march under level (0%), downhill (-10%) and uphill (+10%) conditions. Under each gradient, subjects marched with the following speed-load combinations: 4 km.h-1 carrying 50 kg, 5 km.h-1 carrying 35 kg and 6 km.h-1 carrying 20 kg, a total of nine experimental conditions. Subjects were required to march for six minutes under each condition. Physiological responses (HR, VO2, R, Br, VE, VT, EE) indicated that subjects were not overly taxed by the three speed-load combinations during level marching, which elicited submaximal demands. Furthermore, the results revealed that downhill marching with heavy loads results in similar responses to level marching, while lighter loads may result in significant reductions in physical demands compared to level marching. The physiological responses to uphill marching revealed that subjects were severely physically taxed under these conditions, regardless of speed-load combination. It is unlikely that soldiers would be able to maintain these intensities for an extended period without undue fatigue. It is evident from the psychophysical responses (Rating of Perceived Exertion and Body Discomfort) that subjects perceived the heavy load conditions, regardless of gradient, to be the most stressful on the cardiovascular and muscular systems. The positive gradient conditions also elicited elevated RPE and Body Discomfort responses, while lighter load downhill conditions were perceived to result in the least strain.