In Sweden approximately 25000 distal radius fractures occur annually, which is 37 % of all fractures related to osteoporosis. In this thesis, risk factors for osteoporosis, bone mineral density (BMD) and health-related quality of life (the SF-36) were compared in patients who suffered a distal radius fracture after low energy trauma with a control group matched on the basis of age, gender, and municipality of residence. The aim was also to analyse, among these patients, whether a risk factor questionnaire, tests on dynamic and static balance and a one-leg rise test could identify those, who have osteopenia or osteoporosis, and run a risk of new falls. Moreover, in a three-year follow-up, mortality, the need for in- and outpatient care, and health-related quality of life after radius fracture were investigated and compared between the patients and matched controls. Finally, the effect of a preventive intervention program including patient education and self-training was evaluated. Falls were reported in a risk factor questionnaire and in a fall diary. The patients aged 45-64 years showed lower, although not statistically significant, BMD, compared with the controls of the same age, but there was no difference concerning their history of falls. In contrast, the patients aged 64 years or older had a history of falling more often than the corresponding controls, but no difference in BMD was found. For all other risk factors, except falls, no differences were found between the patients and the controls. The results of the one-leg rise test were associated with those of dynamic and static balance, but none of the functional tests were associated with the number of falls. Decreased height and cigarette smoking were the only risk factors, which predicted osteopenia and osteoporosis. Five patients, although none of the controls, died during the study time. The patients needed statistically significantly more episodes as inpatients than the controls. The patients also had lower SF-36, Role Physical scores, than the controls at three months. This difference disappeared by the time of the follow-up. Both the patients, who participated in a four-week intervention program, “the osteoporosis school” followed by a one-year home-based exercise program, and the controls showed statistically significantly improved dynamic and static balance, ability to walk backwards and to stand on one leg with eyes open and closed at the end of the study. However, no significant differences were found between the patients and the controls in any of the tests, in BMD or in the number of the falls. The thesis shows that, except for the falls in patients aged over 64 years, there were no significant differences between patients and controls with respect to BMD and other risk factors related to osteoporosis. Consequently, in patients aged 45-64 years and older, the underlying cause of a distal radius fracture is more related to falls than to osteoporosis. Furthermore, the thesis shows that the functional tests and the risk factor questionnaire seem to be of limited value for identifying 8 people with a radius fracture, who are at risk of falling or have osteopenia or osteoporosis. If, in spite of this, functional tests on musculoskeletal function are considered for testing of functional ability in patients with a recent radius fracture, the one leg-rise test may be sufficient. There seems to be an increased mortality and morbidity necessitating inpatient care among patients with a recent radius fracture. The osteoporosis school had no significant effect on BMD, balance, muscle strength or falls in this thesis. Therefore, the lack of proven efficacy of the osteoporosis school for the secondary prevention of distal radius fractures highlights the need for more and long-term randomised controlled follow-up studies in this specific population.

Orientador: Rúben de Faria Negrão Filho / Banca: Carlos Marcelo Pastre / Banca: Amélia Pasqual Marques / Resumo: Contextualização: Observa-se na literatura que indivíduos assintomáticos podem não apresentar pré-ativação muscular de estabilizadores primários e não há estudos que apontem para os motivos da alteração no tempo de início de ativação muscular nessa população. Além disso, estudos preliminares em nosso laboratório mostraram que indivíduos assintomáticos apresentaram alterações em testes físicos e funcionais relacionados à capacidade de estabilização da região lombo-pélvica. Objetivo: Estudar o comportamento de pré-ativação dos músculos transverso do abdome/oblíquo interno (TrA/OI) e multífido lombar (ML), a capacidade de estabilização lombo-pélvica e a relação entre ambos. Metodologia: Foram selecionados 27 voluntários assintomáticos de ambos os sexos, com idades entre 20 e 28 anos (média = 23,85 ±2,21). Os voluntários foram submetidos a Testes Físicos Funcionais (TFF) para avaliar a capacidade de estabilização lombo-pélvica (Testes de Coordenação e Equilíbrio, Flexibilidade, Resistência e Comprimento e Força) e à Determinação de início de ativação muscular do TrA/OI e ML por meio da eletromiografia de superfície (EMG-S) durante movimento rápido de flexão do membro superior. Resultados: Embora a pré-ativação tenha sido o comportamento mais freqüente a ausência de pré-ativação do TrA/OI e ML ocorreu para alguns voluntários, sendo mais freqüente no músculo TrA/OI (26.6%) do gênero feminino. Nos TFF nenhum voluntário da amostra conseguiu obter valores de normalidade em todos os testes realizados e aqueles com maior número de voluntários com alteração foram: teste de flexibilidade do reto femoral e espinhais lombares, teste de enrolamento repetitivo do tronco, teste estático de resistência das costas de Sorensen e o teste de comprimento e força para o glúteo máximo. Entretanto, somente o teste de enrolamento... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Contextualization: It is observed in the literature that asymptomatic individuals may not have muscular pre-activation of primary stabilizers and there are no studies that point to the reasons for the change in time of onset of the muscle activation in this population. Furthermore, preliminary studies in our laboratory showed that asymptomatic individuals presented alterations in physical and functional tests with relationship the capacity of lumbo-pelvic stabilization. Objective: The study of pre-activation behavior of transversus abdominis/internal oblique muscle (TrA/OI) and lumborum multifidus (ML), the lumbo-pelvic stabilization capacity and the relationship of both. Methodology: Were selected 27 asymptomatic individuals of both sexes, with age between 20 e 28 years (mean = 23,85 ±2,21). The volunteers were submitted to a Physical Functional Tests (FFT) to evaluate a lumbo-pelvic stabilization capacity (coordination tests, balance, flexibility, endurance, length and force) and the determination of muscle activation onset of the TrA/OI and ML with superficial electromyography (EMG-S) during fast flexion arm movement. Results: Although pre-activation has been a usual result, the pre-activation absent of TrA/OI and ML happened in some volunteers, being more frequent for TrA/OI (26.6%) in the female gender. At TFF neither volunteers of the sample get regular scores in all tests executed. Those tests with more number of alterations were: rectus femoris and spinal lumbar flexibility, Sorensen static back endurance, and length and force to gluteus maximus. However, only repetitive trunk curl test showed great sensibility and specificity value with the primary stabilizers behavior of pre-activation / Mestre

A fadiga de músculos estabilizadores do tornozelo pode piorar o desempenho nas atividades funcionais e no controle postural. É necessário na prática clínica dispor de testes quantitativos que auxiliem na avaliação de possíveis déficits funcionais para proporcionar maior nível de evidência na tomada de decisões clínicas. Este estudo teve por objetivo avaliar o desempenho de pessoas saudáveis em testes funcionais de salto e de equilíbrio estático nas condições pré e pós fadiga dos músculos inversores e eversores do tornozelo. Foram avaliados 30 voluntários saudáveis, de ambos os gêneros com média de idade de 24,3 ± 2,0 (20 - 28) anos de idade, praticantes de atividade física de 2 a 3 vezes na semana e média 1,7 ± 0,6 (1-3) horas por dia. Foram realizados dois dias de avaliação, sendo um dia na condição sem fadiga e outro dia com fadiga dos músculos inversores e eversores do tornozelo. O intervalo mínimo entre os dias de avaliação foi de 48 horas. Os testes realizados foram a posturografia estática na plataforma de força (AMTI) em apoio bipodal olhos abertos e fechados e em apoio unipodal olhos abertos e os testes funcionais de salto (figura em oito, cruzado, lateral e quadrado). A fadiga foi induzida pela dinamometria isocinética (Byodex) nos músculos inversores e eversores de tornozelo com 30 repetições na velocidade de 120°/seg. Os dados obtidos foram tabulados e analisados no software estatístico SPSS, considerando o p <= 0,05. Os resultados demonstraram piora no desempenho dos testes funcionais e do controle postural em todas as condições, após indução de fadiga muscular. A fadiga prejudica a propriocepção e cinestesia da articulação do tornozelo pelo aumento do limiar de descarga do fuso muscular, diminuição da aferência e senso de alerta articular. Os testes funcionais de salto podem ser considerados úteis para a prática clínica, sendo ainda considerados de baixo custo / Muscle fatigue of the stabilizing muscles of the ankle may influence in the performance of functional activities and postural control. It is important to have quantitative tests that helps assess the function of individuals to provide highest level of evidence for clinical practice decisions. This study aimed to evaluate the performance in jumping functional tests and static equilibrium of healthy people in the conditions pre and post fatigue of invertors and evertor ankle muscles. Thirty healthy volunteers of both genders were evaluated with a mean age of 24.3 ± 2.0 (28 - 20) years old and physically active, 2-3 times a week and average 1.7 ± 0.6 (1-3 ) hours per day. Two days of evaluation were performed, one day in the condition without fatigue and the other day with fatigue of invertor and evertor muscles. The minimum interval between the days of evaluation was 48 hours. Tests included: static posturography on the force platform (AMTI) in bipedal support with open and closed eyes and; unipodal support with eyes open; and jumping functional tests (figure eight, cross, side and square). The fatigue was induced by isokinetic dynamometry (Byodex) of the invertor and evertor ankle muscles with 30 repetitions at 120°/sec. Data were analyzed with the statistical software SPSS and p <= 0.05. The results showed worsening in the performance of functional tests and postural control in all conditions, after induction of muscle fatigue. Fatigue impairs proprioception and kinesthetic ankle joint by increasing the threshold for discharge of muscle spindle, decreased articular afference and sense of alert. The jumping functional tests can be considered useful for clinical practice and also is considered low-cost

The aim of the diploma thesis is to evaluate the mobility of the spine, the condition of flaton and the basic anthropological characteristics of boys and girls aged 13 and 15 years. Testing will be performed with non-invasive, standard tests and tests used in anthropological and medical practice. The data will be compared with the results of previous research. From the measured values, basic somatic dimensions, such as body weight, body height, circumference of right arm and head, were selected. The body mass index was calculated from body weight and height values. The diploma thesis deals with the assessment of the mobility of spine and flats. The Stibor test, Otto's test, Schober's test, the Cepoj test, the lateroflex test, and the modified Thomayer test were selected from the tests that evaluated the spine. In spine functional tests, the most interesting results of the Čepoj symptom are that the average values of cervical spine mobility deteriorate with the increasing age of boys. In the lateroflex tests, 13-year-old girls and 15-year-old boys beat the best average values. Additionally, these boys had the worst results in Stibor and Schrober's flag when deflected, but paradoxically achieved the best average values. The findings were compared with the results of previous research.

Submitted by Luciana Sebin (lusebin@ufscar.br) on 2016-09-28T18:20:21Z No. of bitstreams: 1 DissNSS.pdf: 2430631 bytes, checksum: 80e06dbb352e5d774c4359f8a1b25af3 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-10T18:39:35Z (GMT) No. of bitstreams: 1 DissNSS.pdf: 2430631 bytes, checksum: 80e06dbb352e5d774c4359f8a1b25af3 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-10T18:39:46Z (GMT) No. of bitstreams: 1 DissNSS.pdf: 2430631 bytes, checksum: 80e06dbb352e5d774c4359f8a1b25af3 (MD5) / Made available in DSpace on 2016-10-10T18:39:56Z (GMT). No. of bitstreams: 1 DissNSS.pdf: 2430631 bytes, checksum: 80e06dbb352e5d774c4359f8a1b25af3 (MD5) Previous issue date: 2016-01-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Introduction: when any part of the Upper Limb (UL) is injured, the demands brought by customers are assessed from different instruments, however studies show that there is no consensus on an ideal instrument for assessing the quantity and quality of the UL function, demonstrating the need to find tools that can provide precise measurements of how the UL perform tasks. Objectives: characterize the Box and Block Test (BBT), the Functional Dexterity Test (FDT) and the Nine Hole Peg Test (NHPT) regarding the electromyographic activity of the trapezius upper fibers muscle (TUF), deltoid anterior fibers muscle (DAF) and posterior fibers (DPF), the pectoralis major muscle (PM), the biceps (BB) and triceps brachii (TB), extensor carpi radialis brevis (ERB) and flexor digitorum superficialis (FDS) and verify if there are differences in muscle activation during the three tests between genders. Method: non-experimental research, descriptive transversal quantitative approach. Were selected 20 college students of both genders, average age of 24 years and average Body Mass Index (BMI) of 24 kg m-2. Data analysis was made using MiotecSuite 1.0 software and by Friedman, Dunn, Mann-Whitney and Spearman statistical tests. Results: For the three tests, the TUF was the most activated, followed by FDS. DAF, DPF and PM showed a high percentage of neuroactivation in BBT test. ERB showed percentage of activation between intermediate and high in FDT and NHPT tests. Conclusion: FDT and NHPT tests may be more recommended to assess the function of the UL of persons with upper extremity lesions, while the BBT may be indicated for both proximal and distal lesions of UL. Women have a higher muscle activation than men, and this fact can be justified by the muscular genetic difference between them. / Introdução: Ao se lesionar qualquer parte do membro superior (MS), as demandas trazidas pelos clientes são avaliadas a partir de diferentes instrumentos, porém estudos mostram que não há um consenso sobre um instrumento ideal para avaliação da quantidade e qualidade da função do MS, demostrando que é necessário encontrar ferramentas que possam fornecer medidas precisas sobre como o MS executa tarefas. Objetivos: Caracterizar os testes Box and Blocks Test (BBT), Functional Dexterity Test (FDT) e Nine Hole Peg Test (NHPT) em relação à atividade eletromiográfica dos músculos trapézio fibras superiores (TFS), deltóide fibras anteriores (DFA) e posteriores (DFP), peitoral maior (PM), bíceps (BB) e tríceps braquial (TB), extensor radial curto do carpo (ERC) e flexor superficial dos dedos (FSD) e verificar se há diferença na ativação muscular durante os três testes entre os gêneros. Método: Pesquisa não experimental, do tipo transversal descritivo de abordagem quantitativa. Foram selecionados 20 estudantes universitários de ambos os gêneros, idade média de 24 anos e Índice de Massa Corporal (IMC) médio de 24kg/m2. A análise dos dados foi feita pelo Software MiotecSuite 1.0 e pelos testes estatísticos Friedman, Dunn, Mann-Whitney e Spearman. Resultados: Para os três testes o TFS foi o mais ativado, seguido pelo FSD. O DFA, DFP e PM apresentaram uma porcentagem de neuroativação elevada no teste BBT. O ERC apresentou porcentagem de ativação entre intermediária a alta nos testes FDT e NHPT. Conclusão: os testes FDT e NHPT podem ser mais recomendados para avaliarem a função do MS de sujeitos com lesões de extremidade superior, enquanto que o BBT pode ser indicado para lesões tanto proximais quanto distais do MS. As mulheres apresentaram uma ativação muscular maior à dos homens, podendo ser justificada pela diferença genética muscular existente entre ambos.

In this diplomatic work, the issue of low-temperature asphalts and binders for asphalt mixtures is solved. Diploma work is divided into two parts, theoretical and practical. In the theoretical part of diploma work, the purpose was to process a overview of technologies that allow the reduction of working temperature in the production and laying of asphalt mixtures. The purpose of the practical part was to comparison the functional parameters of two types of asphalt mixtures made in two variants, with the common asphalt binder and adding licomont into asphalt. Attention was given to stiffness, wheel drive tests and low temperature parameters.

The aim of the thesis was to determine the four selected body measurements (body height , body weight , chest circumference , waist circumference) , measuring 3 functional tests (spirometry, dynamometry, Ruffini test) and an assessment of the level of motor skills for boys and girls aged between 13 and 15 years who fall into the general population of predolescence and adolescence school age . Using standard methods somatometric were selected 34 boys aged 13, 34 boys aged 15, 34 girls aged 13 and girls aged 34 to 15 years. The selected parameters were monitored: body length, weight, chest circumference and waist. The research findings also motoric performance of boys and girls aged between 13 and 15 years. Motor performance was tested by 14 motor tests. All this research was conducted at elementary and secondary schools in the South Bohemia Data were recorded in a previously prepared data sheets and were then statistically analyzed and processed in tables and graphs. All obtained data were compared with the results of earlier studies and may serve as reference materials for other researches. Furthermore, function tests were included in the results of the selected in this thesis (spirometry, dynamometry and Ruffini test). These functional tests are aimed primarily at first assessment of fitness of the respiratory and circulatory system in this age group.

The aim of this thesis was to describe the evolution of body size, level of motor and physical skills of children aged 13 and 15 years. The research was carried out in primary schools in the South Bohemian Region. The results were processed for each age group separately, they were compared with the reference files and are presented in tables and graphs. To compare the files, there was used Student´s T-test and Z-score. The boys also filled in a questionnaire in which they answered how often in sports and what sports they pursue. A similar questionnaire was presented to their parents. Questionnaires were also focused on diet and nutrition.

Made available in DSpace on 2016-06-02T20:18:16Z (GMT). No. of bitstreams: 1 4184.pdf: 13787055 bytes, checksum: 434e5f6a43d2ae2b1233af9adab7c137 (MD5) Previous issue date: 2012-02-23 / Financiadora de Estudos e Projetos / The aim of Study 1 was to evaluate the effects of using oral contraceptives (OC) on the hip and knee kinematics of healthy women during single-leg squat. Forty two volunteers were divided into two groups: women who had used OC (n= 21) and women who did not use OC (n= 21). The knee abduction/adduction, hip abduction/adduction and medial/lateral rotation excursions (maximum and at 75º of knee flexion) were calculated for the dominant limb during single-leg squat. No significant difference was verified between the groups regarding the maximum excursion of knee abduction (p= 0.26) or hip adduction (p= 0.10) and medial rotation (p= 0.94). When considering the knee flexion at 75º, no significant difference was verified between the groups regarding the excursion of knee abduction (p= 0.31) or hip adduction (p= 0.11) and medial rotation (p= 0.85). These results suggest that the use of OC does not influence the hip and knee kinematics during single-leg squat. As a complement, the aim of Study 2 was to evaluate the effects of using OC on the hip and knee kinematics of healthy women during anterior stair descent. Forty volunteers were divided into two groups: women who had used OC (n= 20) and 2 - women who did not use OC (n= 20). The knee abduction/adduction, hip abduction/adduction and medial/lateral rotation excursions were calculated for the dominant (supporting) limb during anterior stair descent. No significant difference was verified between the groups regarding the maximum excursion of knee abduction (p= 0.58) or hip adduction (p= 0.29) and medial rotation (p= 0.42). When considering the knee flexion at 50º, no significant difference was verified between the groups regarding the excursion of knee abduction (p= 0.92) or hip adduction (p= 0.50) and medial/lateral rotation (p= 0.19). These results suggest that the use of OC does not influence the hip and knee kinematics during anterior stair descent. The aim of Study 3 was to verify the effects of eight-week plyometric training (PT) on hip and knee kinematics and on eccentric hip and knee torques, as well as on lower limb functional performance in healthy women. Thirty-six females were divided into a training group (TG; n= 18), and a control group (CG; n= 18). Kinematic analyses of the hip and knee was carried out during the single-leg squat and the functional performance was evaluated by way of the triple hop (TH) test and the six-meter timed hop (STH) test. The eccentric hip abductor, adductor, lateral rotator and medial rotator as well as the knee flexor and extensor torques/body weight were measured using an isokinetic dynamometer. After 8 weeks, the TG showed a decrease in maximum excursion to knee abduction (p= 0.009) and in maximum excursion to hip adduction (p<0.001), as well as in the excursion to hip adduction at 75º of knee flexion (p=0.002). Moreover, the TG significantly increased the values obtained in the TH test (p=0.05) and significantly decreased those obtained in the STH test (p<0.001) after intervention. However, there was no significant change on hip and knee eccentric torques. Thus, eight weeks of PT were effective to improve hip and knee kinematics and functional performance of women in hop tests. However this was apparently not an effective method to promote strengthening of the hip and knee muscles when used alone / O objetivo do Estudo 1 foi avaliar o efeito do uso dos contraceptivos orais (CO) na cinemática do quadril e do joelho durante o agachamento unipodal em mulheres sadias. Quarenta e duas voluntárias foram divididas em dois grupos: que utilizavam (n=21) ou não (n=21) os CO. As excursões (máximas e no ângulo de 75º de flexão do joelho) em abdução/adução do joelho, em abdução/adução do quadril e em rotação medial/lateral do quadril foram verificadas durante a realização do agachamento unipodal com o membro inferior dominante. Não houve diferença significativa entre os grupos quanto à máxima excursão em abdução do joelho (p=0,26) e em adução (p=0,10) e rotação medial (p=0,94) do quadril. Quando considerado o ângulo de 75º de flexão do joelho, nenhuma diferença significativa foi verificada entre os grupos para os valores de excursão em abdução do joelho (p=0,31) e em adução (p=0,11) e rotação medial (p=0,85) do quadril. Estes achados sugerem que o uso de CO não influencia a cinemática do joelho e do quadril durante a realização do agachamento unipodal. De forma complementar, o Estudo 2 teve por objetivo avaliar os efeitos do uso de CO na cinemática do quadril e do joelho de mulheres sadias durante a descida anterior de degraus. Quarenta voluntárias foram divididas em dois grupos: que utilizavam (n=20) ou não (n=20) os CO. As excursões em abdução/adução do joelho, abdução/adução do quadril e rotação medial/lateral do quadril foram calculadas para o membro dominante durante a descida anterior de degraus. Nenhuma diferença significativa foi verificada entre os grupos para a excursão máxima em abdução do joelho (p=0,58) ou em adução (p=0,29) e rotação medial (p=0,42) do quadril. Quando considerado o ângulo de flexão do joelho de 50º, nenhuma diferença foi verificada entre os grupos para a excursão em abdução do joelho (p=0,92) ou em adução (p=0,50) e rotação medial/lateral (p=0,19) do quadril. Estes resultados sugerem que o uso de CO não influencia a cinemática do quadril e do joelho durante a descida anterior de degraus. A proposta do Estudo 3 foi verificar os efeitos do treinamento pliométrico (TP) de 8 semanas na cinemática e no torque excêntrico do quadril e do joelho, bem como sobre o desempenho funcional do membro inferior de mulheres sadias. Trinta e seis mulheres foram divididas em dois grupos: 1) grupo treinamento (GT; n=18) e 2) grupo controle (GC; n=18). A análise cinemática do quadril e do joelho foi realizada durante o agachamento unipodal e o desempenho funcional foi avaliado por meio do salto triplo unipodal (STU) e pelo salto unipodal em 6 metros cronometrado (SUC). A relação torque excêntrico abdutor, adutor, rotador lateral e rotador medial do quadril/massa corporal e o torque excêntrico flexor e extensor do joelho/massa corporal foram mensurados por meio de um dinamômetro isocinético. Após 8 semanas, o GT apresentou diminuição da excursão máxima em abdução do joelho (p=0,009) e em adução do quadril (p<0,001), bem como da excursão em adução do quadril a 75º de flexão do joelho (p=0,002). Além disso, o GT apresentou melhora no desempenho funcional para o STU (p=0,05) e para o SUC (p<0,001). Entretanto, não houve modificação significativa nos torques excêntricos do quadril e do joelho. Deste modo, o TP oito semanas foi eficiente para induzir alterações positivas de ordem cinemática e funcional nas mulheres avaliadas. Contudo, não apresentou eficiência para promover o fortalecimento dos músculos do quadril o joelho

Ce travail de thèse s'est intéressé à l'étude des facteurs permettant d'expliquer les performances fonctionnelles des membres inférieurs des personnes âgées. Dans une première étude, nous avons montré que la puissance maximale (Pmax) ainsi que sa composante appelée la vitesse optimale (Vopt) obtenues lors d'un test de force-vitesse des extenseurs du genou, sont des facteurs déterminants de la performance fonctionnelle des personnes âgées évaluées sur 3 tests : marche sur 6m, se relever et s'assoir 5 fois de suite à partir d'une chaise et monter 6 marches d'escalier. Ainsi, plus une personne possède une Pmax et une Vopt élevées, plus ses performances lors de tests fonctionnels seront élevées. De plus, la Vopt étant considérée comme une évaluation indirecte du pourcentage de fibres rapides, les sujets ayant les plus grandes valeurs de Vopt sont les plus performantes aux tests fonctionnels. La deuxième étude a mesuré et comparé l'activité électromyographique (EMG) du quadriceps lors des tests de contraction isométrique volontaire maximal (IMVC), de détermination de la puissance maximale et des tests fonctionnels cités cidessus. La mesure du signal EMG au cours de ces différents tests a permis de déterminer dans quelle mesure le type de tâche induit une activation maximale ou non. Les personnes âgées montrent une capacité à davantage activer leurs quadriceps lors des tests de de contraction concentrique plutôt qu'isométrique ou excentrique. Les tests utilisant l'IMVC comparé aux tests de détermination de la puissance et de monté de marche, et de lever de chaise ne seraient pas les tests les plus appropriés pour mesurer les capacités maximales d'activation neuromusculaires chez la personne âgée. Il ressort de ces résultats une amélioration du testing de la personne âgée et des orientations pour la réhabilitation / This work has focused on the study of factors that explain the functionals performances of the lower limbs of the elderly. In a first study we showed that the maximum power (Pmax) and its component called the optimal speed (Vopt) obtained during a test of force-velocity of the knee extensors, are important determinants of functional performance elderly evaluated on three tests: walking on 6m, sit to stand 5 times from a chair and climbing 5 stairs. The more a person has a high Pmax and Vopt, the more its performance during functional tests will be. In addition, Vopt is considered an indirect assessment of the percentage of fast fibers; subjects with the highest values of Vopt are best performers during functional tests. The second study measured and compared the electromyographic (EMG) activity of the quadriceps when tested for isometric maximum voluntary contraction (IMVC), determination of maximum power and functional tests mentioned above. Measurement of EMG signal during these tests was used to determine to what extent the type of task induced a maximum activation or not. Older people show a greater ability to activate their quadriceps muscles when tested for concentric contraction rather than isometric or eccentric contractions. Tests using the IMVC compared to tests for determining the power, sit-tostand and stairs climbing would not be the most appropriate tests to measure the maximum neuromuscular activation capacity in the elderly. From these results improved testing of the elderly and guidelines for rehabilitation are proposed