This thesis examined the change in skeletal muscle architecture with contractile force production, the relationship of architecture with muscle strength parameters and if muscle tendinous tissue stiffness determines in vivo explosive strength (i.e. rate of torque development, RTD). Muscle and tendinous tissue adaptations to contrasting strength training regimes, and the potential capacity of these tissues to adapt following chronic strength training were also explored. Quadriceps femoris fascicle length (FL) decreased, while the pennation angle (PA) increased in a curvi-linearly manner from rest to maximal voluntary contraction (MVC) torque. Consequently, effective physiological cross-sectional area (effPCSA) during MVC was 27% greater than at rest, although effPCSA measured at rest and during MVC had similar correlations to maximal strength. In the earliest phase of contraction, FL, but not PA, was negatively related (R2=0.187) to voluntary RTD. Neither FL nor PA was related to maximal isometric or dynamic strength. Muscle-tendon unit (MTU) and patellar tendon (PT) stiffness were unrelated to voluntary and evoked RTD. Relative PT stiffness was also unrelated to relative RTD, although relative MTU stiffness was related to voluntary RTD (25-55%MVT, R2≤0.188) and evoked RTD (5-50%MVT, R2≤0.194). MTU stiffness increased after sustained-contraction (SCT, +21%), though not explosive-contraction strength training (ECT). PT stiffness increased similarly after ECT (+20%) and SCT (+16%), yet neither induced tendon hypertrophy. SCT produced modest muscle (+8%) and aponeurosis (+7%) hypertrophy. Chronic strength trained (CST: >3 years) males had substantially greater muscle and aponeurosis size, but similar tendon size as untrained controls (UNT) and short-term (12 weeks) strength trained (STT) individuals. Between these groups, at the highest common force, MTU stiffness was indifferent, while PT stiffness was similarly greater in STT and CST than UNT. These results suggest FL and PA have little influence on muscle strength and tendon stiffness has no influence on RTD. Maximum strength negated any qualitative influence of MTU stiffness on in vivo RTD. Component MTU tissues (muscle-aponeurosis vs. external tendon) adapt differentially depending on the strength training regime. Specifically, free tendon appeared to adapt to high magnitude loading, while loading duration is also an important stimulus for the muscle-aponeurosis. However, chronic strength training was not concordant with greater higher force MTU stiffness, and does not further increase higher force PT stiffness beyond the adaptations that occur after 12 weeks of strength training. Finally, no evidence was found for tendon hypertrophy in response to strength training.

Made available in DSpace on 2014-06-11T19:31:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-06-01Bitstream added on 2014-06-13T20:01:41Z : No. of bitstreams: 1 oliveira_ggs_dr_jabo.pdf: 1931508 bytes, checksum: ec37215def296c0d2f60ec5f4d3da9f1 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / No presente estudo, objetivou-se avaliar a utilização do enxerto alógeno de ligamento patelar (OLO) conservado em glicerina 98% e fixado por meio de parafusos de interferência como substituto do ligamento cruzado cranial (LCCr) em cães. Observou-se a exeqüibilidade e eficácia desta técnica cirúrgica e o comportamento do enxerto e dos parafusos durante o período de 120 dias, baseandose na capacidade dos exames clínicos, radiográficos e artroscópicos, em detectar o possível início e a progressão de alterações degenerativas secundárias na articulação do joelho. Para tanto foram utilizados oito animais da espécie canina pesando entre 17,2 e 26,4Kg. O enxerto utilizado correspondeu ao segmento composto pelo terço intermédio da patela, ligamento patelar e porção cranial da tuberosidade da tíbia, coletado de cadáveres de cães e conservado em glicerina 98%. Os oito cães foram separados em dois grupos, A e B e cada um contendo quatro animais para avaliação artroscópica (segunda observação) aos 60 e 120 dias do pós-operatório. Todos os cães foram submetidos ao procedimento cirúrgico no joelho direito. Clinicamente, avaliou-se o grau de claudicação, o perímetro muscular da coxa e o movimento de gaveta cranial nos oito cães no pré-operatório e semanalmente, até completarem-se 120 dias. Foi observada diminuição da circunferência da coxa significativa (p<0,05) após o período de dez dias em que os cães permaneceram com a bandagem compressiva, sendo recuperada de forma significativa até 13° semana. As pontuações obtidas na avaliação do movimento de gaveta (extensão e flexão) tornaram-se significativamente diferentes da pré-operatória entre a 5° e 15° semanas (p<0,05). Quatro cães apresentaram ao final do experimento ausência de instabilidade articular como na avaliação pré-operatória e os outros... / The aim of this study was to evaluate the use of patelar ligament allograft (BLB) conserved in 98% glycerin and fixated with interferemce screws as a substitute of the cranial cruciate ligament in dogs (CrCL). It was observed the feasibility and efficiency of this surgical technique and the graft and screws conduct along 120 days, basing on clinical, radiographic and arthroscopic capacity in detect the beginning and progress of secondary degenerative stifle joint changes. For this purpose, eight mongrel dogs weighting from 17,2 e 26,4 Kg were used. The graft consisted of the intermediate third of the pattela, patellar ligament and cranial portion of the tibial crest, harvested from dog cadavers and preserved in 98% glycerin.The eight dogs were randomly allocated in two groups, A and B, each one with four dogs for arthroscopic evaluation (second-look) at 60 and 120 days postoperative. All the dogs were submitted to the surgical procedure in the right knee. Clinically, lameness degree, thigh girth measurement and cranial-drawer test were evaluated in the eight dogs in preoperative, and weekly, until complete 120 days. A significant decrease in thigh girth (p<0,05) observed after ten days period that the dogs were using compressive bandage was recovered until the 13th week. The cranial-drawer test scores (flexion and extension) became significantly different between the 5th and 15th weeks postoperative (p>0,05). Four dogs presented at the final study period with no articular instability just like the preoperative evaluation, and the other four with just a slight craniocaudal instability. In the lameness evaluation, from the 4th week, all the dogs presented mean score for stands with equal... (Complete abstract click electronic access below)

O mal alinhamento do membro pélvico de cães contribui para o desenvolvimento ósseo anormal e deslocamento medial ou lateral do aparelho extensor do quadríceps. De acordo com o aumento da incidência da luxação de patela em cães de médio e grande porte, o estudo do alinhamento do membro pélvico e das deformidades ósseas associadas recebeu destaque. Assim, o conhecimento do eixo mecânico e do alinhamento do membro pélvico, bem como de seus ângulos articulares no plano frontal, é essencial para o diagnóstico, classificação, quantificação do grau de desvio, e para o delineamento do tratamento cirúrgico corretivo. O presente estudo teve como objetivo mensurar e correlacionar os ângulos articulares do fêmur e da tíbia com o diferentes graus de luxação de patela. Foram obtidos exames radiográficos independentes do fêmur e da tíbia, nas projeções craniocaudal e caudocranial, respectivamente, de cães com e sem luxação de patela. As imagens radiográficas foram processadas digitalmente produzindo 92 exames radiográficos do membro pélvico em extensão total que foram divididos em grupos controle e luxação de patela. O grupo luxação foi subdividido de acordo com o tipo de luxação, medial ou lateral. Foram determinados os ângulos articulares, alinhamento e o eixo mecânico do membro pélvico correlacionando os resultados com a luxação de patela. Concluiu-se que o grau de luxação de patela interferiu na magnitude do desvio do eixo mecânico e no valor do ângulo mecânico femorotibial, e que o valor do ângulo mecânico lateral distal do fêmur foi maior nos cães com luxação de patela, sugerindo a presença de deformidade femoral distal. / The misalignment of the pelvic limb dogs contributes to abnormal bone development and medial or lateral displacement of the extensor mechanism. Increased incidences of the patellar dislocation in medium and large dogs stimulated alignment study and the associated bone deformities. Thus, knowledge of the mechanical axis and the pelvic limb alignment, as well as their joint angles in the frontal plane is essential for the diagnosis, classification, quantification of the degree of deviation and for the design of corrective surgery. The purpose of this study was to measure the femoral and tibial articular angles and and assess the relationship between it and the different degrees of patellar luxation. Independent radiographs of the femur and tibia of dogs with or without patellar luxation were obtained in the craniocaudal and caudocranial projections, respectively. The radiographic images were digitally processed producing 92 x-ray exams of the pelvic limb in full extension that were divided into control and patella luxation groups. The patellar luxation group was divided according to the type of dislocation, medial or lateral, and dislocation grade. The joint angles, alignment and the mechanical axis of the pelvic limb were determined and the results were correlated with the disease. In conclusion, the degree of patellar dislocation interfered with the magnitude of the mechanical axis deviation and the value of mechanical femorotibial angle, the value of the mechanical lateral distal femoral angle was higher in dogs with patellar dislocation, suggesting the presence of femoral distal deformity.

Este trabalho objetivou avaliar através do exame clínico, radiográfico e ultra-sonográfico a articulação fêmuro-tíbio-patelar pós desmotomia patelar medial. Foram utilizados oito equinos, machos e fêmeas, de peso, raça e idade variáveis. Todos animais foram submetidos a desmotomia patelar medial no membro pélvico direito. Os exames clínico e ultra-sonográfico foram realizados no 7&ordm;, 14&ordm;, 21&ordm;, 28&ordm;, 43&ordm;, 58&ordm;, 88&ordm; e 118&ordm; dia do pós-operatório. Os exames radiográficos e do líquido sinovial foram realizados no 15&ordm;, 30&ordm;, 60&ordm;, 90&ordm; e 120&ordm; dia do pós-operatório. No pós-operatório foi observado durante exame radiográfico do joelho direito, aumento do ângulo entre a superfície articular proximal da patela e a superfície cranial distal do fêmur, formação óssea na crista tibial, entesofitos na patela, deslocamento da patela e irregularidade óssea na superfície patelar lateral. No exame ultra-sonográfico foi observado aumento da espessura (p&lt;0,05) no segmento proximal e médio do ligamento patelar intermédio do membro pélvico direito, desmite do patelar intermédio, enteseofitos na patela, distensão do recesso articular medial do fêmur, efusão articular e irregularidade da cartilagem do sulco troclear femoral. Conclui-se que a desmotomia patelar medial causa alterações no joelho devido a instbilidade articular e deve ser indicada apenas nos casos que não responderam a outras forma de tratamento. / This study aimed the evaluation of the femurotibiopatellar joint trough clinical, radiographic and ultrasonographic examinations after experimental medial patellar desmotomy. Medial patellar desmotomy was performed on the right hindlimb in eight mixed-breed horses. The clinical and ultrasonographic evaluation was performed on day 7, 14, 21, 28, 43, 58, 88 e 118 after surgery. The radiographic and synovial fluid evaluation was performed on day 15, 30, 60, 90 e 120 after surgery. It was observed during radiographic evaluation of the right stifle, an increase of the angle between the patellar proximal articular surface and the cranial distal femur surface. During ultrasonographic evaluation it was observed thickening (p&lt;0,05) on the proximal and midlle segment of the midlle patellar ligament on the right hindlimb, entesophyte at the patella, femoral medial joint recess distending, joint effusion and cartilage irregularity of the femoral troclear groove. The medial patellar desmotomy causes stifle changes and must be performed only in animals non responsive to other treatment.

INTRODUÇÃO: O plasma rico em plaquetas (PRP) é utilizado em medicina esportiva para aumentar e acelerar o processo de reparação tecidual em lesões tendineas e ligamentares, no intuito de proporcionar um retorno mais rápido às atividades esportivas. No entanto faltam estudos com alto nível de evidência comprovando sua eficácia no tratamento destas lesões. Com o objetivo de estudar o efeito da aplicação do PRP no sitio doador de enxerto do ligamento da patela para reconstrução do ligamento cruzado anterior (LCA), realizamos ressonância magnética aos seis meses de pós-operatório para avaliar o ligamento da patela. Também aplicamos questionários de função do joelho e realizamos teste isocinético após seis meses da cirurgia. MÉTODOS: O presente estudo prospectivo, randomizado, avaliador cego incluiu 27 pacientes. Comparamos doze pacientes em que foi utilizado o PRP no defeito criado no terço central do ligamento da patela para retirada de enxerto com quinze pacientes do grupo controle. Aos seis meses de cirurgia realizamos ressonância magnética, em que foi avaliada a área não regenerada do defeito no terço central do ligamento da patela, a área de secção transversa do ligamento e a altura da patela pelo índice de Insall- Salvati. Realizamos teste isocinético e aplicamos questionários específicos de função do joelho. Quantificamos a dor pós-operatória imediata com escala visual analógica (EVA) de dor. RESULTADOS: Aos seis meses de pós-operatório a área não regenerada do defeito no terço central do ligamento da patela foi 4,95 mm2 no grupo PRP e 9,38 mm2 no grupo controle (p=0,046, teste t de Student). A área de secção transversa do ligamento da patela no grupo PRP foi de 173,05 mm2 e no grupo controle 176,29 mm2 (p=0,856). O índice de Insall-Salvati nos grupos PRP e controle foi de 1,04 e 1,06, respectivamente (p=0,808). Não houve diferença entre os grupos nos resultados dos questionários e teste isocinético. Nos pacientes em que foi utilizado o PRP houve menos dor pós-operatória imediata (p=0,02). CONCLUSÃO: Concluímos, nessa amostra, que o uso do PRP no defeito do terço central do ligamento da patela na reconstrução do LCA, nos primeiros seis meses; determinou maior regeneração do defeito; diminuiu a intensidade da dor pós-operatória imediata; não ocasionou alterações estruturais na avaliação por ressonância magnética; e não modificou os resultados clínicos e funcionais da cirurgia / INTRODUCTION: Platelet-rich plasma (PRP) has been used in sports medicine to improve and accelerate ligaments and tendons healing, in an effort to provide a faster return to sports activities. However there is a lack of high evidence level studies to support its use. With the purpose to study the effect of PRP, patellar ligament was evaluated six months after harvesting its central third with magnetic resonance imaging (MRI). We also applied specific questionnaires of knee function and isokinetic testing. METHODS: This blinded, randomized, prospective study included 27 patients. Twelve patients in whom we added PRP in the patellar ligament after harvesting its central third for ACL reconstruction were compared to fifteen patients in the control group. After six months we evaluated the non-regenerated area of the patellar ligament, the cross section area of the patellar ligament and its length (Insall-Salvati index) with MRI. We also evaluated the results of isokinetic testing and specific questionnaires of knee function. Immediate post-operative pain was evaluated with visual analogical scale (VAS) score. RESULTS: The non-regenerated area of the patellar ligament was 4,95 mm2 in the PRP group and 9,35 mm2 in the control group (p=0,046 test). The cross section area of the patellar ligament in the PRP group was 173,05 mm2 and in the control group 176,29 mm2 (p=0,856). The Insall- Salvati index in the PRP and control group was 1,04 and 1,06, respectively (p=0,806). There was no difference between the groups in the questionnaires and isokinetic testing results. PRP group patients had less post-operative pain (p=0,02). CONCLUSION: We concluded, in this sample, that the use of PRP in the patellar ligament after harvesting its central third for ACL reconstruction, in the first six months: improved the ligament regeneration; reduced the intensity of immediate post-operative pain; did not cause structural changes in the patellar ligament in MRI; and did not modify the clinical and functional results of the procedure

Syfte Syftet med denna studie var att undersöka om det finns någon skillnad i förekomsten av riskfaktorer för Patellar Tendinopati (PT) mellan volleybollspelande ungdomar med PT och utan PT. Metod Målpopulationen som valdes i studien var 59 elever på volleyboll Riksidrottsgymnasiet. Eleverna var mellan 15 och 19 år. Den elektroniska webbenkäten bestod av 43 frågor uppdelade i 3 huvudområden; icke-träningsrelaterade variabler, träningsrelaterade variabler, och psykologiska variabler användes. Oberoende T-test och Mann-Whitney U-test användes för analys av skillnaden mellan gruppen av individer drabbade av PT (PTG) och kontrollgrupp (KG). Resultat Av alla deltagare som svarat på enkäten led 40 % av PT. Resultatet från enkäten visar att det finns skillnader mellan PTG och KG för faktorerna; BMI (PTG=23,1 ± 1,5 jämfört med KG= 21,7 ± 2.1, P=0,01), vikt (PTG=78,81 ± 6,5, KG= 71,6 ± 10,7, P=0,01), brist på återhämtning och sömn (P=0,001), acceptansen av smärta som en del av elitidrott (P=0,006), samt deltagarnas inställning att träna trots smärta (P=0,006). Resultatet visar ingen skillnad mellan PT-gruppen och kontrollgruppen med avseende på träningsrelaterade variabler. Slutsats BMI, vikt, brist på sömn, acceptansen av smärta samt deltagarnas inställning att träna trots smärta är riskfaktorer som skiljer sig mellan volleybollspelande elever drabbade av PT och elever som inte är drabbade av PT.

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Resumo: No presente estudo, objetivou-se avaliar a utilização do enxerto alógeno de ligamento patelar (OLO) conservado em glicerina 98% e fixado por meio de parafusos de interferência como substituto do ligamento cruzado cranial (LCCr) em cães. Observou-se a exeqüibilidade e eficácia desta técnica cirúrgica e o comportamento do enxerto e dos parafusos durante o período de 120 dias, baseandose na capacidade dos exames clínicos, radiográficos e artroscópicos, em detectar o possível início e a progressão de alterações degenerativas secundárias na articulação do joelho. Para tanto foram utilizados oito animais da espécie canina pesando entre 17,2 e 26,4Kg. O enxerto utilizado correspondeu ao segmento composto pelo terço intermédio da patela, ligamento patelar e porção cranial da tuberosidade da tíbia, coletado de cadáveres de cães e conservado em glicerina 98%. Os oito cães foram separados em dois grupos, A e B e cada um contendo quatro animais para avaliação artroscópica ("segunda observação") aos 60 e 120 dias do pós-operatório. Todos os cães foram submetidos ao procedimento cirúrgico no joelho direito. Clinicamente, avaliou-se o grau de claudicação, o perímetro muscular da coxa e o movimento de gaveta cranial nos oito cães no pré-operatório e semanalmente, até completarem-se 120 dias. Foi observada diminuição da circunferência da coxa significativa (p<0,05) após o período de dez dias em que os cães permaneceram com a bandagem compressiva, sendo recuperada de forma significativa até 13° semana. As pontuações obtidas na avaliação do movimento de gaveta (extensão e flexão) tornaram-se significativamente diferentes da pré-operatória entre a 5° e 15° semanas (p<0,05). Quatro cães apresentaram ao final do experimento ausência de instabilidade articular como na avaliação pré-operatória e os outros... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to evaluate the use of patelar ligament allograft (BLB) conserved in 98% glycerin and fixated with interferemce screws as a substitute of the cranial cruciate ligament in dogs (CrCL). It was observed the feasibility and efficiency of this surgical technique and the graft and screws conduct along 120 days, basing on clinical, radiographic and arthroscopic capacity in detect the beginning and progress of secondary degenerative stifle joint changes. For this purpose, eight mongrel dogs weighting from 17,2 e 26,4 Kg were used. The graft consisted of the intermediate third of the pattela, patellar ligament and cranial portion of the tibial crest, harvested from dog cadavers and preserved in 98% glycerin.The eight dogs were randomly allocated in two groups, A and B, each one with four dogs for arthroscopic evaluation ("second-look") at 60 and 120 days postoperative. All the dogs were submitted to the surgical procedure in the right knee. Clinically, lameness degree, thigh girth measurement and cranial-drawer test were evaluated in the eight dogs in preoperative, and weekly, until complete 120 days. A significant decrease in thigh girth (p<0,05) observed after ten days period that the dogs were using compressive bandage was recovered until the 13th week. The cranial-drawer test scores (flexion and extension) became significantly different between the 5th and 15th weeks postoperative (p>0,05). Four dogs presented at the final study period with no articular instability just like the preoperative evaluation, and the other four with just a slight craniocaudal instability. In the lameness evaluation, from the 4th week, all the dogs presented mean score for stands with equal... (Complete abstract click electronic access below) / Orientador: João Guilherme Padilha Filho / Coorientador: Julio Carlos Canola / Banca: Cintia Lúcia Maniscalco / Banca: Márcia Rita Fernandes Machado / Banca: Patricia Popak Giordano / Banca: Gisleine Cristina Eimantas / Doutor

The ability to kneel is an important function of the knee joint, as it is required for many daily activities, including religious practices, professional occupations and recreational pursuits. The inability to kneel following total knee arthroplasty (TKA) is frequently a source of disappointment. This work investigates patients' understanding of the term 'kneeling' and what proportion of patients can kneel before and after TKA, as well as identifying the factors that can affect the ability to kneel following TKA. The underlying hypothesis tested was: 'There are no differences between kneeling ability before and after TKA'. Kneeling ability after TKA may be affected by many factors, including patient-specific factors, the extent of wear on RPC (Retro patellar Cartilage), postoperative AKP (Anterior Knee Pain) and post-operative ROM (Range of Motion). Thus a consecutive series of TKA patients were assessed to test the afore-mentioned hypothesis. In particular, the thesis has examined: • Interpretation of kneeling and perceptions of kneeling ability after TKA. • The extent of wear on Retro Patellar Cartilage (RPC) and its correlation to kneeling ability. • Sensory changes in the knee after TKA. • Preoperative and Postoperative Anterior Knee Pain (AKP) assessment. • The reality of kneeling ability before and after TKA. • Postoperative ROM of the knee and its correlation to kneeling function. The advice offered by healthcare professionals may contribute to a low postoperative rate of kneeling. The patellofemoral joint plays an essential role in knee function and a person's kneeling ability, may be greatly affected by the performance of this joint. Firstly, this study analysed the responses of two samples of participants drawn from diverse cultural backgrounds (Christian and Muslim), it examined their primary interpretation of what kneeling constitutes, along with a subjective assessment of the importance of kneeling in their everyday lives. Secondly, it explored patients' perceptions of their kneeling ability after TKA, with a comparative analysis of their responses to the kneeling questionnaire specifically constructed by the author and also the question in relation to kneeling in the Oxford Knee Score (OKS). The third component investigated retro-patellar cartilage (RPC) morphology using intraoperative examination and standardised photography. Fourthly, a cohort of patients listed for TKAs was followed prospectively, in order to assess their kneeling ability prior to and following treatment, along with identifying the factors that could affect this function, i.e. knee pain, range of motion, sensory changes and sensitivity to pain on the anterior aspect of the knee as assessed with dolorimetry. Differences were detected in the subjective interpretation of the kneeling function, as well as its importance, for the two diverse cultures involved in this study. Pain, as opposed to poor range of movement, was identified as the main reason which led to kneeling difficulties. The majority of respondents reported that it was either extremely difficult or impossible to kneel on the operated knee. The high flexed position (required for prayer in certain cultures) was the most difficult position to achieve for most of the patients. Prior to surgery, 30 patients were seen during this period, 15 (50%) out of 30 consecutive patients were unable to kneel in any position whatsoever. Of those who could kneel to some degree, the most common posture that they could achieve was the upright kneeling position. Considerable variations were found to occur in patients' understanding of the term 'kneeling'. Consequently, this has significant implications for the design and interpretation of questions in relation to kneeling for diverse cultures, which are characterised by distinct lifestyles. The current patient-based selfV administered questionnaires, such as the OKS, although useful as a simple measure of overall knee function, were found to have limitations as an effective assessment tool in the measurement of kneeling function either before or after TKA and indicate that there is a need for a culturally appropriate questionnaire to assess kneeling function. Retro-patellar cartilage lesions were very prevalent in patients undergoing TKA. However, no significant correlation existed between the total amount of retro-patellar cartilage wear and the ability to kneel. Patients were more likely to be able to kneel if the cartilage of the superior facets of the patella were disease free (P=0.02). At the six months post-surgery stage, of the 14 consecutive patients, who could kneel pre-operatively 6 were able to kneel post-operatively. Of the 13 consecutive patients who were unable to kneel pre-operatively, all were unable to kneel post-operatively. Knee pain was the main reason attributed to this difficulty. However, no link was found to occur between sensory changes and kneeling function in the patients who participated in the study, after TKA performed via an anterior midline incision.

A Síndrome da Dor Femoropatelar (SDFP) é uma das disfunções mais freqüentes do joelho, que acomete adultos jovens do sexo feminino. Embora os fatores etiológicos da SDFP ainda não estejam bem estabelecidos, autores apontam as alterações da cinemática patelar como o principal fator causal. A intervenção conservadora é freqüentemente indicada para o tratamento destes indivíduos, abrangendo exercícios em cadeia cinética aberta (CCA) e cadeia cinética fechada (CCF). O objetivo deste trabalho foi analisar a cinemática patelar durante o repouso e exercícios em indivíduos saudáveis e com SDFP. Participaram deste trabalho, 20 voluntários clinicamente saudáveis e 19 com SDFP submetidos a exames de ressonância nuclear magnética (RNM) durante o repouso, contração isométrica voluntária máxima (CIVM) em CCA e CCF com o joelho posicionado a 15º, 30º e 45º de flexão. As imagens de RNM foram avaliadas pelo programa e-film medical na obtenção dos ângulos do sulco (AS), ângulo de congruência (AC), ângulo de tilt patelar (ATP), ângulo patelar lateral (APL), deslocamento lateral patelar (DLP) e o bisect offset (BO). O coeficiente de correlação intraclasse (ICC) foi aplicado para verificar a confiabilidade intra-examinador e o modelo linear de efeitos mistos aplicado para as comparações inter e intra-grupo, sendo estabelecido nível de significância de 5%. Os resultados do ICC revelaram níveis excelentes de confiabilidade (ICC> 0,75) para todas as medidas de ambos os grupos. De acordo com os dados analisados, pode-se constatar que o grupo SDFP apresenta um maior deslocamento lateral da patela durante o repouso, CIVM em CCA e CCF com o joelho posicionado a 15º de flexão em relação ao grupo controle. Na comparação entre os posicionamentos do joelho e entre as cadeias, para ambos os grupos verificou-se um melhor equilíbrio patelar com o joelho fletido a 30º e a 45º com a CIVM em CCA e CCF. Com o joelho posicionado a 15º de flexão, a patela apresenta-se em sua posição de maior instabilidade, mesmo durante a CIVM em CCF e CCA para ambos os grupos. Desta maneira pode-se concluir que exercícios em CCA e CCF com o joelho posicionado a 30º e a 45º apresentam uma melhor estabilidade patelar em relação aos exercícios com o joelho posicionado a 15º de flexão. / Patellofemoral Pain Syndrome (PPS) is one of the most common knee dysfunctions affecting young adult women. Although PFPS etiologic factors remain uncertain, authors have reported that changes in patellar kinematics as the main cause. Conservative interventions are frequently indicated, which includes open kinetic chain (OKC) and closed kinetic chain (CKC) exercises. This study had the objective to analyze patellar kinematics on individuals with PFPS and health controls, at rest position and while performing exercises. Thirty-nine volunteers participated in this study (20 healthy individuals and 19 with PFPS) and were subjected to nuclear magnetic resonance (NMR) at the following conditions: at rest, maximal voluntary isometric contraction (MVIC) in OKC and CKC with the knee flexed at 15º, 30º, and 45º. NMR images were evaluated using e-film medical for the following angles: sulcus angle (SA), congruence angle (CA), patellar tilt angle (PTA), lateral patellar angle (LPA), lateral displacement of the patella (LDP), and bisect offset (BO). The interclass coefficient correlation (ICC) was applied to verify intra-rater reliability and the linear mixed effects model for inter- and intra-group comparisons, with level of significance at 5%. ICC results revealed excellent reliability levels (ICC> 0.75) for all measurements in both groups. The analyzed data reveal that, compared to the control group, the PFPS group presents greater lateral displacement of the patella at rest, MVIC in OKC and CKC with the knee flexed at 15º. Comparisons among knee positions and kinetic chains, in both groups, it was observed that better patellar balance was obtained with the knee flexed at 30º and 45º with MVIC in OKC and CKC. For both groups, the position with most instability of the patella is with the knee flexed at 15º, even during MVIC in CKC and OKC. Hence, it is concluded that OKC and CKC exercises with the knee flexed at 30º and 45º promote better stability of the patella with regards to exercises performed with the knee flexed at 15º