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Literatura científica selecionada sobre o tema "Instabilité rotatoire"

Autor: Grafiati

Publicado: 7 de setembro de 2024

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Artigos de revistas sobre o assunto "Instabilité rotatoire"

Chamseddine, A., H. Zein, B. Obeid, F. Khodari e A. Saleh. "Instabilité postéro-latérale rotatoire du coude secondaire à une entorse". Chirurgie de la Main 30, n.º 1 (fevereiro de 2011): 52–55. http://dx.doi.org/10.1016/j.main.2011.01.014.

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Cavaignac, Étienne, Karine Wytrykowski, Reina Nicolas, Marie Faruch, Jérôme Murgier e Philippe Chiron. "Corrélation entre lésion du ligament antérolatéral du genou et instabilité rotatoire : étude échographique in vivo". Revue de Chirurgie Orthopédique et Traumatologique 102, n.º 8 (dezembro de 2016): S274. http://dx.doi.org/10.1016/j.rcot.2016.10.010.

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Gottlieb, Uri, e Shmuel Springer. "The Relationship Between Fear Avoidance Beliefs, Muscle Strength, and Short-Term Disability After Surgical Repair of Shoulder Instability". Journal of Sport Rehabilitation 30, n.º 7 (1 de setembro de 2021): 973–80. http://dx.doi.org/10.1123/jsr.2020-0035.

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Context: Arthroscopic surgical repair of the shoulder is recommended when conservative treatment for shoulder instability (SI) fails. However, many patients undergoing this procedure do not return to same level of activity. Psychological factors and muscle strength have been shown to be associated with postoperative outcomes in other musculoskeletal conditions. Objective: To investigate the association between fear avoidance, muscle strength, and short-term function in patients after surgical SI repair. Methods: Twenty-five male patients who underwent shoulder surgery following at least one event of SI were included in this study. Evaluations of fear avoidance related to physical activity and disability were performed at baseline (during the first encounter with the physical therapist) and 7 to 8 weeks postsurgery. Fear avoidance beliefs were assessed using the Fear Avoidance Beliefs Questionnaire. Disability was assessed using the Disabilities of Arm, Shoulder, and Hand questionnaire and the Western Ontario SI index. The follow-up evaluation (weeks 7–8) included measurement of maximal isometric strength of the internal and external rotators. Nonparametric Kendall tau was used to determine the correlations between baseline fear avoidance, muscle strength, and disability at follow-up. Results: Disabilities of Arm, Shoulder, and Hand questionnaire at follow-up was significantly correlated with baseline Disabilities of Arm, Shoulder, and Hand questionnaire (τ = .520, P < .001), baseline fear avoidance (τ = .399, P = .008), and both internal rotator (τ = −.400, P = .005) and external rotator strength (τ = −.353, P = .014). Western Ontario SI index at follow-up was moderately correlated with baseline Western Ontario SI index (τ = .387, P = .007), internal rotator (τ = −.427, P = .003), and external rotator (τ = −.307, P = .032), but not with baseline Fear Avoidance Beliefs Questionnaire (τ = .22, P = .145). Conclusions: The results indicate a possible association between fear avoidance beliefs and short-term disability. Further studies are warranted to better explore and understand these relationships.

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Irrgang, James J., Susan L. Whitney e Christopher D. Harner. "Nonoperative Treatment of Rotator Cuff Injuries in Throwing Athletes". Journal of Sport Rehabilitation 1, n.º 3 (agosto de 1992): 197–222. http://dx.doi.org/10.1123/jsr.1.3.197.

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Shoulder pain in throwing athletes is reviewed. The anatomy and function of the rotator cuff and the biomechanics of the throwing mechanism are described. Physical examination for rotator cuff injuries, treatment considerations, and a protocol are presented. Failure to recognize glenohumeral instability may limit the success of nonoperative management of rotator cuff injuries in throwing athletes. This article provides a comprehensive review of some of the underlying causes of rotator cuff pathology in throwing athletes. Rotator cuff injuries in throwing athletes are closely associated with glenohumeral instability. The role of glenohumeral instability in the pathogenesis of rotator cuff injuries is described.

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Sonar, Satish B., Hemant Parekh e Rajendra Baitule. "POSTEROLATERAL ROTATORY, INSTABILITY, ELBOW". Journal of Evidence Based Medicine and Healthcare 2, n.º 33 (17 de agosto de 2015): 4981–88. http://dx.doi.org/10.18410/jebmh/2015/695.

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Haslam, P. G., e D. R. Bickerstaff. "Postero-lateral rotatory instability". Current Orthopaedics 21, n.º 6 (dezembro de 2007): 451–56. http://dx.doi.org/10.1016/j.cuor.2007.07.008.

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Patiño, Juan Martín, Alejandro Rullan Corna, Alejandro Michelini, Ignacio Abdon e Alejandro José Ramos Vertiz. "Elbow Posterolateral Rotatory Instability due to Cubitus Varus and Overuse". Case Reports in Orthopedics 2018 (5 de agosto de 2018): 1–5. http://dx.doi.org/10.1155/2018/1491540.

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A malunion as a complication of distal humerus fractures has been frequently linked with aesthetic problems but less frequently with posterolateral rotatory instability. We report 2 cases of childhood posttraumatic cubitus varus with subsequent posterolateral rotatory instability and their treatment with a minimum of 2 years of follow-up. The etiology of the so-called posterolateral rotatory instability of the elbow is mostly traumatic, but iatrogenic causes have also been described such as the treatment of tennis elbow and less frequently and chronically due to overuse and overload because of distal humerus malunion.

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Lee, Joo Yeon, Yon-Sik Yoo e Kilhwan Shon. "Teres minor denervation and pathologies resulting in shoulder joint instability and rotator cuff tears: A retrospective cross-sectional MRI study". Medicine 103, n.º 8 (23 de fevereiro de 2024): e37232. http://dx.doi.org/10.1097/md.0000000000037232.

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Teres minor denervation (TMD) has gained increasing attention in recent years, particularly with the advent of magnetic resonance imaging (MRI). The potential association between TMD and shoulder instability or rotator cuff tear remains a subject of interest in the orthopedic community. In this retrospective and cross-sectional study, authors aim to investigate the potential association between TMD and shoulder instability or rotator cuff tears. Authors retrospectively analyzed MRI findings from 105 patients with TMD, focusing on rotator cuff pathologies, posterior labrocapsular complex (PLCC) tears, and posteroinferior glenohumeral joint capsule alterations. Authors assessed the association between TMD and rotator cuff and PLCC tears. For the multivariate analysis, partial proportional odds models were constructed for subscapularis (SSC) and SSP tears. Rotator cuff tears were present in 82.9% of subjects, with subscapularis (SSC) tears being the most frequent (77.1%). A significant association was observed between TMD and rotator cuff pathology (P = .002). PLCC tears were found in 82.3% of patients, and humeral position relative to the osseous glenoid was noted in 60% of patients with TMD. A significant association was identified between TMD and shoulder instability or labral/capsular abnormalities (P < .001). More than half of the cases exhibited a long tethering appearance toward the axillary neurovascular bundle on T1-weighted sagittal images. Our findings suggest that TMD is significantly associated with rotator cuff tears and shoulder instability. This study highlights the importance of identifying and treating PLCC tears in patients with TMD to address shoulder instability. Further research is needed to elucidate the role of TMD in the pathogenesis of shoulder instability and rotator cuff pathology.

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Tsenkov, Tsvetan, e Alexander Gerchev. "CONCOMITANCE OF ROTATOR CUFF DISEASE IN SYMPTOMATIC ANTERIOR SHOULDER INSTABILITY". Journal of IMAB - Annual Proceeding (Scientific Papers) 28, n.º 3 (24 de agosto de 2022): 4517–20. http://dx.doi.org/10.5272/jimab.2022283.4517.

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Purpose: To evaluate the concomitance of rotator cuff disease in patients with symptomatic anterior shoulder instability and its impact on the severity of lesions. Materials and Methods: Retrospective data were collected from 326 patients from a single institution for a 16-year period. The demographic characteristics of the patients were selected randomly. The leading diagnosis was shoulder instability. Excluded from the study were patients with posterior (n=24) or mixed instability (n=5). Primary diagnosis was confirmed with clinical findings and MRI imaging studies. All patients from the group underwent arthroscopic surgery. A throughout analysis was performed of the collected materials. Results: 297 patients with primary anterior instability underwent arthroscopic stabilization in the clinic. 25% (n=75) presented with different grade rotator cuff lesions, of which only 33% (n=25) were discovered on MRI preoperatively. In these patients, rotator cuff tenoplasty was performed. In 27% (n=79) of the patients, an evident subacromial space narrowing without rotator cuff lesions was found during arthroscopy. In these cases, a subacromial decompression was performed, and in some of the cases - acromioplasty. In 52% (n=154) of patients who underwent an arthroscopic stabilization for anterior shoulder instability, additional treatment was necessary. Conclusions: The complex analysis of shoulder pathology can shield the surgeon from diagnostic misses and unsatisfactory results. Coexisting rotator cuff disease may have a role in symptomatic anterior shoulder instability as it is often neglected in clinical evaluations due to the main diagnosis of instability.

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SLOCUM, DONALD B., e ROBERT L. LARSON. "ROTATORY INSTABILITY OF THE KNEE". Journal of Bone and Joint Surgery-American Volume 84, n.º 5 (maio de 2002): 868. http://dx.doi.org/10.2106/00004623-200205000-00026.

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Mais fontes

Teses / dissertações sobre o assunto "Instabilité rotatoire"

Néri, Thomas. "Etude anatomique et biomécanique du ligament antérolatéral ; implication dans sa reconstruction chirurgicale". Thesis, Lyon, 2017. http://www.theses.fr/2017LYSES033/document.

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Il a été démontré que les reconstructions du ligament croisé antérieur (ACL) ne permettaient pas un contrôle parfait de l’instabilité rotatoire antérolatérale (ALRI). Ce postulat a conduit à la redécouverte du ligament antérolatéral (ALL). Toutefois de nombreuses questions persistent, rendant sa reconstruction chirurgicale approximative.Après avoir établi un protocole de dissection non extensif, les principales caractéristiques anatomiques du ALL ont été définies. Puis, une description histologique du ALL a été réalisé afin de confirmer sa nature ligamentaire.Deuxièmement, grâce à la mise au point et à la validation d’un protocole d’analyse cinématique par système optoélectronique tridimensionnel, nous avons pu étudier le rôle du ALL sur la stabilité du genou. A travers une analyse des variations de sa longueur au cours du mouvement, et des conséquences de sa section, nous avons déterminé son rôle sur le contrôle de la l’ALRI.Troisièmement, une technique de reconstruction physiologique du ALL, modifiée selon nos résultats, a été proposée. Afin de l’évaluer, nous avons analysé les cinématiques du genou après cette reconstruction en les comparant avec celles obtenues après une ténodèse latérale extra-articulaire.Enfin, afin de préciser ses indications de reconstruction, différents outils cliniques (laximétrie, accéléromètre triaxial), et morphologiques (IRM, échographie) ont été analysés afin d’évaluer leurs pertinences dans le diagnostic de rupture du ALL.En conclusion, ce travail donne une vue d’ensemble globale du ALL, de sa description anatomique et histologique, en passant par sa fonction biomécanique, jusqu’à à sa reconstruction chirurgicale
Many clinical studies have shown that anterior cruciate ligament (ACL) anatomical reconstruction do not allow a perfect control of anterolateral rotational instability (ALRI). This clinical postulate led to rediscovery of the anterolateral ligament (ALL). However ALL surgical reconstruction are still approximate, due to a lack of knowledge.Initially, we have studied cadaveric knees, using our own non-extensive and reproducible dissection protocol. With tis approach, we were able to define the anatomical parameters relevant to obtaining an effective ALL reconstruction. Then, we performed an histological study in order to confirm ALL ligamentary structure.In a second part, we have developed and validated a kinematic analysis protocol using a three-dimensional optoelectronic system to study the ALL role on the knee stability. Through an analysis of ALL length variations during motion and ALL section consequences, we determined the ALL capacity on ALRI control.In a third part, we were able to define, regarding our previous results, biomechanical and anatomical imperatives to perform an anatomic ALL reconstruction. In order to evaluate this technique, we analyzed and compared knee kinematics after ALL reconstruction and after lateral extra-articular tenodesis on cadaveric knees.Lastly, various clinical (laximeter, triaxial accelerometer) and morphological (MRI, ultrasound) systems were analyzed to evaluate their relevance in ALL tear diagnosis, in order to improve ALL reconstruction indications.In conclusion, this work gives a global view of ALL, from anatomical description and biomechanical function to surgical reconstruction

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Mouilleron-Arnould, Hélène. "Instabilité d'un milieu granulaire cisaillé par un fluide". Toulouse 3, 2002. http://www.theses.fr/2002TOU30054.

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Lutz, Christian. "Analyse, stratégie thérapeutique et innovations technologiques lors de la stabilisation rotatoire du genou dans les reconstructions du ligament croisé antérieur". Electronic Thesis or Diss., Strasbourg, 2024. http://www.theses.fr/2024STRAJ009.

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Le contrôle du ressaut rotatoire induit par la rupture du ligament croisé antérieur est un enjeu majeur de la chirurgie ligamentaire du genou. L’association d’une ténodèse latérale à la reconstruction du ligament croisé antérieur améliore ce contrôle comparativement à une plastie intra-articulaire isolée. Pour autant, l’utilisation de ces ténodèses ne fait pas l’unanimité au sein de la communauté orthopédique. Leur intérêt a été à l’origine de ce projet de recherche anatomique, biomécanique et clinique. Au niveau anatomique et biomécanique, le contrôle rotatoire du genou est assuré par le ligament croisé antérieur et le ligament antéro-latéral. Au niveau technique, la réalisation de ténodèses latérales doit respecter des critères précis pour restituer la fonction du ligament antéro-latéral via le concept d’anisométrie favorable. Au niveau clinique, le contrôle du ressaut est amélioré cette plastie latérale additionnelle. Cette association de plasties ligamentaires a rendu la chirurgie plus complexe et ouvert la voie à un autre projet recherche sur l’utilisation de technologies innovantes pour améliorer la précision et la personnalisation du geste chirurgical
Treatment of the rotational instability induced by rupture of the anterior cruciate ligament is a major challenge in knee ligament surgery. Combining lateral tenodesis with anterior cruciate ligament reconstruction improves this control compared to isolated intra-articular plasty. However, the orthopaedic community is not unanimous about the use of lateral tenodesis. Their interest was at the origin of this anatomical, biomechanical and clinical research project. Anatomically and biomechanically, rotational control of the knee is ensured by the anterior cruciate ligament and the anterolateral ligament. Technically, lateral tenodesis must respect precise criteria to restore the function of the anterolateral ligament, via the concept of favorable anisometry. Clinically, this additional lateral plasty enhances rotational stability.This association of ligament reconstructions has increased the complexity of surgical procedures and spurred further research using innovative technologies to enhance accuracy and a more personalizated surgery

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Charalambous, Charalambos P. "Posterolateral rotatory elbow instability : biomechanical effects of surgery upon the radial head". Thesis, University of Manchester, 2009. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.551310.

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Mejia, Nava Rosa Adela. "Contrôle de l'instabilité et des vibrations de la structure pour les charges non conservatrices". Electronic Thesis or Diss., Compiègne, 2020. http://www.theses.fr/2020COMP2577.

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Dans la première partie de cette thèse, nous étudions l'instabilité et le contrôle des vibrations des structures élancées sous des charges conservatrices. La première difficulté que nous étudions concerne le problème de l'instabilité géométrique non linéaire, illustrée par un treillis bas ou profond, voire une structure en portique. La stratégie de contrôle choisie considère l'ajout d'un amortissement à partir d'un amortisseur visqueux ou d'un dispositif à friction. Ce type de contrôle appartient au concept bien connu de passivité. Dans la deuxième partie de la thèse, nous proposons des procédures de résolution numérique pour résoudre des problèmes d'instabilité sous des charges conservatrices et non conservatrices. La procédure proposée est validée par rapport aux solutions analytiques et semi-analytiques disponibles pour certains cas académiques, précédemment étudiés dans les travaux classiques d'Euler et Bolotin. Dans la dernière partie de ce travail, nous explorons la stratégie de contrôle des phénomènes d'instabilité en ajoutant des amortisseurs visqueux. La procédure est illustrée pour une poutre fixe soumise à une charge de compression non conservatrice et à une petite perturbation transversale, toutes deux appliquées à l'extrémité libre de la poutre. Les détails des développements théoriques sont donnés en termes d'équations dynamiques non linéaires obtenues en utilisant le principe des travaux virtuels. Tous les modèles structuraux utilisés pour résoudre des problèmes plus complexes sont construits avec une approche numérique basée sur la méthode des éléments finis et des modèles de poutre géométriquement exacts capables de décrire des rotations finies. Il est également montré que les modèles proposés peuvent gérer avec succès un grand mouvement global sous instabilité statique et dynamique (ou flottement) sous des charges conservatrices et non conservatrices. Différentes simulations numériques sont présentées pour illustrer les performances des modèles géométriquement exacts proposés dans cette thèse
In the first part of this thesis we study the control of instability and vibrations of slender structures under conservative loads. The first difficulty we study pertains to nonlinear geometric instability problem, asillustrated with a deep and a shallow truss, or yet a frame structure. The corresponding control strategy considers adding damping from either a viscous damper or a friction device. This kind of control belongs to the well-known concept of passivity. In the second part of the thesis we propose numerical solution procedures for solving the instability problems under both conservative and non-conservative loads. The proposed procedure is validated against the known analytical and semianalytic solutions when available for few academic cases, previously studied in classical works by Euler and by Bolotin. In the last part of this work, we explore the control strategy of instability phenomena by adding viscous dampers. The procedure is illustrated for a cantilever beam under a non-conservative compressive load and a small transverse disturbance both applied at the free end of the cantilever. The details of theoretical developments are given in terms of the non-linear dynamical equations obtained by using the principle of virtual work. All the structural models used for solving more complex problems are built with a numerical approach based upon the finite element method and the geometrically exact beam models capable of describing finite rotations. It is show as well that the proposed models can successfully handle large overall motion under static and dynamic instability (or utter) under both conservative and non-conservative loads. Different numerical simulations are presented in order to illustrate the performance of the geometrically exact models proposed in this thesis

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Caceres, Andrea Patricia. "The effects of implant design variations on shoulder instability following reverse shoulder arthroplasty". Thesis, University of Iowa, 2018. https://ir.uiowa.edu/etd/6552.

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Reverse shoulder arthroplasty (RSA) is performed to decrease pain and improve function and range of motion (ROM) primarily for patients with rotator cuff arthropathy, an arthritis of the shoulder secondary to rotator cuff insufficiency. However, RSA has suffered from high early to mid-term rates of complication, with instability being one of the most common. The shoulder biomechanics post-RSA depend on multiple factors such as implant geometry, positioning, and cuff integrity. This study built upon prior finite element (FE) analysis of RSA to investigate the effects of glenoid lateralization and retentive liner design on shoulder stability. A previously validated FE model was extended to model shoulder external rotation (ER) after implantation of the Zimmer Trabecular Metal RSA system. The FE model included the scapula bone with an implanted glenosphere implant, the humerus bone with implanted humeral sections of the RSA implant, and muscle tendons representing the subscapularis, infraspinatus, and deltoid. Six different models matched glenospheres in three cases of lateralization (2mm, 4mm, and 10mm) with two humeral poly liner designs (normal: 150° neck shaft angle or retentive: 155° neck shaft angle). Using Abaqus/Explicit FE software, the proximal ends of the soft tissues were pulled to their anatomical positions, and then fixed in space while the humerus was externally rotated 80° about the humeral long axis from a neutral position with the shoulder abducted 25°. The displacements, deltoid and subscapularis forces, impingement-free ROMs, and subluxation gap distances were recorded. Although greater glenosphere lateralization was associated with higher impingement-free ROM, larger deltoid and subscapularis forces developed. Deltoid tension contributes to shoulder stability and control, but elevated amounts of deltoid tension may contribute to scapular fractures and greater stress at impingement sites post-RSA. Further analysis such as inclusion of more anatomical features and additional motions may offer greater insight to orthopedic surgeons when planning for RSA insertion.

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Von, Kossel Markus. "Instabilidade do ombro : variação do retardo eletromecânico em ombros saudáveis e instáveis". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/108427.

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Introdução: Instabilidades adquiridas do ombro são uma afecção comum do membro superior na prática esportiva, ocasionadas particularmente pela posição de abdução e rotação lateral da articulação glenoumeral durante movimentos explosivos. O manguito rotador proporciona grande parte da estabilidade dinâmica do ombro, sendo que nos movimentos esportivos, a estabilização necessita ser rápida para evitar a movimentação excessiva da cabeça umeral. O tempo entre a ativação do músculo e a produção de tensão é conhecida como Retardo Eletromecânico (REM), podendo este estar associado à velocidade a qual um músculo transmite sua tensão à articulação. Objetivo: avaliar o REM do músculo infraespinhal durante a rotação lateral (RL), o REM do músculo Peitoral Maior durante a rotação medial (RM) e o atraso entre a ativação do Peitoral Maior e Infraespinhal durante uma RM e relacionar estes eventos com a presença ou não da instabilidade glenoumeral adquirida. O comportamento mecânico do infraespinhal foi avaliado também por meio de mecanomiografia, possibilitando subdividir o REM em relação aos eventos elétricos e mecânicos. Métodos: Os músculos Peitoral Maior e Infraespinhal foram monitorados por eletromiografia (EMG) de superfície (2 kHz); o sinal mecanomiográfico (MMG) (2 kHz) foi coletado do Infraespinhal e os torques (2 kHz) explosivos isométricos de RM e RL do ombro foram coletados na posição do ombro de abdução e rotação lateral a 90° em um dinamômetro. Após uma avaliação funcional do membro superior, 18 indivíduos do sexo masculino, praticantes de atividade esportiva overhead, participaram do estudo, sendo nove com ombros saudáveis e nove com instabilidade glenoumeral anterior. Após a coleta e armazenamento dos sinais, esses foram filtrados e analisados. Os sinais EMG do peitoral maior e EMG e MMG do infraespinhal foram filtrados (EMG 5-500 Hz e MMG 4-400 Hz) e um envoltório linear foi calculado. O início dos sinais foi identificado usando-se o limiar de repouso + 3 desvios padrão para EMG e MMG e 2% do pico de torque para o limiar de força. Os limiares de ativação foram usados para calcular o início de cada sinal (EMG, MMG e Torque). Os intervalos de tempo entre os eventos foram mensurados e comparados entre os grupos (ombro instável, ombro contra-lateral e ombro saudável). Os picos de torque e taxa de produção do torque de RM e RL foram calculados para todos os grupos. Resultados: O REM do infraespinhal em ombros com instabilidade e nos ombros contralaterais ao instável foi menor do que nos ombros saudáveis. Pico de Torque, Taxa de Produção de Torque, atraso entre EMG do peitoral maior e EMG do infraespinhal e REM do peitoral maior não apresentaram diferenças significativas entre os grupos. Conclusão: Ombros instáveis e contralaterais aos instáveis apresentam adaptação crônica do manguito rotador com diminuição do REM. O REM está possivelmente associado ao aumento da rigidez dos elementos elásticos em série. O aumento da demanda pelos estabilizadores dinâmicos em decorrência da falência dos mecanismos estáticos de estabilização do ombro poderia explicar tal adaptação do infraespinhal.
Introduction: Acquired shoulder instabilities are a common upper limb injury in sports, mostly related to abduction and external rotation of glenohumeral joint during explosive contractions. Most of the dynamic stabilization of the shoulder joint is provided by the rotator cuff. In sports movements the stabilization must be quick to avoid humeral head excessive motion. The time between muscle activation and force production is named Electromechanical Delay (EMD), and is related to the speed of transmited tension to the joint/bone. Objetive: Evaluate the EMD in the infraspinatus muscle during External Rotation (ER), the EMD of Pectoralis Major during an Internal Rotation (IR) and the delay between Pectoralis Major and Infraspinatus activation during an IR and relate those mesurements to the shoulder stability/instability. The mechanical behaviour of the infraspinatus muscle was also assessed by mechanomyography, enabling to subdivide the EMD with respect to the electrical and mechanical events. Methods: Pectoralis Major and Infraspinatus muscles were monitored by surface Electromyography (EMG) (2kHz); the mechanomyographic (MMG) signal was collected from infraspinatus muscle (2kHz) and the isometric explosive IR and ER of shoulder were collected at 90° of abduction and external rotation on a dynamometer. After a functional evaluation of the shoulder, 18 male subjects, overhead sports participate in the study, nine with stable shoulders and nine with anterior shoulders instability. After data collection and storage, the signals were filtered and analysed. The EMG signals from Pectoralis Major and EMG and MMG from infraspinatus were filtered (EMG 5-500 Hz and MMG 4-400 Hz) and a linear envelope was calculated. The signal onset was identified using the threshold of resting signal plus 3 standart deviations for EMG and MMG and 2% of peak torque to torque threshold. The thresholds were used to calculate the beginning of each signal (EMG, MMG and Torque). The time delays between events were measured and compared between the groups (stable, unstable and contralateral to the unstable). Peak Torque and Rate of Torque Production of IR and ER were calculated to all groups. Results: The infraspinatus EMD in the unstable and contralateral to unstable shoulders were smaller than the healthy shoulders. Peak Torque, Rate of Torque Production, delay between pectoralis major EMG and infraspinatus EMG and pectoralis EMD were not different between the groups. Conclusions: Unstable and contralateral to unstable shoulders showed a chronic adaptation of rotator cuff with decrease in EMD. The EMD could be related to increase in stiffness of series elastic components. The increased demand for the dynamic stabilization caused by the loss of static stabilization mechanism could lead to the infraspinatus adaptation.

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Al-Farkh, Marwan. "Stabilité des écoulements dans un divergent en rotation". Lyon 1, 1998. http://www.theses.fr/1998LYO19013.

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Rémy, David. "Étude expérimentale par la tomographie et la P. I. V des structures instationnaires dans une cavité rotor-stator avec aspiration". Lille 1, 2004. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2004/50376-2004-63-64.pdf.

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Dans ce travail de thèse expérimental, on étudie différentes instabilités hydrodynamiques se développant dans une cavité rotor-stator soumiseà une aspiration. Tout d'abord, l'utilisation de la technique de visualisation par tomographie dans des plans laser horizontaux et méridiens, nous a permis de détailler complètement deux types de structures dans une cavité à fente radiale et jet axial. La première, appelée structure 1, apparaît sous la forme d'une spirale attachée au coin près de la paroi cylindrique fixe. La seconde, appelée structure 2 à longueur d'onde beaucoup plus petite, apparaît également sous la forme d'une spirale mais semble plutôt être attachée au jet. Les seuils d'apparition et de disparition en débit en fonction de la vitesse de rotation, les fréquences, les vitesses de phase et les périodicités azimutales sont étudiés pour les deux structures. Une étude de stabilité linéaire est menée pour la structure 2 et confrontée avec les résultats expérimentaux. On caractérise ensuite en détail la structure 1 au moyen de la tomographie et de la PIV stéréoscopique. On développe une technique de compression temporelle par reclassement des cartes de vitesse en vue d'analyser la structure spatiale tridimensionnelle de cette instabilité et de la comparer aux résultats de la simulation numérique. Enfin, on présente les champs de vitesse de l'écoulement dans une cavité rotor-stator aspirée à fente axiale. Ces champs de vitesse sont mesurés dans différents plans horizontaux ainsi que dans un plan méridien pour plusieurs couples de paramètres de rotation et d'aspiration. Une première analyse des structures et des principaux paramètres qui les régissent est proposée.

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Sauret, Alban. "Forçage harmonique d'écoulements en rotation : vents zonaux, ondes inertielles et instabilités". Phd thesis, Aix-Marseille Université, 2013. http://tel.archives-ouvertes.fr/tel-00795251.

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Une grande quantité d'énergie est présente dans les mouvements de rotations propre et orbitale des planètes. Des forçages harmoniques tels que les déformations de marées, la précession ou la libration peuvent en convertir une partie pour générer des écoulements dans les couches fluides d'une planète. Ces écoulements restent largement méconnus même s'ils sont importants pour contraindre des modèles d'intérieur planétaire ou expliquer la présence de champs magnétiques dans certains astres. Dans cette thèse, nous étudions les mécanismes engendrés par ces forçages en combinant une approche théorique, expérimentale et numérique et soulignons la généricité des phénomènes observés. L'étude d'un forçage de libration longitudinale, i.e. des oscillations de la vitesse de rotation d'un astre, montre la présence d'un écoulement zonal généré par des interactions nonlinéaires dans les couches visqueuses. Nous étudions ensuite l'instabilité qui apparaît à la paroi pour des amplitudes de libration suffisantes et qui peut transférer de l'énergie vers le volume du fluide. Finalement, une étude expérimentale de forçage de marées dans une sphère met en évidence que l'excitation directe d'ondes inertielles induit un écoulement zonal intense et localisé. Cet écoulement peut se déstabiliser par une instabilité de cisaillement et générer un écoulement turbulent dans tout le volume. Pour finir, nous considérons la pertinence de ces résultats pour des applications géo- /astrophysiques, telles que l'étude des océans internes sous la surface de glace des satellites joviens Ganymède, Encelade et Europe.

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Livros sobre o assunto "Instabilité rotatoire"

Musahl, Volker, Jón Karlsson, Ryosuke Kuroda e Stefano Zaffagnini, eds. Rotatory Knee Instability. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-32070-0.

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Ferretti, Andrea, ed. Anterolateral Rotatory Instability in ACL Deficient Knee. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-00115-4.

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Ferretti, Andrea. Anterolateral Rotatory Instability in ACL Deficient Knee. Springer International Publishing AG, 2022.

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Anterolateral Rotatory Instability in ACL Deficient Knee. Springer International Publishing AG, 2023.

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Zaffagnini, Stefano, Jón Karlsson, Volker Musahl e Ryosuke Kuroda. Rotatory Knee Instability: An Evidence Based Approach. Springer, 2016.

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Zaffagnini, Stefano, Jón Karlsson, Volker Musahl e Ryosuke Kuroda. Rotatory Knee Instability: An Evidence Based Approach. Springer London, Limited, 2016.

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Zaffagnini, Stefano, Jón Karlsson, Volker Musahl e Ryosuke Kuroda. Rotatory Knee Instability: An Evidence Based Approach. Springer, 2018.

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Salama, Amir, e David Stanley. Chronic instability of the elbow. Oxford University Press, 2011. http://dx.doi.org/10.1093/med/9780199550647.003.05.03.

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Lambert, Simon M. Instability. Oxford University Press, 2011. http://dx.doi.org/10.1093/med/9780199550647.003.004007.

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♦ The fundamental principle or essence of the shoulder is concavity compression. Stability of the shoulder is the condition in which a balanced centralizing joint reaction force (CJRF) exists to maintain concavity compression of the glenohumeral joint whatever the position of the limb and hand.♦ Instability is a symptom. It can be defined as the condition of symptomatic abnormal motion of the joint. It refers to a perturbation of concavity compression. It is not a diagnosis.♦ Instability is the result of perturbations of structural factors and non-structural factors.♦ The clinical syndrome of instability is a disturbance of one or more of these factors in isolation or together. The relative importance of each factor to the syndrome can change over time. The relationship between these factors is described by the Stanmore triangle.♦ Both structural and non-structural factors can be perturbed by arrested or incomplete development (dysplasia) or by injury (disruption).♦ The aim of treatment is the restoration of (asymptomatic) stable motion by restoration of the CJRF and so restoration of the condition of concavity compression.♦ Management follows simple principles: surgery should be undertaken within the context of a well-considered rehabilitation program largely centred around optimizing rotator cuff function.♦ Failures of management are often due to failure of or incomplete diagnosis, failure of healing, inadequate attention to patient- and pathology- specific rehabilitation programs, or insufficient attention to lifestyle considerations.♦ Disrupted anatomy is restored, preferably by anatomic operations with predictably good outcomes. Dysplastic anatomy is augmented, often by non-anatomic operations with less predictable outcomes. Revision stabilizations are generally nonanatomic, and have higher failure rates.

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Speed, Cathy, e Andrew Wallace. Injuries to the shoulder. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199533909.003.0024.

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The vast majority of shoulder complaints are due to soft tissue lesions, and rotator cuff disorders represent the largest diagnostic category of these. Many shoulder complaints are multifactorial in origin, and articular and extra-articular disorders can coexist. Instability also plays a major role; the shoulder is the most mobile joint of the body, achieving this mobility at the expense of its stability. Loss of the fine balance between optimal mobility of the joint and its stability is a common, albeit frequently subtle, feature of shoulder complaints....

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Capítulos de livros sobre o assunto "Instabilité rotatoire"

Rahnemai-Azar, Amir Ata, Masahito Yoshida, Volker Musahl e Richard Debski. "In Vitro Biomechanical Analysis of Knee Rotational Stability". In Rotatory Knee Instability, 3–14. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-32070-0_1.

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Degen, Ryan M., Thomas L. Wickiewicz, Russell F. Warren, Andrew D. Pearle e Anil S. Ranawat. "Knee Rotation: The HSS School". In Rotatory Knee Instability, 103–13. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-32070-0_10.

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Khan, Najeeb, Eric Dockter, Donald Fithian, Ronald Navarro e William Luetzow. "Development of Arthrometry". In Rotatory Knee Instability, 115–29. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-32070-0_11.

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Anderson, Allen F., James J. Irrgang e Christian N. Anderson. "Development of the IKDC Forms". In Rotatory Knee Instability, 131–46. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-32070-0_12.

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Mouton, Caroline, Daniel Theisen e Romain Seil. "Static Rotational Knee Laxity Measurements". In Rotatory Knee Instability, 149–63. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-32070-0_13.

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Ntagiopoulos, Panagiotis G., e David H. Dejour. "The Use of Stress X-Rays in the Evaluation of ACL Deficiency". In Rotatory Knee Instability, 165–74. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-32070-0_14.

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van Oldenrijk, Jakob, Romain Seil, William Jackson e David Dejour. "Classification, Diagnostics and Anatomical Considerations in Knee Dislocations". In Rotatory Knee Instability, 175–89. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-32070-0_15.

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Shabani, Bujar, Dafina Bytyqi, Laurence Cheze, Philippe Neyret e Sébastien Lustig. "The KneeKG System". In Rotatory Knee Instability, 191–98. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-32070-0_16.

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Branch, Thomas P., Shaun K. Stinton, Jon E. Browne, Timothy D. Lording, Nathan K. deJarnette e William C. Hutton. "A Robotic System for Measuring the Relative Motion Between the Femur and the Tibia". In Rotatory Knee Instability, 199–220. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-32070-0_17.

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Lord, Breck, e Andrew A. Amis. "The Envelope of Laxity of the Pivot Shift Test". In Rotatory Knee Instability, 223–34. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-32070-0_18.

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Trabalhos de conferências sobre o assunto "Instabilité rotatoire"

Jeknic-Dugic, J., I. Petrovic, K. Kojic, M. Arsenijevic e M. Dugic. "Entropy dynamics for a propeller-shaped quantum Brownian molecular rotator". In 2nd International Conference on Chemo and Bioinformatics. Institute for Information Technologies, University of Kragujevac, 2023. http://dx.doi.org/10.46793/iccbi23.082jd.

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We investigate and analyze the time dependence of the so-called differential entropy as a measure of the dynamical stability of a one-dimensional, propeller-shaped quantum Brownian molecular rotator. The larger the entropy change, the more profound the instability (lower control) of the rotator. The quantum molecular rotator is modelled by the quantum Caldeira-Leggett master equation while assuming the external harmonic field for the rotator. Rotational stability is found relatively high for the constructed Gaussian states, especially for molecules with a larger number of blades.

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Chu, Thomas, Jen M. Ty, Bayram Orazov, Nicole Strauss, Oliver M. O’Reilly, Jenni M. Buckley e Lisa L. Lattanza. "Surgeon Experience Level Affects Mechanics of the Pivot Shift Test for Posterolateral Rotatory Instability of the Elbow". In ASME 2009 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2009. http://dx.doi.org/10.1115/sbc2009-206560.

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Posterolateral rotatory instability (PLRI) of the elbow occurs secondary to an injury to the lateral ulnar collateral ligament and lateral stabilizing structures [2]. The lateral pivot-shift test (PST) is a clinical examination for diagnosing PLRI [1]. The test involves moving the elbow from full extension to flexion while applying simultaneous supination torque, valgus moment, and axial compression [2]; a positive result is characterized by ulnohumeral subluxation that is seen clinically as posterolateral movement of the radial head and an incongruent radiocapitellar joint [2]. The PST is difficult to reliably reproduce in an office setting [3]. This can be due to patient-guarding or inexperience of the examiner. It is likely that the experienced examiner may perform the test differently from the inexperienced examiner. The PST has not previously been characterized biomechanically in the laboratory. Thus, the objective of this study is to fully characterize the biomechanics of the PST for PLRI. We will evaluate the repeatability of the PST across multiple surgeons and determine how the clinician’s level of training affects their method of testing. These results will be useful in developing training guidelines to standardize PST application as well as to improve accuracy.

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Quigley, Ryan J., Hideya Ishigooka, Michelle H. McGarry, Yu J. Chen, Akash Gupta, Chris Bui e Thay Q. Lee. "Kinematics of the Posterolateral Corner of the Knee: A Cadaveric Study". In ASME 2010 5th Frontiers in Biomedical Devices Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/biomed2010-32044.

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Combined injuries of the posterior cruciate ligament (PCL) and the posterolateral corner (PLC) of the knee results in posterolateral rotatory instability. The detailed anatomy and kinematics of the PCL is well described in the literature as well as the anatomy of the PLC; however, the detailed kinematics of the posterolateral corner ligaments and tendons are not well understood. This information on the posterolateral corner is important for developing a strategy for accurate anatomical reconstructions. Therefore, the purpose of this study was to quantify the detailed kinematics of the posterolateral corner of the knee ligaments and tendons.

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White, M. F., e S. H. Chan. "Proposed Forcing Mechanisms and Non-Linear Effects on Subsynchronous Vibrations in High Performance Turbomachinery". In ASME 1997 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/97-gt-448.

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This paper suggests that the subsynchronous “instability” observed in many high speed, high performance turbomachines while operating in the supercritical speed range may in some cases be a stable form of lightly damped vibrations. They could be excited by low frequency process forces due to unsteady flow conditions. The non-linearity in the mass, stiffness or damping of the system may have provided a coupling or frequency transformation between the excitation forces and the subsynchronous vibrations. Depending on the kind of non-linear characteristics the critical speeds as defined for a linear system may become regions of “instability”. The degree of non-linearity of the bearing-seal-rotor system has an influence on the sensitivity of the machine to subsynchronous vibrations. Some forcing mechanisms are presented, including non-identical rotor blades, inlet flow distortion and rotating stall. The effect on response of mode shape, internal shaft rotatory damping and frequency dependence of bearing damping at subsynchronous frequencies are discussed. It is recommended that the unsteady fluid dynamic forces, together with the effects of non-linear dynamic characteristics be further investigated to provide more experimental evidence for this hypothesis.

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Quigley, Ryan J., Hideya Ishigooka, Michelle H. McGarry, Yu J. Chen, Akash Gupta, Chris Bui e Thay Q. Lee. "Anatomical Posterolateral Corner Reconstruction of the Knee Using a New Fibula Cross Tunnel Method: A Cadaveric Study". In ASME 2010 5th Frontiers in Biomedical Devices Conference. American Society of Mechanical Engineers, 2010. http://dx.doi.org/10.1115/biomed2010-32041.

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Posterolateral corner (PLC) injury of the knee causes varus and posterolateral rotatory instability. The anatomy of the PLC has been reported in the literature but the importance of PLC reconstruction has only recently been established and ideal reconstruction techniques are still in development. The native function of the PLC is to restrain varus and external rotation. Reconstruction methods should properly restore these functions without overconstraining the joint. Several reconstructions for PLC injury have been reported but with concerns of iatrogenic neurovascular injury, fibular head cutout, and restoration of the knee kinematics. To address these concerns, a new cross fibula tunnel method was developed that may have lower risk of iatrogenic nerve injury and fibula head cutout. The purpose of this study was to verify the stability of this technique using a PLC deficient knee.

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Reuther, Katherine E., Stephen J. Thomas, Jennica J. Tucker, Joseph J. Sarver, Chancellor F. Gray, Elisabeth B. Evans, Sarah Ilkhani-Pour, David L. Glaser e Louis J. Soslowsky. "Returning to Overuse Activity Following a Combined Supraspinatus and Infraspinatus Tear Leads to Shoulder Joint Damage". In ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14464.

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Rotator cuff tendon tears are common conditions which can lead to significant pain and dysfunction. Tears may progress over time from isolated supraspinatus tears to complete ruptures of both the supraspinatus and infraspinatus tendons, disrupting the anterior-posterior force balance provided by the subscapularis anteriorly and infraspinatus posteriorly (commonly referred to as a “force couple”) [1]. This disruption may lead to increased joint instability and result in altered glenohumeral translations which may cause damage to joint structures, such as articular cartilage and adjacent (intact) tendons. This is a particular concern for active individuals who are likely to continue high levels of overuse activity (e.g., laborers, athletes), despite the presence of rotator cuff tears. Previous studies have shown that returning to overuse activity following an isolated supraspinatus tear alters biceps and glenoid articular cartilage properties, but does not alter shoulder function or the adjacent intact subscapularis tendon [2]. However, the consequences associated with disrupting the anterior-posterior force balance (supraspinatus and infraspinatus tears) are not understood. Therefore, the objectives of this study were 1) to investigate the effect of returning to overuse activity following tears of both the supraspinatus and infraspinatus tendons on shoulder function and the remaining intact tendon and glenoid cartilage mechanical properties and 2) to begin to define the biologic mechanisms responsible for these changes. We hypothesized that overuse activity following two-tendon rotator cuff tears would H1) alter shoulder function and H2) lead to damage (indicated by inferior mechanical properties and increased production of degenerative factors, extracellular matrix, and cartilage markers) in the remaining intact tendons (including the biceps and upper and lower subscapularis tendons) and in the anterior-superior region of the glenoid articular cartilage as a result of the excessive joint loading due to overuse following the supraspinatus-infraspinatus tear.

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Chen, Hwang-Kuen, Der-Ming Ku e Lien-Wen Chen. "Nonconservative Stability of Gyroscopic Rotor Systems". In ASME 1993 Design Technical Conferences. American Society of Mechanical Engineers, 1993. http://dx.doi.org/10.1115/detc1993-0119.

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Abstract The stability behavior of a cantilevered shaft, rotating at a constant speed and subjected to a follower force at the free end, is studied by the finite element method. The equations of motion for such a gyroscopic system are formulated by using deformation shape functions developed from Timoshenko beam theory. The effects of translational and rotatory inertia, gyroscopic moments, bending and shear deformations are included. In order to determine the critical load of the present nonconservative system more quickly and efficiently, a simple and direct method that utilizes the eigenvalue sensitivity with respect to the follower force is introduced. The numerical results show that for the present nonconservative system, the onset of flutter instability occurs when the first and second backward whirl speeds are coincident. And also, due to the effect of the gyroscopic moments, the critical flutter load decreases as the rotational speed increases.

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