39 research outputs found
Prédisposition génétique au développement d'une surdité (la mutation mitochondriale A1555G)
CLERMONT FD-BCIU-Santé (631132104) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF
Diagnostic moléculaire du syndrome de Fraser (mise au point de l'analyse du FRAS1)
Le syndrome de Fraser est une maladie rare, à transmission récessive autosomique. C'est un syndrome polymalformatif dans lequel on note principalement une cruptophthalmie, une syndactylie ainsi que des anomalies génitales et urinaires qui sont les critères majeurs du diagnostic clinique. A ce jour, seuls les gènes FRAS1 et FREM2 sont décrits comme responsables de syndrome de Fraser en pathologie humaine. Ces gènes codent pour des protéines de la matrice extracellulaire qui ont un rôle important dans la stabilisation des membranes basales et sont localisées à la jonction entre l'épithélium et le mésenchyme au cours du développement embryonnaire. Des modèles animaux, les souris "bleb", sont des analogues du syndrome de Fraser qui ont beaucoup contriué à une meilleure compréhension des fonctions des protéines de la famille FRAS/FREM et de la physiopathologie de la maladie. En pathologie humaine, 2 mutations différentes ont été décrites dans FREM2 et 19 dans FRAS1. Le but de ce travail de thèse a été d'identifier, à l'aide de techniques de PCR et de séquençage, des mutations pouvant être à l'origine du syndrome de Fraser chez 8 patients diagnostiqués sur des critères cliniques. A l'issue de l'analyse du gène FRAS1 (exons et régions introniques flanquantes), plusieurs mutations ont été mises en évidence et considérées comme responsable de la maladie chez 7 des 8 patients étudiés. L'intérêt de cette analyse est d'avoir pu confirmer le diagnostic clinique de syndrome de Fraser pour ces 7 patients et, dans un 2ème temps, de pouvoir proposer aux familles concernées un diagnostic moléculaire de syndrome de Fraser y compris en période anténatale précoce lorsque la mutation familiale a été identifiée.CLERMONT FD-BCIU-Santé (631132104) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF
Kinematic differences in upper limb joints between flat and topspin forehand drives in competitive male tennis players
International audienc
Paracetamol and Pain Modulation by TRPV1, UGT2B15, SULT1A1 Genotypes: A Randomized Clinical Trial in Healthy Volunteers
International audienc
Rotation sequence to report humerothoracic kinematics during 3D motion involving large horizontal component: application to the tennis forehand drive
The aim of this study was to examine the respective aptitudes of three rotation sequences (YtXf2Yh22, ZtXf2Yh22, and XtZf2Yh22) to effectively describe the orientation of the humerus relative to the thorax during a movement involving a large horizontal abduction/adduction component: the tennis forehand drive. An optoelectronic system was used to record the movements of eight elite male players, each performing ten forehand drives. The occurrences of gimbal lock, phase angle discontinuity and incoherency in the time course of the three angles defining humerothoracic rotation were examined for each rotation sequence. Our results demonstrated that no single sequence effectively describes humerothoracic motion without discontinuities throughout the forehand motion. The humerothoracic joint angles can nevertheless be described without singularities when considering the backswing/forward-swing and the follow-through phases separately. Our findings stress that the sequence choice may have implications for the report and interpretation of 3D joint kinematics during large shoulder range of motion. Consequently, the use of Euler/Cardan angles to represent 3D orientation of the humerothoracic joint in sport tasks requires the evaluation of the rotation sequence regarding singularity occurrence before analysing the kinematic data, especially when the task involves a large shoulder range of motion in the horizontal plane
Glenohumeral contact force during flat and topspin tennis forehand drives
International audience12 The primary role of the shoulder joint in tennis forehand drive is at the expense of the 13 loadings undergone by this joint. Nevertheless, few studies investigated glenohumeral (GH) 14 contact forces during forehand drives. The aim of this study was to investigate GH 15 compressive and shearing forces during the flat and topspin forehand drives in advanced 16 tennis players. 3D kinematics of flat and topspin forehand drives of 11 advanced tennis 17 players were recorded. The Delft Shoulder and Elbow musculoskeletal model was 18 implemented to assess the magnitude and orientation of GH contact forces during the 19 forehand drives. The results showed no differences in magnitude and orientation of GH 20 contact forces between the flat and topspin forehand drives. The estimated maximal GH 21 contact force during the forward swing phase was 3573 ± 1383 N, which was on average 1.25 22 time greater than during the follow-through phase, and 5.8 times greater than during the 23 backswing phase. Regardless the phase of the forehand drive, GH contact forces pointed 24 toward the anterior-superior part of the glenoid therefore standing for shearing forces. 25 Knowledge of GH contact forces during real sport tasks performed at high velocity may 26 improve the understanding of various sport-specific adaptations and causative factors for 27 shoulder problems. 28 2 2
Influence of racket on the variability of humerothoracic joint kinematics during tennis serve: a preliminary study
39ème Congrès de la Société de Biomécanique, Valenciennes, France, 27-/08/2014 - 29/08/2014Previous study showed that kinematic patterns reveal very little variability over repeated tennis strokes for individual player (Knudson 1990). Sport media, however, regularly show difficulties encountered by elite athletes in being accustomed to new equipment, especially in tennis activity. The stability of the pattern would thus be altered by changes in racket specifications. During overhead motion, the shoulder complex has a predominant function as it funnels the energy generated by the lower limbs and trunk to the upper limb and then to the racket, through the so-called kinetic chain (Sciascia et al. 2012). The variability of shoulder kinematic patterns could thus be a key point in habituation to a new equipment. The aim of this study was to explore the variability of the humerothoracic joint kinematic pattern in a highly skilled player when serving with his own racket and with another one. It was hypothesised that the kinematic pattern would be more variable when serving with another racket than with the regular on
Influence of racket polar moment on joint loads during tennis forehand drive
38ième congrès de la Société de Biomécanique francophone, MARSEILLE, FRANCE, 04-/09/2013 - 06/09/2013A tennis racket is characterised by three moments of inertia. The swingweight is measured about the axis perpendicular to the handle of the racket in the perpendicular plane of the frame, the twistweight is measured about the axis perpendicular to the handle of the racket in the plane parallel to the frame and the polar moment is measured about the long axis of the racket (Brody 2000). On an absolute basis, players are more sensitive to polar moment than to the other two moments of inertia (Brody 2000). The main advantage of the increase in the polar moment is to offer more stability against twisting of the racket head with off-axis ball impacts. However, there are no data in the literature investigating the relationship between racket polar moment and joint loads experienced by the tennis player under field conditions. This study aimed at investigating the influence of the racket polar moment on the upper limb joint moments and powers during tennis forehand drive
Upper limb joint muscle/tendon injury and anthropometric adaptations in French competitive tennis players
International audienc
Influence of hand-held racket on scapulothoracic kinematics during humeral elevation in the scapular plane in young tennis players: a preliminary study
38ième congrès de la Société de Biomécanique francophone, MARSEILLE, FRANCE, 04-/09/2013 - 06/09/2013In overhead activities, and particularly in tennis, themajority of the force required to propel the ball forwards is developed in the legs and trunk in a closed chain manner, funnelled through the scapulohumeral complex and transferred to the racket (Sciascia et al. 2012). Specific segment positions and motions are fundamental for an efficient linkage of multiple segments in such kinetic chain (Sciascia et al. 2012).Among the ideal nodes of the tennis serve, the coupled scapular retraction/arm rotation to achieve cocking in the scapular plane is recommended (Sciascia et al. 2012). The scapula is conflicting as it is required to provide both significant mobility through a large arc of motion and a stable base for arm function (McClure et al. 2012). These competing functions make the scapular region vulnerable to scapular dyskinesis. Such alterations in scapular motions are observed in up to two-thirds of overhead athletes' shoulder pathologies (Kibler and Thomas 2012). As a consequence, early evaluation of scapular kinematics is indicated to prevent the athlete's risk of shoulder injury, and potentially minimise the occurrence of such injury later in the player's career. Moreover, tennis is one of the overhead activities involving an implement, hence questioning the racket influence on scapular motions. The aim of this study was therefore to investigate the scapulothoracic kinematics during scaption in young tennis players when holding or not the tennis racket