References of "Tubez, François"
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See detailNormalizing shoulder EMG: an optimal set of maximum isometric voluntary contraction tests considering reproducibility
Schwartz, Cédric ULiege; Tubez, François ULiege; WANG, François-Charles ULiege et al

in Journal of Electromyography and Kinesiology (in press)

Normalization of the electromyography (EMG) signal is often performed relatively to maximal voluntary activations (MVA) obtained during maximum isometric voluntary contraction (MVIC). The first aim was to ... [more ▼]

Normalization of the electromyography (EMG) signal is often performed relatively to maximal voluntary activations (MVA) obtained during maximum isometric voluntary contraction (MVIC). The first aim was to provide an inter-session reproducible protocol to normalize the signal of eight shoulder muscles. The protocol should also lead to a level of activation >90% of MVA for >90% of the volunteers. The second aim was to evaluate the influence of the method used to extract the MVA from the EMG envelope on the normalized EMG signal. Thirteen volunteers performed 12 MVICs twice (one-week interval). Several time constants (100 ms to 2 s) were compared when extracting the MVA from the EMG envelope. The EMG activity was also acquired during an arm elevation. Our results show that a combination of nine MVIC tests was required to meet our requirements including reproducibility. Both the number of MVIC tests and the size of the time constant influence the normalized EMG signal during the dynamic activity (variations up to 15%). A time constant of 1 s was a good compromise to extract the MVA. These findings are valuable to improve the reproducibility of EMG signal normalization. [less ▲]

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See detailMaximal voluntary isometric contraction tests for normalizing surface EMG of scapular stabilizers muscles
Schwartz, Cédric ULiege; Tubez, François ULiege; Soulier, Maxime et al

Conference (2017, July 04)

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See detailHow much should you jump? Reproducibility evaluation of a 3-dimensional fatigability countermovement jump test
Paulus, Julien ULiege; Schwartz, Cédric ULiege; Tubez, François ULiege et al

Conference (2017, July 02)

Introduction With the stop jump, the counter movement jump (CMJ) is probably the most used jump in sport. In the literature, a number of studies use the counter movement jump to explore (neuro-)muscular ... [more ▼]

Introduction With the stop jump, the counter movement jump (CMJ) is probably the most used jump in sport. In the literature, a number of studies use the counter movement jump to explore (neuro-)muscular fatigability [1-4]. However, due to the continuous [1-3] (or semi-continuous [4]) character of the test, the CMJ become drop jumps from the second one. Nevertheless, the drop jump isn't the most frequent jump type in sport. These evaluations, with (semi-)continuous jumps, don't reflect the sport reality and therefore a more effective (neuro-)muscular jumping fatigability evaluation must be validated. Methods Nineteen volleyball players (23,5 ± 3,3 years, 187,6 ± 6,6 cm, 77,5 ± 8,5 kg), with no history of (major) lower limb injury, submitted to two jumping fatigability tests, with seven days between each session, under the direction of a single researcher. The jumping fatigability tests consists of the repetition of 50 maximal CMJ at the rate of 33bpm. Between each CMJ, the subject were asked to make a full triple-extension and to wait the next auditory and visual signal of the metronome to start the hip-knee-ankle flexion. With these instructions, each jump remains a CMJ. Subjects were asked to leap as high as possible from the first to the last CMJ. The jumping height was recorder for each jump with three dimensional camera. The reproducibility was assessed by Standard Error of Measurement (SEM), Minimal Difference needed to be considered real (MD), Coefficient of Variation (CV), Pearson Correlation Coefficient (PCC) with 95% confidence interval, Effect Size Cohen (ES Cohen) with 90% confidence interval, paired Student's t-test, Intraclass Correlation Coefficient (ICC 2,1) with 95% confidence interval and Magnitude-Based Inferences (MBI). Results The results summary is available in the Table 1. In this table, only few parameters are presented and only for the partial sums of the first 10, 20, 25, 30, 40 and 50 jumps. Our analyses were based on the partial sums per interval of one jump and all statistical tests listed in "Methods" section have been considered. The partial sum with twenty-five CMJ have an excellent reproducibility (MBI with 0/99/1; ICC with 0.961 [0.902/0.985]; ES Cohen with -0.03 [-0.17/0.10]; PCC with 0.966 [0.911/0,987] and p-value < 0.0001). Moreover, it induce a great height decrease (-23%) and its duration (45.5 s) is similar to the recommendation for the knee fatigability isokinetic protocol [5]. MBI (+/trivial/-) Height decrease ICC (2,1) Test duration 10 0/100/0 -12,7% 0.967 18 s 20 0/99/1 -19,0% 0.964 36 s 25 0/99/1 -23,0% 0.961 46 s 30 0/98/1 -25,6% 0.955 55 s 40 0/98/1 -32,1% 0.950 73 s 50 0/98/2 -38,4% 0.943 91 s Table 1: reproducibility statistics results depending on the number of jumps considered (magnitude-based inferences (MBI) with percentage chances of better/trivial/worst retest vs test results; height jump decrease (last jump / better jump); ICC (2,1); test duration). Discussion Because of the (semi-)continuous character of a majority of fatigability jumping test [1-4], our test is the first, at our knowledge, to explore the reproducibility of a strict CMJ jumping fatigability task. Considering the statistical (relative and absolute) reproducibility results, twenty-five maximal CMJ seems to be the best compromise between reliability of the data and physiological interpretability of test's results. Indeed, its (relative and absolute) reproducibility is excellent and it induces a greater height decrease than shorter test while remaining similar in total duration than other fatigability tests which explore the anaerobic lactic system. References 1. Bosco et al, Eur J Appl Physiol Occup Physiol, 51(3):357-364, 1983. 2. Cormack et al., Int J Sports Physiol Perform, 3(2):131-44, 2008. 3. Dal Pupo et al., J Sci Med Sport, 17(6):650-5, 2014. 4. Meckel et al., J Strength Cond Res, 29(8):2122-7, 2015. 5. Bosquet et al., Int J Sports Med, 31(2):82-8, 2010. [less ▲]

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See detailRelevance of early stretching in overhead athletes
Schwartz, Cédric ULiege; Tubez, François ULiege; Croisier, Jean-Louis ULiege et al

Conference (2017, June 16)

Overhead athletes often develop, over time, a tightness of the posterior structures of the shoulder, which may be associated with injuries. Ten symptomatic (with pain) and ten asymptomatic players with a ... [more ▼]

Overhead athletes often develop, over time, a tightness of the posterior structures of the shoulder, which may be associated with injuries. Ten symptomatic (with pain) and ten asymptomatic players with a tight shoulder were compared and the effect of a self-applied stretching program was evaluated. Before and after the stretching program, pain and stiffness of the shoulder were evaluated. Our results demonstrate that risk factors for shoulder pain such as glenohumeral internal rotation deficit and total range of motion deficit may only be limited in symptomatic athletes. The mobility of the shoulder was significantly improved after the stretching program for both groups. Pain was reduced when present. Because of the limited differences between the symptomatic and asymptomatic athletes, clinicians may find it advantageous to initiate early prevention or rehabilitation programs. [less ▲]

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See detailInfluence of the laboratory context and the size of the markers set on the tennis serve evaluation
Tubez, François ULiege; Forthomme, Bénédicte ULiege; Croisier, Jean-Louis ULiege et al

Conference (2017, June 15)

The purpose of this study was to identify the influence on the tennis serve evaluation of 1/ the test environment and 2/ the number of the markers placed of the player. Two different studies were ... [more ▼]

The purpose of this study was to identify the influence on the tennis serve evaluation of 1/ the test environment and 2/ the number of the markers placed of the player. Two different studies were performed. The first compared a 4 vs. 28 marker set in a laboratory the same day. The second compared a 4 markers test in a laboratory with a 4 markers test on an official tennis court one week apart. We observed similar results between the different tests of both studies. [less ▲]

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See detailMotion analysis: a prevention tool
Schwartz, Cédric ULiege; CROISIER, Jean-Louis ULiege; Forthomme, Bénédicte ULiege et al

Conference (2017, April 28)

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See detailFactors to be considered to perform a kinematic evaluation of the tennis serve
Tubez, François ULiege; Forthomme, Bénédicte ULiege; Croisier, Jean-Louis ULiege et al

in Journal of Medecine and Science in Tennis (2017), 22

With the 2D video cameras and later the appearance of 3D measurement methods, the tennis serve has been increasingly studied. In order to improve the biomechanical evaluation of the tennis serve. Our goal ... [more ▼]

With the 2D video cameras and later the appearance of 3D measurement methods, the tennis serve has been increasingly studied. In order to improve the biomechanical evaluation of the tennis serve. Our goal is to provide a comprehensive view of the major factors of an evaluation protocol. [less ▲]

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See detailCaractéristiques et évolution de la force après rééducation de la rupture de coiffe des rotateurs
Forthomme, Bénédicte ULiege; Schwartz, Cédric ULiege; MAHIEU, Xavier ULiege et al

in Abstract Book des XVIIIèmes RENCONTRES ISOCINETIQUES MEDIMEX / ROTSCHILD (2016, November)

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See detailReproducibility of a tennis serve protocol
Tubez, François ULiege; FORTHOMME, Bénédicte ULiege; Croisier, Jean-Louis ULiege et al

Conference (2016, July 08)

INTRODUCTION Serve in modern tennis game is a real offensive weapon for players. In kinematic analysis, it is the most studied stroke of this game because it is the only stroke played in a closed skill ... [more ▼]

INTRODUCTION Serve in modern tennis game is a real offensive weapon for players. In kinematic analysis, it is the most studied stroke of this game because it is the only stroke played in a closed skill. Players have a maximum of control on this stroke. It is unclear whether 3D kinematic tests are reproducible for the same player under identical conditions and if a familiarization session is necessary. In practice, with professional players, who have little time available to perform tests, familiarization sessions are difficult. The aim of our study is to measure the reproducibility of a 3D serve protocol test. METHODS Nine tennis players (righties, regional level, 20 ± 2 years) were asked to hit first flat serves in a 1 m² area placed on the "T" zone of deuce diagonal of the tennis court. Two identical tests are performed one week apart. For each test, we selected the three best serves of the 25 trials (with the highest speed and the highest accuracy). Kinetics measurements were performed using a 3D analysis system (Codamotion), a force platform (Kistler) and a radar gun. 28 markers were placed on the players’ bodies to measure kinematics of the movements: ankles, knees, hips, trunk, shoulder, elbow and wrist dominant side. We measured ball speed, leg drive, linear velocity of the racket and joints, joints range of motion and maximum angular velocities at different positions (armed, maximum external rotation and impact) (1). RESULTS All analyzed parameters (linear speeds of racket and joints, leg drive force, joint angles and angular velocities) are reproducible with exception of a small part of them. Our study shows that 5,7% (7 of 122 measurements) joint position parameters and 8,3% (4 of 48 measures) angular velocity parameters are not reproducible from a session to another. DISCUSSION Various errors sources encountered in 3D analysis can justify the presence of non-reproducible parameters (2-3). However, after this work, we can state that the established protocol provides reproducible results when analyzing the tennis serve. [less ▲]

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See detailEvaluation isocinétique et fonctionnelle de la rupture de coiffe des rotateurs non opérée
Forthomme, Bénédicte ULiege; Schwartz, Cédric ULiege; MAHIEU, Xavier ULiege et al

in Abstract book des XVIIèmes RENCONTRES ISOCINETIQUES DE MEDIMEX (2015, November)

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See detailBiomechanical Analysis of Abdominal Injury in Tennis Serves. A Case Report
Tubez, François ULiege; Forthomme, Bénédicte ULiege; Croisier, Jean-Louis ULiege et al

in Journal of Sports Science & Medicine (2015), 14

The serve is an important stroke in any high level tennis game. A well-mastered serve is a substantial advantage for players. However, because of its repeatability and its intensity, this stroke is ... [more ▼]

The serve is an important stroke in any high level tennis game. A well-mastered serve is a substantial advantage for players. However, because of its repeatability and its intensity, this stroke is potentially deleterious for upper limbs, lower limbs and trunk. The trunk is a vital link in the production and transfer of energy from the lower limbs to the upper limbs; therefore, kin-ematic disorder could be a potential source of risk for trunk injury in tennis. This research studies the case of a professional tennis player who has suffered from a medical tear on the left rectus abdominis muscle after tennis serve. The goal of the study is to understand whether the injury could be explained by an inappropriate technique. For this purpose, we analyzed in three dimensions the kinematic and kinetic aspects of the serve. We also performed isokinetic tests of the player’s knees. We then compared the player to five other professional players as refer-ence. We observed a possible deficit of energy transfer because of an important anterior pelvis tilt. Some compensation made by the player during the serve could be a possible higher abdominal contraction and a larger shoulder external rotation. These partic-ularities could induce an abdominal overwork that could explain the first injury and may provoke further injuries. [less ▲]

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See detailHow biomechanical analysis may help to identify abdominal injury causes in high level tennis
Tubez, François ULiege; Forthomme, Bénédicte ULiege; Croisier, Jean-Louis ULiege et al

Conference (2015, July)

This research studies the case of a professional tennis player who has suffered from a medical tear on the left rectus abdominis muscle after a tennis serve. The goal of the study is to understand whether ... [more ▼]

This research studies the case of a professional tennis player who has suffered from a medical tear on the left rectus abdominis muscle after a tennis serve. The goal of the study is to understand whether the injury could be explained by an inappropriate technique. For this purpose, we analyzed the three dimensions kinematic and kinetic of the serve. We also performed isokinetic tests of the knees. We compared the player to five other professional players. We observed a possible deficit of energy transfer because of an important anterior pelvis tilt. Some compensations of the player during serve could be a possible higher abdominal contraction and a larger shoulder external rotation. These particularities could induce an abdominal overwork that would explain the first injury and may provoke a new injury. [less ▲]

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See detailInfluence of players' level on racket speed and ball accuracy in the tennis serve
Tubez, François ULiege; Croisier, Jean-Louis ULiege; Cordonnier, Caroline ULiege et al

Conference (2014, July 06)

INTRODUCTION Serve in modern tennis game is an important offensive weapon for players (1-2). In kinematic analysis, serve is the most studied stroke of this game. The aim of our study was to compare the ... [more ▼]

INTRODUCTION Serve in modern tennis game is an important offensive weapon for players (1-2). In kinematic analysis, serve is the most studied stroke of this game. The aim of our study was to compare the performance of two specific populations: international players versus national players. In particular, racket speed at impact and accuracy of ball were assessed. METHODS A tennis court was reconstructed in a motion analysis laboratory. The position of the racket was evaluated in 3D at a frequency rate of 200 Hz. Tests were performed on 6 professional players (international level) and 9 non-professional players (national level). Each of them served 25 trials in direction of the “T” area of deuce diagonal. Two squares of 1m² and 2 m² respectively were delimited on the corner of the serve square. The instruction for both groups was to serve in the “T” area with the highest ball speed and minimal ball rotation (flat serve). RESULTS Although the forward speed of the racket at impact was identical between the two groups of players (International 36.35 ± 2.37 m/s and national 36.37 ± 2.90 m/s, p-value 0,991), the accuracy and consistency of serves on the target area is better for international players group (1m² area: International 33% ± 7% and national 14% ± 12%, p-value 0.0053; 2m² area (including 1m² area): International 71% ± 8% and national 54% ± 12%, p-value 0.0096; Out of zone: International 29% ± 8% and national 46% ± 12%, p-value 0.014). DISCUSSION High-velocity ball seems to be a key factor for serve performance (3). It is known that there is a relationship between racket speed and ball velocity (4). Both groups have high racket speed. However, international players serve with better accuracy and consistency than national players. We hypothesize that these differences are due to capacity of international players to adapt to a particular environment. Moreover, international players could give priority to consistency over velocity. We conclude that high-velocity serve is not a sufficient criterion to perform at international level; consistency and accuracy are two important factors to reach this level. [less ▲]

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See detailL'apport de l'analyse biomécanique 3-D dans les stratégies préventives à partir de 2 exemples
Schwartz, Cédric ULiege; Croisier, Jean-Louis ULiege; Tubez, François ULiege et al

in Julia, M; Croisier, Jean-Louis; Perrey, S (Eds.) et al Prévention des troubles musculo-squelettiques chez le sportif (2013)

De nouveaux outils de mesure permettent de quantifier la cinématique et la dynamique articulaire fonctionnelle des athlètes (systèmes optoélectroniques 3D, plateforme de forces, électromyographie, …). Ces ... [more ▼]

De nouveaux outils de mesure permettent de quantifier la cinématique et la dynamique articulaire fonctionnelle des athlètes (systèmes optoélectroniques 3D, plateforme de forces, électromyographie, …). Ces données sont importantes dans le sens où elles donnent à l’équipe médicale et sportive des informations objectives sur le geste du sportif dans sa pratique réelle. Elles favorisent la compréhension et l’amélioration de la performance ainsi que la prévention lésionnelle et la détection de situations à risque. Dans le cadre d’un suivi longitudinal des sportifs, ces mesures sont intéressantes pour mettre en place des critères objectifs et spécifiques à l’athlète de retour sur le terrain après une blessure. Ce document a pour objectif de présenter les principaux outils disponibles dans les laboratoires de biomécanique et d’illustrer leurs utilisations à travers 2 exemples : l’influence de la raideur de l’épaule sur la mobilité de l’épaule et l’analyse cinématique du service au tennis. [less ▲]

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See detailAnalyse comparative de différentes modalités d’électrostimulation du quadriceps fémoral
Tubez, François ULiege; Jidovtseff, Boris ULiege; Wang, François-Charles ULiege et al

in Kinesitherapie Revue (2010), 10(107), 36-40

Objective: The purpose of this study is to assess the relevance of a technological innovation (Mi-Scan function, Compex company) offered by the range of rehabilitative and/ or sport oriented stimulators ... [more ▼]

Objective: The purpose of this study is to assess the relevance of a technological innovation (Mi-Scan function, Compex company) offered by the range of rehabilitative and/ or sport oriented stimulators. This analysis examines the effectiveness to induce muscle contraction and the reproductibility of this function. Method: A comparison of electrically evoked torques of the quadriceps was performed with and without the aid of this function, both at submaximal and maximal stimulation intensity. Moreover, this function was studied several times under identical conditions (reproducibility study). Results: No superior efficacy has been found when using a system including the "Mi" function over a system that did not use this feature. Additionally, our results have highlighted a poor reproducibility of measurements obtained by the "Mi"sensor. Discussion: Important doubts must be made concerning the validity and reliability of this tool. [less ▲]

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See detailUSING INERTIA MEASUREMENT UNIT (IMU) FOR EXERCISE ANALYSIS
Jidovtseff, Boris ULiege; Bruls, Olivier ULiege; Tubez, François ULiege et al

in 7th International conference on strength training - abstract book (2010)

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See detailAnalyse comparative de différentes modalités d’électrostimulation du quadriceps fémoral
Tubez, François ULiege

Master's dissertation (2009)

Objectif : Cette étude a pour but d’apprécier la pertinence d’une innovation technologique (fonction Mi-Scan, société Compex) proposée dans la gamme des stimulateurs à vocation rééducative et/ou sportive ... [more ▼]

Objectif : Cette étude a pour but d’apprécier la pertinence d’une innovation technologique (fonction Mi-Scan, société Compex) proposée dans la gamme des stimulateurs à vocation rééducative et/ou sportive. Cette analyse porte sur l’efficacité excitomotrice et sur les qualités métrologiques de cette fonction. Méthode : Une comparaison des moments de forces évoqués électriquement au niveau du quadriceps avec et sans l’aide de cette fonction a été réalisée, et ce à intensité sous-maximale et maximale de stimulation. Par ailleurs, cette fonction a été explorée dans des conditions identiques à diverses reprises (étude de reproductibilité). Résultats : Il n’existait pas d’efficacité supérieure d’un montage utilisant la fonction "Mi" par rapport à un montage ne possédant pas cette fonctionnalité. De manière additionnelle, nos résultats ont permis de mettre en évidence que la reproductibilité des mesures effectuées par le senseur "Mi" était médiocre. Discussion : De grandes réserves doivent donc être émises concernant la validité et la fiabilité de cet outil. [less ▲]

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