Publications of Bénédicte FORTHOMME
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See detailA foot/ground contact model for biomechanical inverse dynamics analysis
Van Hulle, Romain ULiege; Schwartz, Cédric ULiege; Denoël, Vincent ULiege et al

in Journal of Biomechanics (2020), 100

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See detailAlgorithm for extracting initial and terminal contact timings during treadmill running using inertial sensors
Prijot, Laura ULiege; Schwartz, Cédric ULiege; Watrin, Julien et al

Conference (2020)

Inertial measurement units (IMUs) are now considered as an economical solution for long term assessment in real conditions. However, their use in running gait analysis is relatively new and limited ... [more ▼]

Inertial measurement units (IMUs) are now considered as an economical solution for long term assessment in real conditions. However, their use in running gait analysis is relatively new and limited. Detecting the timing at which the foot strikes the ground (initial contact, IC) and the timing at which the foot leaves the ground (terminal contact, TC) gives access to many relevant temporal parameters such as stance, swing or stride durations. In this paper, we present an original algorithm to extract IC and TC timings and associated parameters from running data. These data have been measured using a newly developed IMU-based hardware system in ten asymptotic participants who ran at three speeds (slow, normal, and fast) with different running patterns (natural, rearfoot strike, mid-foot strike, and forefoot strike). This algorithm has been validated against a 200 Hz video camera based on 7056 IC and TC timings and 6861 temporal parameters. This algorithm extracted ICs and TCs with an accuracy and precision of (median [1st quartile; 3rd quartile]) 5 ms [-5 ms, 15 ms] and 0 ms [-5 ms, 5 ms], respectively. The relative errors in the extraction of stride and stance durations are -1.56 ± 3.00% and 0.00 ± 1.32%, respectively. [less ▲]

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See detailPrévention de blessures et triathlon
Delvaux, François ULiege; Forthomme, Bénédicte ULiege

Conference (2019, October 19)

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See detailPrévention de blessures et triathlon
Delvaux, François ULiege; Croisier, Jean-Louis ULiege; SANFILIPPO, Damien ULiege et al

in Journal de Traumatologie du Sport (2019), 36(3), 147-152

Despite a poor literature in the area of triathlon injury prevention, guidelines can be proposed for triathletes and their coaches. In triathlon, overuse injuries of lower limbs (tendinopathies, stress ... [more ▼]

Despite a poor literature in the area of triathlon injury prevention, guidelines can be proposed for triathletes and their coaches. In triathlon, overuse injuries of lower limbs (tendinopathies, stress fractures, tibial stress syndromes) represent a large majority of all injuries. The most important risk factors are a previous history of injury and an inadequate workload. Actually, preventive measures should include: a pre-competition clinical assessment in order to identify every predisposing factor to a potential future injury; a monitoring and subsequent management of workload; physical preparation sessions with core stability and strength training; a high quality of technical movements in each of the three disciplines; a management of other potential risk factors such as inadequate life style or warm-up. Further studies are required in order to improve the quality of triathlon injury prevention. [less ▲]

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See detailFinger dexterity predicts early math skills development: Insight from 3D human motion analyses.
Neveu, Maëlle ULiege; Vossius, Line ULiege; Schwartz, Cédric ULiege et al

Poster (2019, June 18)

Children’s ability to use their fingers in numerical contexts is assumed to contribute to the development of basic mathematical skills (Fayol & Seron, 2005; Gunderson et al., 2015). Some authors pointed ... [more ▼]

Children’s ability to use their fingers in numerical contexts is assumed to contribute to the development of basic mathematical skills (Fayol & Seron, 2005; Gunderson et al., 2015). Some authors pointed to finger gnosia as a good predictor of arithmetic abilities developed some years later (Fayol, Barrouillet, & Marinthe, 1998; Noël, 2005; Penner-Wilger & Anderson, 2008) while others highlighted the relationship between manual dexterity and early numerical and arithmetical abilities (Asakawa & Sugimura, 2009, 2011, 2014; Suggate, Stoeger & Fisher, 2017). At present, the contribution of the fine motor skills to early number development has been less investigated. The aim of this study is to examine how manual dexterity contributes to early number and arithmetical processing using 3D human motion analyses, a technique providing fine-grained measures of finger dissociation and finger coordination –two components of manual dexterity. Thirty preschoolers aged between 3 and 5 years old were tested in finger dissociation and finger coordination tasks as well as in tasks assessing early numerical and arithmetic development (i.e. reciting of numbers words, counting, number words cardinal knowledge, calculating with picture support). The multiple regression analyses showed the predictive value of finger dexterity for cardinality and arithmetic skills while controlling for age differences. This result outline the tight relationship between fine motor skills and early mathematical abilities and suggest that finger coordination could have decisive influences on the use of finger-based strategies in support to the development of numerical concepts and early arithmetic in young children. [less ▲]

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See detailStratégies préventives et blessures sportives
Delvaux, François ULiege; Kaux, Jean-François ULiege; Forthomme, Bénédicte ULiege et al

in AXXON Exclusif (2019)

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See detailInter-Session Reliability of the Tennis Serve and Influence of the Laboratory Context
Tubez, François ULiege; Forthomme, Bénédicte ULiege; Croisier, Jean-Louis ULiege et al

in Journal of Human Kinetics (2019), 66(1), 57-67

To meet the demand of a player's entourage (e.g., coaches and medical staff), it is important for the biomechanics specialist to perform repeatable measures. To the best of our knowledge, to date, it has ... [more ▼]

To meet the demand of a player's entourage (e.g., coaches and medical staff), it is important for the biomechanics specialist to perform repeatable measures. To the best of our knowledge, to date, it has not been demonstrated whether similar results are obtained between two sessions of testing or between laboratory and field sport kinematic protocols with regard to the tennis serve. This study had two primary aims. First, the inter-session repeatability of biomechanical variables of a tennis serve was evaluated. Second, the differences between laboratory and field evaluations were studied. Thirteen national tennis players (ITN 3) performed the same 28 markers' set laboratory test twice two weeks apart, and other thirteen national players (ITN 3) performed two 4 markers' set tests both in the laboratory and on an official tennis court one week apart. A 3D motion system was used to measure lower-limb, pelvis, trunk, dominant arm and racket kinematics. A force plate was used to evaluate kinetics of legs' drive in the laboratory. A personal method based on a point scoring system was developed to evaluate the ball landing location accuracy. We observed that the majority of the studied variables were acceptable for excellent relative reliability for the inter-session analysis. We also showed that the impact of the laboratory versus field context on the player's serve was limited © 2019 2019 François Tubez, Bénédicte Forthomme, Jean-Louis Croisier, Olivier Brüls, Vincent Denoël, Julien Paulus, Cédric Schwartz, published by Sciendo. [less ▲]

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See detailLa prévention des blessures sportives: modèles théoriques et éléments-clés d'une stratégie efficace
Delvaux, François ULiege; KAUX, Jean-François ULiege; Forthomme, Bénédicte ULiege et al

in Journal de Traumatologie du Sport (2018), 35(3), 152-157

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See detailPrévention en sport : quels outils ?
Schwartz, Cédric ULiege; Kaux, Jean-François ULiege; Forthomme, Bénédicte ULiege et al

in Journal de Traumatologie du Sport (2018), 35(3), 176-181

Le suivi du risque lésionnel des sportifs implique l’utilisation d’outils validés. Sous le terme d’outils, nous privilégierons la notion de protocole d’évaluation qui englobe des dimensions variées tel ... [more ▼]

Le suivi du risque lésionnel des sportifs implique l’utilisation d’outils validés. Sous le terme d’outils, nous privilégierons la notion de protocole d’évaluation qui englobe des dimensions variées tel que les outils de mesures, les conditions de passation du test, l’expertise des opérateurs … C’est en effet la somme de ces aspects qui déterminera, in fine, la qualité d’un test. Les protocoles d’évaluation impliquent au préalable l’identification de facteurs de risque puis l’évaluation du caractère prédictif de ces facteurs de risque. En outre, le protocole utilisé devra être reproductible entre les sessions pour permettre un suivi longitudinal du sportif mais aussi, si possible, entre les opérateurs et entre les centres d’évaluation. Le développement d’outils de prévention représente donc un travail considérable mais absolument nécessaire pour s’assurer de l’efficacité de la prise en charge des sportifs. [less ▲]

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See detailP054 - Evaluation of ground reaction forces by inverse dynamics analysis
Van Hulle, Romain ULiege; Schwartz, Cédric ULiege; Denoël, Vincent ULiege et al

in Gait and Posture (2018), 65

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See detailValidated assessment of gait sub-phase durations in older adults using an accelerometer-based ambulatory system
Boutaayamou, Mohamed ULiege; GILLAIN, Sophie ULiege; Schwartz, Cédric ULiege et al

in Proceedings of the 11th International Joint Conference on Biomedical Engineering Systems and Technologies (BIOSTEC 2018) (2018)

Validated extraction of gait sub-phase durations using an ambulatory accelerometer-based system is a current unmet need to quantify subtle changes during the walking of older adults. In this paper, we ... [more ▼]

Validated extraction of gait sub-phase durations using an ambulatory accelerometer-based system is a current unmet need to quantify subtle changes during the walking of older adults. In this paper, we describe (1) a signal processing algorithm to automatically extract not only durations of stride, stance, swing, and double support phases, but also durations of sub-phases that refine the stance and swing phases from foot-worn accelerometer signals in comfortable walking of older adults, and (2) the validation of this extraction using reference data provided by a gold standard system. The results show that we achieve a high agreement between our method and the reference method in the extraction of (1) the temporal gait events involved in the estimation of the phase/sub-phase durations, namely heel strike (HS), toe strike (TS), toe-off (TO), maximum of heel clearance (MHC), and maximum of toe clearance (MTC), with an accuracy and precision that range from ‒3.6 ms to 4.0 ms, and 6.5 ms to 12.0 ms, respectively, and (2) the gait phase/sub-phase durations, namely stride, stance, swing, double support phases, and HS to TS, TO to MHC, MHC to MTC, and MTC to HS sub-phases, with an accuracy and precision that range from ‒4 ms to 5 ms, and 9 ms to 15 ms, respectively, in comfortable walking of a thirty-eight older adults ( (mean ± standard deviation) 71.0 ± 4.1 years old). This demonstrates that the developed accelerometer-based algorithm can extract validated temporal gait events and phase/sub-phase durations, in comfortable walking of older adults, with a promising degree of accuracy/precision compared to reference data, warranting further studies. [less ▲]

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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 (2017), 37

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 detailA gait cycle partitioning method using a foot-worn accelerometer system
Boutaayamou, Mohamed ULiege; Bruls, Olivier ULiege; Denoël, Vincent ULiege et al

Conference (2017, November 30)

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See detailExploring the effect of a second closely-timed PRP infiltration for tendinopathy
Kaux, Jean-François ULiege; Forthomme, Bénédicte ULiege; Le Goff, Caroline ULiege et al

in European Journal of Sports Medicine (2017, September), 5(Supplement 1), 20-21

INTRODUCTION: Although PRP is very popular in sport, especially since it was removed from the doping list, it remains controversed in literature (3). Up to now, there exists no general agreement on the ... [more ▼]

INTRODUCTION: Although PRP is very popular in sport, especially since it was removed from the doping list, it remains controversed in literature (3). Up to now, there exists no general agreement on the preparation and the use of PRP. Some clinical series have previously evaluated the effect of PRP in the treatment of proximal patellar tendinopathies. Although it is possible that a single infiltrative administration may prove to be an effective treatment for this indication, most of the existing studies evaluated the effects of two or three successive infiltrations. The multiplication of infiltrations is arguably likely to increase the risks of complications, and this treatment can be expensive. PURPOSE: We aimed to evaluate whether two infiltrations of PRP prove more effective than a single treatment. METHODS: Our study is a single blinded, randomized controlled clinical trial on leisure sportsmen with chronic proximal patellar tendinopathies, rebel to classical management, including physiotherapy, shock wave therapy… Twenty patients suffering from proximal patellar tendinopathies for over than 3 months were enrolled into the study. PRP was obtained using an aphaeresis machine (1). The subjects were split into two randomized groups and beneficed of 1 or 2 infiltrations of pure PRP, respectively. The one-year followup evaluation consisted of VAS, IKDC and VISAP scores, while algometer, isokinetic and ultrasounds evaluations were carried out up to 3 months. RESULTS: The concentration of the PRP used for each infiltration was similar in both groups (913.20 ± 65.60 × 103/ L for group 1 and 917.90 ± 63.08for group 2, with virtually no red (<0.001 × 106/ L) nor white cells (<0.001 × 103/ L) in either group). The VAS significantly decreased with time over the 3 month followup period (p = 0002), with no difference observed between the two groups (p = 0.2). Values obtained with the pressure algometer increased with time across both groups over the 3 month followup period (p < 0.0001), and values were significantly higher for Group 1 (p = 0.001). The IKDC score increased with time in both groups over the followup period (p = 0.034), with values again significantly higher for Group 1 (p = 0.0026). The VISAP score increased with time in both groups over the followup period (p = 0.0023), with no difference observed between the groups (p = 0.41). No improvements in isokinetic physical performance were observed in either group. However, pain during E30 significantly decreased over the 3 month followup period (p = 0.027) for patients in both groups. No improvement in either jumping performances or in pain was observed in either group during optojump evaluation. No improvements in US findings were observed. However, an increase of the sagittal hypoechoic area was observed in Group1 (p = 0.0038). After one year, 90% patients of group 1 did not report anymore pain during daily activities, in comparison with only 20% in group 2. In group 1, 20% of subjects still described pain during work activities and 40% during practicing sports versus 40% and 70%, respectively, in group 2. One patient in each group did not return to sport; both subjects still experienced pain through daily and occupational work activities. Six subjects among the group 1 (67%) and 7 among the group 2 (78%) returned to their former sport, and 55% of both groups to the former level than before the tendinopathy. However, 44% of the group 1 and 78% of the group 2 still experienced pain during sports activities. The practiced sports were football, handball, cycling, running, fitness.On the other hand, patients with only few months of symptoms did not evolved more favorably than those with symptoms for longer. CONCLUSIONS: The comparison between 1 or 2 infiltrations of PRP did not reveal any difference between the 2 groups after a followup period of 3 months. A second closely timed infiltration of PRP to treat proximal patellar tendinopathies is not necessary to improve the efficacy of this treatment in the short term (2). However, there remains a need to evaluate the longer term results. REFERENCES: Kaux JF, Croisier JL, Bruyere O, Rodriguez De La Cruz C, Forthomme B, Brabant G, Lapraille S, Lonneux V, Noel D, Le Goff C, Gothot A, Collette J, Crielaard JM. One injection of plateletrich plasma associated to a submaximal eccentric protocol to treat chronic jumper's knee. J Sports Med Phys Fitness. 2015 Sep;55(9):95361 Kaux JF, Croisier JL, Forthomme B, Le Goff C, Buhler F, Savanier B, Delcour S, Gothot A, Crielaard JM. Using plateletrich plasma to treat jumper's knees: Exploring the effect of a second closelytimed infiltration. J Sci Med Sport. 2016 Mar;19(3):2004. Kaux JF, Drion P, Croisier JL, Crielaard JM. Tendinopathies and plateletrich plasma (PRP): from preclinical experiments to therapeutic use. J Stem Cells Regen Med. 2015 May 30;11(1):717. A10 [less ▲]

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See detailExperimental characterisation of tape spring nonlinear compliant mechanisms
Dewalque, Florence ULiege; Schwartz, Cédric ULiege; Denoël, Vincent ULiege et al

Conference (2017, June 29)

Tape springs are compliant mechanisms used as alternative to kinematic joints, for example, in deployable space structures. To reach a detailed understanding of their highly nonlinear behaviour, involving ... [more ▼]

Tape springs are compliant mechanisms used as alternative to kinematic joints, for example, in deployable space structures. To reach a detailed understanding of their highly nonlinear behaviour, involving buckling, the formation of folds, nonlinear vibrations and hysteresis, an experimental set-up is designed. Dynamic and quasi-static tests are performed, as well as small amplitude vibration tests and large amplitude deployments in order to collect data in a broad variety of cases. The acquisition equipment consists of a 3D motion analysis system which triangulates the position of active markers and a force plate. The reproducibility of the acquisitions is assessed and the parameters affecting the measurements are identified. In the end, a finite element model is developed and correlated with the experimental results. [less ▲]

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