ARTICLES PUBLIÉS

Influence of regular dance practice on the postural stability during quiet standing in healthy women

Marin T, Houel N, Begou-Mazenc T, Brikci A, Bertucci W

Computer Methods in Biomechanics and Biomedical Engineering. 22(sup1): S354-356; Dec 2019.

DOI: 10.1080/10255842.2019.1668135

Manubrio-sternal joint mobility during forced ventilation using non-invasive opto-electronic plethysmography: cases studies

Gaillard L, Debraux L, Houel N

Computer Methods in Biomechanics and Biomedical Engineering. 22(sup1): S221-223; Dec 2019.

DOI: 10.1080/10255842.2019.1668135

Effects of a lighter discus on shoulder muscle activity in elite throwers, implications for injury prevention. Original research

Dinu D, Houel N, Louis J

International Journal of Sports Physical Therapy. 14(4): 592-602; Jul 2019.

PMID: 31440410

Background. Performance in the discus throw requires high forces and torques generated from the shoulder of the throwing arm, making shoulder muscles at risk of overuse injury. Little is known on muscle activation patterns in elite discus throw. Hypothesis/Purpose. The purpose of this study was to compare the body kinematics and muscle activation patterns of arm and shoulder muscles involved in discus throwing when using discs of different mass (1.7kg vs 2.0kg). It was hypothesized that the use of a lighter discus would modify the activation of the shoulder musculature compared to a standard discus. Study Design. Case-control laboratory study. Methods. Seven male elite discus throwers performed five throws using a standard discus (STD, 2.0kg) and five throws using a lighter weight discus (LGT, 1.7kg). Surface EMG was recorded for the biceps brachii (BB), deltoideus anterior (DA), deltoideus medialis (DM), clavicular head of the pectoralis major (PM), latissimus dorsi (LD), and trapezius medialis (TM). Three-dimensional high-speed video analysis was utilized to record discus speed and identify the different temporal phases of each throw from the preparation phase (P1) to the delivery phase (P5). Results. The EMG activation of LD lasted longer (p<0.01) in P1 and was initiated later in P5 with the LGT discus compared to STD. In P5, the EMG intensity of BB decreased (p = 0.02) with LGT (%EMGmax= 50.4 ±49.6%) compared to STD (64.8 ±77.9%) and the activation of PM increased (p<0.01) with LGT (86.2 ±40.3%) compared to STD (66.2 ±26.9%). The discus speed at release was increased (p=0.04) by using the LGT discus (20.62 ±0.75m.s-1) compared to STD (19.61 ± 0.57m.s-1). The throwing distance was also increased (p<0.01) with the LGT (43.1 ±4.3m) discus compared to STD (39.4 ±3.4m). Conclusion. A lighter discus could be used by elite athletes in training to add variability in muscle solicitation and thus limit the overload on certain muscles of the shoulder region. These results may have implications regarding lowering the risk of injury in discus throw.

Effect of osteopathic treatment on a scar assessed by thermal infrared camera, pilot study

Riquet D, Houel N, Bodnar J-L

Complementary Therapies in Medicine. 45: 130-135; June 2019.

doi: 10.1016/j.ctim.2019.06.005

Background. Scar formation is influenced by mechanical forces and may generate mechanical tension. Scars induce a temperature difference in the body objectified by thermal imaging camera. The osteopath’s task is to ensure the tissue good mobility in the body. The aim of this study was to measure the influence of osteopathic treatment on a scar by thermal camera. Method. 12 subjects were analyzed: 4 scars by wounds and 8 by operations. A thermal camera was used to measure the temperature variations of the scars and peri-scar area after cooled stimulation. Measurements were made before and after osteopathic treatment. Results/Findings. A significant difference was found between the scar and the peri-scar area before osteopathic treatment (p=0.044) and no significant difference after osteopathic treatment (p=0.069). Results showed that osteopathic treatment on a scar induces a more homogeneous local warming temperature. Conclusion. The osteopathic treatment allows different warming between scar and peri-scar area; this suggests a modification of the connective tissue function after osteopathic treatment. Further studies are required to better understand the function of connective tissue and the mechanism of healing.

Background. Congenitally blind subjects developed postural adaptations improving somatosensory and vestibular systems to maintain upright stability and auditory skills to orient them in environment. However, the influence of auditory cues on upright stability in congenitally blind subjects stays unknown. Research question. The aim of this study is to define the influence of an auditory cue in congenitally blind subjects back space on their balance posture. Methods. Eleven sighted subjects and eleven congenitally blind subjects performed upright bipedal and unipedal quiet stances on a force plate with two conditions of auditory cue played by a loudspeaker placed 2 m behind them. Mean CoP velocity were recorded. Student test was used to compare significant difference between blind and sighted subjects bipedal and unipedal postures stability in both conditions of auditory cue. Results and significance. Results showed that congenitally blind subjects had no significant difference in mean sway velocity compared to sighted subjects in bipedal upright posture in auditory signal condition. However, blind subjects had significant lower mean sway velocity than sighted subjects in bipedal upright posture without sound. Blind subjects had significant increased mean sway velocity during unipedal quiet standing in both auditory cue conditions (with and without sound). The results showed that congenitally blind subjects used auditory cues placed behind them in order to improve their balance control in bipedal upright posture. In this case, blind subjects could better use compensatory mechanisms to perform quiet standing as sighted subjects. Without sound or in unipedal upright posture, congenitally blind subjects probably have sensory perturbations or limitations that impose them adaptations in order to avoid falling risk. Auditory cues should be study in the aim to better understand the compensatory mechanisms used by congenitally blind subjects to perform postural balance in usual environment.

Medical Infrared Thermography in back pain osteopathic management

Polidori G, Kinné M, Mereu T, Beaumont F, Kinné M

Complementary Therapies in Medicine. 39: 19-23; Aug 2018.

doi: 10.1016/j.ctim.2018.05.010

Objectives. The objective of this study was to provide proof-of-concept for the use of Medical Infrared Thermography to verify both diagnosis and osteopathic management accuracy in back pain. Methods. A 50-year-old woman with acute back pain syndrome volunteered to participate in this study. Results. Prior the treatment, thermal image reveals that in a sagittal plane, the inflammation extends from vertebra D8 to L3 with a maximum inflammation between vertebrae D10 to L1. Post-treatment, Medical Infrared Thermography only shows a slight inflammation along the lumbar furrow that does not induce pain in the patient. Conclusion. Medical Infrared Thermography has made it possible to scientifically support the osteopathic approach to back pain, both in the initial diagnostic phase and in the validation phase of treatment effectiveness.

Faisabilité et intérêt de l’entraînement en exergames pour des patients Alzheimer en SLD. Données fondamentales

Feasibility and interest of exergame training for Alzheimer patients in long-term care. Fundamental data [publication en français]

Brami C, Trivalle C, Maillot P

NPG Neurologie Psychiatrie Gériatrie. 18(106): 235-244; Aug 2018.

doi: 10.1016/j.npg.2018.04.003

La pathologie démentielle ne cesse de croître avec pour préoccupation l’amélioration de la prise en charge, notamment permise par le développement d’interventions non médicamenteuses. Parmi elles, les exergames combinant des stimulations cognitives et physiques ont fait leurs preuves auprès de certaines populations âgées. L’objectif de cette étude était d’évaluer la faisabilité et les bénéfices d’une telle stimulation chez des sujets âgés souffrant de la maladie d’Alzheimer en unité de soins longues durées (SLD). Un protocole expérimental de 24 séances de danse virtuelle (Dance Central sur Xbox One) réparties sur trois mois, a été dispensé à six sujets (versus sept contrôles). L’analyse des variables utilisées révélant une réelle adhérence (95%) et des améliorations physiques évaluées par le Timed-Up-and-Go (TUG) et le Short Physical Performance Battery (SPPB) atteste de la pertinence de cette prise en charge en unité de SLD.

Does dehydration alter the success rate and technique of three-point shooting in elite basketball?

Dinu D, Tiollier E, Leguy E, Jacquet M, Slawinski J, Louis J

Proceedings. 2(6): 202; Feb 2018.

doi: 10.3390/proceedings2060202

In order to better inform the effects of dehydration and hydration guidelines, we tested the acute effects of a 2% dehydration protocol on performance and technique of 3-point shooting (3PS) in Elite Basketball players (n=9). The 3PS technique was monitored by using nanotechnology inertial measurement units positioned onto body joints during the exercise. When dehydrated (−2.1% ±0.5% of body mass), 7 players experienced a slight decrease (−10.0% ±19.6%, p=0.16) in success rate, while RPE increased from 9.1 ±2.6 to 13.0 ±2.5 in euhydrated (EUH) and dehydrated (DEH) condition respectively (p=0.003). DEH slightly altered the 3PS technique as the knee angle increased (p=0.02) at toe-off time and the hip angle decreased during the 3PS (p=0.01). The speed of ball release tended to be increased (p=0.05) in DEH compared to EUH. Data from this study suggest that a 2% dehydration is tolerable for elite Basketball players, although a stronger dehydration might accentuate the effects observed.

Влияние остеопатической коррекции на увеличение силы мышц промежности при реабилитации после родов

Effect of osteopathic correction on strengthening of the perineal muscles in the postpartum rehabilitation period [publication en russe]

Bui Khac D, Ameur T, Houel N, Stubbe L

Russian Osteopathic Journal. 1-2: 67-75; 2018.

doi: 10.32885/2220-0975-2018-1-2-67-75

Introduction. The effect of the osteopathic treatment in the postpartum period has not been adequately studied in Western countries. The most part of the studies are focused on postpartum pain, whereas there is not enough information on the effect of osteopathic treatment on the recovery of perineal muscles. Goal of research. to study the effect of osteopathic treatment in combination with physical therapy on the recovery of the perineal muscle system in women in the postpartum period. Materials and methods. The study examined 38 women (mean age 30±5 years old) who underwent therapy in order to restore the perineal muscular system in the postpartum period. They were divided into two groups. Patients of the focus group received therapy in combination with the osteopathic correction. Women of the second group received therapy in combination with the imitation of manual treatment. Results. The data analysis shows a significant difference in the results of testing of the perineal muscle strength in patients of both groups by the end of the treatment: from 24,51±18,55 to 148,21±127,51 in the focus group, and from 29,32±20,32 to 94,22±78,51 in the control group. The intensity and the duration of the perineal muscle contraction did not differ significantly by the end of the treatment in both groups. Conclusion. Osteopathic treatment in combination with the rehabilitation therapy of the perineum significantly improves the muscle tone and promotes the restitution of the perineal muscle quality in the postpartum period in comparison with classical treatment.

Effect of spinal manipulative treatment on cardiovascular autonomic control in patients with acute low back pain

Younes M, Nowakowski K, Didier-Laurent B, Gombert M, Cottin F

Chiropractic & Manual Therapies. 25,33; Dec 2017.

doi: 10.1186/s12998-017-0167-6

Background. This study aimed to quantify the effect of spinal manipulative treatment (SMT) from an analysis of baroreflex, systolic blood pressure and heart rate variability (HRV) on patients with acute back pain. It was hypothesized that SMT would increase the parasympathetic cardiovascular autonomic control. Methods. Twenty-two patients with acute back pain were randomly divided into two groups: one receiving sham treatment (Sham) and the other receiving SMT. Recordings were completed during the first day and the seventh day, immediately before and after treatment on both days. ECG and systolic blood pressure were continuously recorded to compute cardiovascular variability and baroreflex sensitivity components. The perceived level of pain was measured with the numeric pain scale (NPS) 48h before, just before and just after each treatment. The NPS ranged from 0 to 100% (peak of pain before treatment). ECG and systolic blood pressure recordings were analyzed in time frequency domain using the Smoothed pseudo Wigner-Ville distribution. Results. Root mean square of the successive differences, high frequency power of the heart rate variability, and high frequency baroreflex sensitivity differences between post and pre tests were higher in the SMT group than in the Sham group (p<0.01), whereas no differences were observed with the other heart rate variability components. Also, no differences were observed with the systolic blood pressure components. Although the estimated pain scale values decreased over time, no difference was observed between the SMT and Sham groups. Conclusions. This seems to be the first study to assess the effect of SMT on both heart rate variability and baroreflex sensitivity in patients with acute back pain. SMT can be seen to provoke an increase in parasympathetic control known to relate to a person’s healthy state. Thus, cardiovascular variability analysis may be a useful tool for clinicians to quantify and objectify the beneficial effects of spinal manipulation treatment.

Evaluations of cranial micro-motion and breathing using kinematic analysis. Comparison between Vicon system and spirometry

Stubbe L, Houel N, Soudain-Pineau M, Billaudel P, Cottin F

Computer Methods in Biomechanics and Biomedical Engineering. 20(sup1): S197-S198; Oct 2017.

doi: 10.1080/10255842.2017.1382930

Principal Component Analysis between perceptions and kinematics of the subject. An ergonomic case study at office work

Picard A, Mahé M, Barbier J-M, Grangé C, Lefebvre M, Duc S, Bertucci W, Houel N

Computer Methods in Biomechanics and Biomedical Engineering. 20(sup1): S159-S160; Oct 2017.

doi: 10.1080/10255842.2017.1382911

Validity of 3D reconstruction of a new tool for postural assessment based on a single optical camera

Marin T, Houel N, Brikci A, Bertucci W

Computer Methods in Biomechanics and Biomedical Engineering. 20(sup1): S159-S160; Oct 2017.

doi: 10.1080/10255842.2017.1382893

Toward automatic detection of acute stress: relevant nonverbal behaviors and impact of personality traits

Gómez Jauregui DA, Castanier C, Chang B, Val M, Cottin F, Le Scanff C, Martin J-C

IEEE 2017 Seventh International Conference on Affective Computing and Intelligent Interaction (ACII). 354-361; Oct 2017.

doi: 10.1109/ACII.2017.8273624

The aim of the present study is to identify relevant nonverbal features allowing the discrimination of different stressful behaviors, with the consideration of personality factors. In order to achieve this aim, we propose a new method for psychological stress induction involving four different stressful tasks. The proposed protocol was tested with 45 PhD students and the analysis of heart rate variability suggests that stress was indeed elicited. PhD students were selected as participants because they often experience stress. Multimodal data was collected and analyzed in order to identify nonverbal behavioral features related to the different stressful tasks. The psychological profile of participants was taken into account to understand how different stressful behaviors are correlated with personality factors. Results suggest that relevant nonverbal behaviors can discriminate between stressful tasks. In addition, relevant behaviors involving movement variability appear to be correlated with personality factors and stressful tasks.

Mechanics of standing and crouching sprint starts

Slawinski J, Houel N, Bonnefoy-Mazure A, Lissajoux K, Bocquet V, Termoz N

Journal of Sports Sciences.35(9): 858-865; 2017.

doi: 10.1080/02640414.2016.1194525

The aim of this study was to compare the kinetic and kinematic parameters of standing and crouch sprint starts. Parallel starts (PS), false starts (FS), jump starts (JS) and crouch starts (3PS) were compared. Eighteen participants performed each start on a force plate and six infrared cameras captured the three-dimensional coordinates of 36 retro-reflective markers. Performance during a five-metre sprint (T5m) was analysed. Duration of the start phase (Tstart), mean values of horizontal and total ground reaction forces (GRFs) (Fx_mean and Ftot_mean), ratio of force (RF), maximal power (Pmax) and kinetic energy (KE) of each limb were calculated. Significant differences were found for T5m, Tstart, KE, Pmax, Fx_mean, Ftot_mean and RF for the crouch start compared to the other starts (p≤ 0.05). Significant correlations were found between T5m and Tstart (r=0.59; p≤0.001), and T5m and Pmax, Fx_mean and RF (−0.73≤r≤−0.61; p≤0.001). To conclude, the crouch start resulted in the best performance because Tstart was shorter, producing greater Pmax, Fx_mean with a more forward orientation of the resultant force. Greater KE of the trunk in each start condition demonstrated the role of the trunk in generating forward translation of the centre of mass (CM).

Introduction. Quatre-vingt-quinze pour cent des patients souffrant de la maladie de Lyme présentent une arthrite du genou. L’objet de cette pré-étude est de présenter l’influence de l’arthrite du genou issue de la maladie de Lyme sur la marche. Matériel et méthodes. Un sujet (âge= 17 ans, taille= 1,64m, masse= 60kg) présentant une mono-arthrite de l’articulation du genou gauche associée à la maladie de Lyme a réalisé une analyse quantifiée de la marche (2 plateformes de force, 8 caméras). La cinématique des membres inférieurs du sujet a été reconstruite selon la méthode Plug-in-Gait (Vicon). La vitesse moyenne de la marche et les amplitudes actives des articulations (AROM) ont été étudiés. La différence d’AROM entre chaque côté a été identifiée à l’aide du test-t de Student pour échantillons appariés. Résultats. Le sujet présente une vitesse moyenne de pas égale à 0,99 ±0,04m.s−1. L’AROM est significativement inférieur du côté de l’arthrite par rapport au côté opposé, pour les articulations de la hanche (AROM hanche gauche= 44,94 ±2,72 degrés vs AROM hanche droit= 49,65 ±1,51 degrés, p=0,002) et du genou (AROM genou gauche= 48,12 ±4,09 degrés vs AROM genou droit= 56,85 ±2,56 degrés, p=0,0004). Au niveau de la cheville, l’AROM est significativement supérieur du côté de l’arthrite (AROM cheville gauche= 57,67 ±4,48 degrés vs AROM cheville droit= 35,01 ±4,6 degrés, p<0,0001). Discussion/Conclusion. L’arthrite du genou consécutive de la maladie de Lyme entraîne une diminution de AROM lors de la marche similaire de celle d’un sujet présentant une arthrite sévère. Comme pour le sujet âgé sain, le sujet pathologique atténue les effets de son arthrite à l’aide de mécanismes compensatoires.

Accuracy of postural human-motion tracking using miniature inertial sensors

Dinu D, Fayolas M, Jacquet M, Leguy E, Slawinski J, Houel N

Procedia Engineering. 147: 655-658; Jul 2016.

doi: 10.1016/j.proeng.2016.06.266

Balance control in upright position has direct impact on shooting performance in various competitive activities like archery, rifle shooting, etc. Feet positions and global posture of the athlete change between each shooting activities. Information and short time feedback about the variation of the centre of mass of the athlete during the time before the shoot appears essential for learning and developing skills in shooting sports. In this aim, the purpose of the study was to explore the accuracy and reliability of a motion analysis system which uses the technology of inertial sensors (MVN Biomech system, Xsens). The MVN Biomech system is composed of 17 miniature inertial centrals attached to the full body. The validation procedure consisted in comparing the data of twenty subject’s centre of mass directly extracted from the MVN Biomech system with those given by an optoelectronic system (Vicon) composed of 8 infrared camcorders. The centre of mass computed by both system was calculated using the same anthropometric model. For each subject, the comparison of mean position of the centre of mass was performed in three quiet standing of 30 s. Paired t-test, r correlation coefficient test and root mean square (RMS) were used to compare the accuracy between both devices. The results of paired t-test showed a significant difference between the measurements (p<0.0001) in each component of the mean centre of mass position. Correlation between the tool’s measurements was significant and better than r>0.99 on each component. RMS computation shows mean difference between tools equal to 5.45mm on X component, 3.25mm on Y component and 0.73mm on Z component. The result of the MVN Biomech system appears accurate comparing to the optoelectronic system. The small differences could be explained by the relative motion of the respective sensors and markers of both systems on the soft tissues of the subject. If the MVN Biomech system was preliminary developed to explore the subject’s motion, the result of the present study showed that this system could also be used in order to estimate posture or micro-movements like postural sway during shooting activities.

Stimulated infrared thermography applied to differentiate scar tissue from peri-scar tissue: a preliminary study

Riquet D, Houel N, Bodnar J-L

Journal of Medical Engineering & Technology. 40(6): 307-314; Jun 2016.

doi: 10.1080/03091902.2016.1193239

Every human injury leads to a scar formation. The healing process leads to the formation of new tissue: the scar, which is different from the original tissue. This process is influenced by mechanical strength and the local vasculature is modified. The purpose of this study is to show that there are various temperatures between the scar and the peri-scar area associated with the healing process that can be estimated using the thermal infrared camera. In the study, 12 scars were stimulated by cold. Several changes of temperature were observed between scar and peri-scar area for 10 min. Scars appeared significantly colder with a Wilcoxon test (p=0.01). Results showed that stimulated infrared thermography can be used to monitor the temperature difference between the scar and peri-scar tissue.

Back pain is a common reason for consultation in primary healthcare clinical practice, and has effects on daily activities and posture. Relationships between the whole spine and upright posture, however, remain unknown. The aim of this study was to identify the relationship between each spinal curve and centre of pressure position as well as velocity for healthy subjects. Twenty-one male subjects performed quiet stance in natural position. Each upright posture was then recorded using an optoelectronics system (Vicon Nexus) synchronized with two force plates. At each moment, polynomial interpolations of markers attached on the spine segment were used to compute cervical lordosis, thoracic kyphosis and lumbar lordosis angle curves. Mean of centre of pressure position and velocity was then computed. Multiple stepwise linear regression analysis showed that the position and velocity of centre of pressure associated with each part of the spinal curves were defined as best predictors of the lumbar lordosis angle (R²=0.54; p=4.89*10-13) and the thoracic kyphosis angle (R²=0.45; p=1.65*10-10) of healthy subjects in quiet stance. This study showed the relationships between each of cervical, thoracic, lumbar curvatures, and centre of pressure’s fluctuation during free quiet standing using non-invasive full spinal curve exploration.

Touching sounds: Audio Virtual Surfaces

Boyer EO, Vandervoorde L, Bevillacqua F, Hanneton S

2015 IEEE 2nd VR Workshop on Sonic Interactions for Virtual Environments (SIVE), Arles. 1-5; Dec 2015.

doi: 10.1109/SIVE.2015.7361291

This prospective study concerning the perception of audio virtual surfaces (AVSs) was inspired by two different research fields: sensory substitution and haptic and touch perception. We define Audio Virtual Surfaces as regions of space that trigger sounds when the user touches it or moves into it. First, we describe an example of interactive setup using an AVS to simulate a sonic interaction with a virtual water tank. Then, we present an experiment designed to investigate the ability of blindfolded adults to discriminate between concave and convex auditory virtual surfaces using only the gesture-sound interaction. Two groups received different sound feedback, a static one indicating presence in the AVS, and a static+dynamic one (related to the component of the hand velocity tangential to the surface). In order to demonstrate that curvature direction was correctly perceived, we estimated their discrimination thresholds with a psychophysical staircase procedure. Results show that most of the participants were able to learn the task. The best results were obtained with the additional dynamic feedback. Gestural patterns emerged from the interaction, suggesting the use of auditory representation of the virtual object. This work proposes a contribution to the introduction in virtual reality of sonic interactions with auditory virtual objects. The setups we present raise new questions, at both experimental (sensory substitution) and application levels (design of gesture-sound interaction for virtual reality).

Effect of oral glucocorticoid intake on autonomic cardiovascular control

Cottin F, Malcurat V, Zorgati H, Prieur F, Labsy Z, Do MC, Gagey O, Collomp K

SpringerPlus. 4, 622; Oct 2015.

doi: 10.1186/s40064-015-1378-8

This study analyzed baroreflex sensitivity, heart rate and systolic blood pressure variabilities during an oral 1 week administration of prednisone. This study examined the hypothesis that prednisone might change both systolic blood pressure level and baroreflex sensitivity. Twelve physically active male subjects participated to a double-blind, randomized cross-over study consisting of two 1-week periods of treatment separated by a 4-week drug-free washout period: placebo (PLA) or prednisone (PRED). Trials were performed by each subject four times on the second (D2) and seventh (D7) day of each treatment period. ECG and blood pressure were continuously recorded to compute heart rate variability, systolic blood pressure variability and baroreflex sensitivity components with the smoothed pseudo Wigner Ville distribution and baroreflex analysis. Following D2 prednisone treatment, both HR (PLA: 60.8 ±10.5 vs. PRED:65.8 ±9.1 beats.min−1, p=0.008) and low frequency component of systolic blood pressure variability (D2: 3.09 ± 0.19 vs. D7: 2.34 ± 0.19, p < 0.041) increased whereas other components did not change. Over 7 days of treatment, LF-SBP amplitude increased (D2: 2.71 ± 0.89 vs. D7: 3.87 ± 0.6 mmHg, p = 0.037). A slight increase in both HR and LF-SBPV were observed suggesting a potential sympathetic cardiovascular stimulus. Although we found a significant effect of the 1-week prednisone treatment on heart rate and low frequency power of systolic blood pressure variability, we reported neither an increase in the systolic blood pressure level nor a decrease in the baroreflex sensitivity. Therefore, the fragility of our results cannot support a deleterious effect of 1-week administration of prednisone on the autonomic cardiovascular control which might be involved in cardiovascular diseases.

Touching sounds: Perception of the curvature of Auditory Virtual Surfaces

Boyer EO, Vandervoorde L, Bevillacqua F, Hanneton S

2015 IEEE Virtual Reality (VR), Arles. 153-154; Aug 2015.

doi: 10.1109/VR.2015.7223341

In this study, we investigated the ability of blindfolded adults to discriminate between concave and convex auditory virtual surfaces. We used a Leap Motion™ device to measure the movements of the hand and fingers. Participants were asked to explore the space above the device with the palm of one hand and an auditory feedback was produced only when the palm was moving into the boundaries of the surface. In order to demonstrate that curvature direction was correctly perceived by our participants, we estimated their discrimination thresholds with a psychophysical staircase procedure. Two groups of participants were fed with two different sonification of the surface. Results showed that most of the participants were able to learn the task. The best results were obtained with an auditory feedback related to the component of the hand velocity tangential to the virtual surface. This work proposes a contribution to the introduction in virtual reality of auditory virtual objects.

An Eddy current system for the study of the cranial rhythmic impulse

Stubbe L, Le Bihan Y, Ozout A-E, Herivan G, Berthelot E

IEEE Transactions on Magnetics. 51(1); Jan 2015.

doi: 10.1109/tmag.2014.2360875

The cranial rhythmic impulse (CRI) is an important osteopathic medicine concept that refers to the health of the individual. The technique of the eddy current (EC) sensors has the advantage to be directly sensitive to the CRI. In this paper, we present an EC system dedicated to the measurement of the CRI. To detect the CRI, a flexible aluminum foil covered with an adhesive layer is placed on the crane of the patient. The oscillations of the aluminum sheet induced by the CRI are detected by a dedicated EC sensor constituted of a printed coil. The sensing coil is put with an identical reference coil in an ac bridge. The bridge output voltage is analyzed with a lock-in amplifier. A spectral analysis is done on the output signal obtained after a 2 min long record on a patient. Different signals can be observed: 1) cardiac signal; 2) respiration signal; and 3) baroreflex signal, showing the capability of the EC system in the analysis of the CRI.

A cluster analysis approach for the determination of a fall risk level classification

Barelle C, Houel N, Koutsouris D

2014 IEEE 19th International Workshop on Computer Aided Modeling and Design of Communication Links and Networks (CAMAD). 130-134; Dec 2014.

doi: 10.1109/CAMAD.2014.7033220

Falls among elderly people have massive social and economic impact. Gait impairments correlated with loss of physical functions are the primary common causes. Today, even if gait deviations between healthy young individuals and elderly ones have been deeply investigated, no standardize fall risk classification have been really established to facilitate fall risk management and prevention. Therefore, the core of this study is to implement a statistic approach to determine a fall risks classification i.e. normal gait, abnormal gait without risk of falling and abnormal gait with risk of falling. In this paper, the method based on a cluster analysis to set up this fall risk level classification is presented. Based on a limited number of easily accessible biomechanics predictors, a fall risk level can be determined and help care providers to earlier and better prevent fall.

Does the use of a light shot put modify the throwing pattern of elite athletes?

Dinu D, Natta F, Huiban C, Houel N

Procedia Engineering 72: 92-96; Jun 2014.

doi: 10.1016/j.proeng.2014.06.019

The aim of this study is to analyse the influence of the weight mass (6 vs 7.26 kg) in kinematics parameters on an expert throwing shot put in rotation, in order to estimate the influence of using a lighter weight to minimise the arm thrower’s risk of injury or during recovery training. This study was done on a sample selection of three elite throwers (best performance 16.51 ±0,81m) from the French national team, who performed three throws with a 6kg weight mass and three others with a 7.26kg weight mass. Motion analysis of each throw were recorded using an optoelectronic system (Vicon612) composed of six infrared camcorders and a 3-D modelling of the throwing movement was processed according to the Dapena method. The thrower and weight center of mass velocities were computed for each throwing phase. Friedman Anova analysis showed no significant difference on the subject center of mass and weight velocities (respectively p=0.86 and p=0.45) between both weight mass conditions. No significant shot put mass effect, (p=0.86) on the phases duration in both conditions of weight (6 vs 7.2kg), were observed. These results suggest that a weight mass lower than 27% could be used for elite athletes training without a change in velocity of the motion throw. This could be used in order to narrow musculo-skeletal overwork and injury during intensive phases of training and/or to quickly return to specific throwing motion during recovery of the shoulder complex. This should allow for the use of a lighter discus during high level training without kinematical alteration of throwing.

Detection of carpal tunnel syndrome by infrared thermography

Maxel X, Bodnar J-L, Stubbe L

Mechanics & Industry. 15(5): 363-370; May 2014.

doi: 10.1051/meca/2014034

The aim of this study is to approach the possibilities of stimulated infrared thermography to the carpal tunnel syndrome diagnosis. Eleven patients were studied. Six of them were affected by the carpal tunnel syndrome. The five others were healthy. The study consists in exciting the patients’ hands and in analyzing their thermal response. The infrared thermograms obtained show that the hands infected by the carpal tunnel syndrome give a different thermal response.

Posture and lumbago: does a stabilometric platform help in identifying pain?

Huard Y, Bertucci W

Computer Methods in Biomechanics and Biomedical Engineering. 14(sup1): 197-198; Aug 2011.

doi: 10.1080/10255842.2011.595178