Collaborative Virtual Environments for Ergonomics: Embedding the Design Engineer Role in the Loop

International audienceThe aim of this paper is to define the role and duties of a design engineer involved in a collaborative ergonomic design session supported by a 3D collaborative virtual environment. For example, such a session can be used to adapt the manual task an operator must achieve in the context of an industrial assembly line. We first present the interest of such collaborative sessions. Then we present a related work explaining the need of proper 3DCVE and metaphors to obtain efficient collaborative ergonomic design sessions. Then, after a short definition of the role of the engineer in such sessions, we propose a use case highlighting the type of metaphor such engineers need to have to be efficient in such a framework. Discussion and future works ends the paper

A SIMPLE METHOD TO CALIBRATE KINEMATICAL INVARIANTS: APPLICATION TO OVERHEAD THROWING

The aim of this paper is to present a simple calibration method aimed at optimizing the kinematical invariants of a whole body motion capture model, meaning limb lengths and some of the marker placements. A case study and preliminary results are presented and give encouraging insights about the generalized use of such a method in motion analysis in sports

Un exemple d'archéologie du geste martial: les guerriers de Paestum

International audienceThe frescoes in the tombs of Paestum, painted during the 4th century BC, depict dueling scenes that are not unlike the XXIII chant of the Iliad. The representations propose a set of martial gestures that seem to indicate that the fighters employed a complex technical panel. Thus, the comparison of the representations allowed the development of assumptions on the kinematics of the strikes from the guard position to the wound. In order to test these assumptions, it is necessary to set up experimental protocols allowing at the verification of the biomechanical plausibility of the represented postures and at the same time the plausibility of the represented wounds and the effectiveness of the protections with regard to the attacks. This article illustrates the possible use of such protocols in a historical analysis framework.Les fresques des tombes de Paestum réalisées au cours du IVe siècle av. J.-C. décrivent des scènes de duels ? qui ne sont pas sans rappeler le chant XXIII de l'Iliade. Les représentations proposent un ensemble de gestes martiaux qui semblent indiquer que les combattants employaient un panel technique complexe. Ainsi, la comparaison des représentations a permis de développer des hypothèses sur la cinématique des frappes depuis la position de garde jusqu'à la blessure. Afin de pouvoir tester ces hypothèses, il est nécessaire de mettre en place des protocoles expérimentaux permettant à la fois de vérifier la plausibilité biomécanique des postures représentées, la plausibilité des blessures représentées et l'efficacité des protections en regard des attaques réalisées avec les armes de l'époque. Cet article illustre l'usage possible de tels protocoles dans un cadre d'analyse historique

Identifying knee prosthesis characteristics during swing phase through optimization

International audienceThis work deals with the use of motion data in an optimization pipeline to retrieve the mechanical properties of a prosthesis

Biomechanical fidelity assessment of a pick and place task with haptic feedback in virtual reality

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Open vs closed articular architecture of the forearm for an analysis of muscle recruitment during throwing motions

The osteoarticular architecture of the forearm can be modeled by an open or a closed-loop. This study aims to compare the impact of the chosen architecture on the muscle activity for overhead throwing motions. Preliminary results show similar muscle behaviors with both models

Open vs closed articular architecture of the forearm for an analysis of muscle recruitment during throwing motions

International audienceThe osteoarticular architecture of the forearm can be modeled by an open or a closed-loop. This study aims to compare the impact of the chosen architecture on the muscle activity for overhead throwing motions. Preliminary results show similar muscle behaviors with both models

Studying the impact of internal and external forces minimization in a motion-based external forces and moments prediction method: application to fencing lunges

International audienceExternal forces and joint torques have been jointly minimized in a motion-based external force prediction method. The prediction of external forces during a fencing lunge demonstrates the interest to consider joint torques during static phases of movements

MusIC MAKES THE MUSCLES WORK TOGETHER

International audienceThis short communication aims at presenting an interpolation and correction method for muscle forces estimation, called the MusIC method

Biomechanical fidelity of simulated pick-and-place tasks: impact of visual and haptic renderings

International audienceVirtual environments (VE) and haptic interfaces (HI) tend to be introduced as virtual prototyping tools to assess ergonomic features of workstations. These approaches are costeffective and convenient since working directly on the Digital Mock-Up in a VE is preferable to constructing a physical mockup in a Real Environment (RE). However it can be usable only if the ergonomic conclusions made from the VE are similar to the ones you would make in the real world. This study aims at evaluating the impact of visual and haptic renderings in terms of biomechanical fidelity for pick-and-place tasks. Fourteen subjects performed time-constrained pick-and-place tasks in RE and VE with a real and a virtual, haptic driven object at three different speeds. Motion of the hand and muscles activation of the upper limb were recorded. A questionnaire assessed subjectively discomfort and immersion. The results revealed significant differences between measured indicators in RE and VE and with real and virtual object. Objective and subjective measures indicated higher muscle activity and higher length of the hand trajectories in VE and with HI. Another important element is that no cross effect between haptic and visual rendering was reported. Theses results confirmed that such systems should be used with caution for ergonomics evaluation, especially when investigating postural and muscle quantities as discomfort indicators. The last contribution of the paper lies in an experimental setup easily replicable to asses more systematically the biomechanical fidelity of virtual environments for ergonomics purposes