https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Fri, 05 Jun 2026 22:05:56 GMT 2026-06-05T22:05:56Z http://hdl.handle.net/10985/18465 Accuracy and kinematics consistency of marker-based scaling approaches on a lower limb model: a comparative study with imagery data PUCHAUD, Pierre; SAURET, Christophe; MULLER, Antoine; BIDEAU, Nicolas; DUMONT, Georges; PONTONNIER, Charles; PILLET, Helene Medical images are not typically included in protocol of motion laboratories. Thus, accurate scaling of musculoskeletal models from optoelectronic data are important for any biomechanical analysis. The aim of the current study was to identify a scaling method based on optoelectronic data, inspired from literature, which could offer the best trade-off between accurate geometrical parameters (segment lengths, orientation of joint axes, marker coordinates) and consistent inverse kinematics outputs (kinematic error, joint angles). The methods were applied on 26 subjects and assessed with medical imagery building EOS-based models, considered as a reference. The main contribution of this paper is to show that the marker-based scaling followed by an optimisation of orientation joint axes and markers local coordinates, gives the most consistent scaling and joint angles with EOS-based models. Thus, when a non-invasive mean with an optoelectronic system is considered, a marker-based scaling is preliminary needed to get accurate segment lengths and to optimise joint axes and marker local coordinates to reduce kinematic errors.AbbrevationsAJCAnkle joint centreCKEcumulative kinematic errorDoFdegree of freedomEBEOS-basedHBheight-basedHJChip joint centreKJCknee joint centreMBmarker-basedMSMmusculoskeletal modelsSPMstatistical parametric mappingSTAsoft tissue artifactEBa.m∗EOS-based with optimised joint axes, and all model markers coordinatesMBa.m∗marker-based with optimised joint axes, and all model markers coordinatesMBl.a.mmarker-based with optimised segment lengths, joint axes, and selected model markers coordinatesASISanterior superior illiac spine PSIS posterior superior illiac spine. Wed, 01 Jan 2020 00:00:00 GMT http://hdl.handle.net/10985/18465 2020-01-01T00:00:00Z PUCHAUD, Pierre SAURET, Christophe MULLER, Antoine BIDEAU, Nicolas DUMONT, Georges PONTONNIER, Charles PILLET, Helene Medical images are not typically included in protocol of motion laboratories. Thus, accurate scaling of musculoskeletal models from optoelectronic data are important for any biomechanical analysis. The aim of the current study was to identify a scaling method based on optoelectronic data, inspired from literature, which could offer the best trade-off between accurate geometrical parameters (segment lengths, orientation of joint axes, marker coordinates) and consistent inverse kinematics outputs (kinematic error, joint angles). The methods were applied on 26 subjects and assessed with medical imagery building EOS-based models, considered as a reference. The main contribution of this paper is to show that the marker-based scaling followed by an optimisation of orientation joint axes and markers local coordinates, gives the most consistent scaling and joint angles with EOS-based models. Thus, when a non-invasive mean with an optoelectronic system is considered, a marker-based scaling is preliminary needed to get accurate segment lengths and to optimise joint axes and marker local coordinates to reduce kinematic errors.AbbrevationsAJCAnkle joint centreCKEcumulative kinematic errorDoFdegree of freedomEBEOS-basedHBheight-basedHJChip joint centreKJCknee joint centreMBmarker-basedMSMmusculoskeletal modelsSPMstatistical parametric mappingSTAsoft tissue artifactEBa.m∗EOS-based with optimised joint axes, and all model markers coordinatesMBa.m∗marker-based with optimised joint axes, and all model markers coordinatesMBl.a.mmarker-based with optimised segment lengths, joint axes, and selected model markers coordinatesASISanterior superior illiac spine PSIS posterior superior illiac spine. http://hdl.handle.net/10985/22135 Manual wheelchair biomechanics while overcoming environmental barriers: a systematic review ROUVIER, Théo; LOUESSARD, Aude; SIMONETTI, Emeline; HYBOIS, Samuel; BASCOU, Joseph; PONTONNIER, Charles; PILLET, Helene; SAURET, Christophe During manual wheelchair (MWC) locomotion, the user's upper limbs are subject to heavy stresses and fatigue because the upper body is permanently engaged to propel the MWC. These stresses and fatigue vary according to the environmental barriers encountered outdoors along a given path. This study aimed at conducting a systematic review of the literature assessing the biomechanics of MWC users crossing various situations, which represent physical environmental barriers. Through a systematic search on PubMed, 34 articles were selected and classified according to the investigated environmental barriers: slope; cross-slope; curb; and ground type. For each barrier, biomechanical parameters were divided into four categories: spatiotemporal parameters; kinematics; kinetics; and muscle activity. All results from the different studies were gathered, including numerical data, and assessed with respect to the methodology used in each study. This review sheds light on the fact that certain situations (cross-slopes and curbs) or parameters (kinematics) have scarcely been studied, and that a wider set of situations should be studied. Five recommendations were made at the end of this review process to standardize the procedure when reporting materials, methods, and results for the study of biomechanics of any environmental barrier encountered in MWC locomotion: (i) effectively reporting barriers’ lengths, grades, or heights; (ii) striving for standardization or a report of the approach conditions of the barrier, such as velocity, especially on curbs; (iii) reporting the configuration of the used MWC, and if it was fitted to the subject’s morphology; (iv) reporting rotation sequences for the expression of moments and kinematics, and when used, the definition of the musculoskeletal model; lastly (v) when possible, reporting measurement uncertainties and model reconstruction errors. Thu, 23 Jun 2022 00:00:00 GMT http://hdl.handle.net/10985/22135 2022-06-23T00:00:00Z ROUVIER, Théo LOUESSARD, Aude SIMONETTI, Emeline HYBOIS, Samuel BASCOU, Joseph PONTONNIER, Charles PILLET, Helene SAURET, Christophe During manual wheelchair (MWC) locomotion, the user's upper limbs are subject to heavy stresses and fatigue because the upper body is permanently engaged to propel the MWC. These stresses and fatigue vary according to the environmental barriers encountered outdoors along a given path. This study aimed at conducting a systematic review of the literature assessing the biomechanics of MWC users crossing various situations, which represent physical environmental barriers. Through a systematic search on PubMed, 34 articles were selected and classified according to the investigated environmental barriers: slope; cross-slope; curb; and ground type. For each barrier, biomechanical parameters were divided into four categories: spatiotemporal parameters; kinematics; kinetics; and muscle activity. All results from the different studies were gathered, including numerical data, and assessed with respect to the methodology used in each study. This review sheds light on the fact that certain situations (cross-slopes and curbs) or parameters (kinematics) have scarcely been studied, and that a wider set of situations should be studied. Five recommendations were made at the end of this review process to standardize the procedure when reporting materials, methods, and results for the study of biomechanics of any environmental barrier encountered in MWC locomotion: (i) effectively reporting barriers’ lengths, grades, or heights; (ii) striving for standardization or a report of the approach conditions of the barrier, such as velocity, especially on curbs; (iii) reporting the configuration of the used MWC, and if it was fitted to the subject’s morphology; (iv) reporting rotation sequences for the expression of moments and kinematics, and when used, the definition of the musculoskeletal model; lastly (v) when possible, reporting measurement uncertainties and model reconstruction errors. http://hdl.handle.net/10985/22136 A penalty method for constrained Multibody kinematics optimisation using a Levenberg-Marquardt algorithm LIVET, Claire; ROUVIER, Théo; SAURET, Christophe; PILLET, Helene; DUMONT, Georges; PONTONNIER, Charles An alternative method for solving constrained Multibody kinematics optimisation using a penalty method on constraints and a Levenberg-Marquardt algorithm is proposed. It is compared to an optimisation resolution with hard kinematic constraints. These methods are applied to two pairs of experiments and models. The penalty method was at least 20 times faster than the optimisation resolution while keeping similar reconstruction errors and constraints violation. The potential of the method is shown to accurately solve the Multibody kinematics optimisation problem in a reasonable amount of time. A computational gain lies in implementing this resolution with a compiled and optimised program code. Sat, 01 Jan 2022 00:00:00 GMT http://hdl.handle.net/10985/22136 2022-01-01T00:00:00Z LIVET, Claire ROUVIER, Théo SAURET, Christophe PILLET, Helene DUMONT, Georges PONTONNIER, Charles An alternative method for solving constrained Multibody kinematics optimisation using a penalty method on constraints and a Levenberg-Marquardt algorithm is proposed. It is compared to an optimisation resolution with hard kinematic constraints. These methods are applied to two pairs of experiments and models. The penalty method was at least 20 times faster than the optimisation resolution while keeping similar reconstruction errors and constraints violation. The potential of the method is shown to accurately solve the Multibody kinematics optimisation problem in a reasonable amount of time. A computational gain lies in implementing this resolution with a compiled and optimised program code. http://hdl.handle.net/10985/20839 An Automatic and Simplified Approach to Muscle Path Modeling LIVET, Claire; ROUVIER, Théo; DUMONT, Georges; PONTONNIER, Charles This paper aims at proposing an automatic method to design and adjust simplified muscle paths of a musculoskeletal model. These muscle paths are composed of straight lines described by a limited set of fixed active via points and an optimization routine is developed to place these via points on the model in order to fit moment arms and musculotendon lengths input data. The method has been applied to a forearm musculoskeletal model extracted from the literature, using theoretical input data as an example. Results showed that for 75% of the muscle set, the relative root-mean-square error between literature theoretical data and the results from optimized muscle path was under 29.23% for moment arms and of 1.09% for musculotendon lengths. These results confirm the ability of the method to automatically generate computationally efficient muscle paths for musculoskeletal simulations. Using only via points lowers computational expense compared to paths exhibiting wrapping objects. A proper balance between computational time and anatomical realism should be found to help those models being interpreted by practitioners. Fri, 01 Jan 2021 00:00:00 GMT http://hdl.handle.net/10985/20839 2021-01-01T00:00:00Z LIVET, Claire ROUVIER, Théo DUMONT, Georges PONTONNIER, Charles This paper aims at proposing an automatic method to design and adjust simplified muscle paths of a musculoskeletal model. These muscle paths are composed of straight lines described by a limited set of fixed active via points and an optimization routine is developed to place these via points on the model in order to fit moment arms and musculotendon lengths input data. The method has been applied to a forearm musculoskeletal model extracted from the literature, using theoretical input data as an example. Results showed that for 75% of the muscle set, the relative root-mean-square error between literature theoretical data and the results from optimized muscle path was under 29.23% for moment arms and of 1.09% for musculotendon lengths. These results confirm the ability of the method to automatically generate computationally efficient muscle paths for musculoskeletal simulations. Using only via points lowers computational expense compared to paths exhibiting wrapping objects. A proper balance between computational time and anatomical realism should be found to help those models being interpreted by practitioners. http://hdl.handle.net/10985/20837 Expected scapula orientation error regarding scapula-locator uncertainty while studying wheelchair locomotion LIVET, Claire; ROUVIER, Théo; SAURET, Christophe; DUMONT, Georges; PONTONNIER, Charles Shoulder complex motion is a fundamental aspect of wheelchair locomotion. However, this motion is difficult to capture with skin marker methods due to soft tissue artefacts (Bourne et al., 2011). To overcome this issue, scapula locators (SL), which are external devices equipped with reflective markers and manually registered on the scapula, have been designed (Brochard et al. 2012) To track scapula motion, the SL first needs to be configured as to simultaneously palpate three anatomical landmarks of the scapula: the acromial angle, inferior angle and root of the scapular spine. For static poses, de Groot et al. (1997) and Jafarian Tangrood et al. (2020) studied the impact of palpation incertitude and inter-observer variability on scapula position reconstruction. They reported a scapula angle error in the range of 3.5 – 5 degrees. However, shoulder motions have not been studied yet and the angle error remains unpredictable. The issue raised in this study was to determine the impact of palpation errors of the scapula’s anatomical landmarks when configuring the SL on the reconstruction of a motion-tracking task. Four angles were studied through a constrained multibody kinematics optimization. The study used a Monte Carlo approach and a statistic analysis. Fri, 01 Jan 2021 00:00:00 GMT http://hdl.handle.net/10985/20837 2021-01-01T00:00:00Z LIVET, Claire ROUVIER, Théo SAURET, Christophe DUMONT, Georges PONTONNIER, Charles Shoulder complex motion is a fundamental aspect of wheelchair locomotion. However, this motion is difficult to capture with skin marker methods due to soft tissue artefacts (Bourne et al., 2011). To overcome this issue, scapula locators (SL), which are external devices equipped with reflective markers and manually registered on the scapula, have been designed (Brochard et al. 2012) To track scapula motion, the SL first needs to be configured as to simultaneously palpate three anatomical landmarks of the scapula: the acromial angle, inferior angle and root of the scapular spine. For static poses, de Groot et al. (1997) and Jafarian Tangrood et al. (2020) studied the impact of palpation incertitude and inter-observer variability on scapula position reconstruction. They reported a scapula angle error in the range of 3.5 – 5 degrees. However, shoulder motions have not been studied yet and the angle error remains unpredictable. The issue raised in this study was to determine the impact of palpation errors of the scapula’s anatomical landmarks when configuring the SL on the reconstruction of a motion-tracking task. Four angles were studied through a constrained multibody kinematics optimization. The study used a Monte Carlo approach and a statistic analysis. http://hdl.handle.net/10985/20838 Open vs closed articular architecture of the forearm for an analysis of muscle recruitment during throwing motions LIVET, Claire; ROUVIER, Théo; PONTONNIER, Charles; DUMONT, Georges 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. Fri, 01 Jan 2021 00:00:00 GMT http://hdl.handle.net/10985/20838 2021-01-01T00:00:00Z LIVET, Claire ROUVIER, Théo PONTONNIER, Charles DUMONT, Georges 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.