Helene Pillet

Helene Pillet
Ecole Nationale Supérieure d'Arts et Métiers | ENSAM · Institut de Biomecanique Humaine Georges Charpak (IBHGC)

PhD

About

217
Publications
36,570
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1,301
Citations
Citations since 2016
122 Research Items
965 Citations
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2016201720182019202020212022050100150
2016201720182019202020212022050100150

Publications

Publications (217)
Article
Full-text available
After a transtibial amputation, the prosthetic foot aims at replacing the missing ankle joint. Due to alteration of proprioception and mobility, the static balance of amputees is challenging. The stiffness of most of the usual prosthetic feet cannot adapt according to the situation. Thus, the control of the user’s balance is closely related to the...
Article
Introduction The Single Leg Hop test (SLHT) is commonly performed to determine readiness to return to sport (RTS) after anterior cruciate ligament (ACL) injury and reconstruction [1]. Usually, the between-limb symmetry of hop distance is considered as a criterion to clear the athletes to RTS. However, athletes may pass this criterion despite ongoin...
Article
Introduction Anterior cruciate ligament (ACL) rupture is one of the most recurrent knee injuries in soccer players [1]. Commonly, global performance measures like jumping/hopping distance or time to perform agility test and side-cutting manoeuvres are used as criteria to determine readiness to return to sport after ACL reconstruction (ACLR) [1]. Ho...
Article
Impingement with surrounding tissues is a major cause of failure of anterior cruciate ligament reconstruction. However, the complexity of the knee kinematics and anatomical variations make it difficult to predict the occurrence of contact and the extent of the resulting damage. Here we hypothesise that a description of wear between the reconstructe...
Article
Full-text available
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 time...
Article
Full-text available
Purpose To assess dynamic postural alignment in ASD during walking using a subject-specific 3D approach. Methods 69 ASD (51 ± 20 years, 77%F) and 62 controls (34 ± 13 years, 62%F) underwent gait analysis along with full-body biplanar Xrays and filled HRQoL questionnaires. Spinopelvic and postural parameters were computed from 3D skeletal reconstru...
Article
Full-text available
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 litera...
Data
Table synthetizing studies, as well as their methods and results, investigating wheelchair biomechanics in environmental barriers. This table is one of the outcomes of a systematic review published in PloS One (10.1371/journal.pone.0269657).
Article
The role of the above-knee socket is to ensure the load transfer via the coupling of residual limb-prosthesis with minimal discomfort and without damaging the soft tissues. Modelling is a potential tool to predict socket fit prior to manufacture. However, state-of-the-art models only include the femur in soft tissues submitted to static loads negle...
Article
Background Pressure-induced tissue strain is one major pathway for Pressure Ulcer development and, especially, Deep Tissue Injury. Biomechanical investigation of the time-dependent stress–strain mechanical behaviour of skeletal muscle tissue is therefore essential. In the literature, a viscoelastic formulation is generally assumed for the experimen...
Article
Background Physiologic aging is associated with loss of mobility, sarcopenia, skin atrophy and loss of elasticity. These factors contribute, in the elderly, to the occurrence of a pressure ulcer (PU). Brightness mode ultrasound (US) and shear wave elastography (SWE) have been proposed as a patient-specific, bedside, and predictive tool for PU. Howe...
Article
Full-text available
During manual wheelchair (MWC) locomotion, the user's upper limbs are subject to significant levels of stress and fatigue because the upper body is permanently engaged to propel the MWC and in all daily activities (van der Woude et al., 2001). This stress can lead to pain and wounds in the upper limbs which in turn may lead to difficulties in auton...
Article
Background The analysis of biomechanical parameters derived from the body center of mass (BCoM) 3D motion allows for the characterization of gait impairments in people with lower-limb amputation, assisting in their rehabilitation. In this context, magneto-inertial measurement units are promising as they allow to measure the motion of body segments,...
Article
Persons with above-knee amputation have increased energy consumption and greater difficulty in negotiating uphill and downhill slopes. Walking on slopes requires an adaptation of the positive and negative work performed by the joints of the lower limb to propel the center of mass. Modern prosthetic feet and knees can only partially adapt to changes...
Article
Full-text available
The kinematics of the body center of mass (bCoM) may provide crucial information supporting the rehabilitation process of people with transfemoral amputation. The use of magneto-inertial measurement units (MIMUs) is promising as it may allow in-the-field bCoM motion monitoring. Indeed, bCoM acceleration might be obtained by fusing the estimated acc...
Article
Background Body Center Of Mass velocity assessment is a prerequisite for several applications in prosthetic control and rehabilitation monitoring. Force plate data integration is a promising alternative to full-body quantitative analysis of segmental kinematics to estimate the velocity. Still, it remains to be implemented and validated for people w...
Chapter
The proper management of the local mechanical environment within soft tissuesSoft tissue is a key challenge central the prevention ofPressure ulcer (PUs) Pressure Ulcers (PUs). Magnetic Resonance (MR) imaging is the preferred imaging modality to measure geometrical features associated with PUs. It is a very time-consuming method and it represents a...
Article
Full-text available
The analysis of the body center of mass (BCoM) 3D kinematics provides insights on crucial aspects of locomotion, especially in populations with gait impairment such as people with amputation. In this paper, a wearable framework based on the use of different magneto-inertial measurement unit (MIMU) networks is proposed to obtain both BCoM accelerati...
Article
Skin Marker (SM) based motion capture is the most widespread technique used for motion analysis. Yet, the accuracy is often hindered by Soft Tissue Artifact (STA). This is a major issue in clinical gait analysis where kinematic results are used for decision-making. It also has a considerable influence on the results of rigid body and Finite Element...
Article
In case of transtibial amputation, the deficit resulting from the loss of the lower limb can be partly compensated with a prosthetic foot and adapted rehabilitation. New prosthetic feet have been developed for transtibial amputees to mimic ankle adaptability to varying terrain. Among them, Microprocessor Prosthetic Ankles (MPA) have a microprocesso...
Preprint
Soft tissue deformation(STD) causes the most prominent source of error in skin marker (SM) based motion analysis, commonly referred to as Soft Tissue Artifact (STA). To compensate for its effect and to accurately assess in vivo joint kinematics, quantification of STD in three-dimension (3D) is essential. In the literature, different invasive and ra...
Preprint
Full-text available
Skin Marker (SM) based motion capture is the most widespread technique used for motion analysis. Yet, the accuracy is often hindered by Soft Tissue Artifact (STA). This is a major issue in clinical gait analysis where kinematic results are used for decision-making. It also has a considerable influence on the results of rigid body and Finite Element...
Article
Full-text available
Subject-specific tensioning of ligaments is essential for the stability of the knee joint and represents a challenging aspect in the development of finite element models. We aimed to introduce and evaluate a new procedure for the quantification of ligament prestrains from biplanar X-ray and CT data. Subject-specific model evaluation was performed b...
Article
Résumé Introduction Chez l’enfant ayant été traité pour un pied bot varus équin idiopathique (PBVE), le lien entre défauts morphologiques constatés cliniquement ou par radiographie standard et anomalies fonctionnelles est difficile à établir objectivement. Le but de ce travail est de démontrer la faisabilité d’une étude combinée par reconstruction...
Article
Finite Element Analysis is a numerical modelling tool vastly employed in research facilities to analyse and predict load transmission between the human body and a medical device, such as a prosthesis or an exoskeleton. Yet, the use of FEM in a framework compatible with clinical constraints is hindered by, amongst others, heavy and time-consuming as...
Article
Introduction In children treated for idiopathic equinovarus clubfoot (EVCF), the relation between morphologic defects on clinical examination and standard X-ray on the one hand and functional abnormalities on the other is difficult to objectify. The aim of the present study was to demonstrate the feasibility of combined 3D analysis of the foot and...
Article
Full-text available
While multiple criteria to quantify gait instability exist, some limitations hinder their computation during realistic walking conditions. A descriptor, computed as the distance between the center of mass of the body and the minimal moment axis ( dCOM-∆), has been proposed recently. This present study aims at characterizing the behavior of the ment...
Article
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-o...
Article
Full-text available
In recent years, inertial measurement units (IMUs) have been proposed as an alternative to force platforms and pressure sensors for gait events (i.e., initial and final contacts) detection. While multiple algorithms have been developed, the impact of gait event timing errors on temporal parameters and asymmetry has never been investigated in people...
Conference Paper
The present study combines low-dose bi planar X-rays with 3D motion capture to obtain a subject-specific 3D model of transfemoral amputated subjects and multibody kinematics optimization is used to obtain a prediction of the movement of the femur relative to the socket during gait.
Conference Paper
Full-text available
The present study combines low-dose bi planar X-rays with 3D motion capture to obtain a subject-specific 3D model of transfemoral amputated subjects and multibody kinematics optimization is used to obtain a prediction of the movement of the femur relative to the socket during gait. https://sb2019-poitiers.sciencesconf.org/268598 DOI: 10.1080/102558...
Article
Full-text available
Purpose: Daily locomotion with a manual wheelchair includes curvilinear movements. However, little is known about the resisting forces in play during turning manoeuvres where the wheels are generally both rolling and swivelling. This study aimed at quantifying the swivelling resistance parameters of several wheels on different surfaces and to evalu...
Article
Full-text available
Multibody kinematic optimization is frequently used to assess shoulder kinematics during manual wheelchair (MWC) propulsion but multiple kinematics chains are available. It is hypothesized that these different kinematic chains affect marker tracking, shoulder kinematics and resulting musculotendon (MT) lengths. In this study, shoulder kinematics an...
Article
Background: Internal soft tissue strains have been shown to be one of the main factors responsible for the onset of Pressure Ulcers and to be representative of its risk of development. However, the estimation of this parameter using Finite Element (FE) analysis in clinical setups is currently hindered by costly acquisition, reconstruction and comp...
Article
Background: The compensations occurrence due to the alteration of the posture and the gait of persons with lower limb amputation is still an issue in prosthetic fitting. Recently, prosthetic feet designed to reproduce the physiological behaviour of the ankle using a microprocessor control have been commercialized to address this issue. Objectives:...
Article
Full-text available
Purpose This study aims to describe the spinopelvic sagittal alignment in transfemoral amputees (TFAs) from a radiologic study of the spine with a postural approach to better understand the high prevalence of low back pain (LBP) in this population. Methods TFAs underwent X-rays with 3-D reconstructions of the full spine and pelvis. Sagittal parame...
Conference Paper
Full-text available
In an effort to improve diagnostics and treatment of knee joint laxity and to minimize post-operative complications, development of patient-specific computational models of the knee joint is subject of current interest and investigation. A key strength of computational models is that they can provide an insight on the relative contributions of the...
Article
Background Amputee gait is known to be asymmetrical, especially during loading of the lower limb. Monitoring asymmetry could be useful in quantifying patient performance during rehabilitation. Wearable insoles can provide normal ground reaction force asymmetry in real-life conditions. Objectives To characterize the validity of Loadsol ® insoles ve...
Article
Full-text available
Several kinematic chains of the upper limbs have been designed in musculoskeletal models to investigate various upper extremity activities, including manual wheelchair propulsion. The aim of our study was to compare the effect of an ellipsoid mobilizer formulation to describe the motion of the scapulothoracic joint with respect to regression-based...
Article
Full-text available
The command of a microprocessor-controlled lower limb prosthesis classically relies on the gait mode recognition. Real time computation of the pose of the prosthesis (i.e., attitude and trajectory) is useful for the correct identification of these modes. In this paper, we present and evaluate an algorithm for the computation of the pose of a lower...
Article
Microprocessor prosthetic knees, able to restore the gait of people with transfemoral amputation, are now often equipped with sensors embedded in the prosthetic shank, which could be used to assess some gait characteristics during real-life activities. In particular, an estimation of the walking speed during the locomotion of those subjects would b...
Article
Purpose: During manual wheelchair (MWC) skill acquisition, users adapt their propulsion technique through changes in biomechanical parameters. This evolution is assumed to be driven towards a more efficient behavior. However, when no specific training protocol is provided to users, little is known about how they spontaneously adapt during overgroun...
Conference Paper
Full-text available
Adequate manual wheelchair (MWC) configuration is crucial for efficient MWC locomotion. Evaluating the effect of various configurations can be done through simulation, which relies on the definition of a mechanical model. The aim of this paper was to propose and evaluate a simplified mechanical model of a rolling and turning MWC. MWC decelerating m...
Conference Paper
Full-text available
Manual wheelchair (MWC) locomotion is an exhausting task for the upper limbs. Hence, reducing energy loss can improve users’ mobility. The purpose of this study was to investigate how numerical optimization could allow decreasing the energy loss (swiveling and rolling resistance) by numerically adjusting MWC settings, including seat height and ante...
Article
Full-text available
Pressure Ulcer (PU) prevention remains a main public health issue. The physio-pathology of this injury is not fully understood, and a satisfactory therapy is currently not available. Recently, several works suggested that mechanical strains are responsible of deformation-induced damage involved in the initiation of Deep Tissue Injury (DTI). A bette...