Design and manufacturing of prosthetic feet for children as a multidisciplinary project for mechanical engineering students

The authors would like to thank all colleagues that helped with the setup of this project, but also all the student groups from ENSAM and EPF engineering school that participated in this pedagogical project. More particularly the students of the “apprentissage” who helped to design the fatigue testing machine which is a next step for this work. And, also Eve Bennett who helped for the writing of English.This paper presents the development of a prosthetic foot designed by engineering-school students. A complete workflow from needs definition to the production and testing was performed. The standards for adults were adapted to children, then a pre-design was performed, and a numerical model was realised to perform numerical testing. The production was carried out through additive manufacturing and the printed prosthetics were tested in flexion, and then in a motion analysis room. This project was aimed at making students put into practice their ability to design and test a mechanical product in a biomechanics context. Their learning outcomes were assessed during their oral presentations, their written reports and the testing session. Students gave positive feedback at the end of the semester about their feeling of the project

Validité d'une centrale inertielle pour la mesure de signaux vibratoires durant une activité de course à pied (S10)

L'Homme est régulièrement soumis à des vibrations extérieures : dans le monde du travail, comme dans la vie de tous les jours. L'impact de ces vibrations sur la santé, mais aussi sur la performance, est aujourd'hui un sujet très préoccupant. Cependant, la notion de mesure de la vibration n'est pas toujours maîtrisée lors de certaines activités qui présentent des contraintes particulières. Cette étude se concentre sur la mesure de la réponse dynamique du corps humain durant une activité de course à pied

Evaluation of Physical Interaction during Walker-Assisted Gait with the AGoRA Walker: Strategies Based on Virtual Mechanical Stiffness

Smart walkers are commonly used as potential gait assistance devices, to provide physical and cognitive assistance within rehabilitation and clinical scenarios. To understand such rehabilitation processes, several biomechanical studies have been conducted to assess human gait with passive and active walkers. Several sessions were conducted with 11 healthy volunteers to assess three interaction strategies based on passive, low and high mechanical stiffness values on the AGoRA Smart Walker. The trials were carried out in a motion analysis laboratory. Kinematic data were also collected from the smart walker sensory interface. The interaction force between users and the device was recorded. The force required under passive and low stiffness modes was 56.66% and 67.48% smaller than the high stiffness mode, respectively. An increase of 17.03% for the hip range of motion, as well as the highest trunk’s inclination, were obtained under the resistive mode, suggesting a compensating motion to exert a higher impulse force on the device. Kinematic and physical interaction data suggested that the high stiffness mode significantly affected the users’ gait pattern. Results suggested that users compensated their kinematics, tilting their trunk and lower limbs to exert higher impulse forces on the device

Variability of motor moment during golf swing: study of a female professional player

Study of th intra-individual variability of the motor moment during the golf swing. It highlighted the variability induced by horizontal ground reaction forces which are rarely taken into account in field

A 1-Year Prospective French Nationwide Study of Emergency Hospital Admissions in Children and Adults with Primary Immunodeficiency.

PURPOSE: Patients with primary immunodeficiency (PID) are at risk of serious complications. However, data on the incidence and causes of emergency hospital admissions are scarce. The primary objective of the present study was to describe emergency hospital admissions among patients with PID, with a view to identifying "at-risk" patient profiles. METHODS: We performed a prospective observational 12-month multicenter study in France via the CEREDIH network of regional PID reference centers from November 2010 to October 2011. All patients with PIDs requiring emergency hospital admission were included. RESULTS: A total of 200 admissions concerned 137 patients (73 adults and 64 children, 53% of whom had antibody deficiencies). Thirty admissions were reported for 16 hematopoietic stem cell transplantation recipients. When considering the 170 admissions of non-transplant patients, 149 (85%) were related to acute infections (respiratory tract infections and gastrointestinal tract infections in 72 (36%) and 34 (17%) of cases, respectively). Seventy-seven percent of the admissions occurred during winter or spring (December to May). The in-hospital mortality rate was 8.8% (12 patients); death was related to a severe infection in 11 cases (8%) and Epstein-Barr virus-induced lymphoma in 1 case. Patients with a central venous catheter (n = 19, 13.9%) were significantly more hospitalized for an infection (94.7%) than for a non-infectious reason (5.3%) (p = 0.04). CONCLUSION: Our data showed that the annual incidence of emergency hospital admission among patients with PID is 3.4%. The leading cause of emergency hospital admission was an acute infection, and having a central venous catheter was associated with a significantly greater risk of admission for an infectious episode

Contribution of accelerometry for a quantified study of mechanical drift duringrunning with respect to fatigue.

La fatigue est un phénomène bien connu dans le monde du sport provoquant une chute des performances et une augmentation du risque de blessures. La communauté scientifique s’intéresse donc à la quantification de ce phénomène au moyen de différents outils d’analyse du mouvement. Cependant certains sports comme la course à pied soumettent les athlètes à des sollicitations mécaniques violentes impactant fortement sur leur santé et leurs performances. Ces sollicitations se traduisent souvent par des chocs importants, un nombre de cycles élevé et sont accompagnées de postures complexes du corps. Les outils d’analyse du mouvement ne sont alors pas toujours adaptés pour la mesures de ces données ni à l’étude du mouvement de l’athlète dans des conditions réelles de pratique. L’accélération apparait alors comme une caractéristique riche en informations. Elle peut permettre de mesurer et d’analyser la pratique de la course à pied afin de quantifier la dérive de la réponse mécanique du corps humain. Par la validation d’outils issus de l’accélérométrie, ces travaux de thèse permettront d’étudier les phénomènes mécaniques intervenant durant la pratique de la course à pied afin de quantifier et prédire leurs effets sur les phénomènes de fatigue des athlètes.Fatigue is a well known phenomenon in the sports world causing a decrease of performance and an increase of injury risk. The scientific community is therefore concerned with the quantification of this phenomenon using different motion analysis tools. However some sports like running inflict violent mechanical loads to the athletes strongly impacting their health and performance. These loads frequently result in significant shocks, a high number of cycles and are accompanied by complex postures of the body. The motion analysis tools are then not always suitable for the measurement of this information or to study the athlete’s movement in real conditions of practice. The acceleration then appears as a feature rich in information.It can allow to measure and analyze the practice of running in order to quantify the drift of the mechanical response of the human body. By validating accelerometric tools, these thesis works will allow to study the mechanical phenomena intervening in the practice of running in order to quantify and predict their effects on the athlete’s fatigue

Intra and Inter Test Repeatability of Accelerometric Indicators Measured While Running

Recently the use of Inertial Measurement Units (IMU's) has been extended to several applications in human activity. In running, several studies show the possibility of using IMU's to measure different indicators of speed and foot strike. However, few studies describe the repeatability of those indicators. In this context, the aim of this study is to analyse the intra and inter test repeatability of several temporal and spectral indicators using an IMU under constant running conditions. Accelerations were measured using three IMU's mounted on the trunk near the lumbar, the right tibia and the dorsal surface of the right shoe above the metatarsals. The subject follows two different protocols to realize the intra test and the inter test repeatability of eight different parameters: root mean square (RMS) values of acceleration, kurtosis, total energy, median frequency, mechanical stiffness, mean stride duration, contact and flying duration. For all parameters the mean, standard deviation and coefficient of variation were computed for each set of test. The coefficient of variation was lower than 5% for both test for all parameters except kurtosis and the median frequency. Parameters with acceptable value at constant conditions of surface and speed can be used as an indicator to compare several conditions, such as the influence of speed, surface or anthropometry of the subjects.Recientemente, el uso de unidades de medida inercial (IMU) se ha extendido a varias aplicaciones en la actividad humana. En carrera, varios estudios muestran la posibilidad de utilizar IMU para medir diferentes indicadores de velocidad y pisada. Sin embargo, pocos estudios describen la repetibilidad de esos indicadores. En este contexto, el objetivo de este estudio es analizar la repetibilidad intra e interensayos de varios indicadores temporales y espectrales utilizando una IMU en condiciones de funcionamiento constante. Las aceleraciones se midieron utilizando tres IMU montadas en el tronco cerca de la zona lumbar, la tibia derecha y la superficie dorsal del zapato derecho por encima de los metatarsianos. El sujeto sigue dos protocolos diferentes para realizar la repetibilidad intraprueba y entre pruebas de ocho parámetros diferentes: valores de la raíz cuadrada media (RMS) de aceleración, curtosis, energía total, frecuencia media, rigidez mecánica, duración media de la zancada, duración del contacto y del vuelo. Para todos los parámetros, se calcularon la media, la desviación estándar y el coeficiente de variación para cada conjunto de pruebas. El coeficiente de variación fue inferior al 5% para ambas pruebas para todos los parámetros excepto la curtosis y la frecuencia media. Los parámetros con valor aceptable en condiciones constantes de superficie y velocidad se pueden utilizar como indicador para comparar varias condiciones, como la influencia de la velocidad, superficie o antropometría de los sujetos. El coeficiente de variación fue inferior al 5% para ambas pruebas para todos los parámetros excepto la curtosis y la frecuencia media. Los parámetros con valor aceptable en condiciones constantes de superficie y velocidad se pueden utilizar como indicador para comparar varias condiciones, como la influencia de la velocidad, superficie o antropometría de los sujetos. El coeficiente de variación fue inferior al 5% para ambas pruebas para todos los parámetros excepto la curtosis y la frecuencia media. Los parámetros con valor aceptable en condiciones constantes de superficie y velocidad se pueden utilizar como indicador para comparar varias condiciones, como la influencia de la velocidad, superficie o antropometría de los sujetos