Asymétrie et faiblesse musculaire lors des tâches de se lever et de s'asseoir chez l'adulte avec une hémiparésie

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

Hip joint forces in hip replacement patients and normal subjects during activities of daily living

A high number of revision hip replacement operations are currently performed due to loosening of the primary implant. The loading imposed on the prosthetic joint and its fixation mechanisms may be one of the many factors contributing to the loosening process. Previous work to determine hip joint loading has concentrated on gait, stair negotiation and rising from a chair. However, since patients often comment on the difficulty of getting into and out of a car and bath, these activities are also included in the current project. The 3 orthogonal components of hip joint force have been calculated for 16 postoperative hip replacement patients between one and two years after surgery and also for 10 age-matched normals. A biomechanical model of the lower limb was developed including 37 muscle elements. Algorithms were incorporated to correct for curved muscle paths, providing realistic muscle moment arms with changing joint angle configuration. An optimization routine which minimizes the overall maximum muscle stress was incorporated to determine muscle forces which were then used in the calculation of joint force. The model utilizes anatomical muscle and bone data, kinematics measured using a 6 camera Vicon motion analysis system and ground reaction forces measured using force platforms. In validity tests, the predicted muscle activity patterns for normal subjects were found to be consistent with published EMG data for most muscles. The mean peak resultant hip joint force of 3.8 times body weight calculated for the patients during gait at 1.01 m/s was consistent with the results published for patients with instrumented hip prostheses at a measurement time of more than 12 months after surgery. The maximum mean peak resultant hip joint force determined for patients was 5 times body weight, calculated at the left hip when getting out of the passenger side of a right hand drive car. A simple calculation of torsional moment about the stem of the femoral component during this and other activities showed it to be close to or to exceed the experimentally determined limits of torsional strength of implant fixations, reported in the literature. The maximum mean peak resultant hip joint force calculated for normals was 6.3 times body weight, determined at the left hip on getting into the passenger side of a right hand drive car. It is suggested that car entry and exit and other activities should be performed in safer styles rid that the results of this thesis should be incorporated into the design and testing of hip prostheses.A high number of revision hip replacement operations are currently performed due to loosening of the primary implant. The loading imposed on the prosthetic joint and its fixation mechanisms may be one of the many factors contributing to the loosening process. Previous work to determine hip joint loading has concentrated on gait, stair negotiation and rising from a chair. However, since patients often comment on the difficulty of getting into and out of a car and bath, these activities are also included in the current project. The 3 orthogonal components of hip joint force have been calculated for 16 postoperative hip replacement patients between one and two years after surgery and also for 10 age-matched normals. A biomechanical model of the lower limb was developed including 37 muscle elements. Algorithms were incorporated to correct for curved muscle paths, providing realistic muscle moment arms with changing joint angle configuration. An optimization routine which minimizes the overall maximum muscle stress was incorporated to determine muscle forces which were then used in the calculation of joint force. The model utilizes anatomical muscle and bone data, kinematics measured using a 6 camera Vicon motion analysis system and ground reaction forces measured using force platforms. In validity tests, the predicted muscle activity patterns for normal subjects were found to be consistent with published EMG data for most muscles. The mean peak resultant hip joint force of 3.8 times body weight calculated for the patients during gait at 1.01 m/s was consistent with the results published for patients with instrumented hip prostheses at a measurement time of more than 12 months after surgery. The maximum mean peak resultant hip joint force determined for patients was 5 times body weight, calculated at the left hip when getting out of the passenger side of a right hand drive car. A simple calculation of torsional moment about the stem of the femoral component during this and other activities showed it to be close to or to exceed the experimentally determined limits of torsional strength of implant fixations, reported in the literature. The maximum mean peak resultant hip joint force calculated for normals was 6.3 times body weight, determined at the left hip on getting into the passenger side of a right hand drive car. It is suggested that car entry and exit and other activities should be performed in safer styles rid that the results of this thesis should be incorporated into the design and testing of hip prostheses

A Novel Simplified System to Estimate Lower-Limb Joint Moments during Sit-to-Stand

To provide effective diagnosis and rehabilitation, the evaluation of joint moments during sit-to-stand is essential. The conventional systems for the evaluation, which use motion capture cameras, are quite accurate. However, the systems are not widely used in clinics due to their high cost, inconvenience, and the fact they require lots of space. To solve these problems, some studies have attempted to use inertial sensors only, but they were still inconvenient and inaccurate with asymmetric weight-bearing. We propose a novel joint moment estimation system that can evaluate both symmetric and asymmetric sit-to-stands. To make a simplified system, the proposal is based on a kinematic model that estimates segment angles using a single inertial sensor attached to the shank and a force plate. The system was evaluated with 16 healthy people through symmetric and asymmetric weight-bearing sit-to-stand. The results showed that the proposed system (1) has good accuracy in estimating joint moments (root mean square error < 0.110 Nm/kg) with high correlation (correlation coefficient > 0.99) and (2) is clinically relevant due to its simplicity and applicability of asymmetric sit-to-stand. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.1

慣性センサおよび力センサを用いた立ち上がり時の関節角度推定手法に関する研究

Standing-up motion from a chair is directly connected with walking and which is frequently performed every day. It is difficult for some elders because of the weakened function of muscles or motor. The training of standing-up motion and assisting the elderly with the standing-up motion from a chair is important to the elderly Quality of Life (QOL). Analysis of the posture parameters during standing up motion is useful for the physical therapists and care-giver in rehabilitation training or movement assist. The motion capture system can measure the movement of body posture in any direction precisely. However, it is difficult to use in daily life because of high cost and specific requirements for the space. And the use of motion capture system will give unpleasant feeling to users because many reflective makers are attached in the body. The purpose of this study is to develop a new estimation system, which can be used in daily life for angle estimation of extension phase during standing-up motion. This paper discusses the estimation system consist of: 1) the estimation of body joint angles and COG during extension phase; 2) the improvement of the proposed system for angle estimation. In 1), an estimation model was proposed that was able to estimate knee and ankle joint angles by combining angle and acceleration of trunk, which came from the inertial sensor attached to the chest of users during the extension phase. The estimate result of joint angle shows higher accuracy than previous research. In 2), in order to expand the use of proposed system and improve the estimation accuracy of proposed system, we estimated the initial angle of knee and ankle by combining foot pressure which measured by a force sensor plate before standing-up motion. The estimation model of initial lower limb angle shows high accuracy. It can be used for angle estimation of extension phase even though the initial knee and ankle joint angle were unknown.九州工業大学博士学位論文 学位記番号：生工博甲第317号 学位授与年月日：平成30年3月23日1 Introduction|2 Previous Researches|3 Angle Estimation of Extension Phase|4 Estimation of Initial Lower Limb Angle|5 Conclusion and Future Work九州工業大学平成29年

Semi-wearable seating concepts for vehicle control, medical, and wellbeing applications

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2007.Includes bibliographical references (p. 89).This thesis explores how natural bodily movements can be translated into a control interface for vehicles. Focusing on the car, our goal is to increase human performance and wellbeing while eliminating the traditionally antagonistic relationship between comfort and freedom of movement vs. support, safety and sensing the car. We will discuss seating, traditional controls, their origins, evolution, and their implications in the context of today's cars. Based on the physical demands of the vehicle environment, and on positive body experiences from sports and other concepts of movement, we will then explore how we could re-think the function, self-image, and presentation of the human body in the context of cars. We will develop a seat prototype, which will encourage beneficial body sensations and - motions, taking into account the shapes, textures, and emotional significance of touch and movement in and by itself, and in the car environment. The core of our concept will focus on natural movements of the lower back and hips, as experienced when walking or skiing. Building on the exoskeleton-like "Athlete Seat," which blurs the boundaries between wearing and sitting in, we will develop the core prototype out towards the upper body and limbs.(cont.) We will develop a second prototype, which will have pelvic movements in the frontal plane as done when walking, bicycling, or dancing, as the basis of its concept. This prototype will be connected to a car simulator to investigate if good vehicle control can be achieved with our method. In a second stage, we will systematically evaluate the car control, wellbeing, and fun aspects in a user study. Our modular design will be usable in parts and adaptable to various uses, in vehicles, for entertainment, exercise, wellbeing, and medical purposes, improving physical condition and the way we relate to our bodies.by Patrik A. Künzler.S.M

Body sensor networks: smart monitoring solutions after reconstructive surgery

Advances in reconstructive surgery are providing treatment options in the face of major trauma and cancer. Body Sensor Networks (BSN) have the potential to offer smart solutions to a range of clinical challenges. The aim of this thesis was to review the current state of the art devices, then develop and apply bespoke technologies developed by the Hamlyn Centre BSN engineering team supported by the EPSRC ESPRIT programme to deliver post-operative monitoring options for patients undergoing reconstructive surgery. A wireless optical sensor was developed to provide a continuous monitoring solution for free tissue transplants (free flaps). By recording backscattered light from 2 different source wavelengths, we were able to estimate the oxygenation of the superficial microvasculature. In a custom-made upper limb pressure cuff model, forearm deoxygenation measured by our sensor and gold standard equipment showed strong correlations, with incremental reductions in response to increased cuff inflation durations. Such a device might allow early detection of flap failure, optimising the likelihood of flap salvage. An ear-worn activity recognition sensor was utilised to provide a platform capable of facilitating objective assessment of functional mobility. This work evolved from an initial feasibility study in a knee replacement cohort, to a larger clinical trial designed to establish a novel mobility score in patients recovering from open tibial fractures (OTF). The Hamlyn Mobility Score (HMS) assesses mobility over 3 activities of daily living: walking, stair climbing, and standing from a chair. Sensor-derived parameters including variation in both temporal and force aspects of gait were validated to measure differences in performance in line with fracture severity, which also matched questionnaire-based assessments. Monitoring the OTF cohort over 12 months with the HMS allowed functional recovery to be profiled in great detail. Further, a novel finding of continued improvements in walking quality after a plateau in walking quantity was demonstrated objectively. The methods described in this thesis provide an opportunity to revamp the recovery paradigm through continuous, objective patient monitoring along with self-directed, personalised rehabilitation strategies, which has the potential to improve both the quality and cost-effectiveness of reconstructive surgery services.Open Acces

The Development of an assistive chair for elderly with sit to stand problems

A thesis submitted to the University of Bedfordshire in partial fulfilment of the requirements for the degree of Doctor of PhilosophyStanding up from a seated position, known as sit-to-stand (STS) movement, is one of the most frequently performed activities of daily living (ADLs). However, the aging generation are often encountered with STS issues owning to their declined motor functions and sensory capacity for postural control. The motivated is rooted from the contemporary market available STS assistive devices that are lack of genuine interaction with elderly users. Prior to the software implementation, the robot chair platform with integrated sensing footmat is developed with STS biomechanical concerns for the elderly. The work has its main emphasis on recognising the personalised behavioural patterns from the elderly users’ STS movements, namely the STS intentions and personalised STS feature prediction. The former is known as intention recognition while the latter is defined as assistance prediction, both achieved by innovative machine learning techniques. The proposed intention recognition performs well in multiple subjects scenarios with different postures involved thanks to its competence of handling these uncertainties. To the provision of providing the assistance needed by the elderly user, a time series prediction model is presented, aiming to configure the personalised ground reaction force (GRF) curve over time which suggests successful movement. This enables the computation of deficits between the predicted oncoming GRF curve and the personalised one. A multiple steps ahead prediction into the future is also implemented so that the completion time of actuation in reality is taken into account