下肢不等长对步态影响的实验分析

目的采用正常人体单侧增高模拟下肢不等长,分析下肢不等长步态特征,研究下肢不等长对步态的影响,为下肢假肢穿戴者因下肢不等长引起的慢性疾病提供理论依据。方法通过单侧穿鞋增高人为制造下肢不等长,利用三维动态捕捉系统和地面反力采集设备采集受试者在正常步态和下肢不等长步态下的时空参数、地面反力和关节角度,并进行对比分析。结果下肢不等长步态与正常步态在步长、步长时间和单侧支撑期存在显著差异。下肢不等长步态左右腿足跟着地期垂直方向地面反力均大于正常步态,髋、膝、踝角度存在明显变化。结论下肢不等长是造成行走步态异常的重要原因,可能是下肢假肢穿戴者产生腿部关节疾病的原因。     

Problématique de la mise en place d''une unité de métrologie dans le futur centre de biologie du CHRU de Lille

Regional and University Hospitals of Lille holds many of analysis laboratories with a great diversity of biology specialities. To date, a great biology center is building to accommodate there all these laboratories at the beginning of 2007. In this biology center, a room of metrology is foreseen where will be carried out the update of the metrological checks on the equipment concerned and the metrological traceability. The analysis laboratories of medical biology must have a perfect control of their equipment within the framework of the analytical process in order to ensure the quality of their results. This first work is a reflection on the failures of the metrology function within the laboratories from the biomedical point of view. Finally, the objective will be to provide to the laboratories of a coherent and homogeneous metrology tool to all the specialities of the biology of the CHRU of Lille to the service of their quality assurance.     

Fibroscan : un outil non invasif de mesure de la dureté du foie par élastométrie

Fibroscan^® is a new medical device that measures liver stiffness noninvasively. The method is based on one-dimensional transient elastography. Ultrasound signals (3,5 MHz) are used to follow the propagation of a low-frequency shear elastic wave (50 Hz) that propagates at a velocity that depends on liver stiffness. Measurement is performed on the right lobe of the liver using a probe that is placed on the skin surface. Result is obtained at the end of examination that takes about 5 minutes. Pilot and multicentre studies have shown that liver stiffness is strongly correlated to fibrosis stage obtained from liver biopsy on patients with chronic hepatitis C. Fibroscan^® could be used to improve the evaluation of patients with liver chronic diseases by reducing the number of liver biopsies and by allowing the following of treatments.     

Implication du personnel infirmier dans la sécurité transfusionnelle : évaluation des connaissances et de la pratique à l''institut Gustave-Roussy

BACKGROUND: A first survey on nurses transfusion practices at our Hospital revealed poor knowledge. Good Transfusion Practices were written, a training program was implemented and a second survey was carried out two years later. STUDY DESIGN AN METHODS: We conducted the second survey in which 4 of the questions were identical to those in the first survey in order to assess the impact of this training strategy. The 4 questions were on blood sample identification, checking patient identification, checking "use by date" on blood product bag and the pre-transfusion bedside compatibility test. Behaviours were evaluated by checking the pre-transfusion procedures, including interpretation of bedside compatibility tests. We investigated the impact of attendance at the training course, the period of employment, day versus night shift and attempted to correlate these factors with the results of the second survey. RESULTS: A significant improvement was observed in knowledge of Good Practices between the first and the second survey (P = 10(-4)). However, the multivariate analysis showed that the impact of training was heterogeneous. Pre-transfusion protocol checks have improved significantly (P = 0.05) as well as pre-transfusion bedside compatibility test interpretation of ABO compatibility (P = 0.007). CONCLUSION: In our study, the implementation of Good practices has significantly improved nurses' knowledge about transfusion safety requirements but it is essential to continue and adapt the training and cheek regularly the impact of these implementations.     

Nouveau container de prélèvement : rôle dans la réduction de la contamination bactérienne des unités plaquettaires standard

BACKGROUND: Bacterial contamination of unstable blood products constitutes today the most frequent infectious risk transmitted by blood transfusion. Platelet concentrates are often incrimineted. As responsible germs are in general of cutaneous origin, a sample procedure with diversion of the first 20 ml during blood donation is studied. The aim of this study is to evaluate the results of this technique on bacterial contamination rate of standard platelet units prepared at the regional blood transfusion center in Casablanca. STUDY DESIGN AND METHODS: A comparative study of two types of sample pockets is made: 500 Standard Platelet concentrates (CPS) are prepared after collection using standard triple bags (Baxter) (group 1) and 560 pockets of CPS were prepared after collection using triple bags with Sample Diversion Pouch sampling system for elimination of the first 20 ml of donation (Macopharma and Terumo) (group 2). The skin was disinfected in two times with alcohol 70%. The bacteriological study was made in the two groups at the third day of conservation. RESULTS: Six CPS of group 1 were contaminated, of which five were staphylococci coagulase negative and one bacillus sp. Six CPS of group 2 were contaminated, of which five were staphylococci coagulase negative and one staphylococcus aureus. The bacteria isolated were those of cutaneous flora at 100%. Diversion of first 20 ml of blood donation results in a 16.6% reduction in bacterial contamination of CPS (P>0.05). CONCLUSION: The non-significant reduction in the prevalence of the bacterial infection of CP formulates the problem of the indication of the sampling devices with derivation of first 20 ml during blood collection.     

假肢步态实验平台设计

背景：目前对于假肢的评价还停留在主观感受,缺乏一套客观的评价系统,建立模拟人体运动的在线假肢参数检测系统对于假肢性能的评价、假肢研究设计具有重要意义。 目的：实现假肢的多种步态运动,并通过运动学、动力学数据的比对,评价其仿真程度。 方法：根据仿生学原理,将下肢假肢简化成四杆四轴的力学模型,利用采集得到的多种步态模式,驱动下肢假肢运动,并搭建动态力学测试平台,实时测量假肢运动的地面垂直反力和前后剪力。 结果与结论：假肢步态运动,髋膝关节的变化曲线与正常步态数据相一致,而其地面垂直反力与前后剪力也与正常人体相接近。提示假肢步态实验平台模拟了下肢假肢步态运动,并实时采集假肢运动的多项运动学、动力学参数,具备较高的仿真程度。     

基于表面肌电的步态分析

背景：步态分析在人体运动系统和神经系统疾病的病因分析,诊断,功能、疗效与残疾评定中是重要的评价手段,其中肌肉活动是影响步行动力的基础因素。 目的：分析人体自然行走过程中下肢前后肌群的表面肌电变化,分析对应于步态周期不同时相前后肌群的表面肌电特征和机制。 方法：采用德国zebris FDM 步态分析系统(6 m)配套的同步肌电仪采集7例健康人正常步态过程中下肢胫骨前肌和腓肠肌外侧表面肌电信号,利用Matlab软件进行消噪和归一化,得到完整步态周期不同时相对应的表面肌电信号图,观察其峰值变化。采用芬兰ME6000肌电仪测试15 m自由行走人体左右侧下肢胫骨前肌和腓肠肌外侧表面肌电信号,提取时域和频域特征参数。 结果与结论：下肢胫骨前肌和腓肠肌外侧表面肌电信号在一个完整步态周期中呈特征性变化,即胫骨前肌表面肌电的峰值发生在后跟着地处,而腓肠肌外侧其峰值发生在中后支撑相处。进一步分析发现,人体在自由行走时其下肢肌肉优势侧与非优势侧差异有显著性意义(P < 0.05),且不同肌肉其差异趋势不同。     

Avancées technologiques et intégration de la biologie délocalisée dans les établissements de soins

Practice of Point of Care Testing in medical care centre is very unequal in France despite official guidelines of governmental agencies and laboratory professionals. Last years, a lot of advances in devices technology have been performed particularly in term of connectivity, quality control and traceability with apparition of new global solutions. These possibilities open new perspectives in point of care testing organization in France. We suggest an overall view with the introduction of a coordinator of all point of care testing to coordinate the different actors at every step of the project, from decision to installation of the chosen solutions.     

Gait analysis: Comparative evaluation of conventional total knee replacement and modular distal femoral megaprosthesis

BackgroundGait alterations have been studied with computer-assisted gait analysis after megaprosthetic replacement for tumors around the knee. It has never been proven that megaprostheses affects gait more than total knee arthroplasty (TKA); this study aims to compare via gait analysis patients who underwent megaprosthesis with patients with TKA.MethodsWe analyzed 26 patients with a megaprosthetic replacement of the distal femur and 21 patients with a standard TKA. For each subject computerized gait analysis was performed. Range of motion (ROM) of the knee was recorded, Quality of Life and functional evaluation in the oncologic group were assessed with the Musculoskeletal Tumor Society (MSTS) questionnaire, while Short Form-36 (SF-36) scores were calculated for both groups.ResultsAll patients walked slower than healthy people (P < 0.05). Gait analysis showed a lower cadence than in the healthy population but no significant difference between the two groups. A longer swing and a shorter stance phase were detected in the megaprosthetic sample. The osteoarthritis group showed greater flexion during the phase of loading response, even if this was lower than the contralateral limb or healthy population. There was a statically significant difference between the healthy limb and the operated one in both groups regarding ROM, but no significant difference was registered between the two implants. MSTS score and most of SF-36 parameters showed no significant differences compared with literature data.ConclusionsGait analysis shows little discrepancy between the two groups; gait pattern abnormalities do not affect patients with a megaprosthetic replacement more significantly than patients undergoing TKA.     

Gait and surface electromyography characteristics in hurdle athletes in a total gait cycle北大核心

BACKGROUND: In recent years, the technical parameters about hurdle athletes are mainly obtained through video analysis and DLT algorithm. However, the gait and surface electromyography (sEMG) characteristics during normal walking are little reported. OBJECTIVE: To explore the changes of the gait and lower limb sEMG signals relative to gait period in hurdle athletes. METHODS: Eight male professional hurdlers were selected to perform gait and lower limb sEMG tests on the trail, and the differences in gait and sEMG signals were analyzed by mathematical statistics. RESULTS AND CONCLUSION: The gait parameters of hurdlers showed no significant differences (except step length). In the total gait cycle, along with the gait changing, the right and left side muscles of the same name moved alternately. The median frequency and average power frequency of the tapping leg in the lower limb muscles were greater than those of the swinging leg (except biceps femoris, tibialis anterior and lateral gastrocnemius), but the mean EMG and EMG integral values of the tapping leg were smaller than those of the swinging leg. At the stand phase, the median frequency and average power frequency of the tapping leg in the lower limb muscles were greater than those of the swinging leg (except tibialis anterior), but the mean EMG and EMG integral values of the tapping leg were smaller than those of the swinging leg (except soleus). At the swing phase, the median frequency and average power frequency of the tapping leg in the lower limb muscles were greater than those of the swinging leg (except tibialis anterior and lateral gastrocnemius), but the mean EMG and EMG integral values of the tapping leg were smaller than those of the swinging leg (except soleus). To conclude, there are different degrees of differences in the frequency domain and time domain of the lower limb muscles between tapping and swinging legs. Additionally, the muscle strength of the tapping leg is less than that of the swinging leg. © 2017, Journal of Clinical Rehabilitative Tissue Engineering Research. All rights reserved.     

Le CIT de Rennes : une opération pilote entre le CHU de Rennes et l'université de Rennes-I

Rennes CITH has a double objective innovative and evaluative functions of health technologies. More specifically, multivariate monitoring system and active prosthesis allowing the exploration, the evaluation and the treatment of the cardiovascular, nervous and respiratory functions. This paper describes briefly its origin, the partnerships and some technological activities developed since 2001.     

Étude comparative des caractéristiques physicochimiques de substituts osseux phosphocalciques

Bone substitutes are more and more used in bone surgery for their biologic safety, clinic efficiency and facility to synthesize. However many devices are actually marketed which are not similar according to their theoretical composition. We did not find any comparative physicochemical or clinical study which allows to evaluate them. The aim of this study is to compare with the same analysis methods the physicochemical properties of 14 marketed materials (blocs and granules). X-ray diffraction and infrared spectroscopy were used for components determination. Secondary electron microscopy (SEM) was performed for porosity measurements and micro-indentation method was applied to determine the elastic limits. At last a dissolution test was performed. The results have shown that the composition is likely those claimed by manufacturers excepted for one material. However mineral impurities were detected in some substitutes. All materials are not macroporous (some of them have macroporosity less than 30%). Moreover we observed a large diversity between materials (macroporosity comprised between 30 and 60%). Micro-indentation method allowed to characterize three groups of substitutes (elastic limit lower than 10 MPa, comprised between 30 and 40 MPa, upper 100 MPA). Results from dissolution experiments did not show any correlation with theoretical composition. This study shows that all materials have a nearby composition. The macroporosity and mechanical properties are not similar according the several studied substitutes. However these last properties have a great influence on the osseous integration and it would be on interest to perform some clinical comparative study with these bone substitutes.     

Effect of a robotic restraint gait training versus robotic conventional gait training on gait parameters in stroke patients

Kinematic and kinetic gait parameters have never been assessed following robotic-assisted gait training in hemiparetic patients. Previous studies suggest that restraint of the non-paretic lower limb during gait training could be a useful rehabilitation approach for hemiparetic patients. The aim of this study is to compare a new Lokomat^® asymmetrical restraint paradigm (with a negative kinematic constraint on the non-paretic limb and a positive kinematic constraint on the paretic limb) with a conventional symmetrical Lokomat^® training in hemiparetic subjects. We hypothesized that hip and knee kinematics on paretic side would be more improved after the asymmetrical Lokomat^® training than after the conventional training. In a prospective observational controlled study, 26 hemiparetic subjects were randomized to one of the two groups Lokomat^® experimental gait training (LE) or Lokomat^® conventional gait training (LC). They were assessed using 3D gait analysis before, immediately after the 20 min of gait training and following a 20-min rest period. There was a greater increase in peak knee flexion on the paretic side following LE than LC (p = 0.04), and each type of training induced different changes in vertical GRF during single-support phase on the paretic side. Several other spatiotemporal, kinematic and kinetic gait parameters were similarly improved after both types of training. Lokomat^® restrained gait training with a negative kinematic constraint on the non-paretic limb and a positive kinematic constraint on the paretic limb appears to be an effective approach to specifically improve knee flexion in the paretic lower limb in hemiparetic patients. This study also highlights spatiotemporal, kinematic and kinetic improvements after Lokomat^® training, in hemiparetic subjects, rarely investigated before.     

Effect of different inertial parameter sets on joint moment calculation during stair ascending and descending

The reliability of internal joint moment calculation in gait analysis during daily living activities is fundamental for clinical decisions based on joint function. This calculation, obtained by means of the inverse dynamics, depends on several modelling factors, such as assumptions on the segments and on the relevant joints constituting the kinematic chain. In this study, the effect of five different sets of inertial parameters on three-dimensional calculation of lower limb joint moments was investigated during the stair ascending and descending of 10 young subjects. The lower limb was represented as a chain of three rigid segments: foot, shank and thigh. The inertial parameters sets were taken from the literature. The root mean square value over the step cycle of the difference between joint moments calculated at the lower limb with different inertial parameter sets expressed in percentage of their corresponding range was computed. The results showed small differences between ex vivo and in vivo data, between data from different populations and among different modality of inertial parameters acquisition. The root mean square value was negligible at the ankle and increased as moving proximally among the joints: the maximum was 21.8% in the internal/external rotation moment at the hip. In order to achieve accurate estimate of lower limb joint moments other factors should be investigated rather than optimal inertial parameter set.     

Quantification des propriétés mécaniques du système musculotendinoarticulaire chez l'homme : de la recherche à la valorisation

The article presents an innovative and original ergometer device allowing the characterization of the mechanical properties of skeletal muscles crossing a joint in terms of contractile and elastic properties. The different tests, which can be used, and the methods of quantification will be focused on the elastic properties. Research studies, which were conducted in different applications, will show the usefulness of such measurements, as well as, the interest of these measurements in clinical research, physical medicine and rehabilitation or sports application.     

Amygdaloid atrophy in frontotemporal dementia and Alzheimer's disease

The study examined whether the generation of the forward propulsive force (PF) during gait initiation resulted mainly from the electromyogram activity of stance ankle plantar flexor muscles (APF) which 'push' on the ground as is generally claimed in the literature. Six unilateral above-knee amputees performed a specific gait initiation protocol, i.e. they were asked to walk as fast as possible from an upright posture. Data from a force platform were collected and processed to obtain gait parameters (centre of mass (CoM) acceleration, anteroposterior (A/P) progression velocity, step length, etc.). The results showed that the A/P CoM velocity at the time of foot-off differed depending on the state of the lower limb (sound or prosthetic limb) performing the step. However, the A/P velocity of the CoM reached at the time of foot contact was similar whatever the state of the lower limb initiating the gait. Thus, the absence of ankle and knee muscles did not affect the velocity of body progression, i.e. the generation of the PF in gait initiation. Furthermore, the comparable slopes of the A/P velocity between the stance sound limb and the stance prosthetic limb suggest that the organization of the motor synergy underlying the production of the PF remained the same and did not directly involve the APF. However, other mechanisms could explain PF generation. PF could be generated by the swing leg oscillation, by the trunk movement, or by other mechanisms such as the energy transfer and the exchange of gravity potential energy into kinetic energy.     

Les tissus articulaires sous la contrainte

Mechanobiological data from “in vivo”and “in vitro” studies attest that tissues modify their metabolism in relation to mechanical stress they experiment and its parameters. The central target of these modifications are local chimiomediators, which modulate contents of tissular biomaterials, specially collagen and proteoglycans, by regulating their synthesis and degradation by specific enzymes. Biomaterial histological organization is also affected.Finally, these biochemical and histological modifications provide tissu with mechanical properties appropriate to in situ stress.     

Principal component analysis of the power developed in the flexion/extension muscles of the hip in able-bodied gait

This study was undertaken to demonstrate how principal component analysis (PCA) can be used: (a) to detect the main functional structure of actions taken by hip extensors and flexors during two consecutive gait cycles of able-bodied subjects, and (b) to determine whether or not symmetrical behaviour exists between right and left hip muscle power activity. Twenty young, healthy male subjects walked along a 13 m path at a freely-chosen speed. Applying curve structure detection methods such as PCA to walking patterns can provide insight into the functional tasks accomplished by the lower limbs of able-bodied and disabled subjects. PCA was applied as a classification and curve structure detection method to hip sagittal muscle power calculated for the right and left lower limbs. Over 70% of the information provided by the first four principal components (PCs) was chosen for further biomechanical interpretation. PC1 for both right and left sides mainly described the action taken by the hip extensors/flexors corresponding to the vertical component of ground force on the respective limbs during mid-stance. Propulsion and limb preparation were identified as the second and third tasks attributed to right hip muscle power, while between limb co-ordination was recognised as the second and third functional tasks of the left hip extensors/flexors. Balance was identified as the fourth main functional contribution of the hip extensors/flexors at the right limb while for the left limb, these muscles were mainly responsible for preparing the limb to enter into new gait cycle. PCA was able to identify the four main functional contributions of hip sagittal muscle power during able-bodied gait. PCA was also able to examine the existence of functional asymmetry in gait by highlighting different task priorities at the hip level for the right and left lower limbs.     

Let your feet do the walking: constraints on the stability of bipedal coordination

In this paper we consider whether the behaviour of the neural circuitry that controls lower limb movements in humans is shaped primarily by the spatiotemporal characteristics of bipedal gait patterns, or by selective pressures that are sensitive to considerations of balance and energetics. During the course of normal locomotion, the full dynamics of the neural circuitry are masked by the inertial properties of the limbs. In the present study, participants executed bipedal movements in conditions in which their feet were either unloaded or subject to additional inertial loads. Two patterns of rhythmic coordination were examined. In the in-phase mode, participants were required to flex their ankles and extend their ankles in synchrony. In the out-of-phase mode, the participants flexed one ankle while extending the other and vice versa. The frequency of movement was increased systematically throughout each experimental trial. All participants were able to maintain both the in-phase and the out-of-phase mode of coordination, to the point at which they could no longer increase their frequency of movement. Transitions between the two modes were not observed, and the stability of the out-of-phase and in-phase modes of coordination was equivalent at all movement frequencies. These findings indicate that, in humans, the behaviour of the neural circuitry underlying coordinated movements of the lower limbs is not constrained strongly by the spatiotemporal symmetries of bipedal gait patterns.     

坐骨神经痛患者的步态特征

目的分析总结坐骨神经痛患者的步态特征,辅助临床的诊断评估。方法连续住院治疗的43例伴有坐骨神经痛的腰椎间盘突出症患者,佩戴便携式步态分析仪后自由下平地行走120 m,同时纳入性别、年龄、身体质量指数(body mass index,BMI)匹配的43例健康受试者作为对照组。采集受试者的步态数据,包括7个时空参数(单支撑时间、双支撑时间、单双腿支撑时间比、步态周期时间、步速、步频、步长)以及4个加速度参数(拔腿强度、摆腿强度、地面冲击、足落地控制),对比患者与正常人、患者患侧与健侧下肢之间的步态差异。结果患者单支撑时间、单双腿支撑时间比、步速、步频、步长及4个加速度参数明显小于正常人,而双支撑时间延长。相比于患者健侧下肢,患侧下肢支撑时间、步频及4个加速度参数显著性减小,步长增加。结论坐骨神经痛患者患侧下肢运动功能出现障碍,影响步行能力。便携式步态分析仪可反映坐骨神经痛患者下肢的异常步态特征,为临床诊断评估提供参考。