妊娠妇女步态的动力学分析

怀孕,是人类传宗接代的伟大过程,孕妇体重的增加主要是集中在躯干部位,而使原脊柱的荷重情况改变,导致对髋关节产生较大之惯性矩。且由于内分泌的改变,造成骨盆关节变松,致使孕妇发生姿势与步态改变,而增加不少日常生活上的困扰,如下背痛等。因此,对孕妇动作如步态的研究分析,将有益于协助孕妇解决这些问题。本研究之受测者包括10倍健康的孕妇与10位无怀孕经历之健康女性。为解决缺乏孕妇完整人体检测资料的困境,实验中以最佳化方法来求取孕妇的髋关节中心,并求得运动学与动力学资料。结果显示,受测孕妇皆有下背痛且均发生在骶骨－髂骨区域,与无怀孕经历之健康妇性比较,孕妇在下肢各关节角度的变化方面主要是最大屈曲角度变大与最大伸展角度变小。髋关节的伸展力矩增加、膝关节的伸展力矩减少,而踝跖屈力矩减少。     

基于足底动力学测试的步态分析

目的：分析连续步态的特征参数,研究一个完整步态周期所对应的垂直反作用力变化以及能量消耗变化,为扩展和完善步态分析系统提供依据。方法：采用德国zebrisFDM步态测试系统测得173名正常人自然行走过程中足底压力数据,根据连续信号和时相对称性指标进行两次数据筛选,最终选取了23名（相对称性指数〉0．95）较适宜的步态数据,分别导人SPSS软件进行统计分析及matlab软件进行编程画图。结果：通过分析步速的影响因素得出步速与跨步长,身高的相关性最高（r=．884）,而与步态周期、站立相时间高度负相关;编程实现了一个完整步态周期中均值与标准差同时显示的左右脚压力曲线,峰值定量化得出第一峰值约为体重的1．05—1．08倍,出现在步态周期的14％左右,第二峰值约为体重的1．13～1．16倍,出现在步态周期的47％左右;独立样本检验得出能量消耗指数与时相对称性指数用于正常人步态检验无显著差异（P〉0．05）。结论：人在自然行走时其步速与跨步长／身高高度相关,其垂直反作用力与体重高度相关：并且能量消耗指数在评定正常人步态功能方面是可行的。     

正常成人步态与偏瘫步态的比较与分析

本文首先介绍了步态分析的基本概念，正常步态与偏瘫步态进行的比较分析在临床上具有重要意义。步态分析系统对正常受试者和偏瘫患者进行检测。给出了人体下肢关节，地面反作用力等参数的测试结果，并对下沉成人与偏瘫患者的测试结果进行比较和分析，得出了初步结论。     

自然步态摆动期动力学协调模式的研究

建立了包含肌肉一肌腱动力特性和神经兴奋一肌肉收缩动力学方程在内的人体下肢生物力学模型，并针对自然步态摆动期的运动过程，采用最优控制方法进行了计算分析。计算结果与实验测量结果在运动学、肌电信号和肌肉活性参数等方面均具有很好的一致性；同时利用模型分析了肌肉协调运动模式，结果表明在自然步态摆动期运动过程中，神经系统将肌肉结成不同的协同肌群，并按照特定的时序结构控制不同肌群实现步行运动的加速、制动和姿态控制。     

偏瘫患者步态特征的动力学仿真分析

目的研究偏瘫步态特征与下肢异常肌力之间的内在关系,阐明导致偏瘫步态的肌力原因并为临床治疗提供建议。方法以偏瘫步态和正常步态为研究对象进行建模仿真,通过正常步态下仿真模型与实测数据对比验证模型有效性,对两种模型的运动学数据、地面反作用力(ground reaction force,GRF)及肌力等特征曲线进行差异分析。结果 LifeMOD仿真结果与测力台实测GRF曲线复相关系数为0.922,动力学模型合理有效。偏瘫步态患者初始着地期胫前肌肌力小导致踝关节背屈不足,摆动前期腓肠肌肌力小,起不到蹬离推动作用。结论胫前肌、腓肠肌软弱无力是偏瘫患者出现足下垂等偏瘫步态特征的主要原因,LifeMOD建模仿真可协助诊断偏瘫患者的异常肌力。     

痉挛型脑瘫儿童步态运动学特征

目的基于步态分析方法研究痉挛型脑瘫儿童行走的运动学特征。方法应用便携式步态分析仪对16例痉挛型脑瘫儿童和16例健康儿童平地常速来回行走的步态进行测试,比较痉挛型脑瘫儿童患侧与健侧、痉挛型脑瘫儿童与健康儿童的步态差异。结果与健侧相比,痉挛型脑瘫儿童患侧单步时间、摆动时间和跖骨离地期显著长于健侧(P 0. 05),患侧步频、步速、支撑相末期显著低于健侧(P 0. 05)。痉挛型脑瘫儿童患侧步态周期时间、单步时间、站立时间、摆动时间、站立相所占百分比、支撑相中期、摆动前期和跖骨离地期相比于正常儿童均显著增加(P 0. 05)。痉挛型脑瘫儿童跨步长、步速、步频、支撑相末期相比于正常儿童均显著降低(P 0. 05),拔腿强度也降低(P=0. 05)。结论痉挛型脑瘫儿童行走时稳定性降低,其患侧单步时间、摆动时间、跖骨离地期和拔腿强度或许可以作为敏感指标应用于临床评估,指导脑瘫儿童的康复治疗。     

三维步态分析系统在儿童运动功能评价中的运用

背景：三维步态分析系统是一组通过网络将运动分析系统,动态体表肌电图和压力板连接起来的系统。 目的：利用三维步态分析提供的实时力学等数据,对步态进行运动学和动力学方法定量评定,为异常运动儿童患者提供相关客观依据。 方法：应用计算机检索1991-01/2010-02PubMed数据库(http://www.ncbi.nlm.nih.gov/PubMed),检索词为“Three-dimensional gait analysis,children”。检索文献量总计136篇,选择三维步态分析系统在儿童运动功能评价中科研及其临床应用方面的文献,排除陈旧及重复实验文章,同一领域文献则选择近期发表或发表在权威杂志的文章,最终纳入28篇符合标准的文献。 结果与结论：三维步态分析系统的可靠性优于视觉步态分析。可诊断并分析异常运动,作治疗前评价,治疗后的效果评价和预后评价。在国外科研和成人运动功能评估中运用广泛,但在儿童运动功能评价中的运用还不是很成熟。     

基于RSSCAN步态系统的脑梗死偏瘫患者步态分析

背景：量化脑梗死偏瘫患者步态特征能够作为其后期康复治疗的重要参考依据,而RSSCAN步态系统能够实时定量地采集受试者行走时的步态参数。目的：探究脑梗死偏瘫患者的步态特征及健、患侧足之间的步态差异。方法：纳入北京中医药大学东直门医院与北京中医医院怀柔医院收治的脑梗死偏瘫患者134例,其中男102例,女32例,年龄(60±9)岁。通过RSSCAN步态系统采集受试者步行时的步态参数,选取中间段测试中两对步态周期连续的清晰足印,并将受试者双侧足底手动分成十分区(第1趾区、第2-5趾区、第1跖骨区、第2跖骨区、第3跖骨区、第4跖骨区、第5跖骨区、中足区、足跟内侧区、足跟外侧区),获取偏瘫患者步态时-空参数及生物力学相关参数进行分析。结果与结论：(1)步态时-空参数：健侧足支撑时间大于患足(P <0.01),患侧足摆动时间、步长均大于健足(P <0.05);Pearson或Spearman秩相关分析表明,健侧足与患侧足的支撑时间、步态周期、步长、步宽、步幅具有显著正相关关系(P <0.01);(2)生物力学相关参数：与患侧足相比,健侧足在第1趾区、第2-5趾区、第1跖骨区的最大压...     

微机化步态分析系统的研制

本文介绍一种可直接应用于临床的S 9-2型微机化步态分析系统,并着重讨论其软硬件的设计思想及实现方法。本系统采用六个核心模块完成通道数据采样、平滑、站立相和步态周期确定,波形处理、波形显示、样本存贮和结果打印。可即刻获得直观的、便于阅读的实验报告,包括步速、足-地接触力、关节三维活动的各曲线图和24个特征参数值。本系统附有监视程序,能不断检测系统的工作情况。     

GaitaBase: Web-based repository system for gait analysis

The need to share gait analysis data to improve clinical decision support has been recognised since the early 1990s. GaitaBase has been established to provide a web-accessible repository system of gait analysis data to improve the sharing of data across local and international clinical and research community. It is used by several clinical and research groups across the world providing cross-group access permissions to retrieve and analyse the data. The system is useful for bench-marking and quality assurance, clinical consultation, and collaborative research. It has the capacity to increase the population sample size and improve the quality of ‘normative’ gait data. In addition the accumulated stored data may facilitate clinicians in comparing their own gait data with others, and give a valuable insight into how effective specific interventions have been for others.     

Automated detection of gait initiation and termination using wearable sensors

This paper presents algorithms for detection of gait initiation and termination using wearable inertial measurement units and pressure-sensitive insoles. Body joint angles, joint angular velocities, ground reaction force and center of plantar pressure of each foot are obtained from these sensors and input into supervised machine learning algorithms. The proposed initiation detection method recognizes two events: gait onset (an anticipatory movement preceding foot lifting) and toe-off. The termination detection algorithm segments gait into steps, measures the signals over a buffer at the beginning of each step, and determines whether this measurement belongs to the final step. The approach is validated with 10 subjects at two gait speeds, using within-subject and subject-independent cross-validation. Results show that gait initiation can be detected timely and accurately, with few errors in the case of within-subject cross-validation and overall good performance in subject-independent cross-validation. Gait termination can be predicted in over 80% of trials well before the subject comes to a complete stop. Results also show that the two sensor types are equivalent in predicting gait initiation while inertial measurement units are generally superior in predicting gait termination. Potential use of the algorithms is foreseen primarily with assistive devices such as prostheses and exoskeletons.     

Do people with Parkinson's disease change strategy during unplanned gait termination?

In light of the movement control problems reported for patients with Parkinson's disease (PD), we examined the lower extremity control strategies used by these subjects to stop walking in planned and unplanned situations. We compared how patients with PD and age and gender-matched control subjects modulated lower extremity muscular activity and ground reaction forces during planned and unplanned stoppings. The main findings were that control subjects did not alter muscle activation from planned to unplanned stopping, relative to stance limb kinetic events; they just increased the amplitude of the response (by approximately 800%). We speculate that these data provide preliminary evidence in support of a stereotypical sequence of muscle activation for gait termination whether planned or unplanned. In contrast, subjects with PD appeared to adopt a different strategy when stopping unexpectedly compared to planned stopping. Additional data show that subjects with PD required additional steps to stop walking when stopping unexpectedly as compared to control subjects.     

A kinematic and kinetic analysis of locomotion during voluntary gait modification in the cat

As part of a study to characterize the postural reactions that occur during voluntary gait modification, we examined the kinematic, electromyographic (EMG), and kinetic responses that occurred when cats stepped over an obstacle placed in their path. Analyses of the kinematics as each of the forelimbs stepped over the obstacle showed that changes in joint angles were most pronounced at the elbow of the first (lead) limb, and at the shoulder of the second (trailing) limb. In the hindlimbs, there was a pronounced change in the knee joint angle in both the leading and trailing limbs. Examination of the horizontal and vertical velocities of the tip of the forepaw suggests that the movements can be divided into two phases: one in which the limb is rapidly lifted above and over the obstacle, and a slower one during which the limb is carefully repositioned on the floor. On the basis of the velocity profiles, we suggest that the repositioning of the paw on the support surface is more critically controlled for the forelimb than for the hindlimb. Analysis of the changes in the ground reaction forces in the supporting limbs during these gait modifications showed that there were two major increases in vertical reaction force. One of these occurred as the two forelimbs were straddling the obstacle, the other when the two hindlimbs were straddling it. There was also a net increase in the anteroposterior force that resulted in a small increase in propulsion as the cat stepped over the obstacle. Each change in the vertical ground reaction force was paralleled by a similar change in the amplitude of the EMG recorded from the respective extensor muscles. An analysis of the vertical displacement of the scapula and of the pelvis showed that there was a slight increase in the height of the scapula in the support limb just prior to and during the swing phase of the trailing forelimb, and a more pronounced and progressive change in the height of the pelvis prior to and during the passage of both hindlimbs over the obstacle. We suggest that the increases in vertical ground reaction force raise the height of the body sufficiently to allow, respectively, passage of the trail forelimb and each of the hindlimbs over the obstacle. The results are discussed with respect to both the biomechanical changes underlying these gait modifications and the neuronal mechanisms implicated in their control.     

Instrumented gait analysis in patients with medial osteoarthritis of the knee after mobile-bearing unicompartmental knee arthroplasty

Background

Unicompartmental knee arthroplasty (UKA) is an effective treatment for patients with medial osteoarthritis of the knee joint. Instrumented gait analysis provides an objective measure to quantify and qualify postoperative changes of gait. The purpose of this study was to evaluate standardized instrumented gait analysis for functional recovery and gait as an outcome of mobile-bearing UKA in patients with medial osteoarthritis of the knee.

A wearable comprehensive data sampling system for gait analysis

Abstract

Gait analysis is important for lower limb movement evaluation and rehabilitation research. More and more laboratories focus on it. Researchers need biomechanical data sampling equipment to obtain original signals for their analysis, sometimes even need kinds of signals for data fusion processing. But, the market supply of relative products is very limited. Moreover, one device acquires only one kind of signal, and needs computer as the control centre. So, there are two problems: moving range limitation, and synchronisation in data fusion processing. Most researchers plan experiments only indoors, and sometimes need to do secondary development for data fusion synchronisation. This article represents a compact-embedded system for lower limb biomechanical signals acquisition. Four kinds of signals are collected: foot plantar pressure, inertial measurement, laser distance sensing and electromyography. The embedded circuit is powered by a lithium battery. All the signals are synchronised by the embedded clock, and stored in secure digital memory card for offline analysis. It is convenient to plan experiments in all kinds of terrains indoors or outdoors. It is unique for its wearable, low power and comprehensive characters. Experimental results show that it is a useful tool for gait analysing research.     

Clinical meaning of the torque between stance leg and ground for the analysis of gait mechanism

Summary Transversal torque between the stance leg and the ground was measured in 169 test persons with normal gait (91 women, 78 men; ages 15–79 years) using three-dimensional force plates. Taking the average of six to ten single steps produces reproducible person- and group-specific data. This permits the isolation and study of individual solutions to specific problems of locomotion, so-called gait mechanisms. The relatively great torque during the double-stance phase is caused mainly by the medially directed, short-term impact peak at heel strike, with the stride length as lever arm. Double-stance torque is therefore determined by motion dynamics and does not help in understanding individual gait mechanisms. Torque measured during the single-stance phase is, in comparison, rather small and is interindividually relatively variable. Experimentally measured torque is considered in terms of various hypotheses concerning the creation of torque in the human gait. Men obviously tend, for reasons of equilibrium and stability, to compensate the various torques. Better than the more known vertical, sagittal, and frontal force components, the remaining torque represents the individual problem solution and therefore permits the study of specific gait mechanisms, both physiological and pathological. Using the characteristic gait of patients with hemiplegia as an example, it is shown that pathological torque observed systematically on the nonaffected side in such patients is a quantitative measure of the trunk rotation necessary to move the plegic side forward. Measurement of this torque therefore permits precise determination of the degree of damage, as well as quantitative control and objective documentation of the rehabilitation progress.Dedicated to Prof. Dr. N. Zöllner on the occasion of his 70th birthday     

Representing and clustering electromyographic gait patterns with multivariate techniques

The population distribution of the electromyographic patterns from several muscles in 25 normal subjects walking at free speed was investigated. The utility and sufficiency of Karhunen-Loeve expansions for reducing the dimension of electromyographic patterns was demonstrated. Cluster analysis was used to separate the constituent patterns into major groups.     

The effect of load carriage on movement kinematics and respiratory parameters in children during walking

The objective of this study was to investigate the influence of different backpack weights on trunk kinematics and respiratory parameters during walking in 10-year-old children. Fifteen boys with a mean age of 10.31 (0.26) years were selected from a primary school to participate in four walking trials on a treadmill: one with a backpack of 0% of body mass, and three whilst carrying backpacks that weighed 10%, 15%, and 20% of the child's body mass. The walking speed was set at 1.1 m s^-1 for 20 min duration. The walking movement was recorded on video and analysed in two dimensions. The breathing frequency, tidal volume, and respiratory muscles activity were measured with a cardiopulmonary system (Oxycon Champion, Jaeger) and a respiratory inductance plethysmograph (TR-601T, Nihon Kohden, Japan). A repeated ANOVA and Pearson correlation analysis were used to examine any significant differences in the measured parameters when comparing the different loads. The results showed a significant positive linear relationship between load weight, trunk inclination angle, and breathing frequency (P<0.01). Walking for 20 min, carrying a load that weighed 20% of body mass induced a significantly increased trunk inclination angle. A significant increase in ventilation during walking with a backpack of 15% and 20% of bodymass was associated with a more rapid breathing frequency. Walking with a backpack of 10% body mass did not significantly change trunk posture or respiratory parameters. However, the results suggested that walking with a backpack of greater than 10% body mass induced significant changes in trunk posture and respiratory parameters in 10-year-old children.     

Internal work estimation in three-dimensional gait analysis

Many studies concerning the internal work of human motion have used two-dimensional kinematic models to estimate kinetic energy of the segments. The generalised co-ordinate concept has been applied here to a simultaneous and bilateral gait analysis. A three-dimensional kinematic model based on quaternions has been developed. To estimate the kinetic energy of a multi-body system, only two constants and two variables are needed: the segment body mass, the inertia tensor, the position and the orientation of the local co-ordinate system with respect to the inertial co-ordinate system. The variation of the kinetic energy is used in the calculation of the internal work for an able-bodied subject during the gait cycle. Both the internal work and the instantaneous energy correlation coefficient enable the determination of a conservative phase delimited by the beginning of the single support phase until the flat-foot phase, and a non-conservative phase corresponding to the period from heel-off to contralateral heel-strike including the double support phase.