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Source publication
This paper introduces a simple, quantitative assessment tool to follow up the recovery of gait. Today, micro-electro-mechanical systems (MEMS) technology provides with small, simple, low-power consuming and easy to don and doff sensors. In our approach we have selected an accelerome-ter and introduced a new quantity that characterizes the gait patt...
Context in source publication
Context 1
... FAC scale has five grades: 1 -person needs to be physically supported for any ambulation (the worst), and 5 -the person can walk independently anywhere (the best). All hemiplegic individuals could walk with their usual walking aid (13 patients used cane or tripod, 4 patients had also an ankle or foot orthosis) as shown in Tables 3 and 4. ...
Citations
... The positions of the markers were tracked using a calibrated 12-camera motion capture system sampling at 200 Hz (Raptor-E, Motion Analysis Corporation, USA). The participants were instructed to mount a treadmill, which was already operating at the set walk velocity (1.5 m/s) for a minimum of 60 seconds of walking.Analysis methods were developed to assess harmonic ratio (lower values indicate less harmonicity)3 with harmonic summing of the multiples of the fundamental frequency23 (higher values indicates increased smoothness). In addition, MSE (higher values indicates increased complexity) 8 , and short-and long-term maximum Lyapunov exponent (higher values indicates were implemented for both the vertical and the resultant accelerations. ...
Inertial measurement units (IMU) provide a convenient tool for gait stability assessment. However, it is unclear how various gait characteristics relate to each other and whether gait characteristics can be obtained from resultant acceleration. Therefore, step duration variability was measured in treadmill walking from 39 young ambulant volunteers (age 24.2 [±2.5] years; height 1.79 [±0.09] m; mass 71.6 [±12.0] kg) using motion capture. Accelerations and gyrations were simultaneously recorded with an IMU. Harmonic ratio, maximum Lyapunov exponents, and multiscale sample entropy (MSE) were calculated. Step duration variability was positively associated with MSE with coarseness levels = 3 to 6 (r = -0.33 to -0.42, p≤0.045). Harmonic ratio, and MSE with all coarseness levels were negatively associated (r = -0.45 to -0.57, p≤0.004). The MSE with coarseness level = 2 was negatively associated with short-term maximum Lyapunov exponents (r = -0.32, p=0.047). The agreement between resultant and vertical-acceleration derived gait characteristics was excellent (ICC = 0.97 to 0.99). In conclusion, MSE with varying coarseness levels was associated with the other gait characteristics evaluated in the study. Resultant and vertical acceleration-derived results had excellent agreement which suggests that resultant acceleration is a viable alternative to considering the acceleration dimensions independently.
... All subjects had normal vision, no difficulty in performing daily activities, and no color-blindness or color-weakness. The elderly scored 5 of 5 full points on the Function Ambulatory Category (FAC), which is a gait ability level test, and could walk more than 10 m consistently [12]. Their cognitive state was normal, scoring more than 24 points on the Mini-Mental State Exam (MMSE) test. ...
The purpose of this study was to compare changes in the gait pattern between the elderly and young during level (i.e., even surface) walking under low illumination. Vision during walking plays a role in avoiding obstacles and uneven surfaces, as well as an important role in the proactive control of dynamic stability and route planning for level walking. Fourteen elderly and fourteen young male subjects walked on a 7 m walkway with two illumination conditions using self-selected walking speed: walking with normal (>300 lux) and low illumination (<10 lux). Walking speed, stance phase ratio, toe clearance on swing phase, and range of motion at the center of mass were used to compare the differences in gait pattern between two illumination conditions and ages. During walking with low illumination, walking speed and stance phase ratio of the young decreased, and toe clearance of the young increased. However, there was no difference in these variables due to low illumination in the elderly subjects. Despite level walking conditions, there were some differences in gait pattern between the young and the elderly due to illumination conditions. This implies that the young showed a more positive change of gait pattern, due to low illumination, than that of the elderly. In this respect, further study is necessary to identify differences between the young and the elderly, when they walk on an uneven or obstacle walkway with low illumination.
... There are several providers of such devices worldwide (see for example [3], [4], [5] and [6]). Their performance in terms of accuracy and bandwidth is generally sufficient for a wide range of applications, among them guidance and control of small aerial vehicles, motion capture in virtual reality, human-machine interfaces and analysis of the motion of living organisms, with a strong emphasis on gait analysis (see [7], [8] and [9] as examples of the many publications available). One current trend is to arrange the sensors within a specific class of network known as a Body Area Network or BAN [10]. ...
This paper presents a new system for analysis of walking and running gaits. The system is based on a network of wireless nodes with various types of embedded sensors. It has been designed to allow long-term recording in outdoor environments and was tested during the 2010 “Sultan Marathon des Sables” desert race. A runner was fitted with the sensory network for six days of the competition. Although technical problems have limited the amount of data recorded, the experiment was nevertheless successful: the system did not interfere with the runner, who finished with a high ranking, the concept was validated and high quality data were acquired. It should be noted that the loss of some of the measurements was mainly due to problems with the cable connectors between the nodes and batteries. In this paper, we describe the technical aspects of the system developed, the experimental conditions under which it was validated, and give examples of the data obtained with some preliminary processing.
... Especially for pathological gait, frequency content of kinematics may be even lower. For example, Héliot et al. (2010), using gait spectral index, provided data which indicate that both fundamental and second harmonic of frequency band present lower amplitudes for stroke patients compared with normal adults. Therefore, even a sampling frequency of 25 Hz is theoretically adequate. ...
To investigate what sampling frequency is adequate for gait, the correlation of spatiotemporal parameters and the kinematic differences, between normal and CP spastic gait, for three sampling frequencies (100 Hz, 50 Hz, 25 Hz) were assessed. Spatiotemporal, angular, and linear displacement variables in the sagittal plane along with their 1st and 2nd derivatives were analyzed. Spatiotemporal stride parameters were highly correlated among the three sampling frequencies. The statistical model (2 × 3 ANOVA) gave no interactions between the factors group and frequency, indicating that group differences were invariant of sampling frequency. Lower frequencies led to smoother curves for all the variables, with a loss of information though, especially for the 2nd derivatives, having a homologous effect as the one of oversmoothing. It is proposed that in the circumstance that only spatiotemporal stride parameters, as well as angular and linear displacements are to be used, in gait reports, then commercial video camera speeds (25/30 Hz, 50/60 Hz when deinterlaced) can be considered as a low-cost solution to produce acceptable results.
... More recently, the availability of IMUs made easier approaches derived from motion capture. And yet simpler, accelerometers sound very useful for applications in human walking analysis, for example in [5] for assessing gait performance, in [6] for human motion imitation, in [7] for classifying postural transfers of elderly, or in [8] for monitoring children walking trajectories. ...
We introduce a simple approach to segment in homogeneous phases a long-duration record of locomotion data consisting of body segment acceleration and foot pressure information only. The association of acceleration norms with impact detections allows us to successfully apply K-means algorithm in order to automatically classify the locomotion in terms of walking and various running speeds. The method is validated on experimental data. One subject, equipped with IMUs and foot pressure units is asked to successively walk and run around an indoor running track. The algorithm is able to detect the different types of motions.
Background
A wide variety of indices have been developed to quantify gait performance markers and associate them with their respective pathologies. Indices scores have enabled better decisions regarding patient treatments and allowed for optimized monitoring of the evolution of their condition. The extensive range of human gait indices presented over the last 30 years is evaluated and summarized in this narrative literature review exploring their application in clinical and research environments.
Methods
The analysis will explore historical and modern gait indices, focusing on the clinical efficacy with respect to their proposed pathology, age range, and associated parameter limits. Features, methods, and clinically acceptable errors are discussed while simultaneously assessing indices advantages and disadvantages. This review analyses all indices published between 1994 and February 2021 identified using the Medline, PubMed, ScienceDirect, CINAHL, EMBASE, and Google Scholar databases.
Findings
A total of 30 indices were identified as noteworthy for clinical and research purposes and another 137 works were included for discussion. The indices were divided in three major groups: observational (13), instrumented (16) and hybrid (1). The instrumented indices were further sub-divided in six groups, namely kinematic- (4), spatiotemporal- (5), kinetic- (2), kinematic- and kinetic- (2), electromyographic (1)- and Inertial Measurement Unit-based indices (2).
Interpretation
This work is one of the first reviews to summarize observational and instrumented gait indices, exploring their applicability in research and clinical contexts. The aim of this review is to assist members of these communities with the selection of the proper index for the group in analysis.
The purpose of this study is to propose the quantitative evaluation indices for the hemiplegic gait characteristics by accelerometers attached to the right and left lumbar part. Subjects are 16 patients with hemiplegia, 8 males and 8 females whose ages are from 46 to 83 years. Twenty-six healthy adults also participated as a control group. An FFT analysis for both hemiplegic gait and healthy normal walking test results is carried out paying attention to the component with frequency of 0.5fw (half frequency component of the gait cycle fw) . Based on these analytical results, it is revealed that the component with frequency of 0.5fw in the fore and after direction is obviously prominent for the hemiplegic gait compared with measured values of healthy normal gait. The parameter PR is defined as the power spectrum ratio of 0.5fw to fw component. The relationship between gait stage (GS) and PR is investigated for both subjects of hemiplegic patients and healthy adults. Dynamic load factor (DLF) corresponding to the vertical walking force and lateral displacement of the waist are also calculated using power spectrum density for time history signals measured by the accelerometers. This led to the conclusion that the parameter PR in the fore and after direction, DLF in the vertical direction and lateral displacement of the waist are the useful evaluation indices for the hemiplegic gait analysis from the viewpoint of rehabilitation medicine.
Assistance fonctionnelle : exploiter les fonctions résiduelles du système sensori-moteur déficient
