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1.
Treadmill training has been used as a promising technique to improve overground walking in patients with spinal cord injury (SCI). Previous findings showed that a gait pattern may adapt to a force perturbation during treadmill training and show aftereffects following removal of the force perturbation. We hypothesized that aftereffects would transfer to overground walking to a greater extent when the force perturbation was resisting rather than assisting leg swing during treadmill training. Ten subjects with incomplete SCI were recruited into this study for two treadmill training sessions: one using swing resistance and the other using swing assistance during treadmill stepping. A controlled resistance/assistance was provided to the subjects’ right knee using a customized cable-driven robot. The subjects’ spatial and temporal parameters were recorded during the training. The same parameters during overground walking were also recorded before and after the training session using an instrumented walkway. Results indicated that stride length during treadmill stepping increased following the release of resistance load and the aftereffect transferred to overground walking. In contrast, stride length during treadmill stepping decreased following the release of assistance load, but the aftereffect did not transfer to overground walking. Providing swing resistance during treadmill training could enhance the active involvement of the subjects in the gait motor task, thereby aiding in the transfer to overground walking. Such a paradigm may be useful as an adjunct approach to improve the locomotor function in patients with incomplete SCI.  相似文献   

2.
Healthy persons exhibit relatively small temporal and spatial gait variability when walking unimpeded. In contrast, patients with a sensory deficit (e.g., polyneuropathy) show an increased gait variability that depends on speed and is associated with an increased fall risk. The purpose of this study was to investigate the role of vision in gait stabilization by determining the effects of withdrawing visual information (eyes closed) on gait variability at different locomotion speeds. Ten healthy subjects (32.2 ± 7.9 years, 5 women) walked on a treadmill for 5-min periods at their preferred walking speed and at 20, 40, 70, and 80 % of maximal walking speed during the conditions of walking with eyes open (EO) and with eyes closed (EC). The coefficient of variation (CV) and fractal dimension (α) of the fluctuations in stride time, stride length, and base width were computed and analyzed. Withdrawing visual information increased the base width CV for all walking velocities (p < 0.001). The effects of absent visual information on CV and α of stride time and stride length were most pronounced during slow locomotion (p < 0.001) and declined during fast walking speeds. The results indicate that visual feedback control is used to stabilize the medio-lateral (i.e., base width) gait parameters at all speed sections. In contrast, sensory feedback control in the fore-aft direction (i.e., stride time and stride length) depends on speed. Sensory feedback contributes most to fore-aft gait stabilization during slow locomotion, whereas passive biomechanical mechanisms and an automated central pattern generation appear to control fast locomotion.  相似文献   

3.
The aim of this study was to investigate whether cognitive processing for defining step precision during walking could induce changes in electrocortical activity. Ten healthy adults (21–36 years) were asked to walk overground in three different conditions: (1) normal walking in a straight path (NW); (2) walking in a pre-defined pathway forcing variation in step width and length by stepping on green marks on the floor (only one color: W1C), and (3) walking in the same pre-defined W1C pathway while evaluating different combinations among the colors green, yellow and red, in which only one color was the footfall target (evaluating two colors: W2C). Walking speed, stride duration and scalp electroencephalography (EEG) were recorded from all conditions. Event-related spectral perturbation was calculated for channels Fz, Cz, C3, C4, Pz and Oz in each condition, which were all time-normalized in relation to the gait cycle. The results showed that walking speed was reduced and stride duration was increased for W2C when compared to both NW and W1C (p?<?0.01). Moreover, Event-related spectral perturbation analysis revealed significant changes (p?<?0.05) during mid-stance in the frontal lobe and motor/sensorimotor regions, a phase in the gait cycle in which participants define the correct foot placement for the next step. These results suggest that greater cognitive demands during precision stepping influences electrocortical dynamics especially towards step transitions. Therefore, increased electrocortical activity in cognitive, motor and sensorimotor areas may be relevant to produce patterned and safe locomotion through challenging paths.  相似文献   

4.
BackgroundPerforming gait analysis in a clinical setting can often be challenging due to time, cost and the availability of sophisticated three-dimensional (3D) gait analysis systems. This study has developed and tested a portable wireless gait assessment tool (wi-GAT) to address these challenges.AimTo investigate the concurrent validity of the wi-GAT in measuring spatio-temporal gait parameters such as stride length, stride duration, cadence, double support time (DST), stance and swing time compared to a 3D Vicon motion analysis system.MethodsTen healthy volunteers participated in the study (age range 23–30 years). Spatio-temporal gait parameters were recorded simultaneously by the Vicon and the wi-GAT systems as each subject walked at their self-selected speed.ResultsThe stride length and duration, cadence, stance duration and walking speed recorded using the wi-GAT showed strong agreement with those same parameters recorded by the Vicon (ICC of 0.94–0.996). A difference between the systems in registering “toe off” resulted in less agreement (ICC of 0.299–0.847) in gait parameters such as %stance and %swing and DST.Discussion and conclusionThe study demonstrated good concurrent validity for the wi-GAT system. The wi-GAT has the potential to be a useful assessment tool for clinicians.  相似文献   

5.
背景:全髋关节置换可以为患者缓解疼痛、恢复步行功能,数年后步态是否能达到正常化仍存在争议。 目的:分析单侧髋关节置换后遗症期患者平地步行中下肢的时空参数特征,探讨患者步行能力。 方法:根据运动重建实验室检测病例数据库资料分析的方法,选择全髋关节置换后5-10年的患者14例为实验组,14例相匹配的健康人为对照组。采用Vicon Nexus采集患者平地步行时下肢的步态参数,应用Polygon分析步态周期中下肢时空参数特征。 结果与结论:与对照组相比,实验组术侧和健侧步速减慢,步频减小,步幅、跨步长变短,双支撑相延长,对侧足离地比增大(P < 0.05);术侧跨步时间、单步时间增大(P < 0.05);健侧足离地比增大(P < 0.05)。术侧与健侧比较,各时空参数差异均无显著性意义(P > 0.05)。结果表明全髋关节置换后5-10年的患者步态对称性较好,但仍没有达到正常水平,步行能力差于正常人,需要系统康复训练以恢复其步行能力。中国组织工程研究杂志出版内容重点:人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程全文链接:  相似文献   

6.
In this paper we implemented machine learning (ML) and strap-down integration (SDI) methods and analyzed them for their capability of estimating stride-by-stride walking speed. Walking speed was computed by dividing estimated stride length by stride time using data from a foot mounted inertial measurement unit. In SDI methods stride-by-stride walking speed estimation was driven by detecting gait events using a hidden Markov model (HMM) based method (HMM-based SDI); alternatively, a threshold-based gait event detector was investigated (threshold-based SDI). In the ML method a linear regression model was developed for stride length estimation. Whereas the gait event detectors were a priori fixed without training, the regression model was validated with leave-one-subject-out cross-validation. A subject-specific regression model calibration was also implemented to personalize the ML method.Healthy adults performed over-ground walking trials at natural, slower-than-natural and faster-than-natural speeds. The ML method achieved a root mean square estimation error of 2.0% and 4.2%, with and without personalization, against 2.0% and 3.1% by HMM-based SDI and threshold-based SDI. In spite that the results achieved by the two approaches were similar, the ML method, as compared with SDI methods, presented lower intra-subject variability and higher inter-subject variability, which was reduced by personalization.  相似文献   

7.
Step characteristics during obstacle avoidance in hemiplegic stroke   总被引:3,自引:0,他引:3  
Whereas several animal studies have indicated the important role of the motor cortex in the control of voluntary gait modifications, little is known about the effects of cortical lesions on gait adaptability in humans. Obstacle avoidance tasks provide an adequate paradigm to study the adaptability of the stepping pattern under controlled, experimental conditions. In the present study, an exploratory assessment was made of the failure rate, the preferred stepping strategies (step lengthening vs step shortening), and the spatiotemporal stride characteristics (percentage increases in stride length, duration, and velocity of the crossing and postcrossing strides) during obstacle avoidance in 11 hemiplegic stroke patients and seven healthy controls. Patients were less successful in avoiding obstacles than controls (14% failure rate vs 0.5% in controls), independent of whether the affected or the unaffected leg led the obstacle avoidance. The number of failed trials increased systematically when the available response time became shorter. During successful trials, lengthening of the step was generally preferred over shortening. This bias towards step lengthening was more pronounced in stroke patients (step lengthening in 91% of the trials vs 75% in controls), irrespective of the side of obstacle presentation. For both groups, overall strategy preference did not adhere to a principle of minimal foot displacement, since step lengthening was used even if it would be more spatially efficient to shorten the step. No statistically significant group differences were found for the increases in length, duration, and velocity of the crossing and postcrossing strides. However, for a subgroup of more slowly walking patients, large percentage increases were found in crossing stride length, duration, and velocity. Similar results were obtained for the postcrossing stride, indicating that, for this subgroup of patients, restoration of the normal walking cadence was more difficult. Overall, no systematic differences were found between the affected and the unaffected leg in stroke patients with respect to failure rates, stepping strategies, or spatiotemporal measures of obstacle avoidance. The present findings suggest that the ability to adequately modify the stepping pattern in response to imposed spatiotemporal constraints is impaired in persons with stroke, especially when modifications have to be performed under time pressure. In addition, the stepping strategies employed by subjects with stroke are different from those found in controls, possibly to reduce the complexity of the avoidance maneuver and to enhance safety. Finally, unilateral cortical damage results in an impaired ability to avoid obstacles on both sides of the body, suggesting that the reduced ability of stroke patients to negotiate obstacles may be related to problems of a more general coordinative nature.  相似文献   

8.
Gait variability in the context of a deterministic dynamical system may be quantified using nonlinear time series analyses that characterize the complexity of the system. Pathological gait exhibits altered gait variability. It can be either too periodic and predictable, or too random and disordered, as is the case with aging. While gait therapies often focus on restoration of linear measures such as gait speed or stride length, we propose that the goal of gait therapy should be to restore optimal gait variability, which exhibits chaotic fluctuations and is the balance between predictability and complexity. In this context, our purpose was to investigate how listening to different auditory stimuli affects gait variability. Twenty-seven young and 27 elderly subjects walked on a treadmill for 5 min while listening to white noise, a chaotic rhythm, a metronome, and with no auditory stimulus. Stride length, step width, and stride intervals were calculated for all conditions. Detrended Fluctuation Analysis was then performed on these time series. A quadratic trend analysis determined that an idealized inverted-U shape described the relationship between gait variability and the structure of the auditory stimuli for the elderly group, but not for the young group. This proof-of-concept study shows that the gait of older adults may be manipulated using auditory stimuli. Future work will investigate which structures of auditory stimuli lead to improvements in functional status in older adults.  相似文献   

9.
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。  相似文献   

10.
OBJECTIVE: The present study was undertaken to assess whether footedness has effects on selected spatial and angular parameters of able-bodied gait by evaluating footprints of young adults. SUBJECTS AND METHODS: A total of 112 males and 93 females were selected from among students and staff members of the University of Malawi using a simple random sampling method. Footedness of subjects was assessed by the Waterloo Footedness Questionnaire Revised. Gait at natural speed was recorded using the footprint method. The following spatial parameters of gait were derived from the inked footprint sequences of subjects: step and stride lengths, gait angle and base of gait. The anthropometric measurements taken were weight, height, leg and foot length, foot breadth, shoulder width, and hip and waist circumferences. RESULTS: The prevalence of right-, left- and mix-footedness in the whole sample of young Malawian adults was 81%, 8.3% and 10.7%, respectively. One-way analysis of variance did not reveal a statistically significant difference between footedness categories in the mean values of anthropometric measurements (p > 0.05 for all variables). Gender differences in step and stride length values were not statistically significant. Correction of these variables for stature did not change the trend. Males had significantly broader steps than females. Normalized values of base of gait had similar gender difference. The group means of step length and normalized step length of the right and left feet were similar, for males and females. There was a significant side difference in the gait angle in both gender groups of volunteers with higher mean values on the left side compared to the right one (t = 2.64, p < 0.05 for males, and t = 2.78, p < 0.05 for females). One-way analysis of variance did not demonstrate significant difference between footedness categories in the mean values of step length, gait angle, bilateral differences in step length and gait angle, stride length, gait base and normalized gait variables of male and female volunteers (p > 0.05 for all variables). CONCLUSIONS: The present study demonstrated that footedness does not affect spatial and angular parameters of walking gait.  相似文献   

11.
Recently, there has been great improvement in the field of movement analysis, which is a worldwide tendency. There is a continuous improvement of new methods, combined with traditional ones. In the last few years, we have managed to set up a modern, absolutely up-to-date motion analysis laboratory at the Budapest University of Technology and Economics (BUTE). The primary purpose of this study was to determine usual walking and running parameters as a function of speed and compare our results with the data of other studies. We tested the gait and running characteristics of people at different speeds, measuring the usual parameters of walking and running. On the basis of these measurements, we observed the interrelation of the three main parameters of gait and running (speed, cadence, stride length) and determined the dependence of cadence and stride length on speed as well. The determined energetically optimal walking speed (EOWS) and the usual walking speed (UWS) correlate well with the values in literature. Our measurements were performed on a running corridor, and at the facilities provided by the Biomechanical Laboratory, including an instrumented treadmill connected to the measurement system.  相似文献   

12.
Microprocessor-based gait analysis system to retrain Trendelenburg gait   总被引:1,自引:0,他引:1  
A microprocessor-based gait analysis system is described that uses two electromyogram (EMG) amplifiers, two foot switches and an audio feedback device to allow the retraining of one type of improper gait, where the hip abductors (gluteus medius muscles) are weak on one side of the body, causing the opposite hip to drop during the swing phase of gait (Trendelenburg gait). As the abnormality is strictly on one side of the body in most people, the circuitry is minimised, as gait can be analysed by only comparing muscle activity in the affected gluteus medius muscle with that in the unaffected gluteus medius muscle, through the EMG. Two foot contact switches are used to help assess timing of the step cycle. If gait is different on the two sides of the body, an audio cue directs the patient to correct the abnormality by increasing activity on the affected side. The device is tested on five patients. Trendelenburg gait is reduced by an average of 29 degrees through the use of the device. The average stride length at the beginning of the study is 0.32±0.3 m. By the end of the study, the stride length is increased to 0.45±0.2m for the entire group of five subjects. The speed of gait has increased from 1.6±0.4 kmh−1 to 3.1±0.5 kmh−1.  相似文献   

13.
Stepping over obstacles to avoid tripping is an essential component in safe and smooth locomotion. Obstacle avoidance during locomotion is completed in several steps during the approach phase toward the obstacle and stepping over the obstacle. The purpose of this study was to investigate gait modification during the approach phase when stepping over obstacles of different heights in rats. In all four limbs, the toe height when the toe was just above the obstacle increased depending on the obstacle height, leaving a safe margin. However, the horizontal distance between toe and obstacle just prior to stepping over was not influenced by obstacle height. In the fore- and hindlimbs that served as trailing limbs, it was found that the stride length and its related swing phase duration in the final step were significantly shorter than those in both the penultimate step and overground locomotion. These results suggest that adjustment of trailing limb in the final step during the approach phase is important in preparation for the stepping movement over an obstacle.  相似文献   

14.
The segmentally trisomic mouse Ts65Dn is a model of Down syndrome (DS). Gait abnormalities are almost universal in persons with DS. We applied a noninvasive imaging method to quantitatively compare the gait dynamics of Ts65Dn mice (n=10) to their euploid littermates (controls) (n=10). The braking duration of the hind limbs in Ts65Dn mice was prolonged compared to that in control mice (60+/-3 ms vs. 49+/-2 ms, P<.05) at a slow walking speed (18 cm/s). Stride length and stride frequency of forelimbs and hind limbs were comparable between Ts65Dn mice and control mice. Stride dynamics were significantly different in Ts65Dn mice at a faster walking speed (36 cm/s). Stride length was shorter in Ts65Dn mice (5.9+/-0.1 vs. 6.3+/-0.3 cm, P<.05), and stride frequency was higher in Ts65Dn compared to control mice (5.9+/-0.1 vs. 5.3+/-0.1 strides/s, P<.05). Hind limb swing duration was prolonged in Ts65Dn mice compared to control mice (93+/-3 vs. 76+/-3 ms, P<.05). Propulsion of the forelimbs contributed to a significantly larger percentage of stride duration in Ts65Dn mice than in control mice at the faster walking speed. Indices of gait dynamics in Ts65Dn mice correspond to previously reported findings in children with DS. The methods used in the present study provide quantitative markers for genotype and phenotype relationship studies in DS. This technique may provide opportunities for testing the efficacy of therapies for motor dysfunction in persons with DS.  相似文献   

15.
BackgroundUnicompartmental knee replacement (UKR) can provide reliable clinical and functional outcomes when performed simultaneously in both knees for treating bilateral osteoarthritis (OA). No studies to date have evaluated gait pattern after simultaneous bilateral UKR. The aim of this study was to evaluate changes in gait variables after bilateral single-stage UKR (B-UKR) and to compare them with the outcomes after unilateral UKR in two other groups of patients: one with bilateral knee OA (P-UKR) and one with the contralateral knee unaffected (H-UKR).MethodsThree-dimensional motion cohort data were prospectively collected before and six months after surgery; 37 were allocated to the B-UKR (n = 13), P-UKR (n = 12) or H-UKR (n = 12) group. Spatiotemporal variables (stride length, gait speed, gait cadence, stance phase, swing phase, and double support phase) and kinematic parameters (knee flexion and extension peak values, knee range of motion (ROM), and hip abduction peak value) were analyzed using mixed analysis of variance (ANOVA). The magnitude of effect for significant outcomes (ES) was determined using Cohen's d.ResultsPostoperative improvement in gait cadence (P < 0.01; ES = 1.20), walking speed (P < 0.05; ES = 0.58), stride length (P < 0.05; ES = 0.67), knee ROM (P < 0.05; ES = 0.89), knee flexion (P < 0.05; ES = 0.94), and hip abduction (P < 0.001; ES = 1.16) was noted for the B-UKR group, whereas only stride length improved (P < 0.05; ES = 0.48) for the H-UKR group, and no changes in any gait parameter were seen for the P-UKR group.ConclusionsPostoperative improvement in gait parameters was observed in the B-UKR patients with bilateral OA. Whenever possible, simultaneous bilateral UKR should be considered in such patients.  相似文献   

16.
Objective: The present study was undertaken to assess whether footedness has effects on selected spatial and angular parameters of able-bodied gait by evaluating footprints of young adults.

Subjects and methods: A total of 112 males and 93 females were selected from among students and staff members of the University of Malawi using a simple random sampling method. Footedness of subjects was assessed by the Waterloo Footedness Questionnaire Revised. Gait at natural speed was recorded using the footprint method. The following spatial parameters of gait were derived from the inked footprint sequences of subjects: step and stride lengths, gait angle and base of gait. The anthropometric measurements taken were weight, height, leg and foot length, foot breadth, shoulder width, and hip and waist circumferences.

Results: The prevalence of right-, left- and mix-footedness in the whole sample of young Malawian adults was 81%, 8.3% and 10.7%, respectively. One-way analysis of variance did not reveal a statistically significant difference between footedness categories in the mean values of anthropometric measurements (p?>?0.05 for all variables). Gender differences in step and stride length values were not statistically significant. Correction of these variables for stature did not change the trend. Males had significantly broader steps than females. Normalized values of base of gait had similar gender difference. The group means of step length and normalized step length of the right and left feet were similar, for males and females. There was a significant side difference in the gait angle in both gender groups of volunteers with higher mean values on the left side compared to the right one (t?=?2.64, p?<?0.05 for males, and t?=?2.78, p?<?0.05 for females). One-way analysis of variance did not demonstrate significant difference between footedness categories in the mean values of step length, gait angle, bilateral differences in step length and gait angle, stride length, gait base and normalized gait variables of male and female volunteers (p?>?0.05 for all variables).

Conclusions: The present study demonstrated that footedness does not affect spatial and angular parameters of walking gait.  相似文献   

17.
Gait topography in rat locomotion   总被引:3,自引:0,他引:3  
Gait topography has been quantified and normative data established for free, spontaneous locomotion in rats. The normal walking pattern has been compared for male and female rats and for three rat strains. The normal walking gait was found to be symmetrical, and measures of stride width (SW) and stride length (SL) were consistent, with coefficients of variability ranging between 10 and 21%. A study of gait ontogeny found that for both male and female rats, SL increased as a linear function of body weight, whereas SW increased curvilinearly. The results indicate that repeated measures of gait topography were not subject to interference from habituation. A sex difference in gait ontogeny was observed. The developmental pattern is similar for both sexes, but males increase both SL and SW faster than females. It is proposed that gait topography may yield valuable information in activity studies.  相似文献   

18.
19.
Gait disturbances are common in the rat model of Parkinson's disease (PD) by administrating 6-hydroxydopamine. However, few studies have simultaneously assessed spatiotemporal gait indices and the kinematic information of PD rats during overground locomotion. This study utilized a simple, accurate, and reproducible method for quantifying the spatiotemporal and kinematic changes of gait patterns in hemiparkinsonian rats. A transparent walkway with a tilted mirror was set to capture underview footprints and lateral joint ankle images using a high-speed and high-resolution digital camera. The footprint images were semi-automatically processed with a threshold setting to identify the boundaries of soles and the critical points of each hindlimb for deriving the spatiotemporal and kinematic indices of gait. Following PD lesion, asymmetrical gait patterns including a significant decrease in the step/stride length and increases in the base of support and ankle joint angle were found. The increased footprint length, toe spread, and intermediary toe spread were found, indicating a compensatory gait pattern for impaired locomotor function. The temporal indices showed a significant decrease in the walking speed with increased durations of the stance/swing phase and double support time, which was more evident in the affected hindlimb. Furthermore, the ankle kinematic data showed that the joint angle decreased at the toe contact stage. We conclude that the proposed gait analysis method can be used to precisely detect locomotor function changes in PD rats, which is useful for objective assessments of investigating novel treatments for PD animal model.  相似文献   

20.
This paper presents an analysis of spatio-temporal gait parameters during overground walking based upon a method that needs only lower trunk accelerations. Twenty-six healthy young subjects and 15 healthy elderly subjects participated in an experiment where overground walking was studied at different speeds. Accelerations of the lower trunk were measured by a tri-axial accelerometer connected to a portable data logger carried on the body. An analysis of trunk acceleration data produced temporal gait parameters (duration of subsequent stride cycles and left/right steps) and convincing estimations of spatial parameters (step length and walking speed). Typical differences in spatio-temporal gait parameters between young and elderly subjects could be demonstrated, i.e. a limited range of walking speeds, smaller step lengths, and a somewhat higher variability of temporal parameters in elderly subjects. It is concluded from these results that essential spatio-temporal gait parameters can be determined during overground walking using only one tri-axial accelerometer. The method is easy-to-use and does not interfere with regular walking patterns. Both the accelerometer and the data logger can be miniaturised to one small instrument that can be carried on the trunk during hours of walking. Thus, the method can easily be incorporated in current activity monitors so that 24-h monitoring of postures and activities can be combined with assessment of gait characteristics during these monitoring periods. In addition, the presented method can be a basis for more sophisticated gait analyses during overground walking, e.g. an analysis of kinematic signals or muscle activity within subsequent stride cycles.  相似文献   

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