Walking Style Research Articles

Assessing leg health in chickens using a force plate and gait scoring: how many birds is enough?

Meat chickens from experimental flocks were tested repeatedly from three to six weeks of age using gait score (GS) and force plate (FP) techniques, and the findings were related to...

Person Identification Using Gait

in this paper, Principal Component Analysis (PCA) with and without Radon Transform (RT) are applied for gait recognition purposes. The Radon Transform is used to detect features within an image and PCA is used to the reduce dimension of the images without much loss of information. The side view of slow walk, fast walk and carrying a ball walk have been selected from the CMU MoBo database for experimental purposes. The two techniques experimental result achieved equal recognition rates (EER) of 85.40%, 78.07% and 90.05% for RT with PCA and 85.18%, 80%, and 89.90% for PCA only for slow walk, fast walk and carrying a ball walk respectively. Gait recognition system can be classified depending on the sensors used into three groups namely; motion vision based, wearable sensor based and floor sensor based. The motion vision can be divided into two groups namely; appearance based methods and model based methods. The appearance based method can be also subdivided in two types; state space methods and spatio-temporal methods. The classification of the recognition system is shown in Fig 1, (1-7). Biometric gait recognition refers to verifying or identifying persons using their walking style. Human recognition based on gait is relatively recent compared to other biometric approaches such as fingerprint, iris, facial etc. The wearable sensors and floor sensors systems are also able to identify persons but in different conditions compared to motion vision technique. The wearable sensors technique needs to carry necessary sensors which enable to measure the different walk styles. The sensors can be set on any part of the body according to the sensors characteristics to get gait data to match up with training dataset. The sensors may be set up on hip, legs, arms or other parts of the body (8). The floor sensors are put into the floor or on the floor which enable to detect the required measurement. The most important point is to match up testing dataset with training dataset to identify the subjects. Both systems are useful for access control such as office, airport, mega mall and other restricted places (9). Fig 2 shows a typical motion vision based system flow chart, while Fig 3 shows a general block diagram of gait recognition system. Motion vision can be used for surveillance, access control, detection and other monitoring purposes. The most important advantage is that person walking image can be captured from long distance and the image is then processed

Human Gait Recognition for Multiple Views

Gait recognition is a promising topic in the biometric technology. The technique identifies individuals based on their walk style. Gait energy image combines frames of one gait cycle together to enhance the relevance among them, to reduce the noise interference. In this paper, Fourier transform was carried out on the gait energy image. Their low frequency components were adopted to perform multi-view gait identification. The method was applied to CASIA database. The experiment results demonstrate that the proposed method is fast and effective.

Biometrics System based on Human Gait Patterns

To day's commercially available biometric systems show good reliability. However, they generally lack user acceptance. In general, people favour systems with the least amount of interaction. Using gait as a biometric feature would lessen such problems since it requires no subject interaction other than walking by. Consequently, this would increase user acceptance. And since highly motivated users achieve higher recognition scores, it increases the overall recognition rate as well. The latest research on gait-based identification—identification by observation of a person's walking style provides evidence that such a system is realistic and is likely to be developed and used in the years to come. This article outlines the application of gait technologies for security and other purposes. Gait analysis and recognition can form the basis of unobtrusive technologies for the detection of individuals who represent a security threat or behave suspiciously.

2A2-C05 24自由度6脚ロボットの整地における旋回歩行と並進歩行(脚移動ロボット)

To make a six-legged robot move efficiently, it is necessary for us to make the robot change its walking style depending on the situation. Thus, employing our six-legged robot with 24-DOF, we measured its electric power consumption for turning and translational motions in walking on level terrain. In an experiment on turning motion in walking, we compared two types: one mimicking an ant, and one by wave gait. We found that electric power consumption of the turning motion in walking by wave gait was smaller. In addition, as a result of an experiment on translational motion in walking, when we compared differences of movement direction, we found that electric power consumption increased in the order of slantwise direction, sideways direction, and forward direction.

People Identification Using Floor Pressure Sensing and Analysis

This paper presents an approach to people identification based on gait using floor pressure data. By using a large-area, high-resolution pressure sensing floor, we are able to obtain both the 1D pressure profile and 2D position trajectories of the centers of pressure (COP) of both feet to form a 3D COP trajectories over a footstep. From the 3D COP trajectories of a pair of footsteps, a set of features are extracted and used together with other features such as the mean pressure and stride length for people identification. The Fisher linear discriminant is used as the classifier. The speed-invariant properties of different features are examined and we have shown that the pressure features have good speed-invariance properties, much better than the stride length feature. The proposed algorithm has been extensively tested using a floor pressure dataset collected from 11 subjects in different walking styles, including varying speed walking and free style walking. Decent people identification results have been obtained using the proposed method with an average recognition rate of 92.3% and false alarm rate of 6.79% using the best performing feature set.

Contour extraction of gait recognition

Gait recognition is a new biometric identification technology. Its aim is to recognize people and detect physiological, pathological and mental characters by their walk style. The feature extraction of gait is the key step in gait recognition. This paper combines the background subtraction method with symmetric differential method to segment the motion human image, and then extracts the contour of motion human with improved GVF (gradient vector flow) Snake model. The experimental results show that the proposed method can extract contour features effectively for the gait recognition.

J1102-2-3 装着者の体重を利用した歩行支援シューズの開発([1102-2]ライフサポート(2))

Among the elderly person, most of their injuries are reported to be caused by falling down with stumbling. It is due to their shuffling walking style resulted from deterioration of their dorsiflexion muscle force along with aging. Walking plays an important role in their independent day life. We aim at developing a wearable walking support shoes for a purpose of fall prevention of elderly people and to support walking rehabilitation training. A commercial product of Ankle Foot Orthosis is introduced and newly developed wire type pneumatic actuator is equipped on to support dorsiflexion motion during swing period at walking motion actively. In generally, these kind of active supporting systems require power source. We propose a driving scheme with no use of electric power, but with only potential energy of the wearer. Improvement of the devices toward embedding into a shoes is mainly reported here.

1A1-F19 4自由度で直進・旋回が可能な6足歩行ロボット

This paper proposes a new configuration of six legged robot which can walk forward/backward, on curbed path, and with pivot turn. It basically can walk on uneven terrain. A relationship of locomotion function and required number of actuators is discussed, based on a tripod walking style. For a straight walk and pivot turn, 2 actuators are required for a horizontal movement. For a terrain adapting function, required number of vertical actuators can be reduced to 2 if the maximum number of ground contact foot at once limits 5 instead of 6. A 4-actuator six legged robot can be designed by a combination of these 2 and 2.

EXTENDED-KNEE WALK FOR HUMANOID ROBOT WITH PARALLEL LINK LEGS

This paper proposes a method of giving humanoid robots a natural humanlike walk, which we call the extended-knee walk. Unlike the bent-knee walk of most humanoid robots to date, this walk includes a period in which the knee is fully extended. A parallel mechanism is used in the legs and a method of calculating the walk trajectory copes with the difficulty of the singularity in achieving a humanlike walk. The advantages of this walk were verified from two aspects: good visual appearance and good energy efficiency. An experiment comparing the trajectories of the knee angle during walking showed that the walking style produced by the proposed method is more humanlike than the usual walking style of other humanoid robots. The energy efficiency was verified through power consumption and motor temperature measurements and the possibilities for practical use of this method are discussed with reference to the results of the worldwide soccer competition RoboCup 2008.

Optimizing walking controllers

This paper describes a method for optimizing the parameters of a physics-based controller for full-body, 3D walking. A modified version of the SIMBICON controller [Yin et al. 2007] is optimized for characters of varying body shape, walking speed and step length. The objective function includes terms for power minimization, angular momentum minimization, and minimal head motion, among others. Together these terms produce a number of important features of natural walking, including active toe-off, near-passive knee swing, and leg extension during swing. We explain the specific form of our objective criteria, and show the importance of each term to walking style. We demonstrate optimized controllers for walking with different speeds, variation in body shape, and in ground slope.

Wearable Assistant for Parkinson’s Disease Patients With the Freezing of Gait Symptom

In this paper, we present a wearable assistant for Parkinson's disease (PD) patients with the freezing of gait (FOG) symptom. This wearable system uses on-body acceleration sensors to measure the patients' movements. It automatically detects FOG by analyzing frequency components inherent in these movements. When FOG is detected, the assistant provides a rhythmic auditory signal that stimulates the patient to resume walking. Ten PD patients tested the system while performing several walking tasks in the laboratory. More than 8 h of data were recorded. Eight patients experienced FOG during the study, and 237 FOG events were identified by professional physiotherapists in a post hoc video analysis. Our wearable assistant was able to provide online assistive feedback for PD patients when they experienced FOG. The system detected FOG events online with a sensitivity of 73.1% and a specificity of 81.6%. The majority of patients indicated that the context-aware automatic cueing was beneficial to them. Finally, we characterize the system performance with respect to the walking style, the sensor placement, and the dominant algorithm parameters.

Influence of major pulmonary resection on postoperative daily ambulatory activity of the patients

To describe and compare the daily ambulatory activity of the patients before and one month after major lung resection. Daily activity was measured using a pedometer (OMROM Walking Style PRO) given preoperatively in a prospective way to a series of 21 consecutive cases scheduled for lobectomy or pneumonectomy. Analyzed variables were age, pulmonary function, mean number of total and aerobic steps per day, walked distance and mean daily time of aerobic activity. Activity variables were analyzed individually and as a new differential variable DELTA. Wilcoxon and Mann-Whitney nonparametric tests were used for comparison between groups. General series data: 19 male. Age: 63+/-10.9 years. FEV(1)%: 88.4+/-22.7. DLCO: 86.2+/-21.6. Eleven cases had COPD criteria. Type of surgery: 3 pneumonectomy/18 lobectomy. Activity data: all patients showed a global decrease of their activity one month after surgery but, patients in the pneumonectomy group are unable to keep aerobic activity meanwhile patients that undergone lobectomy showed only a 25% reduction in the measured variables. Major pulmonary resection decreases the time and the quality of the daily ambulatory activity of the patients during the first postoperative month. Despite limitations, the chosen pedometer OMRON Walking Style Pro is an efficient tool to evaluate the perioperative daily ambulatory activity of patients.

Walking patterns and micromechanical load-transfer properties of human bone

When the foot of a person walking is lifted off the floor, electrical charge accumulates on the sole of the shoe or foot, which is then transferred to the body. When the foot is put back on the floor, the body uncharges. The combined effects of these charges induced stresses, in additional to the mechanical stresses due to walking cycle, on the micromechanical load-transfer properties of tibia bone (idealised as a piezoelectric assembly) are studied here using Discrete Element Method simulations. The study shows that the difference in normal walking patterns alone do not significantly affect the load-transfer properties of bone. Human bone is naturally versatile enough to regulate the load transfer for normal walking styles. However, the variations in the charge generated from the footwear seem to influence the load-transfer properties of bone, in particular, during the beginning stages of walking. This influence diminishes at longer periods of walking. Though more research is required, the current study is a step towards understanding the complexities of the stress distribution at micro scale in human bones due to walking.

Experimental Analysis of Slip Potential in Normal-Style Walking and Nanba-Style Walking

The maximum peak value of traction coefficient between a shoe sole and a floor at heel-strike period |Fh/Fn|h and that at toe-off period |Fh/Fn|t for normal-style and Nanba-style walking were investigated in this paper. The Nanba-style walking is known as Japanese traditional walking style. The characteristics of the Nanba-style walking different from the normal-style walking are knee flexion, anteversion of the upper body and small swing of the arms. Gait experiments were carried out on a dry level walkway. Four healthy male adults participated in the gait experiments, and they were asked to walk in the normal-style and the Nanba-style walking under a wide range of step length and walking speed. Ground reaction forces and full body kinematics were captured. The results indicated that |Fh/Fn|h of the Nanba-style walking was significantly (p<0.05) smaller than that of the normal-style walking under a wide range of walking conditions. Kinematic analysis of the Nanba-style walking indicated that reduction in friction requirement for such walking style would be due to anteriorly displacing the whole body COM as compared with that of the normal-style walking, resulting in decrease of the distance between the whole body COM and the COP in horizontal-plane. While a statistically significant difference of |Fh/Fn|t between these two walking styles were not observed, mean |Fh/Fn|t of the Nanba-style walking was smaller than that of the normal-style walking under a wide range of walking conditions.

Development of Pneumatic Walking Support Shoes using Potential Energy of Human

Among the elderly person, most of their injuries are reported to be caused by falling down with stumbling. It is due to their shuffling walking style resulted from deterioration of their dorsiflexion muscle force along with aging. Walking plays an important role in their independent day life. In this study we aim at developing a wearable walking support equipment embedded into shoes for a purpose of fall prevention of elderly person. A commercial product of Ankle Foot Orthosis is introduced and newly developed wire type pneumatic actuator is equipped on to support dorsifl exion motion during swing period at walking motion actively. In generally, these kind of active supporting systems require power source. We propose a driving scheme with no use of electric power, but with only potential energy of the wearer. Required specifications for the equipment are derived and the validity of proposed walking support shoes is verified through some experiments.

Whole body mechanics of stealthy walking in cats.

The metabolic cost associated with locomotion represents a significant part of an animal's metabolic energy budget. Therefore understanding the ways in which animals manage the energy required for locomotion by controlling muscular effort is critical to understanding limb design and the evolution of locomotor behavior. The assumption that energetic economy is the most important target of natural selection underlies many analyses of steady animal locomotion, leading to the prediction that animals will choose gaits and postures that maximize energetic efficiency. Many quadrupedal animals, particularly those that specialize in long distance steady locomotion, do in fact reduce the muscular contribution required for walking by adopting pendulum-like center of mass movements that facilitate exchange between kinetic energy (KE) and potential energy (PE) [1]–[4]. However, animals that are not specialized for long distance steady locomotion may face a more complex set of requirements, some of which may conflict with the efficient exchange of mechanical energy. For example, the “stealthy” walking style of cats may demand slow movements performed with the center of mass close to the ground. Force plate and video data show that domestic cats (Felis catus, Linnaeus, 1758) have lower mechanical energy recovery than mammals specialized for distance. A strong negative correlation was found between mechanical energy recovery and diagonality in the footfalls and there was also a negative correlation between limb compression and diagonality of footfalls such that more crouched postures tended to have greater diagonality. These data show a previously unrecognized mechanical relationship in which crouched postures are associated with changes in footfall pattern which are in turn related to reduced mechanical energy recovery. Low energy recovery was not associated with decreased vertical oscillations of the center of mass as theoretically predicted, but rather with posture and footfall pattern on the phase relationship between potential and kinetic energy. An important implication of these results is the possibility of a tradeoff between stealthy walking and economy of locomotion. This potential tradeoff highlights the complex and conflicting pressures that may govern the locomotor choices that animals make.

Gender differences exist in the hip joint moments of healthy older walkers

Gender differences in the incidence of symptomatic hip osteoarthritis (OA), changes in hip cartilage volume and hip joint space and rates hip arthroplasty of older people are reported in the literature. As the rate of progression of OA is in part mechanically modulated it is possible that this gender bias may be related to inherent differences (if they exist) in walking mechanics between older males and females. The purpose of this study was to examine potential mechanisms for gender differences in hip joint mechanics during walking by testing the hypotheses that females would exhibit higher hip flexion, adduction and internal rotation moments but not significantly greater normalized ground reaction forces (GRFs). Forty-two healthy subjects (21 male, 21 female), ages 50–79 yr were recruited for gait analysis. In support of the hypotheses, greater external hip adduction and internal rotation along with hip extension moments were found for females compared to males after normalizing for body size for all self-selected walking speeds. Differences in walking style (kinematics) were the main determinants in the joint kinetic differences as no differences in the normalized GRFs were found. As external joint moments are surrogate measures of the joint contact forces, the results of this study suggest the hip joint stress for the female population is higher compared to male population. This is in favor of a hypothesis that the increased joint contact stress in a female population could contribute to a greater joint degeneration at the hip in females as compared with males.

Human detection algorithm for seismic and ultrasonic detectors.

Range detection methodologies for human acoustic signals are discussed. Seismic, passive, and active Doppler ultrasonic sensors are used in the presented methods. The algorithm developed for recognition of human’s presence in the measured signals is based on detection of the specific acoustic signatures resulting from specific human motion characteristics. These signatures have two characteristic times, T1 (the footstep repetition time, which is equal to the time of the whole body periodic motion) and T2 (the footstep duration time). The footstep duration time is equal to the time interval for a single footstep from “heel strike” to “toe slap and weight transfer.” Taking advantage of these times in signal processing for optimization of the signal‐to‐noise ratio and applying a procedure of cadence frequency detection allow recognition of human presence in the analyzed signals. This algorithm was tested and it was experimentally demonstrated that cadence frequencies for walking human and their harmonics for seismic and ultrasonic signatures (passive and active Doppler signatures) were the same. Cadence frequencies were stable and had no detectable variation in time for a regular walking style. This stability feature potentially may be used for human tracking. [Work supported by the Department of the Army, Army Research Office, Contract No. W911NF‐04‐1‐0190.]

Views of Persons With Schizophrenia on Their Own Disorder: An Italian Participatory Study

This study explored the views of 241 patients with schizophrenia about their own disorder. Patients' knowledge of their diagnosis, confidence that they will be well again, and perception of limitations in their own life as a result of the disorder were explored in relation to patients' opinions about the social consequences of schizophrenia. Study results were presented to participants, and suggestions were collected regarding how these study results should be used. Seventy-two respondents (30%) reported that a psychiatrist told them that they have schizophrenia. Respondents who were confident that they would be well again had a lower duration of contact with psychiatric services and a less pronounced perception of affective and social difficulties related to schizophrenia. Respondents who did not feel limited in their life by the disorder reported less social distance and more optimism about the usefulness of treatments. Participatory studies may provide ideas for a more constructive interaction between patients and professionals.