Stable Walking Research Articles

Vision, cognition, and walking stability in young adults

Downward gazing is often observed when walking requires guidance. This gaze behavior is thought to promote walking stability through anticipatory stepping control. This study is part of an ongoing effort to investigate whether downward gazing also serves to enhance postural control, which can promote walking stability through a feedback/reactive mechanism. Since gaze behavior alone gives no indication as to what information is gathered and the functions it serves, we aimed to investigate the cognitive demands associated with downward gazing, as they are likely to differ between anticipatory and feedback use of visual input. To do so, we used a novel methodology to compromise walking stability in a manner that could not be resolved through modulation of stepping. Then, using interference methodology and neuroimaging, we tested for (1) interference related to dual tasking, and (2) changes in prefrontal activity. The novel methodology resulted in an increase in the time spent looking at the walking surface. Further, while some dual-task interference was observed, indicating that this gaze behavior is cognitively demanding, several gaze parameters pertaining to downward gazing and prefrontal activity correlated. These correlations revealed that a greater tendency to gaze onto the walking surface was associated with lower PFC activity, as is expected when sensory information is used through highly automatic, and useful, neural circuitry. These results, while not conclusive, do suggest that gazing onto the walking surface can be used for purposes other than anticipatory stepping control, bearing important motor-control and clinical implications.

Hybrid Metric K-Nearest Neighbor Algorithm and Applications

The K-Nearest Neighbor (KNN) algorithm is a classical machine learning algorithm. Most KNN algorithms are based on a single metric and do not further distinguish between repeated values in the range of K values, which can lead to a reduced classification effect and thus affect the accuracy of fault diagnosis. In this paper, a hybrid metric-based KNN algorithm is proposed to calculate a composite metric containing distance and direction information between test samples, which improves the discriminability of the samples. In the experiments, the hybrid metric KNN (HM-KNN) algorithm proposed in this paper is compared and validated with a variety of KNN algorithms based on a single distance metric on six data sets, and an HM-KNN application method is given for the forward gait stability control of a bipedal robot, where the abnormal motion is considered as a fault, and the distribution of zero moment points when the abnormal motion is generated is compared. The experimental results show that the algorithm has good data differentiation and generalization ability for different data sets, and it is feasible to apply it to the walking stability control of bipedal robots based on deep neural network control.

Flexible gait transition for six wheel-legged robot with unstructured terrains

The flexibility of gait and trajectory planning with heavy payload are the main challenges for legged stable walking of hexapod robots in unstructured terrain, especially in time-varying and local terrain mutation conditions. To guarantee adaptability in unstructured terrain environment, the factors, including the obstacle height, terrain depth, and secure foothold as well as stability state, should be considered in the gait and trajectory planning. In this article, a novel gait transition hierarchical control framework based on a flexible gait planner (FGP), and gait feedback regulator (GFR) with behavior rules is proposed for the developed hexapod wheel-legged robot (BIT-6NAZA). The core of this gait planner is to select the optimal footholds and change gait types according to secure foothold and stability margin and kinematic margin of legs, and the GFR is applied to modify the foot-end trajectory of the selected gait according to the terrain feedback information to adapt to unstructured terrain. Finally, taking BIT-6NAZA robot as an example, the simulation and experiment are carried out under the proposed control framework. The co-simulation and experimental results show that the robot can modify the foot-end trajectory in dynamic unstructured terrain and obtain elastic gait in obstacle avoidance.

Functional activity and communication-social ability of youths with developmental disabilities: a qualitative study.

[Purpose] To describe the functional activity and the communication-social ability levels of youths with developmental disabilities and to determine whether demographic factors predict these levels. [Participants and Methods] A mixed, observational and qualitative, study in which parents of students with developmental disabilities were interviewed based on the WeeFIM questions. Both quantitative and qualitative data were analysed. [Results] Data were collected for 30 youths with mild to severe developmental disabilities with mean age 18.5 ± 2.7 years (19 males). Mean WeeFIM total score was 106.2 ± 10.9, indicating relatively high functional and communication-social ability. No significant difference was observed for the total WeeFIM score between males and females and between adolescents and young adults with developmental disabilities. Main themes emerged from the interviews were: Difficulties with smooth and stable walking, transfers to/from bathtub and stairs. Also, youths are expressing a need for independence in self-care, while relationships with their peers are difficult and problems are primarily solved with help from their parents. [Conclusion] Despite the high functional and communication-social ability levels of a group of youths with developmental disabilities, parents revealed that youths had certain difficulties. Therapy should address such difficulties to promote independence and participation of these young people in the community.

Humanoid Biped Robot Locomotion via Quadratic Programming with Compound Constraints

This paper introduces a quadratic programming-based stable motion control method for humanoid robots. This method is based on the virtual model and the optimal force distribution. We added a six-dimensional mixed constraint on the sole of the foot to prevent the robot from sliding and overturning. At the same time, a more comprehensive swing planning and pre-touchdown planning were added when the robot's legs were swinging to improve the stability of the robot's walking on the ground. Finally we verified the algorithm in the robot simulation software and proved the feasibility of the algorithm.

Reinforcement Learning-Based Cascade Motion Policy Design for Robust 3D Bipedal Locomotion

This paper presents a novel reinforcement learning (RL) framework to design cascade feedback control policies for 3D bipedal locomotion. Existing RL algorithms are often trained in an end-to-end manner or rely on prior knowledge of some reference joint or task space trajectories. Unlike these studies, we propose a policy structure that decouples the bipedal locomotion problem into two modules that incorporate the physical insights from the nature of the walking dynamics and the well-established Hybrid Zero Dynamics approach for 3D bipedal walking. As a result, the overall RL framework has several key advantages, including lightweight network structure, sample efficiency, and less dependence on prior knowledge. The proposed solution learns stable and robust walking gaits from scratch and allows the controller to realize omnidirectional walking with accurate tracking of the desired velocity and heading angle. The learned policies also perform robustly against various adversarial forces applied to the torso and walking blindly on a series of challenging and unstructured terrains. These results demonstrate that the proposed cascade feedback control policy is suitable for navigation of 3D bipedal robots in indoor and outdoor environments.

The Effects of Ship’s Roll Motion on the Center of Mass and Margin of Stability During Walking: A Simulation Study

Walking strategies in an unstable environment like a ship differ from walking on stable ground. Extreme ship motions may endanger the safety of the crews. Notably, a loss of balance on board can lead to an injury or an accident of falling off a ship. Keeping one’s balance on board a ship is strongly influenced by the ship’s motion. Therefore, the objective of this study is to determine how walking on a ship differs from walking in a stable environment and explore the effects of the ship’s roll motion on balance control and stability while walking in sea environments. We hypothesized that step time variability, center of mass (COM), and margin of stability (MOS) would significantly differ between stable and unstable walking conditions. We also hypothesized that there would be an effect of rolling cycles and angles on increasing step time variability, COM excursion, and MOS variability. We recruited 30 healthy individuals between 21 and 39 years old for this study. Participants walked for two minutes at their self-selected speeds during the study with and without rolling on a computer-assisted rehabilitation environment (CAREN) system. The CAREN system was used to simulate the parametric roll motion of ships up to 20 degrees. This study quantified step time variability, peak COM excursion, and MOS variability in different rolling conditions. We found a significant difference in step time variability (p < 0.001), lateral peak COM excursion (p < 0.001), and MOS variability (p < 0.001) between waking on land and walking at sea.

Walking dynamics for an ascending stair biped robot with telescopic legs and impulse thrust

&lt;abstract&gt;&lt;p&gt;In this study, an ascending stair biped robot model with impulse thrust is presented. The biped robot contains a hip joint and two legs with massless telescoping actuator. Impulse thrust is applied at the ankle joint of robot's stance leg to simulate the forward push-off of the ankle during human walking. The nonlinear ascending stair biped model is linearized and a discrete map is obtained. The conditions for the existence and stability of period-1 gait are obtained by means of this discrete map. The expressions of torques to ensure robot walking are derived and Flip bifurcation is investigated. Numerical simulations, such as phase diagram of period-1, 2, 4 gaits and bifurcation diagram, are given in an example. Theoretical analysis and numerical results obtained in this study provide a theoretical basis for stable walking of ascending stair biped robot with periodic gaits.&lt;/p&gt;&lt;/abstract&gt;

The walking stability control method of robots based on sensing quantitative fusion tracking

The walking stability control method of robots based on sensing quantitative fusion tracking

A TD-Learning Based Bionic Cerebellar Model Controller For Humanoid Robots

The cerebellum is a crucial component of the human body that plays a vital role in human walking. To design a robot gait controller by referring the working mechanism of the cerebellum is one of the hotspots in the bionic control field. This paper designs a bionic cerebellar motion control model to control the slope gait of a humanoid robot. The cerebellum model refers to the connection method between neurons in a human cerebellum, and expresses from a bionic perspective how the neurons in the cerebellum process external information and generate control commands during walking. Inspired by how human walking is learned, this model employs reinforcement learning in the learning process of the bionic cerebellar model. A corresponding simulation environment is also designed to train and test the cerebellar control model's effectiveness when regulating a robot's slope walking stability. The simulation experimental results demonstrate that the cerebellum model can achieve stable control of the walking motion of the humanoid robot after training, verifying its effectiveness, and laying a foundation for further realization of human-like artificial intelligence.

스마트폰 주시 보행이 시선추적 및 보행 패턴에 미치는 영향

The purpose of this study is to investigate the effect of smartphone gaze walking on gaze tracking and walking patterns. The study subjects measured and compared 8 adults in D Metropolitan City once each of general walking and smartphone gaze walking using eye trackers. The results of this study are as follows. First, there was a statistically significant difference in general walking in step length, double support, step time, and speed compared to smartphone walking (p.05). Second, in general walking, while walking with overall eyes on areas of interest, such as middle → top → bottom → bottom, smartphone walking only looked at the smartphone and walked.BR According to the above results, unlike general walking, smartphone walking appeared unstable in walking mechanisms and walking stability, and eye tracking during walking was indirectly judged that it would be difficult to cope with various situations that may appear when walking by focusing on smartphone without looking forward. Therefore, policy operations such as installing signs, installing crosswalk LEDs, and installing smartphone pedestrian lanes will be important for each country, and efforts should be made to prevent various accidents caused by smartphone use.

The Influence of Historic and Cultural TourismAttribute of a City on Leisure Satisfaction

This research is to reveal the influence of historic and cultural tour attribute of city on leisure satisfaction. A method of research was the empirical study, a survey of 305 visitors, consists of descriptive statistic analysis, exploratory factorial analysis, reliability analysis, validity analysis and multiple regression analysis using SPSS 23.0 for windows. This research was planned to study on whether historic and cultural tour attribute factors can be divided to 5 factors such as spatial environment, historicity, culture, authenticity, walking stability and to discover historic and cultural tour attribute on leisure satisfaction. The result shows the factors of spatial environment, historicity, cultural factor, authenticity, walking stability are positively related to leisure satisfaction. Municipal government has to preserve and develop historic and cultural heritage for citizens and visitors‘ leisure. This research suggests that the historic and cultural heritages should has an effect on the visitors’ leisure satisfaction.

Застосування тест-ортезів на нижні кінцівки для визначення фізичних можливостей та реабілітаційного потенціалу осіб із тяжкими порушеннями функції опори й ходьби

Застосування тест-ортезів на нижні кінцівки для визначення фізичних можливостей та реабілітаційного потенціалу осіб із тяжкими порушеннями функції опори й ходьби

Development of quadruped robot for inspection of underground pipelines in nuclear power plants

Structural integrity of seawater pipelines in nuclear power plants is a very important issue. In accordance with the operating technical guidelines, the human operators directly enter the pipe and inspect it at every maintenance test. However, in this regard, safety issues such as narrow space and harmful gas are emerging every year. In response to these needs, a quadruped robot that can inspect underground pipes and assist workers has been developed. The robot has an articulated robotic arm that can receive an impact sound of hammering a pipe wall to test pipe integrity. The state of the pipe was examined using a Convolutional Neural Network algorithm. On the other hand, moving in a plumbing environment requires stable walking ability. To determine the gait sequence, a hierarchical gait controller is proposed. The hybrid controller, which consists of joint impedance and torque control, calculated from Model Predictive Control, can switch the gait modes comparing the reference and the current foot contact condition at each control cycle.

Adaptive gait planning for quadruped robot based on center of inertia over rough terrain

Controlling the quadruped robot for walking on a rough terrain without any visual perception is a great challenge. In the present study, a simple measuring method is proposed for obtaining the total force applied on the center of inertia of the quadruped robot with force sensing information in the static gait. Based on the zero moment point stable criterion, an extended criterion on the virtual supporting plane is presented to guarantee the stable walking of the quadruped robot. Moreover, an adaptive omnidirectional gait planning is developed for the quadruped robot applying the extended zero moment point on the center of inertia to obtain the stable criterion over rough terrain. It is found that when the proposed gait planning is applied on the quadruped robot, unknown surroundings successfully adapted without establishing the huge height map. Experiments are carried out to investigate walking of the quadruped robot at three different conditions, including the flat, rough terrain, and rough slope. It is concluded that the proposed method has reasonable performance in the studies case.

Nonlinear analysis of dynamic stability in walking with toe-only rocker sole shoes in elderly

BackgroundElderly subjects are at the risk of falling. One type of shoe intervention used for this group of the subjects is the shoe with rocker. The aim of this study was to investigate the effects of shoes with various degrees of rockers on dynamic stability of elderly subjects while walking. Method15 elderly subjects were recruited in this study. A motion analysis system was used to record the motions of body while walking on a treadmill. The local dynamic stability (LDS) was evaluated based on use of Lyapunov exponent of center of mass (COM) movement. The subjects were asked to walk barefoot, with shoe with no rocker and with shoe with various rockers (10, 20, 30 and 40°). ResultsThe mean values of LDS (λmax-S) in anteroposterior direction were 0.95 ± 0.46, 0.78 ± 0.51 and 0.74 ± 0.54 in bare foot, shoes with no rocker and shoe with 10° rocker, respectively. The mean value of LDS (λmax-S) in vertical direction varied between 1.21 and 1.23. There was no significant difference between LDS of elderly subjects while walking with shoes with various rocker angles. DiscussionUse of shoes with various rocker angles dose not influence on dynamic stability of elderly subjects while walking. Therefore, it is recommended to use this kind of shoe intervention for other trapeutic purposes.

Applying Grey Relational Analysis in the Evaluation of the Balance of Children with Intellectual Disability

In addition to intellectual performance, children with intellectual disability also seem to have lower performance than children without intellectual disability in terms of balance. Therefore, they often experience walking instability or fall due to imbalance, causing injuries. With regard to balance training courses provided by medical or special education personnel for children with intellectual disability, although there are subjective observation scales that describe their balance in a qualitative way, there are still few direct measurement methods that can provide personnel with the ability to evaluate the training results of an intervention program. The purpose of this study was to provide a method for evaluating the balance of children with intellectual disability to facilitate a general inspection or evaluation of balance before and after the implementation of various intervention programs that help movement development. In recent years, the force platform system has been widely used in the research of the elderly balance, yet the research on balance assessment tools applied to children is rare. This study used the objective, fast, and accurate characteristics of the force platform system to analyze the key points of the sit-to-stand movement and the movement balance parameters of children with intellectual disability and children without intellectual disability. Using the grey relational analysis (GRA) method, the time factors and weight factors from the average performance of children without intellectual disabilities was used as the analysis data. After analyzing the relevance between each participant and the target, a norm for evaluating the balance of children with intellectual disability was established. Hence, this valuable result can provide researchers, special education teachers, and related professionals with an effective and time-saving evaluation of the balance of children with intellectual disability.

Sensorimotor outcomes in adrenomyeloneuropathy show significant disease progression.

Current outcomes used to evaluate adrenomyeloneuropathy are limited by rater bias, not sensitive to preclinical changes, and require years to decades to detect disease progression. Quantitative outcomes are needed that detect meaningful change in a short time period over a broad range of disability. The study aim was to track sensorimotor outcomes in adults with adrenomyeloneuropathy and evaluate differences in progression between men and women. This prospective observational cohort study analyzes data collected annually in the Phase III study of adults with adrenomyeloneuropathy. Outcomes include postural sway in four static standing conditions, great-toe vibration, hip strength, walking velocity, timed up-and-go, and 6-minute walk distance. Linear mixed model analysis was used to detect change in the outcomes in 2 years, correcting for age, sex, disability, symptom duration, and treatment across the cohort. Modeling was repeated for each sex to evaluate differences. Power computations were carried out by sex and for the full dataset. Sixty-one men and 87 women participated. Average age, 46 ± 12 years; Expanded Disability Status Scale, 3 (1-6.5); symptom duration, 10.8 ± 9.4 years. The cohort showed significant worsening in all standing conditions (P < .001), sensation (P=.0223) and strength (P=.001); but more stability in walking with only velocity (P < .0337) significantly declining. For each sex, postural sway declines significantly in all conditions (P < .01) except for eyes closed feet together for women. Strength declines significantly by sex for hip flexion (P < .03). Sex-specific significant decline is seen in walking (velocity P=.0276; distance P=.0072) for men only. Quantitative measures of postural sway, sensation strength, and walking are effective measures of adrenomyeloneuropathy progression in 2 years.

Postural balance and running technique: is there a relationship? Review article

Purpose: to determine the existence of a relationship between the development of muscles responsible for postural balance in a person and running efficiency.Research methods. A literature search was carried out using data from Scopus, Web of Science Core Collection and Pub Med. 40 sources were selected for analysis. Preference was given to works published in publications with a Q1 - Q2 rating.Results. Different sports have different requirements for a person's postural stability. The postural balance is of the greatest importance for the representatives of football, hockey, basketball. Running is the basis of many sports. Therefore, the study of postural balance during running loads is the basis for understanding the mechanisms of maintaining dynamic balance. There is currently research showing that jogging alone improves postural balance. It has also been shown that strengthening the muscles responsible for the postural balance of a person increases the stability of walking and running. The dynamic and static postural balance is influenced by aerobic fatigue, as well as accumulated fatigue in the annual training cycle of athletes. Deterioration of the work of the muscles responsible for the postural balance of a person can lead to injuries, diseases, and also limit the achievement of high sports results in running.Conclusions. This is one of the first studies of postural balance in running. In the work, data will be obtained on the positive influence of the development of postural balance (with the use of exercises for strengthening muscles - local stabilizers, balance exercises) on the running technique and the functional state of runners.

Automated prescreening of MCI through deep learning models based on wearable inertial sensors data

AbstractBackgroundDuring mild cognitive impairment (MCI), a precursor of dementia, often the mild symptoms go unnoticed and are assumed as normal aging signs by elderly people, resulting in late diagnosis and progression to dementia. Recently, several studies investigated the potential of behavioral analysis (ADL assessment, speech analysis etc.) based biomarkers for automated early screening of MCI in home settings. In this work, different deep learning models with walking data have been examined and a 2D‐CNN‐GRU model for automatic diagnosis of MCI based on wearable inertial sensors gait data is proposed.MethodSixty subjects (30 Cognitively Normal‐CN and 30 MCI) recruited from National Research Center of Dementia Database, Gwangju, South Korea, underwent comprehensive medical assessments by Chosun hospital doctors. The gait data of each participant was recorded using Shimmer3 inertial sensors under dual‐task settings. The subjects wore 7 shimmer3 sensors at five different body locations, i.e. waist, each thigh, each shank and each foot and performed 5 trials of dual‐task walking. For each experiment trials, the subject walked straight 10m and returned 10m while naming animals, food, fruits, colors and plants. Out of 10 meters, the central 6m stable walking signals were extracted and used for post processing. A total of eight features utilized for deep learning models’ training were, angular velocity along each axis of tri‐axial gyroscope sensor, 3‐axis acceleration data, and the signal vector magnitude of both sensors. In order to learn the gait pattern and time series characteristics for each step, the proposed model was built using six Convolutional Neural Networks‐(CNNs) as input for three Gated Recurrent Units‐(GRUs). Finally, the Leave One subject Out (LOO) Cross‐Validation (CV) was used to report the model's performance.ResultAs compared to individual representative deep learning models, the proposed combined model 2D‐CNN‐GRU proved to be more effective in MCI detection by learning discriminating walk signal characteristics and achieved Sensitivity 83.33%, Accuracy 73.33 % and Specificity 63.34% (Refer Table below).ConclusionThis research work is the pioneer to investigate deep learning approaches for MCI diagnostic research using inertial sensor data and has the potential to facilitate early detection of MCI in home settings.