Free Gait Research Articles

Traumatic Complete Loss of Knee Extensor Mechanism and Its Reconstruction With a Fresh-frozen Patellar Allograft With Patellar and Quadriceps Tendon.

We report on an 18-year-old female who sustained complete loss of her knee extensor mechanism (patella, quadriceps and patellar tendon) due to a motorbike injury with severe soft tissue loss of the ventral aspect of the knee and subsequent infection. After infection control and successful latissimus dorsi free flap surgery, reconstruction of the knee extensor mechanism was performed using a fresh frozen extensor mechanism allograft with patella, quadriceps- and patellar tendon and integrated tibia tuberosity fragment. After a follow-up of 18 months, there was infection free integration of the allograft with a range of motion 0-0-90° (extension/flexion) and pain free gait.

Role of tear size and tendon degeneration for development of pain in rat models of rotator cuff tear

BackgroundRotator cuff tear (RCT) is a frequent etiology of shoulder pain and disability; however, the triggers for the onset and aggravation of pain remain obscure. In this study, we established novel rat RCT models to examine the impact of tear size and tendon degeneration on pain. MethodsFifty-five adult male Sprague-Dawley rats were allocated into 4 study groups: large tear (L group, n=10); small tear (S group, n=15); small tear with scratching (S+ group n=15); sham surgery (sham group, n=15). Pain-related behaviors were evaluated by weight distribution of forelimbs during a 5-minute free gait using a dynamic weight-bearing apparatus at 2, 4, 6 and 8 weeks. Calcitonin gene-related peptide (CGRP) expressions in ipsilateral dorsal root ganglion (DRG) neurons of C4/5/6 were evaluated at 4 and 8 weeks. The area of scar tissues around the torn tendon, infiltration of inflammatory cells, and severity of tendon degeneration (modified Bonar score) were histologically assessed at 4 and 8 weeks. Additionally, enzyme-linked immunosorbent assay (ELISA) was conducted to evaluate the levels of cyclooxygenase-2 (COX-2) and nerve growth factor (NGF) expression in torn tendons and surrounding tissues at 4 weeks. ResultsThe weight distribution ratio (ipsilateral /contralateral side) was significantly decreased in the L and S+ group compared with its baseline and sham group (P<0.05), but the S group showed no significant difference compared with the Sham. The ratio of CGRP-immunoreactive neurons in the DRGs was significantly higher in the L and S+ groups than in the S and sham groups. The histological assessment indicated that scar tissue formation was more extensive in the L group than in the S and S+ groups. Still, there was no significant difference between the S and S+ groups. The Modified Bonar Score was considerably higher in the S+ group than in the S group. Furthermore, ELISA analysis demonstrated no significant disparity in COX-2 levels between the groups; however, NGF levels were substantially higher in the S+ group than in the S and sham groups. ConclusionThe present study provides compelling evidence that large RCT is strongly associated with heightened pain severity in a rat mode. Nevertheless, even a small tear can significantly aggravate pain when the torn tendon is degenerated. CGRP upregulation driven by peripheral NGF possibly played a pivotal role in the genesis and exacerbation of pain in small RCT.

Free Gait Generation of Quadruped Robots via Impulse-Based Feasibility Analysis

Online gait adaptation is crucial for improving the dynamic performance of quadruped locomotion systems, while current approaches often adopt the predefined periodic gait pattern. This article proposes a free gait generation algorithm that only takes the robot state as input. Specifically, we introduce the feasible impulse polytope, which takes into account both linear and angular momentum impulses acting on the body in a prediction horizon. This naturally leads us to formulate a leg capability metric related to the effect of take-off and touch-down on the body motion. Then, gait sequence, take-off timing, and touch-down location can be automatically adjusted online as long as a metric threshold is given. To cope with rough terrain, a series of quadratic programming problems are established for online pose optimization under mild assumptions. Furthermore, we fully integrate the proposed algorithms with the robot control and estimation framework for real-time implementation. We first validate our approach with the quadruped robot SCIT-Dog through locomotion with speed changes, on stairs and slopes, and under lateral disturbances. Besides, a push-recovery experiment is established to show the superiority of the proposed approach over the baseline method with prespecified gait patterns. Experiment results verify the ability of the proposed algorithms to achieve autonomous gait transitions in response to various emergencies.

A Model Free Gait Recognition using Random Forest Method

This paper presents an approach for model free gait recognition using supervised learning. The method involves utilizing gait entropy images (GEnIs) as features to represent gait information. These GEnI are generated by calculating entropy for individual pixels within silhouettes throughout a full gait cycle. To enhance the robustness of gait recognition, we introduce the inclusion of view angle information, which corresponds to the perspective from which the gait sequence is captured. This additional feature is combined with the GEnI in order to create a comprehensive representation. In scenarios such as real-time CCTV footage, the view angles are frequently unknown. To address this, we propose a two phase algorithm. In the first phase, we predict the view angle of a gait sequence. This prediction is achieved by training a random forest classifier. Once the predicted angle feature is obtained, it is integrated with the GEnI feature. Subsequently, in the second phase, another random forest classifier is trained for gait recognition based on this combined feature set. The capabilty of the proposed approach is assessed through experiments performed on public dataset CASIA-B. Experimental outcomes and comparison with the state-of-the-art provide substantial evidence supporting the effectiveness of our approach. In a cross-walking scenario, we attain accuracies of 95.91% for regular walking, 62.21% for walking while carrying a bag, and 27.64% for walking while wearing a coat.

Hierarchical Free Gait Motion Planning for Hexapod Robots Using Deep Reinforcement Learning

This paper addresses the problem of legged locomotion in unstructured environments, and a novel Hierarchical multi-contact motion planning method for hexapod robots is proposed by combining Free Gait motion planning and Deep Reinforcement Learning (HFG-DRL). We structurally decompose the complex free gait multi-contact motion planning task into path planning in discrete state space and gait planning in continuous state space. Firstly, the Soft Deep Q-Network (SDQN) is used to obtain the global prior path information in the Path Planner (PP). Secondly, a Free Gait Planner (FGP) is proposed to obtain the gait sequence. Finally, based on the PP and the FGP, the Center-of-Mass (CoM) sequence is generated by the trained optimal policy using the designed Deep Reinforcement Learning (DRL) algorithm. Experimental results in different environments demonstrate the feasibility, effectiveness, and advancement of the proposed method. Videos are shown at <uri xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">http://www.hexapod.cn/hfg-drl.html</uri> .

The contribution of walking speed versus recent stroke to temporospatial gait variability

BackgroundInconsistent results have been reported for temporospatial gait variability after stroke. Given the large differences in gait speed across stroke subjects and relative to healthy controls, it is not clear which changes in temporospatial gait variability can be ascribed to the walking speed during gait evaluation versus the consequences of stroke. Research questionsDoes temporospatial gait variability differ between (1) stroke subjects grouped in clinically-relevant functional ambulation classes, (2) the paretic and non-paretic legs within each class, and (3) stroke and healthy subjects after controlling for gait speed? MethodsStroke subjects were evaluated at their comfortable speed < 2 months post-onset and classified into the household (<40 cm/s, n = 38), limited-community (40–80 cm/s, n = 35), and full-community (>80 cm/s, n = 14) walkers. Coefficients of variation (CVs) for paretic and non-paretic stance, initial double-support, and single-support times, step length, step cadence, and step width were compared across the stroke ambulation classes and between the two legs. For the parameters with significantly different CVs between stroke subjects and 33 age-matched controls walking at very-slow and free speeds, a 1-way ANCOVA was used with the gait speed as a covariate. ResultsFor most step parameters, CVs were greater in slower stroke ambulation classes except for the smaller step width CV. The differences between the paretic and non-paretic legs emerged in slower walkers only. After controlling for the gait speed, CVs of stroke subjects no longer significantly differed from controls walking at very-slow speed. With controls walking at free speed, however, CVs for the paretic and non-paretic single-support times and the non-paretic step time remained significantly different. SignificanceGait is more variable at slower speeds both in stroke subjects and healthy controls. After accounting for the free gait speed, the increased variability of only a few temporal parameters may be attributed to a recent stroke.

Experience of using gait adaptability training in medical rehabilitation of patients after cerebrovascular accident in the late recovery period

The article presents the treatment data of 80 patients who had an ischemic stroke with movement disorders in the form of hemiparesis with increased muscle tone in the lower limb due to spasticity. The patients were divided into 2 groups comparable in terms of clinical and functional characteristics: group 1 included patients who, in addition to standard treatment, had gait adaptability training with video reconstruction on the C–Mill biofeedback system (BFB), and group 2 consisted of 40 people who underwent a course of standard drug therapy and medical rehabilitation (exercise therapy and medical massage). The characteristics of the main static and locomotor parameters were assessed according to the C–Mill data and the Tinetti assessment tool, and the range of motion in the lower extremities was assessed according to goniometry data at all control points (before and after treatment, 3 and 6 months after treatment). The obtained data indicate the benefit of including gait adaptability training in the standard complex of medical rehabilitation of patients who have undergone acute cerebrovascular accident with motor disorders in the form of hemiparesis with post-stroke spasticity of the lower extremity. This was confirmed by the normalization of the parameters of the gait adaptability, namely, a decrease in the duration of free gait (step cycle) by an average of 32 %, an increase in the frequency of a free gait step by an average of 30 % and in the length of a free gait step by 16 % immediately after treatment, with the results maintained at all control points.

Virtual Breathalyzer: Towards the Detection of Intoxication Using Motion Sensors of Commercial Wearable Devices.

Driving under the influence of alcohol is a widespread phenomenon in the US where it is considered a major cause of fatal accidents. In this research, we present Virtual Breathalyzer, a novel approach for detecting intoxication from the measurements obtained by the sensors of smartphones and wrist-worn devices. We formalize the problem of intoxication detection as the supervised machine learning task of binary classification (drunk or sober). In order to evaluate our approach, we conducted a field experiment and collected 60 free gait samples from 30 patrons of three bars using a Microsoft Band and Samsung Galaxy S4. We validated our results against an admissible breathalyzer used by the police. A system based on this concept successfully detected intoxication and achieved the following results: 0.97 AUC and 0.04 FPR, given a fixed TPR of 1.0. Our approach can be used to analyze the free gait of drinkers when they walk from the car to the bar and vice versa, using wearable devices which are ubiquitous and more widespread than admissible breathalyzers. This approach can be utilized to alert people, or even a connected car, and prevent people from driving under the influence of alcohol.

Classification of Subjects With Balance Disorders Using 1D-CNN and Inertial Sensors

The article presents the concept of detecting subjects with balance disorders by the use of machine learning techniques. The proposed solution has been developed and tested based on a group of 40 subjects, the group included both patients with uncompensated dysfunction in the vestibular system and healthy volunteers. Presence of dysfunction was verified prior to the study by detailed clinical examination. The data for the study were collected with the use of miniature micromachine sensors, mounted on the body at selected locations. The task performed by the subjects consisted of free gait over a distance of three meters; the task was selected to make it easy to perform in any surroundings and not requiring additional equipment. The collected data was used as an input to an artificial neural network based on a one-dimensional convolution kernel. The proposed solution allows to classify subjects into healthy and non-healthy with an accuracy of 87.5%.

Relationship between gait speed and trunk muscles in frail elderly individuals.

[Purpose] The external and internal abdominal muscles may be related to gait speed; however, this has not yet been elucidated. In this study, we aimed to clarify the relationship between gait speed and trunk muscle thickness in elderly individuals. [Participants and Methods] The participants were 12 elderly individuals (4 males and 8 females, mean age 83.4 years old, SD ± 0.5) that attend a day service center. We measured the 5 m free gait speed, the 5 m fastest gait speed, and the thickness of five trunk muscles (the rectus abdominis [divided into three parts: upper, central, and lower], external oblique, internal oblique, transverse abdominis, and iliopsoas muscles). [Results] There were positive correlations between the free gait speed and the thickness of the lower rectus abdominis, internal oblique, and transverse abdominis muscles. There were also positive correlations between the fastest gait speed and the thickness of the lower rectus abdominis, internal oblique, and transverse abdominis muscles. [Conclusion] Incorporating muscle strength training of the lower rectus abdominis, internal oblique, and transverse abdominis muscles into existing lower limb muscle training protocols is important to effectively maintain the gait speed of elderly individuals.

Validity and sensitivity of instrumented postural and gait assessment using low-cost devices in Parkinson\u2019s disease

BackgroundAccurate assessment of balance and gait is necessary to monitor the clinical progress of Parkinson’s disease (PD). Conventional clinical scales can be biased and have limited accuracy. Novel interactive devices are potentially useful to detect subtle posture or gait-related impairments.MethodsPosturographic and single and dual-task gait assessments were performed to 54 individuals with PD and 43 healthy controls with the Wii Balance Board and the Kinect v2 and the, respectively. Individuals with PD were also assessed with the Tinetti Performance Oriented Mobility Assessment, the Functional Gait Assessment and the 10-m Walking Test. The influence of demographic and clinical variables on the performance in the instrumented posturographic and gait tests, the sensitivity of these tests to the clinical condition and phenotypes, and their convergent validity with clinical scales were investigated.ResultsIndividuals with PD in H&Y I and I.5 stages showed similar performance to controls. The greatest differences in posture and gait were found between subjects in H&Y II.5 and H&Y I–I.5 stage, as well as controls. Dual-tasking enhanced the differences among all groups in gait parameters. Akinetic/rigid phenotype showed worse postural control and gait than other phenotypes. High significant correlations were found between the limits of stability and most of gait parameters with the clinical scales.ConclusionsLow-cost devices showed potential to objectively quantify posture and gait in established PD (H&Y ≥ II). Dual-tasking gait evaluation was more sensitive to detect differences among PD stages and compared to controls than free gait. Gait and posture were more impaired in akinetic/rigid PD.

Free gait in a shallow pool accelerates recovery after exercise in model mice with fibromyalgia.

This study aimed to determine the effect of pool gait exercise using fibromyalgia-induced model mice. The sensory threshold, locomotive behavior, electrocardiogram, and onset time after the gait test in shallow water using male C57BL/6J mice (weight, 30–35 g; n=21) were investigated. To induce fibromyalgia in model mice, reserpine was injected intraperitoneally into wild-type mice once a day for 3 days. Subsequently, the fibromyalgia-induced model mice were randomly classified into two groups as follows: the control group (n=11) and the pool gait group (n=10). The mice in the pool gait group walked in the same cage containing shallow warm water 5 times per week. Both groups underwent sensory thresholds and video recordings to determine locomotive behaviors weekly. Further, both heart rate and video recordings for observation of a recovery after the gait test in shallow water were undertaken (control group; n=5, pool gait group; n=5). The pool gait did not affect sensory thresholds and locomotive behavior; however, in the pool gait group, both the recovery after the test, such as onset time and gait distance, were considerably better than those of the control group. Furthermore, changes in heart rate and heart rate irregularity after the test were more apparent in the control group than in the pool gait group. The free gait in a shallow pool accelerated recovery after exercise, unlike the sensory threshold.

Excessive exercise induces cardiac arrhythmia in a young fibromyalgia mouse model.

Fibromyalgia patients experience cardiovascular complications in addition to musculoskeletal pain. This study aimed to investigate the cardiac effects of a prolonged shallow water gait in a fibromyalgia-induced young mouse model. To produce a fibromyalgia mouse model, wild-type mice were administered an intraperitoneal injection of reserpine once a day for three days, and two primary experiments were performed. First, three types of gait tests were performed before and after the reserpine injections as follows: (i) 5 minutes of free gait outside the water, (ii) 1 minute of free gait in shallow warm water, and (iii) 5 minutes of free gait in shallow warm water. Second, electrocardiogram recordings were taken before and after the three gait tests. The average heart rate and heart rate irregularity scores were analyzed. Exercise-induced cardiac arrhythmia was observed at 1-minute gait in shallow water during the acute stage of induced FM in young mice. Further, both cardiac arrhythmia and a decrease in HR have occurred at 5-minute gait in shallow water at the same mice. However, this phenomenon was not observed in the wild-type mice under any test conditions. Although a short-term free gait in shallow warm water may be advantageous for increasing the motor activity of FM-model mice, we should be aware of the risk of prolonged and excessive exercise-induced cardiac arrhythmia. For gait exercises in shallow water as a treatment in FM patients. We suggest a gradual increase in exercise duration may be warranted.

Polymer Optical Fiber-Based Integrated Instrumentation in a Robot-Assisted Rehabilitation Smart Environment: A Proof of Concept.

Advances in robotic systems for rehabilitation purposes have led to the development of specialized robot-assisted rehabilitation clinics. In addition, advantageous features of polymer optical fiber (POF) sensors such as light weight, multiplexing capabilities, electromagnetic field immunity and flexibility have resulted in the widespread use of POF sensors in many areas. Considering this background, this paper presents an integrated POF intensity variation-based sensor system for the instrumentation of different devices. We consider different scenarios for physical rehabilitation, resembling a clinic for robot-assisted rehabilitation. Thus, a multiplexing technique for POF intensity variation-based sensors was applied in which an orthosis for flexion/extension movement, a modular exoskeleton for gait assistance and a treadmill were instrumented with POF angle and force sensors, where all the sensors were integrated in the same POF system. In addition, wearable sensors for gait analysis and physiological parameter monitoring were also proposed and applied in gait exercises. The results show the feasibility of the sensors and methods proposed, where, after the characterization of each sensor, the system was implemented with three volunteers: one for the orthosis on the flexion/extension movements, one for the exoskeleton for gait assistance and the other for the free gait analysis using the proposed wearable POF sensors. To the authors’ best knowledge, this is the first time that optical fiber sensors have been used as a multiplexed and integrated solution for the simultaneous assessment of different robotic devices and rehabilitation protocols, where such an approach results in a compact, fully integrated and low-cost system, which can be readily employed in any clinical environment.

Research on gait planning of Hexapod wheel legged robot based on STM32 single chip microcomputer

In this paper, the rectangular wheel legged hexapod robot is used as the experimental robot, the STM32 single-chip microcomputer is used as the main control core, the steering control board is used as the auxiliary board, the upper computer programming is used to write the action group of the hexapod robot, the command is sent to the single-chip microcomputer through the PS2 handle, the single-chip microcomputer controls the steering board to achieve the corresponding action group, and the Arduino control board is used to change the environment through the sensor in the later stage The control of action group can be realized by the detection. In addition, in order to solve the gait planning problem of hexapod robot and realize the optimal learning of robot’s free gait on specific terrain, based on the discretization of the robot’s single foot distance, integrating the time rhythm principle of CPG model and the space rule constraint mechanism of reflection model, a discrete gait model of Hexapod robot is constructed. Ant colony algorithm is used to study the gait path planning of the robot. MATLAB and C language technology are used to realize the simulation of the gait planning of the hexapod robot.

Effect of preferred walking speed on the upper body range of motion and mechanical work during gait before and after spinal fusion for patients with idiopathic scoliosis

BackgroundScoliosis may have an effect on gait parameters, the kinematics of the lower limbs and the spine, and mechanical work with specific gait speed. Imposed gait speed may influence these effects. Following spinal fusion in the case of idiopathic scoliosis, patients fear subsequent and considerable back stiffness and kinetic consequences. The aim of this retrospective study was to evaluate the upper body range of motion and mechanical work before and after spinal fusion in of free gait speed conditions. MethodsTwenty-two patients with idiopathic scoliosis and twenty-two asymptomatic controls were included. Patients were analyzed before and one year after spinal fusion. Based on full body modeling and motion capture, we measured gait speed, cadence, stride length, the mobility of the upper and lower spinal segments (in each plane), and mechanical work (with and without dimensionless scaling strategy). FindingsPatients walked significantly slower than controls. The same speed was noticed before and after fusion. Only the lower back kinematics in the frontal plane was reduced before fusion. Spinal fusion further reduced the mobility of the pelvis segment in the sagittal plane in comparison to controls. Scaling external work was associated with higher values for patients. InterpretationSpinal fusion improves pelvic and thorax-pelvis mobility (during the stance phase) in the frontal plane. The impact of scoliosis on the upper body range of motion was limited on the thorax-pelvis, corresponding to a stiffening effect. With such restrictions, an increase in normalized external work was observed for similar normalized internal work.

A free gait controller designed for a heavy load hexapod robot

As macroscopic rough terrains are time varying and full of local topographic mutations, stable locomotions of legged robots moving through such terrains in a fixed gait form can be hardly obtained. This problem becomes more severe as the size and weight of the robot increase. An ideal pre-planned gait changing method can also be hardly designed due to the same limitations. Aiming to solve the problem, a new kind of free gait controller applied to a large-scale hexapod robot with heavy load is developed. The controller consists of two parts, a free gait planner and a gait regulator. Based on the observed macro terrain changes, the free gait planner adopts the macro terrain recognition method and the status searching method for selecting the best leg support status automatically. The gait regulator is adopted for the correction of the selected status to cope with local topographic mutations. Detailed simulation experiments are presented to demonstrate that, with the designed controller, the adopted hexapod robot can change moving gaits automatically in terms of the terrain conditions and obtain stable locomotions through rough terrains.

Generation of a continuous free gait for quadruped robot over rough terrains

ABSTRACTGenerating a robust gait is one of the most important factors to improve the adaptability of quadruped robots on rough terrains. This paper presents a new continuous free gait generation method for quadruped robots capable of walking on the rough terrain characterized by the uneven ground and forbidden areas. When walking with the proposed gait, the robot can effectively maintain its stability by using the Center of Gravity (COG) trajectory planning method. After analyzing the point cloud of rough terrain, the forbidden areas of the terrain can be obtained. Based on this analysis, an optimal foothold search strategy is presented to help quadruped robot to determine the optimum foothold for the swing foot automatically. In addition, the foot sequence determining method is proposed to improve the performance of robot. With the free gait proposed in this paper, quadruped robot can walk through the rough terrains automatically and successfully. The correctness and effectiveness of the proposed method is verified via simulations.

Free Gait Planning for a Hexapod Robot Based on Reinforcement Learning

Free Gait Planning for a Hexapod Robot Based on Reinforcement Learning

Wpływ nadruchomości stawu podskokowego na obciążenie układu mięśniowo-szkieletowego stopy podczas chodu swobodnego – przegląd literatury

ENWEndNote BIBJabRef, Mendeley RISPapers, Reference Manager, RefWorks, Zotero AMA Łukasik E, Kapiński N, Mioduszewski A, Wychowański M, Wit A. Effects of subtalar joint hypermobility on load-bearing capability of the musculoskeletal system of the foot during free gait- literature review. Advances in Rehabilitation. 2018;32(3):37-44. doi:10.5114/areh.2018.80968. APA Łukasik, E., Kapiński, N., Mioduszewski, A., Wychowański, M., & Wit, A. (2018). Effects of subtalar joint hypermobility on load-bearing capability of the musculoskeletal system of the foot during free gait- literature review. Advances in Rehabilitation, 32(3), 37-44. https://doi.org/10.5114/areh.2018.80968 Chicago Łukasik, Edyta, Norbert Kapiński, Andrzej Mioduszewski, Michał Wychowański, and Andrzej Wit. 2018. "Effects of subtalar joint hypermobility on load-bearing capability of the musculoskeletal system of the foot during free gait- literature review". Advances in Rehabilitation 32 (3): 37-44. doi:10.5114/areh.2018.80968. Harvard Łukasik, E., Kapiński, N., Mioduszewski, A., Wychowański, M., and Wit, A. (2018). Effects of subtalar joint hypermobility on load-bearing capability of the musculoskeletal system of the foot during free gait- literature review. Advances in Rehabilitation, 32(3), pp.37-44. https://doi.org/10.5114/areh.2018.80968 MLA Łukasik, Edyta et al. "Effects of subtalar joint hypermobility on load-bearing capability of the musculoskeletal system of the foot during free gait- literature review." Advances in Rehabilitation, vol. 32, no. 3, 2018, pp. 37-44. doi:10.5114/areh.2018.80968. Vancouver Łukasik E, Kapiński N, Mioduszewski A, Wychowański M, Wit A. Effects of subtalar joint hypermobility on load-bearing capability of the musculoskeletal system of the foot during free gait- literature review. Advances in Rehabilitation. 2018;32(3):37-44. doi:10.5114/areh.2018.80968.