scholarly journals Research on Kinematic Parameters of Multiple Gait Pattern Transitions

2021 ◽  
Vol 11 (15) ◽  
pp. 6911
Author(s):  
Chaoyue Guo ◽  
Yali Liu ◽  
Qiuzhi Song ◽  
Shuting Liu
Keyword(s):  
Angular Velocity ◽  
Sagittal Plane ◽  
Gait Recognition ◽  
Angular Acceleration ◽  
Gait Pattern ◽  
Kinematic Parameters ◽  
Gait Patterns ◽  
Time Points ◽  
Axis Direction ◽  
Significant Difference

Gait recognition technology is the key technology in the field of exoskeletons. In the current research of gait recognition technology, there is less focus on the recognition of the transition between gait patterns. This study aims to determine which kinematic parameters have significant differences in the transitions (between level and stair walking and between level and ramp walking) of different gait patterns, to determine whether these parameters change differently in different gait pattern transitions, and the order the significant differences occur through a comparative analysis of various kinematic parameters between the transition stride and the before stride in the former pattern. We analyzed 18 parameters concerning both lower limbs and trunk. We compared each time point of the transition strides to the corresponding time points of the before stride using a series of two-sample t-tests, and we then evaluated the difference between the transition stride and the before stride based upon the number of time points within the gait cycle that were statistically different. We found that the sagittal plane angular velocity and the angular acceleration of all joints and the resultant velocity of the thigh and shank of the leading limb had significant differences in the process of transition; the sagittal plane angular velocity of all joints of the trailing limb and the velocity of the trunk in the coronary axis direction also showed a significant difference. The angular acceleration of all joints, the sagittal plane angular velocity of the ankle joint of the leading limb, and the acceleration of the trunk in the coronal axis direction showed a difference in the early stage of the transition. In general, the leading limb had a significant difference earlier than the trailing limb, and the acceleration parameters changed earlier than the velocity parameters. These parameters showed different combinations of changes in the transition of different gait patterns, and the changes in these parameters reflected different gait pattern transitions. Therefore, we believe that the results of this study can provide a reference for the gait pattern transition recognition of wearable exoskeletons.

Head Kinematics in Mini-Sled Tests of Foam Padding: Relevance of Linear Responses From Free Motion Headform (FMH) Testing to Head Angular Responses

2003 ◽  
Vol 125 (4) ◽  
pp. 523-532 ◽  
Author(s):  
J. Ivarsson ◽  
D. C. Viano ◽  
P. Lo¨vsund ◽  
Y. Parnaik
Keyword(s):  
Angular Velocity ◽  
Brain Injuries ◽  
Motor Vehicle ◽  
Sagittal Plane ◽  
Angular Acceleration ◽  
Linear Acceleration ◽  
Free Motion ◽  
Constant Thickness ◽  
Head Impacts ◽  
Hybrid Iii

The revised Federal Motor Vehicle Safety Standard (FMVSS) No. 201 specifies that the safety performance of vehicle upper interiors is determined from the resultant linear acceleration response of a free motion headform (FMH) impacting the interior at 6.7 m/s. This study addresses whether linear output data from the FMH test can be used to select an upper interior padding that decreases the likelihood of rotationally induced brain injuries. Using an experimental setup consisting of a Hybrid III head-neck structure mounted on a mini-sled platform, sagittal plane linear and angular head accelerations were measured in frontal head impacts into foam samples of various stiffness and density with a constant thickness (51 mm) at low (∼5.0 m/s), intermediate (∼7.0 m/s), and high (∼9.6 m/s) impact speeds. Provided that the foam samples did not bottom out, recorded peak values of angular acceleration and change in angular velocity increased approximately linearly with increasing peak resultant linear acceleration and value of the Head Injury Criterion HIC36. The results indicate that the padding that produces the lowest possible peak angular acceleration and peak change in angular velocity without causing high peak forces is the one that produces the lowest possible HIC36 without bottoming out in the FMH test.

The Effect of Impaired Plantar Sensation on Gait in People with Multiple Sclerosis

2009 ◽  
Vol 11 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Kevin J. Kelleher ◽  
William D. Spence ◽  
Stephan E. Solomonidis ◽  
Dimitrios P. Apatsidis
Keyword(s):  
Multiple Sclerosis ◽  
Sensory Feedback ◽  
Sagittal Plane ◽  
Gait Pattern ◽  
Knee Extensors ◽  
Control Group ◽  
Plantar Flexors ◽  
Gait Patterns ◽  
Ambulatory Ability ◽  
Reaction Forces

People with multiple sclerosis (MS) often experience debilitating motor and sensory dysfunction. The aim of this study was to determine whether impaired plantar sensation affects gait patterns in MS patients, as it does in other patient populations such as those with diabetes mellitus. Sixteen patients with MS were recruited and divided into two groups according to their ambulatory ability. Ten healthy subjects made up a control group. Plantar sensation thresholds were measured and kinematic and kinetic gait data were collected for both MS groups and the control group. The MS patients had less sensation than the control group at all plantar sites tested. Gait speed and hip, knee, and ankle joint sagittal plane excursion were significantly lower in both MS groups than in the control group. Braking and push-off ground reaction forces were significantly lower in both MS groups than in the control group, and patients were found to carry the limb through the swing phase using the hip flexors and knee extensors owing to insufficient push-off from the ankle plantar flexors. The reduced plantar sensation in MS patients is likely to be a significant factor in this “cautious” gait pattern. Improving sensory feedback from the sole of the foot through the prescription of specialized footwear and orthoses may facilitate gait in people with MS.

scholarly journals Changes in Gait Pattern During Smartphone and Tablet Use

2020 ◽  
Vol 18 (4) ◽  
pp. 475-484
Author(s):  
Sirinthip Pakdee ◽  
◽  
Praphatson Sengsoon ◽  
Keyword(s):  
Text Message ◽  
Step Length ◽  
Gait Pattern ◽  
Gait Velocity ◽  
Stride Time ◽  
Normal Walking ◽  
Time Step ◽  
Gait Patterns ◽  
Significant Difference ◽  
Smartphone Use

Objectives: There exists no study concerning gait pattern while engaging in dual-task activities on different sizes of mobile devices. The present study aimed to compare gait patterns during normal walking, walking with smartphone use, and walking with tablet use. Methods: Seventeen healthy female participants with an age range of 19-24 years (Mean±SD age: 20.29±1.61 years, weight: 49.82±4.46 kg, height: 156.59±4.87 cm, body mass index: 20.47±0.84 kg/m2, and leg length: 81.35±3.79 cm.) participated in the present research. The study subjects were requested to walk for 10 meters under the following conditions: normal walking; walking while typing a text message with a smartphone, and walking while typing a text message with a tablet. The Vicon® Three-Dimensional (3D) motion analysis recorded the motion of reflective markers attached to the study participant’s body. Gait parameters (step length, stride length, step time, stride time, step width, velocity, and cadence) were compared between the explored walking conditions. Results: The gait parameter of normal walking, compared with walking during smartphone use as well as tablet use were significantly different in the gait pattern (P<0.05). Using either a smartphone or tablet during walking presented decreased step length for legs, gait velocity, and cadence. However, there was an increase in the right leg’s step time and stride time. Moreover, there was no significant difference in gait patterns between walking during smartphone use and walking during tablet use (P>0.05). Discussion: Changes in gait pattern during walking while typing a text message with either a smartphone or tablet may lead to greater attention and concentration required to type the message; such actions resulted in decreased gait speed and step length.

Meniscal Extrusion Does Not Progress During the Midterm Follow-up Period After Lateral Meniscal Transplantation

2016 ◽  
Vol 45 (4) ◽  
pp. 900-908 ◽  
Author(s):  
Nam-Ki Kim ◽  
Seong-Il Bin ◽  
Jong-Min Kim ◽  
Chang-Rack Lee ◽  
Jae-Hyan Kim
Keyword(s):  
Sagittal Plane ◽  
Lysholm Score ◽  
Coronal Plane ◽  
Meniscal Extrusion ◽  
Time Points ◽  
Meniscal Allograft ◽  
Significant Difference ◽  
The Mean ◽  
The Absolute

Background: Meniscal extrusion is related to degeneration of the native knee joint. However, the clinical effect of the phenomenon after meniscal allograft transplantation (MAT) has not been clearly identified. Purpose/Hypothesis: The purpose of this study was to evaluate the change in meniscal extrusion in both the coronal and sagittal planes after lateral MAT through the midterm follow-up period. We hypothesized that meniscal extrusion does not progress during the midterm follow-up period. Study Design: Case series; Level of evidence, 4. Methods: A total of 46 patients with a mean follow-up of 51.1 ± 7.1 months were included in the study. The patients underwent lateral MAT using the keyhole technique. Postoperative magnetic resonance imaging (MRI) was performed at 6-week, 1-year, and midterm (3- to 5-year) follow-up. In the coronal plane, the absolute value of meniscal subluxation and the relative percentage of extrusion (RPE) were measured. In the sagittal plane, meniscal subluxation was measured as the absolute and relative anterior cartilage meniscal distance (ACMD) and posterior cartilage meniscal distance (PCMD). The joint-space width (JSW) on weightbearing radiographs with 2 different knee positions was measured preoperatively and at 1-year and midterm follow-up. The Lysholm score was assessed at the same time points. Results: In the coronal plane, the mean absolute meniscal extrusion at 6-week, 1-year, and final follow-up was 2.90 ± 0.94, 2.85 ± 0.97, and 2.83 ± 0.89 mm, respectively, and the mean RPE was 27.0% ± 9.4%, 27.1% ± 10.1%, and 27.8% ± 9.7%, respectively. There were no statistically significant differences in absolute and relative coronal extrusion among the 3 time periods ( P > .05). The percentage of patients with meniscal extrusion (≥3 mm) was 37.0% at 6-week follow-up and 34.8% at 1-year and final follow-up. In the sagittal plane, the mean absolute ACMD was 2.59 ± 1.75, 2.58 ± 1.85, and 2.37 ± 1.60 mm, respectively, and the mean relative ACMD was 20.7% ± 13.1%, 20.6% ± 13.8%, and 19.0% ± 12.2%, respectively, at the 3 follow-up time points. The mean absolute PCMD was −1.23 ± 3.34, −1.28 ± 3.08, and −1.42 ± 2.77 mm, respectively, and the mean relative PCMD was −10.3% ± 25.9%, −11.0% ± 24.6%, and −12.2% ± 23.2%, respectively, at the same time points. Sagittal extrusion was not significantly different between the time points ( P > .05). The mean JSW at 2 days preoperatively, 1 year postoperatively, and midterm follow-up was 5.40 ± 1.07, 5.44 ± 1.04, and 5.43 ± 0.98 mm, respectively, on anterior-posterior radiographs with full extension, and it was 4.90 ± 0.94, 4.94 ± 0.98, and 4.89 ± 0.96 mm, respectively, on posterior-anterior radiographs with 45° of flexion. The mean JSW values were not significantly different between the 3 different time points ( P > .05). The mean preoperative Lysholm score was 58. 9 ± 8.3; the score increased to 90.4 ± 9.7 at 1 year postoperatively and 90.5 ± 10.1 at final follow-up, which is a significant improvement compared with the preoperative status ( P < .05). There was no statistically significant difference between the scores at the 2 postoperative time points ( P > .05). Conclusion: This study demonstrated that extrusion of the meniscal allograft did not significantly progress either in the coronal or sagittal plane after lateral MAT during the midterm follow-up period.

scholarly journals Effect of Carrying Load on Gait Recognition using J48 with Knee Joint Movements

2020 ◽  
Vol 9 (7S) ◽  
pp. 16-20
Keyword(s):  
Knee Joint ◽  
Flat Surface ◽  
Research Question ◽  
Gait Recognition ◽  
Gait Pattern ◽  
Age Group ◽  
Knee Angle ◽  
Gait Patterns ◽  
Decision Tree Classification ◽  
The Subject

Background: Gait patterns are influenced by various factors. Every person walks differently in different scenarios and it becomes difficult to identify the person correctly by his walking style. Research question: Is it possible to correctly recognize a person through his gait while he walks carrying load? What is the effect of distance on a person’s gait while he walks with carrying load? Objective: The paper is an attempt to study the effect of load on gait of a person. As the knee angle varies from person to person in varying conditions, we have studied the effect of load on knee angle and thus on gait recognition. Methods: Experimentation is done on 41 subjects of age group 18-30 years carrying bilateral weights of 2.5kg in both hands. Data collected from accelerometer has been studied using J48 decision tree classification algorithm. Results: Results of experiments shows 86.12% accuracy in recognizing subjects carrying load up to a distance of 60 meters on a flat surface. The FAR and FRR are found to be 0.77% and 27.52% respectively. Conclusion: Carrying load affects the gait of the subject. This makes it difficult to recognize the subject while he walks carrying load. After walking for some distance, the gait pattern and knee angle of the subject shows significant variations

Kinematic Analysis Planar Mechanism of a Pump Using MSC Adams

2014 ◽  
Vol 611 ◽  
pp. 98-106 ◽  
Author(s):  
Patrik Šarga ◽  
Darina Hroncová
Keyword(s):  
Numerical Methods ◽  
Angular Velocity ◽  
Kinematic Analysis ◽  
Angular Acceleration ◽  
Displacement Velocity ◽  
Basic Operation ◽  
Kinematic Parameters ◽  
Planar Mechanism ◽  
Pump Mechanism ◽  
Analysis Of Motion

The aim of the paper is to present the application of MSC Adams/View for kinematic analysis of motion of a pump mechanism. The first section describes the program Adams and its modules Adams/View, work with this module and its basic operation. In the following section there is the kinematics solved using numerical methods. This work deals with the assembly of the models in Adams/View, simulations, plotting of the trajectory of the mechanisms points, and kinematic parameters of mechanism members. The software shows displacement, velocity and acceleration, angular velocity and angular acceleration. Finally, the paper presents the results with graphic representation of parameters such as displacement, velocity and acceleration.

Time Course of Simulator Sickness in Asian Military Pilots

2020 ◽  
Vol 91 (11) ◽  
pp. 892-896
Author(s):  
Janine En Qi Loi ◽  
Magdalene Li Ling Lee ◽  
Benjamin Boon Chuan Tan ◽  
Brian See
Keyword(s):  
Air Force ◽  
Time Course ◽  
Simulator Training ◽  
Simulator Sickness ◽  
Time Points ◽  
True Prevalence ◽  
Subjective Scale ◽  
Significant Difference ◽  
Simulator Sickness Questionnaire ◽  
Military Pilots

INTRODUCTION: This study sought to determine the incidence, severity, and time-course of simulator sickness (SS) among Asian military pilots following flight simulator training.METHODS: A survey was conducted on Republic of Singapore Air Force pilots undergoing simulator training. Each subject completed a questionnaire immediately after (0H), and at the 3-h (3H) and 6-h (6H) marks. The questionnaire included the simulator sickness questionnaire (SSQ) and a subjective scale to rate their confidence to fly.RESULTS: In this study, 258 pilots with a median age of 31.50 yr (range, 2155 yr) and mean age of 32.61 6.56 yr participated. The prevalence of SS was 48.1% at 0H, 30.8% at 3H, and 16.4% at 6H. Based on a threshold of an SSQ score >10, the prevalence of operationally significant SS was 33.3% at 0H, 13.2% at 3H, and 8.1% at 6H. The most frequent symptoms were fatigue (38.1%), eye strain (29.0%), and fullness of head (19.9%). There was no significant difference in mean scores between rotary and fixed wing pilots. Older, more experienced pilots had greater scores at 0H, but this association did not persist. A correlation was found between SSQ score and self-reported confidence.DISCUSSION: To our knowledge, this study is the first to report the prevalence of operationally significant SS in Asian military pilots over serial time points. Most pilots with SS are able to subjectively judge their fitness to fly. Sensitivity analysis suggests the true prevalence of SS symptoms at 3H and 6H to be closer to 23.8% and 12.0%, respectively.Loi JEQ, Lee MLL, Tan BBC, See B. Time course of simulator sickness in Asian military pilots. Aerosp Med Hum Perform. 2020; 91(11):892896.

scholarly journals Cytotoxicity assessment of different doses of ozonated water on dental pulp cells

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ferdiye Küçük ◽  
Sibel Yıldırım ◽  
Serap Çetiner
Keyword(s):  
Cell Viability ◽  
Repeated Measures ◽  
Dental Pulp ◽  
Control Group ◽  
Dental Pulp Cells ◽  
Time Points ◽  
Significant Difference ◽  
Pulp Cells ◽  
Time Point ◽  
Ozonated Water

Abstract Background The purpose of this study was to assess the cytotoxicity of various concentrations of ozonated water (OW) on human primary dental pulp cells. Methods Human primary dental pulp cells were isolated from exfoliated primary canine teeth of an 11-year-old patient with good systemic and oral health. Afterwards, cells were divided into 6 experimental groups; four groups of OW in concentrations of 2 mg/L, 4 mg/L, 8 mg/L, and 16 mg/L, untreated control group, and cell culture without cells. Cytotoxicity was evaluated after exposure for 5-min exposure using Mosmann’s Tetrazolium Toxicity (MTT) assay at 0 h and 48 h time points. Data were analyzed using a repeated measures analysis of variance and Post-hoc tests were performed using Bonferroni correction for multiple comparisons. Results All experimental groups showed proliferation at 0 h time point. However, all groups also experienced a decrease in overtime at 48 h time point (p < 0.05). At both time points 2 mg/L OW showed the highest cell viability as well as proliferation. At 0 h time point, the increase in cell viability for all experimental groups was found statistically significant when compared to positive control group (p < 0.05). At 48 h time point, although 8 mg/L and 16 mg/L OW showed statistically significant reduction in compare to 0 h time point, 2 mg/L and 4 mg/L OW groups didn’t experience any statistically significant difference (p < 0.05). Conclusion Considering our findings, due to ozonated water's induced a higher proliferation rate of dental pulp cells, indicating their biocompatibility and a possible adjuvant on irrigating agent in regenerative endodontic procedures.

Simulation of athlete gait recognition based on spectral features and machine learning

2020 ◽  
pp. 1-12
Author(s):  
Linuo Wang
Keyword(s):  
Machine Learning ◽  
Angular Velocity ◽  
Gait Recognition ◽  
Spectral Feature ◽  
Velocity Signal ◽  
Comparison Results ◽  
Computer Vision Technology ◽  
Feature Technology ◽  
Leg Movement ◽  
Recognition Efficiency

The current technology related to athlete gait recognition has shortcomings such as complicated equipment and high cost, and there are also certain problems in recognition accuracy and recognition efficiency. In order to improve the efficiency of athletes’ gait recognition, this paper studies the different recognition technologies of athletes based on machine learning and spectral feature technology and applies computer vision technology to sports. Moreover, according to the calf angular velocity signal, the occurrence of leg movement is detected in real time, and the gait cycle is accurately divided to reduce the influence of the signal unrelated to the behavior on the recognition process. In addition, this study proposes a gait behavior recognition method based on event-driven strategies. This method uses a gyroscope as the main sensor and uses a wearable sensor node to collect the angular velocity signals of the legs and waist. In addition, this study analyzes the performance of the algorithm proposed by this paper through experimental research. The comparison results show that the method proposed by this paper has improved the number of recognition action types and accuracy and has certain advantages from the perspective of computation and scalability.

scholarly journals Knee Muscle Strength Recovery in the Early Period After ACL Reconstruction

2014 ◽  
Vol 2 (11_suppl3) ◽  
pp. 2325967114S0014
Author(s):  
Gulcan Harput ◽  
Hasan Erkan Kılınc ◽  
Hamza Özer ◽  
Gül Baltacı ◽  
Carl G. Mattacola
Keyword(s):  
Acl Reconstruction ◽  
Early Period ◽  
Quadriceps Strength ◽  
Isometric Strength ◽  
Time Points ◽  
Hamstring Muscles ◽  
Significant Difference ◽  
Isometric Torque ◽  
Over Time ◽  
Time Point

Objectives: The aim of this study was to investigate quadriceps and hamstrings isometric strength at 4, 8 and 12 week time points following ACL Reconstruction (ACLR) and to document the strength changes of these muscles over time. The primary hypothesis was that there would be significant increases in quadriceps and hamstring muscle strengths between the 4th, 8th and 12th weeks following ACLR. The secondary hypothesis was that the quadriceps index would be higher than hamstring index at 12th week after ACLR. Methods: Thirty patients (Mean ± SD [age, 29.1±2.3yrs; weight, 77.3±13.2kg; height, 172.1±7.1cm; BMI, 21.2±3.5kg/m2, time to surgery: 7.1±7.2 months]) who underwent ACLR with Hamstring Tendon Autograft (HTG) were enrolled in this study. The isometric strength of quadriceps and hamstring muscles was measured on an isokinetic dynamometer at 60° knee flexion angle at 4th, 8th and 12th weeks after surgery. The recovery of quadriceps and hamstring muscles strength following rehabilitation was expressed as a Quadriceps Index (QI) and Hamstring Index (HI) and calculated with the following formula:[(maximum voluntary isometric torque of the involved limb / maximum voluntary isometric torque by uninvolved limb) × 100]. Torque output of the involved and uninvolved limbs and quadriceps and hamstring indexes were used for the statistical analysis. A repeated measures of ANOVA was used to determine the strength changes of quadriceps and hamstrings over time. Results: Quadriceps and Hamstrings strengths significantly increased over time for both involved (Quadriceps: F (2,46)=58.3, p<0.001, Hamstring: F (2,46)=35.7, p<0.001) and uninvolved limb (Quadriceps: F(2,46)=17.9, p<0.001, Hamstring: F(2,46)=56.9, p=0.001 ). Quadriceps strength was higher at 12th week when compared to the 8 and 4 week time points for the involved limb (p<0.001), and it was higher at 8th week when compared to 4 week time point for the involved limb (p<0.001). For the uninvolved limb, quadriceps strength was also higher at 12th week when compared to the 8 (p=0.02) and 4 week time point (p<0.001), and higher at 8 week when compared to the 4 week time point (p=0.02). Hamstring strength was higher at 12 week when compared to the 8 and 4 week time points (p<0.001) and it was higher at 8 week when compared to 4 week time point for the involved limb (p<0.001). For the uninvolved limb hamstring strength was also higher at 12 week when compared to 4 week time point (p=0.01). There was no significant difference between the 4 and 8 week time points (p>0.05) or between the 8 and 12 week time points (p=0.07). Quadriceps and hamstring indexes significantly changed from 4th weeks (QI:57.9, HI:54.4 ) to 8th weeks (QI:78.8, HI:69.9 ) and from 8th weeks to 12th weeks (QI:82, HI:75.7 ) (p<0.001); however, there was no difference between indexes at the 12-week time point (p=0.17). Conclusion: Isometric strength of quadriceps and hamstring muscles for the involved and uninvolved limb increased during the early period of ACLR. The results of this study could be a baseline for clinicians while prescribing a rehabilitation protocol for ACLR patients with HTG to better appreciate expected strength changes of the muscles in the early phase.

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