scholarly journals Kinematics Analysis of Cervical Rotation-Traction Manipulation Measured by a Motion Capture System

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Zhu Liguo ◽  
Feng Minshan ◽  
Yin Xunlu ◽  
Wang Shangquan ◽  
Yu Jie
Keyword(s):  
Motion Capture ◽  
Rotation Angle ◽  
Head Rotation ◽  
Motion Capture System ◽  
Kinematics Analysis ◽  
Active Range Of Motion ◽  
Significant Difference ◽  
Spine Motion ◽  
Low Amplitude ◽  
Cervical Rotation

Objectives. To analyze the kinematics of cervical rotation-traction manipulation (CRTM). Methods. An experimental study measuring the kinematics of CRTM was conducted. A total of 18 healthy volunteers participated in the study. A single manipulator operated the CRTM for all subjects. Motion capture technology was adopted to track the trajectory during the CRTM operation. Results. The manipulated side did not influence the cervical spine motion. The motion ranges obtained during CRTM were well below the active range of motion reported in the literature. The head rotation angle after thrusting was less than the angle of the rotary-position (P<0.05). There was no significant difference in the head rotation angle between pretraction and upward-thrust. The thrust direction of CRTM was mainly upward. The thrust operation was of high-velocity and low-amplitude (thrust velocity: 203.06±49.95 mm/s; thrust acceleration: 3836.27±1262.28 mm/s2; thrust displacement: 3.25±1.30 mm). Conclusions. CRTM has clear operation steps and repeatability that is suitable for clinical application.

scholarly journals Closing the Wearable Gap—Part VI: Human Gait Recognition Using Deep Learning Methodologies

Electronics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 796 ◽  
Author(s):  
Samaneh Davarzani ◽  
David Saucier ◽  
Preston Peranich ◽  
Will Carroll ◽  
Alana Turner ◽  
...  
Keyword(s):  
Linear Regression ◽  
Motion Capture ◽  
Mean Squared Error ◽  
Error Rates ◽  
Human Gait ◽  
Motion Capture System ◽  
3D Motion ◽  
Ankle Kinematics ◽  
Significant Difference ◽  
3D Motion Capture

A novel wearable solution using soft robotic sensors (SRS) has been investigated to model foot-ankle kinematics during gait cycles. The capacitance of SRS related to foot-ankle basic movements was quantified during the gait movements of 20 participants on a flat surface as well as a cross-sloped surface. In order to evaluate the power of SRS in modeling foot-ankle kinematics, three-dimensional (3D) motion capture data was also collected for analyzing gait movement. Three different approaches were employed to quantify the relationship between the SRS and the 3D motion capture system, including multivariable linear regression, an artificial neural network (ANN), and a time-series long short-term memory (LSTM) network. Models were compared based on the root mean squared error (RMSE) of the prediction of the joint angle of the foot in the sagittal and frontal plane, collected from the motion capture system. There was not a significant difference between the error rates of the three different models. The ANN resulted in an average RMSE of 3.63, being slightly more successful in comparison to the average RMSE values of 3.94 and 3.98 resulting from multivariable linear regression and LSTM, respectively. The low error rate of the models revealed the high performance of SRS in capturing foot-ankle kinematics during the human gait cycle.

scholarly journals Biomechanical study of screw fixation and plate fixation of a posterior malleolar fracture in a simulation of the normal gait cycle

2017 ◽  
Vol 2 (3) ◽  
pp. 2473011417S0004
Author(s):  
Xu Wang
Keyword(s):  
Motion Capture ◽  
Gait Cycle ◽  
Fatigue Loading ◽  
Repeated Loading ◽  
Motion Capture System ◽  
Spatial Motion ◽  
Malleolar Fracture ◽  
Posterior Malleolar Fracture ◽  
Significant Difference ◽  
Loading System

Category: Ankle Introduction/Purpose: Fixation of the posterior malleolar fracture with plate or screws is under debating. A fatigue loading system and a spatial motion capture system will provide a theoretical basis for the selection. Methods: Thirty-six below-knee specimens with Haraguchi I type posterior malleolar fracture model was obtained. The specimens were randomly divided into two groups, Group A used two parallel-placed 3.5 mm semi-threaded hollow titanium alloy screws to fix the fracture from back to front; group B used an anatomical plate to fix the posterior malleolus. According to the ratio S of the area of the sagittal fracture over the total area of the distal tibial articular surface, each group was subdivided into three groups recorded as A1, B1; A2, B2; and A3, B3. In group A1 and B1, S=1/4; in A2 and B2, S=1/3; in A3 and B3, S=1/2. In the simulations of gait cycle, 4 kinds of ankle joints were subjected to mechanical loading. A fatigue loading system was used for repeated loading. The spatial motion capture system was used to measure the displacement X (mm) in the final stage of loading. Results: At different locations and different loading conditions, the posterior malleolar fracture displacement X in the three groups of posterior malleolar fracture showed no statistically significant difference. Conclusion: here is no biomechanical difference between the internal fixation of two parallel 3.5-mm hollow screws and anatomical plate for Haraguchi I type posterior malleolar fractures with an average fracture block height of 19.27 mm.

Testing a Quaternion Conversion Method to Determine Human 3D Tibiofemoral Angles During an in Vitro Simulated Jump Landing

2021 ◽  
Author(s):  
Mirel Ajdaroski ◽  
James A. Ashton-Miller ◽  
So Young Baek ◽  
Payam Mirshams Shahshahani ◽  
Amanda Esquivel
Keyword(s):  
Motion Capture ◽  
Knee Kinematics ◽  
Motion Capture System ◽  
Limits Of Agreement ◽  
Jump Landing ◽  
Significant Difference ◽  
Measurement Units ◽  
Validation Testing ◽  
Cadaveric Knee

Abstract Lower limb joint kinematics have been measured in laboratory settings using fixed camera-based motion capture systems; however, recently inertial measurement units (IMUs) have been developed as an alternative. The purpose of this study was to test a quaternion conversion (QC) method for calculating the three orthogonal knee angles during the high velocities associated with a jump landing using commercially available IMUs. Nine cadaveric knee specimens were instrumented with APDM Opal IMUs to measure knee kinematics in one-legged 3-4x bodyweight simulated jump landings, four of which were used in establishing the parameters (training) for the new method and five for validation (testing). We compared the angles obtained from the QC method to those obtained from a commercially available sensor and algorithm (APDM Opal) with those calculated from an active marker motion capture system. Results showed a significant difference between both IMU methods and the motion capture data in the majority of orthogonal angles (p&lt;0.01), though the differences between the QC method and Certus system in the testing set for flexion and rotation angles were smaller than the APDM Opal algorithm, indicating an improvement. Additionally, in all 3 directions both the limits of agreement and root mean square error between the QC method and the motion capture system were smaller than between the commercial algorithm and the motion capture.

scholarly journals Comparison of Vertical Breast Displacement during Rope Skipping, Walking, Jogging and Running

2021 ◽  
Vol 237 ◽  
pp. 04033
Author(s):  
X Sheng ◽  
X Chen ◽  
Y Li ◽  
G Sun ◽  
H Xie
Keyword(s):  
Motion Capture ◽  
Three Dimensional ◽  
Motion Capture System ◽  
Exercise Modality ◽  
Significant Difference ◽  
Rope Skipping

In order to investigate the effect of exercise modality and bra type on vertical breast displacement, seven participants with similar ages and body types were selected to take part in this study. Three-dimensional motion capture system (NDI Optotrak Certus) was used to collect the data of vertical breast displacement when participants were walking at the speed of 5 km/h, jogging at the speed of 7.5 km/h, running at the speed of 10 km/h on a treadmill, and rope skipping at the frequency of twice per second. It was found that there was no significant difference in vertical breast displacement between rope skipping, jogging and running. And the vertical breast displacement when wearing sports bra is significantly less than everyday bra in four exercise modalities. The results of this study might be useful for designing special sports bra for rope skipping modality.

scholarly journals Mechanical Parameters and Trajectory of Two Chinese Cervical Manipulations Compared by a Motion Capture System

2021 ◽  
Vol 9 ◽  
Author(s):  
Xuecheng Huang ◽  
Dongxin Lin ◽  
Zeyu Liang ◽  
Yuping Deng ◽  
Zaopeng He ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Motion Capture ◽  
Experimental Research ◽  
Mechanical Parameters ◽  
Motion Capture System ◽  
Mean Velocity ◽  
Motion Trajectories ◽  
Cervical Rotation ◽  
Kinematics Parameters

Objective: To compare the mechanical parameters and trajectory while operating the oblique pulling manipulation and the cervical rotation–traction manipulation.Methods: An experimental research measuring kinematics parameter and recording motion trajectories of two cervical manipulations were carried out. A total of 48 healthy volunteers participated in this study, who were randomly divided into two groups of 24 representing each of the two manipulations. A clinician performed two manipulations in two groups separately. A motion capture system was used to monitor and analyze kinematics parameters during the operation.Results: The two cervical manipulations have similar thrust time, displacement, mean velocity, max velocity, and max acceleration. There were no significant differences in active and passive amplitudes between the two cervical rotation manipulations. The thrust amplitudes of the oblique pulling manipulation and the cervical rotation–traction manipulation were 5.735 ± 3.041° and 2.142 ± 1.742°, respectively. The thrust amplitudes of the oblique pulling manipulation was significantly greater than that of the cervical rotation–traction manipulation (P &lt; 0.001).Conclusion: Compared with the oblique pulling manipulation, the cervical rotation–traction manipulation has a less thrust amplitudes.

Gender differences in the Achilles tendon load during the fencing lunge

2014 ◽  
Vol 6 (3) ◽  
Author(s):  
Jonathan Kenneth Sinclair ◽  
Lindsay Bottoms
Keyword(s):  
Gender Differences ◽  
Achilles Tendon ◽  
Motion Capture ◽  
Tendon Injury ◽  
Force Platform ◽  
Motion Capture System ◽  
3D Motion ◽  
Loading Rates ◽  
Tendon Pathology ◽  
3D Motion Capture

AbstractRecent epidemiological analyses in fencing have shown that injuries and pain linked specifically to fencing training/competition were evident in 92.8% of fencers. Specifically the prevalence of Achilles tendon pathology has increased substantially in recent years, and males have been identified as being at greater risk of Achilles tendon injury compared to their female counterparts. This study aimed to examine gender differences in Achilles tendon loading during the fencing lunge.Achilles tendon load was obtained from eight male and eight female club level epee fencers using a 3D motion capture system and force platform information as they completed simulated lunges. Independent t-tests were performed on the data to determine whether differences existed.The results show that males were associated with significantly greater Achilles tendon loading rates in comparison to females.This suggests that male fencers may be at greater risk from Achilles tendon pathology as a function of fencing training/ competition.

Magnetic motion capture system using LC resonant magnetic marker composed of Ni–Zn ferrite core

2006 ◽  
Vol 99 (8) ◽  
pp. 08B312 ◽  
Author(s):  
S. Hashi ◽  
M. Toyoda ◽  
M. Ohya ◽  
Y. Okazaki ◽  
S. Yabukami ◽  
...  
Keyword(s):  
Motion Capture ◽  
Motion Capture System ◽  
Ferrite Core ◽  
Zn Ferrite ◽  
Magnetic Marker

scholarly journals Modeling and evaluating beat gestures for social robots

2021 ◽  
Author(s):  
Unai Zabala ◽  
Igor Rodriguez ◽  
José María Martínez-Otzeta ◽  
Elena Lazkano
Keyword(s):  
Motion Capture ◽  
Motion Capture System ◽  
Generative Adversarial Network ◽  
Adversarial Network ◽  
Desirable Feature ◽  
Quantitative Results ◽  
Path Lengths ◽  
End Effectors ◽  
The One ◽  
Made In

AbstractNatural gestures are a desirable feature for a humanoid robot, as they are presumed to elicit a more comfortable interaction in people. With this aim in mind, we present in this paper a system to develop a natural talking gesture generation behavior. A Generative Adversarial Network (GAN) produces novel beat gestures from the data captured from recordings of human talking. The data is obtained without the need for any kind of wearable, as a motion capture system properly estimates the position of the limbs/joints involved in human expressive talking behavior. After testing in a Pepper robot, it is shown that the system is able to generate natural gestures during large talking periods without becoming repetitive. This approach is computationally more demanding than previous work, therefore a comparison is made in order to evaluate the improvements. This comparison is made by calculating some common measures about the end effectors’ trajectories (jerk and path lengths) and complemented by the Fréchet Gesture Distance (FGD) that aims to measure the fidelity of the generated gestures with respect to the provided ones. Results show that the described system is able to learn natural gestures just by observation and improves the one developed with a simpler motion capture system. The quantitative results are sustained by questionnaire based human evaluation.

Assessing the Ergonomic Benefits of a New Adjustable Forklift Backrest

2020 ◽  
Vol 64 (1) ◽  
pp. 976-980
Author(s):  
Pranav Madhav Kuber ◽  
Ehsan Rashedi
Keyword(s):  
Comparative Study ◽  
Motion Capture ◽  
Center Of Pressure ◽  
Body Movement ◽  
Pressure Change ◽  
Motion Capture System ◽  
Design Features ◽  
Wide Range ◽  
Body Sizes ◽  
The Mean

A new forklift backrest has been developed by incorporating adjustability concepts into the design to facilitate comfort to a wide range of users. We have conducted a comparative study between the new and original backrests to assess the effectiveness of design features. Using the phenomenon of restlessness, discomfort of the user was associated with the amount of body movement, where we have used a motion- capture system and a force platform to quantify the individuals’ movement for a wide range of body sizes. Meanwhile, subjective comfort and design feedback were collected using a questionnaire. Our results showed a reduction in the mean torso movement and the maximum center of pressure change of location by 300 and 6 mm, respectively, for the new design. Taking advantage of adjustability feature, the new backrest design exhibited enhanced comfort for longer durations and reduced magnitude of discomfort for a wide range of participants’ body sizes.

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