scholarly journals Analysis of Spiders’ Joint Kinematics and Driving Modes under Different Ground Conditions

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Xin Hao ◽  
Wenxing Ma ◽  
Chunbao Liu ◽  
Yilei Li ◽  
Zhihui Qian ◽  
...  
Keyword(s):  
High Speed ◽  
Gait Pattern ◽  
Joint Kinematics ◽  
Duty Factor ◽  
Joint Angles ◽  
3D Tracking ◽  
Biomimetic Systems ◽  
Transmission Mechanisms ◽  
Movement Characteristics ◽  
Ground Conditions

Although the hydraulic transmission system in spider legs is well known, the spider’s mechanism of locomotion during different terrain conditions still need to be explored further. In this study, spider locomotion was observed in detail on three pavement test platforms: horizontal hard pavement, horizontal soft pavement, and sloped soft pavement. The movement characteristics and joint kinematics of Grammostola rosea legs were captured by high-speed cameras and Simi Motion 3D tracking software. These observations showed that the gait pattern was basically consistent with an alternating tetrapod gait; however, the pattern observed on the sloped soft pavement was slightly different from that of the two horizontal pavements. In particular, the duty factor of the spiders was 0.683 when walking on the horizontal hard pavement, 0.668 on the horizontal soft pavement, and 0.630 on the sloped soft pavement. The duty factor was greater than 60% in all three pavement environments, which was minimal when walking on the sloped soft pavement. This pattern showed that spiders might have superior stability when walking, but their stability decreased in the sloped soft pavement environment. The ranges of joint angles through the spiders’ gait cycles in every pavement environment were also analysed and compared. The findings showed that the hydraulically driven femur-patella and tibia-metatarsal joint angles varied widely, which confirmed that hydraulically driven joints had major functions and obvious effects on the walking process. The kinematic patterns identified in this study provide improved understanding of the hydraulic transmission mechanisms, the factors that affect motion stability, and the design of biomimetic systems.

Effects of speed on pheasant gaits and hindlimb joint angles

2019 ◽  
Vol 69 (3) ◽  
pp. 293-306
Author(s):  
Rui Zhang ◽  
Dianlei Han ◽  
Qiaoli Ji ◽  
Guoyu Li ◽  
Xian Li ◽  
...  
Keyword(s):  
Kinematic Analysis ◽  
High Speed ◽  
Stride Length ◽  
Joint Angle ◽  
Duty Factor ◽  
Joint Angles ◽  
Walking Gait ◽  
Intermittent Flight ◽  
Lift Off ◽  
Intertarsal Joint

Abstract When studying the gait of pheasants, an intermittent-flight bird, it is necessary to take into account changes in the gaits and hindlimb joint angles resulting from increases of speed. In this study, pheasant locomotion postures were recorded on a speed-variable treadmill with high-speed cameras. Firstly, kinematic analysis showed that the stride cycle of pheasants decreased and the stride length increased with increasing speed. The duty factor also decreased, but was less than 0.5 in only about 10% of measurements. Thus, pheasants are more inclined to choose the grounded running or walking gait in laboratory situations. Secondly, changes in the tarsometatarso-phalangeal joint angle and the intertarsal joint angle at touch-down, mid-stance and lift-off concomitant with speed variation were studied. Tarsometatarso-phalangeal joint angle was found not to be significantly affected by changes in speed, but changed over larger ranges than the intertarsal joint angle. Thirdly, the continuous changes in the joint angles were studied during a complete stride cycle. The curves shifted leftward with increasing speed. Finally, the changes at four main positions were analyzed with increasing speed.

Rapid ankle extension during paw shakes: selective recruitment of fast ankle extensors

1980 ◽  
Vol 43 (3) ◽  
pp. 612-620 ◽  
Author(s):  
J. L. Smith ◽  
B. Betts ◽  
V. R. Edgerton ◽  
R. F. Zernicke
Keyword(s):  
Ankle Joint ◽  
High Speed ◽  
Joint Kinematics ◽  
Time Constraints ◽  
Lateral Gastrocnemius ◽  
Peak Displacement ◽  
Cyclic Movements ◽  
Flexion Extension ◽  
Low Threshold

1. Electromyographic (EMG) signals from slow (soleus) and fast (lateral gastrocnemius) ankle extensors of six cats were recorded during rapid and alternate flexion-extension of the hindlimb elicited by placing the paw in water or by sticking tape to the plantar pads. High-speed 16-mm film, taken at 100 or 200 frames/s, was analyzed to determine the knee and ankle joint kinematics. 2. During 77 typical records, which averaged eight paw shakes each, a single extension-flexion cycle measured by the paw shake interval (PSI) of the electromyogram record, averaged 88 ms and ranged from 55 to 110 ms. LG EMG bursts of 10 ms in duration were synchronized with the peak displacement of ankle flexion. The SOL was inactive throughout these typical records. 3. During four atypical records from one cat, the average OSI was 141 ms, and both lateral gastrocnemius (LG and soleus (SOL) were active simultaneously. At a range of 6--8 cycles/s, these slower shakes are comparable to rhythmic actions of scratching )12) and locomotion (27); cyclic movements that typically include the recruitment of soleus. 4. It is suggested that paw shaking is an automatic movement triggered primarily by large, low-threshold afferents innervating the central plantar pads, which may selectively recruit the fast extensors while inhibiting the slow extensor. This is the only movement of the hindlimb recorded to date in our laboratory in which the tlg was active without the SOL. This unique dissociation of recruitment of slow and fast ankle extensors may be dictated by the time constraints imposed by the rapid cyclic movements of paw shaking.

Three-dimensional CoM energetics, pelvis and lower limbs joint kinematics of uphill treadmill running at high speed

2020 ◽  
Vol 38 (5) ◽  
pp. 518-527
Author(s):  
Masamichi Okudaira ◽  
Steffen Willwacher ◽  
Seita Kuki ◽  
Kaito Yamada ◽  
Takuya Yoshida ◽  
...  
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Joint Kinematics ◽  
Lower Limbs ◽  
Treadmill Running

How too big shoes affect to the joint kinematics of kids gait pattern?

2015 ◽  
Vol 7 (sup1) ◽  
pp. S53-S55 ◽  
Author(s):  
Yoshiyuki Kobayashi ◽  
Maki Akimoto ◽  
Kazuya Imaizumi ◽  
Hiroaki Hobara ◽  
Makiko Kouchi ◽  
...  
Keyword(s):  
Gait Pattern ◽  
Joint Kinematics

Quantitative Measurement of Mucosal Wave by High-Speed Photography in Excised Larynges

1998 ◽  
Vol 107 (2) ◽  
pp. 98-103 ◽  
Author(s):  
Jack J. Jiang ◽  
Yoshimi Kadota ◽  
Eiji Yumoto ◽  
Hironobu Kurokawa ◽  
Samuel J. Lin ◽  
...  
Keyword(s):  
Fundamental Frequency ◽  
Phase Difference ◽  
Vocal Fold ◽  
High Speed ◽  
High Speed Photography ◽  
Airflow Rate ◽  
Quantitative Studies ◽  
Movement Characteristics ◽  
Dependent Variables ◽  
Measured Displacement

The movement characteristics of mucosal waves of the vocal fold are important components in normal phonation. Quantitative studies of the mucosal wave have used stroboscopic techniques from a supraglottic view. The current study measured displacement of mucosal epithelium during experimental phonation by using high-speed photography from an infraglottic view. Effects of thyroarytenoid contraction, increased mean airflow rate, and variation of vocal fold length were examined in canine larynges. Top and bottom vocal fold “lip” amplitude, fundamental frequency, and phase difference were the dependent variables examined. Thyroarytenoid contraction increased the amplitude of the top and bottom lips, decreased the fundamental frequency, and increased the phase difference. Increase in airflow through the glottis decreased the top lip amplitude and phase difference and appeared to increase the fundamental frequency and to decrease the bottom lip amplitude. Vocal fold lengthening decreased the bottom lip amplitude and increased the fundamental frequency and appeared to decrease the top lip amplitude and phase difference.

scholarly journals The importance of a consistent workflow to estimate muscle-tendon lengths based on joint angles from the conventional gait model

2021 ◽  
Author(s):  
Hans Kainz ◽  
Michael H Schwartz
Keyword(s):  
Cerebral Palsy ◽  
Inverse Kinematics ◽  
Clinical Decision Making ◽  
Joint Kinematics ◽  
Joint Angles ◽  
Modified Model ◽  
Model Driven ◽  
Tendon Length ◽  
Musculoskeletal Models ◽  
Children With Cerebral Palsy

AbstractBackgroundMusculoskeletal models enable us to estimate muscle-tendon length, which has been shown to improve clinical decision-making and outcomes in children with cerebral palsy. Most clinical gait analysis services, however, do not include muscle-tendon length estimation in their clinical routine. This is due, in part, to a lack of knowledge and trust in the musculoskeletal models, and to the complexity involved in the workflow to obtain the muscle-tendon length.Research questionCan the joint angles obtained with the conventional gait model (CGM) be used to generate accurate muscle-tendon length estimates?MethodsThree-dimensional motion capture data of 15 children with cerebral palsy and 15 typically developing children were retrospectively analyzed and used to estimate muscle-tendon length with the following four modelling frameworks: (1) 2392-OSM-IK-angles: standard OpenSim workflow including scaling, inverse kinematics and muscle analysis; (2) 2392-OSM-CGM-angle: generic 2392-OpenSim model driven with joint angles from the CGM; (3) modif-OSM-IK-angles: standard OpenSim workflow including inverse kinematics and a modified model with segment coordinate systems and joint degrees-of-freedom similar to the CGM; (4) modif-OSM-CGM-angles: modified model driven with joint angles from the CGM. Joint kinematics and muscle-tendon length were compared between the different modelling frameworks.ResultsLarge differences in hip joint kinematics were observed between the CGM and the 2392-OpenSim model. The modif-OSM showed similar kinematics as the CGM. Muscle-tendon length obtained with modif-OSM-IK-angles and modif-OSM-CGM-angles were similar, whereas large differences in some muscle-tendon length were observed between 2392-OSM-IK-angles and 2392-OSM-CGM-angles.SignificanceThe modif-OSM-CGM-angles framework enabled us to estimate muscle-tendon lengths without the need for scaling a musculoskeletal model and running inverse kinematics. Hence, muscle-tendon length estimates can be obtained simply, without the need for the complexity, knowledge and time required for musculoskeletal modeling and associated software. An instruction showing how the framework can be used in a clinical setting is provided on https://github.com/HansUniVie/MuscleLength.

scholarly journals DeepBBWAE-Net: A CNN-RNN Based Deep SuperLearner For Estimating Lower Extremity Sagittal Plane Joint Kinematics Using Shoe-Mounted IMU Sensors In Daily Living

2021 ◽  
Author(s):  
Md Sanzid Bin Hossain ◽  
Joseph Drantez ◽  
Hwan Choi ◽  
Zhishan Guo
Keyword(s):  
Neural Networks ◽  
Motion Capture ◽  
Daily Living ◽  
Sagittal Plane ◽  
Human Motion ◽  
Joint Kinematics ◽  
Weighted Averaging ◽  
Measurement Unit ◽  
Accurate Estimation ◽  
Joint Angles

<div>Measurement of human body movement is an essential step in biomechanical analysis. The current standard for human motion capture systems uses infrared cameras to track reflective markers placed on the subject. While these systems can accurately track joint kinematics, the analyses are spatially limited to the lab environment. Though Inertial Measurement Unit (IMU) can eliminate the spatial limitations of the motion capture system, those systems are impractical for use in daily living due to the need for many sensors, typically one per body segment. Due to the need for practical and accurate estimation of joint kinematics, this study implements a reduced number of IMU sensors and employs machine learning algorithm to map sensor data to joint angles. Our developed algorithm estimates hip, knee, and ankle angles in the sagittal plane using two shoe-mounted IMU sensors in different practical walking conditions: treadmill, level overground, stair, and slope conditions. Specifically, we proposed five deep learning networks that use combinations of Convolutional Neural Networks (CNN) and Gated Recurrent Unit (GRU) based Recurrent Neural Networks (RNN) as base learners for our framework. Using those five baseline models, we proposed a novel framework, DeepBBWAE-Net, that implements ensemble techniques such as bagging, boosting, and weighted averaging to improve kinematic predictions. DeepBBWAE-Net predicts joint kinematics for the three joint angles under all the walking conditions with a Root Mean Square Error (RMSE) 6.93-29.0% lower than base models individually. This is the first study that uses a reduced number of IMU sensors to estimate kinematics in multiple walking environments.</div>

scholarly journals EFFICIENT MULTI-VIEW 3D TRACKING OF ARBITRARY ROCK FRAGMENTS UPON IMPACT

2020 ◽  
Vol XLIII-B2-2020 ◽  
pp. 589-596
Author(s):  
D. E. Guccione ◽  
K. Thoeni ◽  
A. Giacomini ◽  
O. Buzzi ◽  
S. Fityus
Keyword(s):  
3D Reconstruction ◽  
High Speed ◽  
Visual Hull ◽  
Post Processing ◽  
Tracking Accuracy ◽  
3D Tracking ◽  
Rock Fragments ◽  
Fragmentation Test ◽  
Impact Fragmentation ◽  
Improved Performance

Abstract. This paper presents a new methodology to accurately obtain 3D rotational velocities of blocks and fragments. Four high speed cameras are used to capture the scene. An additional two tilted mirrors are used to multiply the number of views. Hence, a total of six different viewing perspectives can be used to track translational and rotational velocities in 3D. The focus in the current work is on the rotational velocities, as tracking of the translation is generally straightforward. A common outline tracking algorithm based on the visual hull is adapted. The visual hull is further meshed using triangular elements to approximate the shape of the object. This 3D reconstruction is then used to track the 3D motion of the object. However, the accuracy of the results strongly depends on the accuracy of the 3D reconstruction which is mainly influenced by the number and position of the available views. In any case, the 3D reconstruction from the visual hull is only an approximation and significant errors can be introduced which influence the tracking accuracy. Hence, an in-house post-processing algorithm based on the knowledge of the real geometry of the object, which can generally be accurately determined after a test, was developed. The improved performance of this new post-processing method is shown by controlled spinning tests. Finally, results of a real example of an impact fragmentation test are discussed.

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