scholarly journals Evaluating Viscoelastic Properties of the Wrist Joint During External Perturbations: Influence of Velocity, Grip, and Handedness

2021 ◽  
Vol 15 ◽  
Author(s):  
Valeria Falzarano ◽  
Michael W. R. Holmes ◽  
Lorenzo Masia ◽  
Pietro Morasso ◽  
Jacopo Zenzeri
Keyword(s):  
Viscoelastic Properties ◽  
Grip Force ◽  
Mechanical Characteristics ◽  
Wrist Joint ◽  
Maximum Voluntary Contraction ◽  
Mechanical Impedance ◽  
Experimental Conditions ◽  
External Perturbations ◽  
Custom Made ◽  
Flexion Extension

In this study, we designed a robot-based method to compute a mechanical impedance model that could extract the viscoelastic properties of the wrist joint. Thirteen subjects participated in the experiment, testing both dominant and nondominant hands. Specifically, the robotic device delivered position-controlled disturbances in the flexion-extension degree of freedom of the wrist. The external perturbations were characterized by small amplitudes and fast velocities, causing rotation at the wrist joint. The viscoelastic characteristics of the mechanical impedance of the joint were evaluated from the wrist kinematics and corresponding torques. Since the protocol used position inputs to determine changes in mean wrist torque, a detailed analysis of wrist joint dynamics could be made. The scientific question was whether and how these mechanical features changed with various grip demands and perturbation velocities. Nine experimental conditions were tested for each hand, given by the combination of three velocity perturbations (fast, medium, and slow) and three hand grip conditions [self-selected grip, medium and high grip force, as percentage of the maximum voluntary contraction (MVC)]. Throughout the experiments, electromyographic signals of the extensor carpi radialis (ECR) and the flexor carpi radialis (FCR) were recorded. The novelty of this work included a custom-made soft grip sensor, wrapped around the robotic handle, to accurately quantify the grip force exerted by the subjects during experimentation. Damping parameters were in the range of measurements from prior studies and consistent among the different experimental conditions. Stiffness was independent of both direction and velocity of perturbations and increased with increasing grip demand. Both damping and stiffness were not different between the dominant and nondominant hands. These results are crucial to improving our knowledge of the mechanical characteristics of the wrist, and how grip demands influence these properties. This study is the foundation for future work on how mechanical characteristics of the wrist are affected in pathological conditions.

scholarly journals Accuracy and repeatability of wrist joint angles in boxing using an electromagnetic tracking system

2019 ◽  
Vol 23 (1) ◽  
Author(s):  
Ian T. Gatt ◽  
Tom Allen ◽  
Jon Wheat
Keyword(s):  
Wrist Joint ◽  
Tracking System ◽  
Testing Procedure ◽  
Electromagnetic Tracking ◽  
Good Reliability ◽  
Flexion Extension ◽  
In Vivo Testing ◽  
Accuracy And Repeatability ◽  
Electromagnetic Tracking System

AbstractThe hand-wrist region is reported as the most common injury site in boxing. Boxers are at risk due to the amount of wrist motions when impacting training equipment or their opponents, yet we know relatively little about these motions. This paper describes a new method for quantifying wrist motion in boxing using an electromagnetic tracking system. Surrogate testing procedure utilising a polyamide hand and forearm shape, and in vivo testing procedure utilising 29 elite boxers, were used to assess the accuracy and repeatability of the system. 2D kinematic analysis was used to calculate wrist angles using photogrammetry, whilst the data from the electromagnetic tracking system was processed with visual 3D software. The electromagnetic tracking system agreed with the video-based system (paired t tests) in both the surrogate (< 0.2°) and quasi-static testing (< 6°). Both systems showed a good intraclass coefficient of reliability (ICCs > 0.9). In the punch testing, for both repeated jab and hook shots, the electromagnetic tracking system showed good reliability (ICCs > 0.8) and substantial reliability (ICCs > 0.6) for flexion–extension and radial-ulnar deviation angles, respectively. The results indicate that wrist kinematics during punching activities can be measured using an electromagnetic tracking system.

Quantification of Hand Grip Force under Dynamic Conditions

1993 ◽  
Vol 37 (10) ◽  
pp. 715-719 ◽  
Author(s):  
Katherine R. Lehman ◽  
W. Gary Allread ◽  
P. Lawrence Wright ◽  
William S. Marras
Keyword(s):  
Grip Force ◽  
Wrist Flexion ◽  
Range Of Movement ◽  
Ulnar Deviation ◽  
Dynamic Conditions ◽  
Radial Deviation ◽  
Hand Grip ◽  
Flexion Extension ◽  
Maximum Grip ◽  
Lower Grip

A laboratory experiment was conducted to determine whether grip force capabilities are lower when the wrist is moved than in a static position. The purpose was to determine the wrist velocity levels and wrist postures that had the most significant effect on grip force. Maximum grip forces of five male and five female subjects were determined under both static and dynamic conditions. The dominant wrist of each subject was secured to a CYBEX II dynamometer and grip force was collected during isokinetic wrist deviations for four directions of motion (flexion to extension, extension to flexion, radial to ulnar, and ulnar to radial). Six different velocity levels were analyzed and grip forces were recorded at specific wrist positions throughout each range of movement. For flexion-extension motions, wrist positions from 45 degrees flexion to 45 degrees extension were analyzed whereas positions from 20 degrees radial deviation to 20 degrees ulnar deviation were studied for radial-ulnar activity. Isometric exertions were also performed at each desired wrist position. Results showed that, for all directions of motion, grip forces for all isokinetic conditions were significantly lower than for the isometric exertions. Lower grip forces were exhibited at extreme wrist flexion and extreme radial and ulnar positions for both static and dynamic conditions. The direction of motion was also found to affect grip strength; extension to flexion exertions produced larger grip forces than flexion to extension exertions and radial to ulnar motion showed larger grip forces than ulnar to radial deviation. Although, males produced larger grip forces than females in all exertions, significant interactions between gender and velocity were noted.

Reflex Inhibition of Normal Cramp Following Electrical Stimulation of the Muscle Tendon

2007 ◽  
Vol 98 (3) ◽  
pp. 1102-1107 ◽  
Author(s):  
Serajul I. Khan ◽  
John A. Burne
Keyword(s):  
Electrical Stimulation ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Muscle Cramp ◽  
Emg Activity ◽  
Reflex Inhibition ◽  
Experimental Conditions ◽  
Inhibitory Feedback ◽  
Two Phases ◽  
Stimulation Of

Muscle cramp was induced in one head of the gastrocnemius muscle (GA) in eight of thirteen subjects using maximum voluntary contraction when the muscle was in the shortened position. Cramp in GA was painful, involuntary, and localized. Induction of cramp was indicated by the presence of electromyographic (EMG) activity in one head of GA while the other head remained silent. In all cramping subjects, reflex inhibition of cramp electrical activity was observed following Achilles tendon electrical stimulation and they all reported subjective relief of cramp. Thus muscle cramp can be inhibited by stimulation of tendon afferents in the cramped muscle. When the inhibition of cramp-generated EMG and voluntary EMG was compared at similar mean EMG levels, the area and timing of the two phases of inhibition (I1, I2) did not differ significantly. This strongly suggests that the same reflex pathway was the source of the inhibition in both cases. Thus the cramp-generated EMG is also likely to be driven by spinal synaptic input to the motorneurons. We have found that the muscle conditions that appear necessary to facilitate cramp, a near to maximal contraction of the shortened muscle, are also the conditions that render the inhibition generated by tendon afferents ineffective. When the strength of tendon inhibition in cramping subjects was compared with that in subjects that failed to cramp, it was found to be significantly weaker under the same experimental conditions. It is likely that reduced inhibitory feedback from tendon afferents has an important role in generating cramp.

scholarly journals The Influence of Composite Polymeric Materials Topology Over the Shearing Modulus Using Virtual Instruments

2018 ◽  
Vol 55 (4) ◽  
pp. 524-530
Author(s):  
Marinela Marinescu ◽  
Larisa Butu ◽  
Claudia Borda ◽  
Delicia Arsene ◽  
Mihai Butu
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Virtual Instrument ◽  
Mechanical Characteristics ◽  
Polymeric Materials ◽  
Mechanical Impedance ◽  
Impedance Analysis ◽  
Cross Linking ◽  
Labview Software ◽  
Different Temperatures

This study presents research regarding the calculation of the mechanical characteristics of composite polymeric materials. By using LabVIEW� software a virtual instrument was created used for monitoring in real time the process of cross-linking the composite polymeric materials. The experiments were realized based on composite materials containing epoxy/fiberglass resin of different topologies. By means of the virtual instrument and of a sensor created based on the mechanical impedance analysis, implanted in the composite material, it was determined the G shearing module of the composite material at different temperatures.

Upper limb involuntary tremor reduction using cantilever beam TMDs

2022 ◽  
pp. 107754632110518
Author(s):  
Sarah Gebai ◽  
Gwendal Cumunel ◽  
Mohammad Hammoud ◽  
Gilles Foret ◽  
Emmanuel Roze ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Objective Function ◽  
Cantilever Beam ◽  
Upper Limb ◽  
Wrist Joint ◽  
Angular Displacement ◽  
Damping Ratio ◽  
Vertical Plane ◽  
Cross Sectional ◽  
Flexion Extension

Tuned mass dampers (TMDs) are proposed as a solution to reduce the involuntary tremor at the upper limb of a patient with postural tremor. The upper limb is modeled as a three-degrees-of-freedom rotating system in the vertical plane, with a flexion-extension motion at the joints. The measured extensor carpi radialis signal of a patient is used to excite the dynamic model. We propose a numerical methodology to optimize the parameters of the TMDs in the frequency domain combined with the response in the time domain. The objective function for the optimization of the dynamic problem is the maximum angular displacement of the wrist joint. The optimal stiffness and damping of the TMDs are obtained by satisfying the minimization of the selected objective function. The considered passive absorber is a cantilever beam–like TMD, whose length, beam cross-sectional diameter, and mass position reflect its stiffness for a chosen additional mass. A parametric study of the TMD is conducted to evaluate the effect of the TMD position along the hand segment, the number of TMDs, and the total mass of TMDs. The sensitivity of the TMD to a decrease of its modal damping ratio is studied to meet the range of stainless steel. TMDs are manufactured using stainless steel beams of the same length (9.1 cm) and cross-sectional diameter (0.79 mm), for which the mass (14.13 g) position is adjusted to match the optimal frequency. Three TMDs holding a mass of 14.13 g each cause 89% reduction in the wrist joint angular displacement.

scholarly journals Significance Testing and Multivariate Analysis of Datasets from Surface Plasmon Resonance and Surface Acoustic Wave Biosensors: Prediction and Assay Validation for Surface Binding of Large Analytes

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3541 ◽  
Author(s):  
Mihaela Puiu ◽  
Lucian-Gabriel Zamfir ◽  
Valentin Buiculescu ◽  
Angela Baracu ◽  
Cristina Mitrea ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Statistical Significance ◽  
Surface Binding ◽  
Experimental Conditions ◽  
Custom Made ◽  
Binding Curves

In this study, we performed uni- and multivariate data analysis on the extended binding curves of several affinity pairs: immobilized acetylcholinesterase (AChE)/bioconjugates of aflatoxin B1(AFB1) and immobilized anti-AFB1 monoclonal antibody/AFB1-protein carriers. The binding curves were recorded on three mass sensitive cells operating in batch configurations: one commercial surface plasmon resonance (SPR) sensor and two custom-made Love wave surface-acoustic wave (LW-SAW) sensors. We obtained 3D plots depicting the time-evolution of the sensor response as a function of analyte concentration using real-time SPR binding sensograms. These “calibration” surfaces exploited the transient periods of the extended kinetic curves, prior to equilibrium, creating a “fingerprint” for each analyte, in considerably shortened time frames compared to the conventional 2D calibration plots. The custom-made SAW sensors operating in different experimental conditions allowed the detection of AFB1-protein carrier in the nanomolar range. Subsequent statistical significance tests were performed on unpaired data sets to validate the custom-made LW-SAW sensors.

Characterizing the Human Wrist for Improved Haptic Interaction

2003 ◽  
Author(s):  
Katherine J. Kuchenbecker ◽  
June Gyu Park ◽  
Gu¨nter Niemeyer
Keyword(s):  
Grip Force ◽  
Force Measurement ◽  
Wrist Joint ◽  
Calibration Procedure ◽  
Order System ◽  
Response Characteristics ◽  
Haptic Displays ◽  
Positive Linear Correlation ◽  
Improved Performance ◽  
Sense Of Touch

Haptic displays provide the user with a sense of touch in both simulation of virtual environments and teleoperation of remote robots. The instantaneous impedance of the user’s hand affects this force interaction, changing the transients experienced during activities such as exploratory tapping. This research characterizes the behavior of the human wrist joint while holding a stylus in a three-fingered grasp. Nonparametric identification methods, evaluating frequency-and time-responses, support a second-order system model. Further analysis shows a positive linear correlation between grip force and wrist impedance for all subjects, though each individual’s trend is unique. These findings suggest that a quick calibration procedure and a realtime grip force measurement could enable a haptic display to predict user response characteristics throughout an interaction. Such knowledge would enable haptic control algorithms to adapt continuously to the user’s instantaneous state for improved performance.

Activity of precentral neurons during torque-triggered hand movements in awake primates

1979 ◽  
Vol 57 (2) ◽  
pp. 174-184 ◽  
Author(s):  
Y. C. Wong ◽  
H. C. Kwan ◽  
J. T. Murphy
Keyword(s):  
Wrist Joint ◽  
Wrist Flexion ◽  
Somatosensory Stimulation ◽  
Sensory Stimuli ◽  
Neuronal Populations ◽  
Supportive Role ◽  
Flexion Extension ◽  
Cortical Responses ◽  
Early Portion ◽  
Temporally Correlated

In monkeys performing a handle-repositioning task involving primarily wrist flexion–extension (F–E) movements after a torque perturbation was delivered to the handle, single units were recorded extracellularly in the contralateral precentral cortex. Precentral neurons were identified by passive somatosensory stimulation, and were classified into five somatotopically organized populations. Based on electromyographic recordings, it was observed that flexors and extensors about the wrist joint were specifically involved in the repositioning of the handle, while many other muscles which act at the wrist and other forelimb joints were involved in the task in a supportive role. In precentral cortex, all neuronal responses observed were temporally correlated to both the sensory stimuli and the motor responses. Visual stimuli, presented simultaneously with torque perturbations, did not affect the early portion of cortical responses to such torque perturbations. In each of the five somatotopically organized neuronal populations, task-related neurons as well as task-unrelated ones were observed. A significantly larger proportion of wrist (F–E) neurons was related to the task, as compared with the other, nonwrist (F–E) populations. The above findings were discussed in the context of a hypothesis for the function of precentral cortex during voluntary limb movement in awake primates. This hypothesis incorporates a relationship between activities of populations of precentral neurons, defined with respect to their responses to peripheral events at or about single joints, and movements about the same joint.

Use of the curvature method to determine the misfit stress of epitaxial semiconducting systems: the case of samples thinned for TEM observation.

2003 ◽  
Vol 795 ◽  
Author(s):  
A. Ponchet ◽  
M. Cabié ◽  
L. Durand ◽  
M. Rivoal ◽  
A. Rocher
Keyword(s):  
Electron Microscopy ◽  
Mechanical Characteristics ◽  
Substrate Thickness ◽  
Element Calculation ◽  
Experimental Conditions ◽  
Misfit Stress ◽  
Reliable Determination ◽  
Substrate Side ◽  
Transmission Electron

ABSTRACTThe curvature method which allows to measure the stress in epitaxial layers has been adapted to transmission electron microscopy observations. The samples thinned by the substrate side present some particular mechanical characteristics. The ratio between the substrate thickness and the layer thickness should be taken into account. The experimental conditions allowing a reliable determination of the stress have been established. A finite element calculation has been used to show that the dimensions of the area where the measure is performed can not systematically be neglected. This method has been applied to the semiconducting systems Ga1-xInxAs/GaAs and Ga1-xInxAs/InP.

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