Vertical Torque Research Articles

Using a saddle-assistive device equipped with mechanical orthosis for walking of the person with incomplete spinal cord injury.

The majority of the people with incomplete spinal cord injury lose their walking ability, due to the weakness of their muscle motors in providing torque. As a result, developing assistive devices to improve their conditionis of great importance. In this study, a combined application of the saddle-assistive device (S-AD) and mechanical medial linkage or thosis was evaluated to improve the walking ability in patients with spinal cord injury in the gait laboratory. This mobile assistive device is called the saddle-assistive device equipped with medial linkage or thosis (S-ADEM). In this device, a mechanical orthosis was used in a wheeled walker as previously done in the literature. Initially, for evaluation of the proposed assistive device, the experimental results related to the forces and torques exerted on the feet and upper limbs of a person with the incomplete Spinal Cord Injury (SCI) during walking usingthe standard walker were compared with an those obtained from using the S-ADEM on an able-bodied subject. It was found that using this combination of assistive devices decreases the vertical force and torque on the foot at the time of walking by 53% and 48%, respectively compared to a standard walker. Moreover, the hand-reaction force on the upper limb was negligible instanding and walking positions usingthe introduced device. The findings of this study revealed that the walking ability of the patients with incomplete SCI was improved using the proposed device, which is due to the bodyweight support and the motion technology used in it.

Analysis of the Bearing Characteristics of Single Piles under Vertical and Torsional Combined Loads

To investigate the bearing characteristics of single piles under the combined action of vertical loads (V) and torque (T) on a pile head, the displacement governing equations of the pile shaft were proposed in consideration of the load transfer method, and the nonlinear solution of a single‐loaded pile (vertical load or torque) was calculated by the finite difference method. According to the above mentioned investigation, a new numerical analysis model was proposed to modify the vertical and circumferential ultimate friction resistance of the pile side. Subsequently, the nonlinear solutions of single piles under the combined loads of V-T loading with different loading paths were obtained by MATLAB programming, and the bearing capacity envelopes were plotted. Based on the comparison with the existing research results, the correctness of the theoretical calculation method proposed in this article was verified. The results show that compared with a single loaded pile (V or T), with the action of the V-T combined loads, the bearing capacity of a single pile will decrease, and the single piles under the V⟶T loading path will have a higher bearing capacity than those under the T⟶V loading path. When the aspect ratio is comparatively small, the influence of the loading path is negligible; however, when the aspect ratio is comparatively large, it is necessary to avoid the preliminary application of the torque to a single pile to prevent the decrease in the ultimate bearing capacity on account of the formation of the T⟶V loading mode. The deformation of the pile body mainly occurs in the range from 0 to 0.6L, so effective deformation reduction can be achieved by reinforcing the shallow foundation. It is inadvisable for a single friction pile to be used to improve the bearing capacity by increasing the concrete grade.

Test-Retest Reliability of Static and Countermovement Power Push-Up Tests in Young Male Athletes.

Bohannon, NA, Gillen, ZM, Shoemaker, ME, McKay, BD, Gibson, SM, Cramer, JT. Test-Retest Reliability of Static and Counter-Movement Power Push-Up Tests in Young Male Athletes. J Strength Cond Res 34(9): 2456-2464, 2020-The primary purpose of this study was to evaluate test-retest reliability of the static (SP) and countermovement (CMP) power push-up test in young male athletes. The secondary purpose was to compare the reliability of vertical ground reaction forces versus torque measurements during the power push-up tests. Twenty boys (age = 11.60 ± 1.15 years) performed SPs and CMPs on force plates with the knees as the fulcrum on 2 laboratory visits separated by 2-7 days. Performance measurements included peak force (PF), peak rate of force development (pRFD), peak torque (PT), peak rate of torque development (pRTD), peak power (PP), average power (AP), eccentric impulse (ECC), and concentric impulse (CON) for both power push-up techniques. Age, maturity offset, height, body mass, fat-free mass, and estimated arm cross sectional area were obtained as measurements of growth. Intraclass correlation coefficients (ICC), SEM, coefficients of variation, and minimum detectable changes (MDC) were reported. Only PF (ICC = 0.87-0.88, SEM = 59-84 N) and PT (ICC = 0.89-0.90, SEM = 60-88 N·m) showed acceptable reliability. Neither pRFD, pRTD, PP, AP, ECC, or CON were reliable outcomes. There were no meaningful differences between force-time and torque-time curve measurements. The SP showed slightly lower CVs (33-34%) than the CMP (CVs = 39-40%). Coaches and practitioners would need to see 58-71% increases in upper-body strength measurements evaluated via power push-up on force plates to be 95% confident that the improvements exceeded the measurement variability.

Measurement of force and torque in friction stir welding of low carbon steels

In the present work, a strain gauge based dynamometer was designed and developed for monitoring the vertical force, traverse force and torque during the friction stir welding (FSW) of low carbon steels. The finite element analysis was performed to detect the suitable positions for mounting the strain gauges on the octagonal ring members under real time loading conditions (i.e., vertical force, traverse force and torque). Analytical methods were used to estimate the mechanical responses, i.e., stress, strain, and vibration frequency of the octagonal ring members. The induced strain in the octagonal members was recorded by the data acquisition system, which was connected to the dynamometer with the essential software and hardware to record the strain data during the welding process. After completing the construction, the dynamometer was successfully tested by performing the FSW on DH36 shipbuilding steel and mild steel (UNS G10080 steel) plates in similar and dissimilar combinations.

Comparison Between the FLUIDICS Experiment and Direct Numerical Simulations of Fluid Sloshing in Spherical Tanks Under Microgravity Conditions

The fluids behaviour within a spherical tank under microgravity conditions is investigated through a comparison between the original data from the FLUIDICS experiment carried out in the ISS and Direct Numerical Simulations for two-phase flows. The study case consists in the rotation of a spherical tank around a fixed axis. The tank is filled with a liquid with physical properties similar to those of liquid propellants and gases used in the space industry. Two tanks with different filling ratios have been tested in space. Cameras and sensors allow extracting the fluids dynamics and the temporal evolution of the force and torque exerted by the fluids on the tank wall. Several manoeuvres corresponding to different angular velocities and angular accelerations are submitted on both tanks. The velocity profile is divided into four phases: from zero, the angular velocity around the vertical axis increases linearly until it reaches the required constant value for which the fluids stabilise in the second phase, then the angular velocity decreases until it recovers zero. Numerical simulations are computed with the home-made code DIVA which is based on the Level Set method coupled with the Ghost Fluid Method. The force in the radial direction gives the value of the centrifugal force during the constant angular velocity phase. The average centrifugal force is well predicted by the simulations, the comparison with the experimental data exhibits errors lower than 3% for the half-filled tank. Considering the vertical torque, the effect of the Euler acceleration is clearly visible through the important peaks of opposite sign observed during the acceleration and the deceleration phases. Moreover, the oscillations of the gas bubble during the second phase can be observed from the torque evolution. Their magnitude decreases throughout time until the steady state is reached. The measured and predicted temporal evolutions match together until the magnitude of the oscillations reaches the noise level of the data. The bubble oscillations are much more damped for the tank containing a larger amount of liquid (75%). The frequency of these oscillations are investigated applying the Fourier transform of the torque signals and by looking at the videos taken during the experiment. Similar oscillation frequencies are observed with the experimental setup and the numerical simulations, even for the manoeuvre with the lower Bond numbers. We verify that the oscillation frequency increases with the angular velocity. Finally, the comparison exhibits that the numerical simulations provide an accurate prediction of the fluids behaviours in microgravity conditions for this range of Bond numbers.

The degree of postural automaticity influences the prime movement and the anticipatory postural adjustments during standing in healthy young individuals

Less attention to a balance task reduces the center of foot pressure (COP) variability by automating the task. However, it is not fully understood how the degree of postural automaticity influences the voluntary movement and anticipatory postural adjustments. Eleven healthy young adults performed a bipedal, eyes closed standing task under the three conditions: Control (C, standing task), Single (S, standing + reaction tasks), and Dual (D, standing + reaction + mental tasks). The reaction task was flexing the right shoulder to an auditory stimulus, which causes counter-clockwise rotational torque, and the mental task was arithmetic task. The COP variance before the reaction task was reduced in the D condition compared to that in the C and S conditions. On average the onsets of the arm movement and the vertical torque (Tz, anticipatory clockwise rotational torque) were both delayed, and the maximal Tz slope (the rate at which the torque develops) became less steep in the D condition compared to those in the S condition. When these data in the D condition were expressed as a percentage of those in the S condition, the arm movement onset and the Tz slope were positively and negatively, respectively, correlated with the COP variance. By using the mental-task induced COP variance reduction as the indicator of postural automaticity, our data suggest that the balance task for those with more COP variance reduction is less cognitively demanding, leading to the shorter reaction time probably due to the attention shift from the automated balance task to the reaction task.

Final report on the torque comparison EURAMET.M.T-S2, measurand torque: 10 N·m, 20 N·m, 40 N·m, 60 N·m, 80 N·m, and 100 N·m

The purpose of the EURAMET comparison EURAMET.M.T-S2 was to compare the measuring capabilities up to 100 N·m of a reference-type torque calibration machine of ZAG, Slovenia, with the torque standard machine of the Physikalisch-Technische Bundesanstalt (PTB, Braunschweig, Germany) acting as pilot laboratory. A very stable TT1 torque transducer with well-known properties and two torque measuring bridges was used as travelling standard.According to the technical protocol, torque steps of at least 10 N·m, 20 N·m, 40 N·m, 60 N·m, 80 N·m, and 100 N·m had to be measured both in clockwise and anticlockwise directions. For each of the torque steps and both senses of direction of the torque vector, En values were calculated.The results are in general in good agreement with the claimed measurement uncertainties except for the very first measurement at ZAG with additional support and four plate couplings. It seems to be sufficient in a vertical set-up (vertical torque axis) to use only two flexible couplings and there is no need for a further support between the transducers. The measurements with two couplings fulfill the requirement to the En value and support ZAG's claimed uncertainties of measurement.Main textTo reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

ANALYSIS OF TORQUE VERTICAL ON STRING MODEL

Different to other motion of torque, motion the torque modeled by McKenna (1999) is the motion of torque into a vertical direction, a consequence of the imposition of downward. Mckenna lowering the model of two pieces of rope in fastening on a beam then in hanging, then McKenna replaces the parameters with forensic data from Tacoma bridge, to analyze a wave of what happened at the bridge collapse that resulted in the bridge. In this research will be shown that the solution of the equation of vertical torque from the results of having a conspicuous disparity linearization with a numerical solution

Anticipatory Postural Adjustments in Standing Reach Tasks Among Middle-Aged Adults With Diplegic Cerebral Palsy

ABSTRACTPrevious studies reported that children with cerebral palsy (CP) exhibited premature anticipatory postural adjustments (APAs) with high variability and excessive activity in the frontal plane. To better understand the effects of gross motor functioning level on APAs over the life course, the authors examined the presence and consistency of APAs in 11 adults with diplegia at 2 functioning levels against 8 age-matched healthy adults during unilateral and bilateral reaching. Results revealed an anticipatory vertical torque (TZ) and an increased likelihood of APAs during bilateral reaching for the lower functioning group. It is postulated that APAs may first emerge in TZ in CP. Results also indicated an excessive premovement postural activity in the frontal plane in both CP groups.

Shifting the balance of human standing: Inter-limb coordination for the control of a robotic balance simulation.

Learning to maintain standing balance in the presence of a paretic limb is an important recovery process for many stroke survivors. In this study, we used a robotic balance simulator to investigate whether manipulating medial-lateral or anterior-posterior torque contributions (i.e. input gains) could shift the control of balance toward a targeted lower limb in healthy controls. Manipulation of medial-lateral (ML) torque gains shifted the vertical load distribution toward the virtually weakened limb, but did not result in a significant shift in anterior-posterior (AP) torque control. Instead individual participants were observed to shift AP torque control in either direction, although participants more often shifted control toward the virtually weakened limb at larger ML asymmetries. In contrast, manipulation of AP torque gains did not produce any observable changes in measured torque signals. The shift in torque contributions during ML manipulations shows promise as an implicit training method for reducing weight-bearing asymmetry. However, further work is required to ensure both vertical load and AP torque control shift in the desired direction as well as to determine the applicability of the protocol in a patient population.

Effects of asymmetrical stance and movement on body rotation in pushing

Pushing objects in the presence of body asymmetries could increase the risk of back injury. Furthermore, when the object is heavy, it could exacerbate the effects induced by asymmetrical posture. We investigated how the use of asymmetrical posture and/or upper extremity movement affect vertical torque (Tz) and center of pressure (COP) displacement during pushing. Ten healthy volunteers were instructed to push objects of three different weights using two hands (symmetrical hand use) or one hand (asymmetrical hand use) while standing in symmetrical or asymmetrical foot-positions. The peak values of Tz and COP displacement in the medial–lateral direction (COPML) were analyzed. In cases of isolated asymmetry, changes in the Tz were mainly linked with effects of hand-use whereas effects of foot-position dominated changes in the COPML displacement. In cases of a combined asymmetry, the magnitudes of both Tz and COPML were additive when asymmetrical hand-use and foot-position induced the rotation of the lower and upper body in the same direction or subtractive when asymmetries resulted in the rotation of the body segments in the opposite directions. Moreover, larger Tz and COP displacements were seen when pushing the heavy weight. The results point out the importance of using Tz and COPML to describe the isolated or combined effects of asymmetrical upper extremity movement and asymmetrical posture on body rotation during pushing. Furthermore, it suggests that a proper combination of unilateral arm movement and foot placements could help to reduce body rotation even when pushing heavy objects.

Ground reaction forces and lower-limb joint kinetics of turning gait in typically developing children

Turning is a common locomotor task essential to daily activity; however, very little is known about the forces and moments responsible for the kinematic adaptations occurring relative to straight-line gait in typically developing children. Thus, the aims of this study were to analyse ground reaction forces (GRFs), ground reaction free vertical torque (TZ), and the lower-limb joint kinetics of 90° outside (step) and inside (spin) limb turns. Step, spin, and straight walking trials from fifty-four typically developing children were analysed. All children were fit with the Plug-in Gait and Oxford Foot Model marker sets while walking over force plates embedded in the walkway. Net internal joint moments and power were computed via a standard inverse dynamics approach. All dependent variables were statistically analysed over the entire curves using the mean difference 95% bootstrap confidence band approach. GRFs were directed medially for step turns and laterally for spin turns during the turning phase. Directions were reversed and magnitudes decreased during the approach phase. Step turns showed reduced ankle power generation, while spin turns showed large TZ. Both strategies required large knee and hip coronal and transverse plane moments during swing. These kinetic differences highlight adaptations required to maintain stability and reorient the body towards the new walking direction during turning. From a clinical perspective, turning gait may better reveal weaknesses and motor control deficits than straight walking in pathological populations, such as children with cerebral palsy, and could potentially be implemented in standard gait analysis sessions.

Does overestimation of an object's mass during arm-raising modify postural adjustments?

By using a dummy weight during an arm-raising movement, we sought to determine whether (i) postural adjustments are modified and (ii) the required focal movement can be performed adequately. Standing on a force platform, 30 healthy young adults performed voluntary, arm-raising movements with cube-shaped boxes: a small 1kg box, a large 4kg box and a large 1kg box (i.e. the dummy weight, which looked as if it weighed 4kg). Postural adjustments were quantified in terms of the latency, intensity and duration of the positive phase of the vertical torque (Tz) and displacements of the center of pressure. Lifting the dummy and lifting the small 1kg box were associated with similar arm velocity curves. The characteristics of the positive Tz phase for the dummy box were intermediate between those observed for the small 1kg box and the large 4kg box. There were no differences between the three box-lifting conditions in terms of the latency and duration of Tz. We conclude that overestimation of the dummy's mass was rapidly corrected by a feedback mechanism. Postural control was modified online as soon as the dummy's true weight was perceived, which therefore enabled the maintenance of balance and adequate execution of the voluntary (focal) movement.

AN ANALYTIC MODEL FOR BUOYANCY RESONANCES IN PROTOPLANETARY DISKS

Zhu, Stone, and Rafikov (2012) found in 3D shearing box simulations a new form of planet-disk interaction that they attributed to a vertical buoyancy resonance in the disk. We describe an analytic linear model for this interaction. We adopt a simplified model involving azimuthal forcing that produces the resonance and permits an analytic description of its structure. We derive an analytic expression for the buoyancy torque and show that the vertical torque distribution agrees well with results of Athena simulations and a Fourier method for linear numerical calculations carried out with the same forcing. The buoyancy resonance differs from the classic Lindblad and corotation resonances in that the resonance lies along tilted planes. Its width depends on damping effects and is independent of the gas sound speed. The resonance does not excite propagating waves. At a given large azimuthal wavenumber k_y > 1/h (for disk thickness h), the buoyancy resonance exerts a torque over a region that lies radially closer to the corotation radius than the Lindblad resonance. Because the torque is localized to the region of excitation, it is potentially subject to the effects of nonlinear saturation. In addition, the torque can be reduced by the effects of radiative heat transfer between the resonant region and its surroundings. For each azimuthal wavenumber, the resonance establishes a large scale density wave pattern in a plane within the disk.

Self-excitation of oscillations of wheeled tractors frame when working in traction mode

The article theoretically substantiates a possibility of self-excitation of oscillations of wheeled tractors frame in the longitudinal plane when working in traction mode. There was used the dependence of rolling pneumatic wheel radius from the vertical load and torque, mathematical model of a rolling pneumatic wheel with variable vertical load and dual-mass linear model of oscillations of the tractor frame in the longitudinal plane.

Galvanic Vestibular Stimulation Produces Sensations of Rotation Consistent with Activation of Semicircular Canal Afferents

Galvanic Vestibular Stimulation Produces Sensations of Rotation Consistent with Activation of Semicircular Canal Afferents

Vertical torque responses to vestibular stimulation in standing humans

The effects of electrical vestibular stimulation upon movement and perception suggest two evoked sensations: head roll and inter-aural linear acceleration. The head roll vector causes walking subjects to turn in a direction dependent on head pitch, requiring generation of torque around a vertical axis. Here the effect of vestibular stimulation upon vertical torque (T(z)) was investigated during quiet stance. With the head tilted forward, square-wave stimuli applied to the mastoid processes evoked a polarity-specific T(z) response accompanied by trunk yaw. Stochastic vestibular stimulation (SVS) was used to investigate the effect of head pitch with greater precision; the SVS–T(z) cross-correlation displayed a modulation pattern consistent with the head roll vector and this was also reflected by changes in coherence at 2–3 Hz. However, a separate response at 7–8 Hz was unaffected by head pitch. Head translation (rather than rotation) had no effect upon this high frequency response either, suggesting it is not caused by a sense of body rotation induced by an inter-aural acceleration vector offset from the body. Instead, high coherence between medio-lateral shear force and T(z) at the same frequency range suggests it is caused by mechanical coupling to evoked medio-lateral sway. Consistent with this explanation, the 7–8 Hz response was attenuated by 90 deg head roll or yaw, both of which uncouple the inter-aural axis from the medio-lateral sway axis. These results demonstrate two vertical torque responses to electrical vestibular stimulation in standing subjects. The high frequency response can be attributed to mechanical coupling to evoked medio-lateral sway. The low frequency response is consistent with a reaction to a sensation of head roll, and provides a novel method for investigating proprioceptive-vestibular interactions during stance.

The influence of misalignment on the uncertainty of vertical torque calibration machine

Misalignment of torque calibration machines can cause parasitic bending loads inside the torque transducers in use. These parasitic loads may affect the machine uncertainty, specially for secondary torque calibration machines. Therefore, this study discusses the contribution of misalignment to the measurement uncertainty for a newly designed 3 kNm secondary vertical torque calibration machine. Radial axes shift up to 4 mm was applied which introduce small increased uncertainty.

Analysis of a passive microforce sensor based on magnetic springs and upthrust buoyancy

Abstract This paper is focused on the design and modeling of a new micro and nano force sensor using magnetic springs. The force sensitive part is a macroscopic horizontal rigid platform used as a floating seismic mass. This platform presents a naturally stable equilibrium state for its six degrees of freedom (dof) thanks to the combination of upthrust buoyancy and magnetic forces. This force sensor allows the measurement of the external horizontal force and the vertical torque applied to the platform. Thanks to the magnetic springs configuration used, the seismic mass presents a 0.02 N/m horizontal mechanical stiffness (similar to the stiffness of a thin AFM micro-cantilever). The measurement range typically varies between ±50 μN. The resolution depends on the displacement sensors used to measure the seismic mass displacement and on the environmental conditions (ground, liquid and air vibrations). In steady state, this displacement is proportional to the applied force. Resolution of less than 10 nN can be reached with the use of an anti-vibration table.

Effect of bilateral subthalamic nucleus deep brain stimulation on postural adjustments during arm movement

Objective Although it is well known that postural adjustment (PA) is impaired in advanced Parkinson’s disease (PD), the potentially compensatory effects of bilateral subthalamic nucleus deep brain stimulation (STN DBS) in this respect are less clear. Methods While standing on a force platform and in the absence of antiparkinsonian medication, 10 patients performed voluntary, unilateral arm movements before surgery (the ‘off stim’ condition) and then afterwards (the ‘on stim’ condition). The patients’ PAs were monitored by vertical torque ( Tz) and compared with those recorded in control subjects. Results Patients with STN DBS and control subjects showed similar values for PA amplitude, duration and latency. Conclusions STN stimulation may induce better postural control during the movement preparation and execution phases. Our results argue in favour of a positive effect of STN DBS on PA. Significance The PA amplitude (provided by Tz) may be a strong marker reflecting the clinical improvement seen in stimulated PD patients.