BIOMECHANICAL STUDY OF MUSCLE MOVEMENT IN THE PROCESS OF FOOTBALL TECHNICAL TRAINING

2020 ◽  
Vol 20 (02) ◽  
pp. 1950082
Author(s):  
YIBO YUE ◽  
YUCHENG YANG
Keyword(s):  
Sports Injuries ◽  
Piezoelectric Sensor ◽  
Angular Speed ◽  
Biomechanical Study ◽  
Knee Joints ◽  
Concentric Exercise ◽  
Isokinetic Muscle Strength ◽  
Force Moment ◽  
Electromyographic Signal ◽  
The Moment

Study of biomechanical characteristics of muscles can provide an effective reference for the training of athletes. Football is a vigorous sport, and physical collision and damage are frequent during competition and training. In order to improve football skills and prevent sports injuries, 10 athletes from Sport College of Shaoyang University, Hunan, China, were tested for isokinetic muscle strength. The moment of flexors and extensors was measured when the flexion and extension angular speed of hip and knee joints was 50∘, 100∘, 150∘, 200∘, 250∘, 300∘, 350∘ and 400∘, respectively. Moreover the characteristics of force moment of flexor and extensor were verified by testing the electromyographic signal of the flexor and extensor of the hip and knee joints with isokinetic concentric exercise using piezoelectric sensor. The results showed that the electromyographic signal of the flexor and extensor of the hip and knee joint decreased with the increase of angular velocity of isokinetic concentric exercise; the electromyographic signal obtained by the piezoelectric sensor verified the law that the output of the flexor and extensor decreased, the extensor of the hip joint had incoordination during rapid movement, and the output of the extensor was always larger than that of the flexor no matter how fast the extensor moved.

scholarly journals Exploratory study of electromyographic behavior of the vastus medialis and vastus lateralis at neuromuscular fatigue onset

2014 ◽  
Vol 20 (2) ◽  
pp. 213-220 ◽  
Author(s):  
Cristiano Rocha da Silva ◽  
Danilo de Oliveira Silva ◽  
Deisi Ferrari ◽  
Rúben de Faria Negrão Filho ◽  
Neri Alves ◽  
...  
Keyword(s):  
Exploratory Study ◽  
Vastus Lateralis ◽  
Knee Extension ◽  
Neuromuscular Fatigue ◽  
Isometric Contractions ◽  
Median Frequency ◽  
Vastus Medialis ◽  
Mean Square ◽  
Electromyographic Signal ◽  
The Moment

This study aimed to determine and analyze the neuromuscular fatigue onset by median frequency (MDF) and the root mean square (RMS) behavior of an electromyographic signal (EMG). Eighteen healthy men with no prior knee problems initially performed three maximum voluntary isometric contractions (MVIC). After two days of MVIC test, participants performed a fatiguing protocol in which they performed submaximal knee-extension contractions at 20% and 70% MVIC held to exhaustion. The MDF and RMS values from the EMG signals were recorded from the vastus medialis (VM) and the vastus lateralis (VL). Analysis of the MDF and RMS behavior enabled identification of neuromuscular fatigue onset for VM and VL muscles in 20% and 70% loads. Alterations between the VM and VL in the neuromuscular fatigue onset, at 20% and 70% MVIC, were not significant. These findings suggest that the methodology proposal was capable of indicating minute differences sensible to alterations in the EMG signals, allowing identification of the moment when the MDF and the RMS showed significant changes in behavior. The methodology used was also a viable one for describing and identifying the neuromuscular fatigue onset by means of the analysis of EMG signals.

The Vibration Based on Non-Zero Point Force Moment Elasticity Theory

2014 ◽  
Vol 590 ◽  
pp. 27-31 ◽  
Author(s):  
Wen Ba Han ◽  
Shuang Hua Huang ◽  
Jie Liu ◽  
Jin Kun Sun
Keyword(s):  
Shear Stress ◽  
Normal Stress ◽  
Elasticity Theory ◽  
Damage Mechanics ◽  
Natural Frequencies ◽  
Bending Moment ◽  
Zero Point ◽  
Pure Bending ◽  
Force Moment ◽  
The Moment

The traditional elastic theory believes that there exists normal stress in pure bending body (PBB) and shear stress in pure torsion body (PTB). However, the author proved that there is no normal stress but ‘Bent Point Moment’ (BPM) in PBB. And it also concluded that there is no shear stress but ‘Shear Point Moment’ (SPM) in PTB. This article overturns the preliminary theorems of the Elasticity Theory, which believes that the value of the moment (Bending moment & Torsion moment) on a unit area converges to zero. Just as the completely different natural frequencies of the forced vibration can lead to completely different resonant conditions. Besides, this theory has also been validated in the Damage Mechanics National Key Laboratory of Tsinghua University. Therefore, it is significant to avoid destruction produced by resonance.

scholarly journals INFLUENCE OF CHANGE PARAMETERS OF TECHNOLOGICAL PROCESS ON COEFFICIENT OF DYNAMISM OF THE EQUIPMENT

2021 ◽  
pp. 25-27
Author(s):  
Oleksii Hrechanyi ◽  
Tatiana Vasilchenko ◽  
Daria Tsimakhovych ◽  
Eduard Huz ◽  
Maksym Karmazin
Keyword(s):  
Functional Equation ◽  
Dynamic Load ◽  
Equation Of Motion ◽  
Dynamic Loads ◽  
Dynamic Factor ◽  
Technological Equipment ◽  
Rolling Mills ◽  
Elastic Forces ◽  
Force Moment ◽  
The Moment

The influence of changing the technological modes of rolling on the dynamic load of the coilers of rolling mills has been established. The functional equation of motion for strip winding has been determined, the solution of which makes it possible to establish the dependence of the elastic force moment on the strip winding time. The moment of elastic forces is used when calculating the dynamic factor, which characterizes the dynamic loads on the nodes of technological equipment. Investigated the change in the coefficient of dynamism at different thicknesses of the wound strip.

scholarly journals Design of a Non-Contact Radial Torque Sensor with Variable Torque Range by Electromagnetic Coil Coupling with Piezoelectric Sensor

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7695
Author(s):  
Sheng-He Wang
Keyword(s):  
Magnetic Force ◽  
Piezoelectric Sensor ◽  
Torque Sensor ◽  
Detection Range ◽  
External Torque ◽  
Electromagnetic Coil ◽  
Beam Mechanism ◽  
The Moment ◽  
Monitoring Technologies ◽  
Automation Technology

Recently, due to the development of automation technology, torque measuring and monitoring technologies have been brought to the focus. However, the commercially available sensors have the disadvantage of large volume, which results in the difficulty of installation on existing automated machines. Responding to the above-mentioned problem, a contactless torque sensor that uses an electromagnetic coil combined with a permanent magnet was proposed. By adjusting the input electric current in the coil, the strength of the magnetic field can be controlled to generate a non-contact magnetic force to resist external torque loading. For the measurement of such a magnetic force, a cantilever-beam mechanism comprising a piezoelectric-loading (PZT-L) sensor is employed to estimate the external static force by measuring the variation of the electric impedance. According to the measured results, the proposed PZT-L sensor demonstrates the accuracy of the proposed design, for which the maximum estimated error was around 6%. Finally, the proposed contactless torque sensor with 11 cm in diameter and 2 cm in thickness was employed to verify the effectiveness of theoretical analysis. From the sensor characteristic measurement, the detection range for external torque can be from 7.8 to 125.6 N-mm when the driven current input ranged from 2 to 10 A. Therefore, the experimental results presented that the moment of inertia via the resisted torque can be adjusted by the proposed non-contact torque-sensing system according to the measuring condition.

Use of a load cell and force–moment curves to compare transverse plane moment loads on transtibial residual limbs: A preliminary investigation

2013 ◽  
Vol 38 (3) ◽  
pp. 253-262 ◽  
Author(s):  
Edward S Neumann ◽  
Justin Brink ◽  
Kartheek Yalamanchili ◽  
Joon S Lee
Keyword(s):  
Preliminary Investigation ◽  
Transverse Plane ◽  
Load Cell ◽  
Mass Force ◽  
Residual Limb ◽  
Straight Path ◽  
Prosthetic Foot ◽  
Force Moment ◽  
The Moment ◽  
Transtibial Amputees

Background and aim: The objective of this study was to demonstrate how a load cell and force–moment curves can be used outside of a gait lab to directly measure and evaluate the transverse plane loading moment on transtibial residual limbs. Technique: A load cell was attached distally to the socket of three transtibial amputees who walked a straight path and a circle of 3.048-m diameter with the prosthetic foot both inside and outside the curved path. Discussion: Compared to straight path walking, transverse plane moment decreased when the foot was on the outside of the curved path. When the foot was on the inside, the moment did not exceed that for straight path walking for two participants; maximum transverse moment was approximately 0.15 N m/kg of body mass. Force–moment curves indicated that each participant’s gait was unique, but underlying similarities were observed with respect to each of the three conditions. Clinical relevance A load cell in conjunction with curved and straight path walking and force–moment curves can be used outside of a gait lab to measure and examine the transverse plane loading on the residual limb.

Initiating Rotation in Back and Reverse Armstand Triple Somersaults Tuck Dives

2001 ◽  
Vol 17 (4) ◽  
pp. 312-325 ◽  
Author(s):  
Karen Murtaugh ◽  
Doris I. Miller
Keyword(s):  
Angular Momentum ◽  
Lower Extremity ◽  
Upper Extremity ◽  
Reaction Force ◽  
Moment Arm ◽  
Angular Momenta ◽  
Force Moment ◽  
The Moment ◽  
Trunk Position

To determine strategies for initiating rotation in armstand back and reverse triple somersaults tuck dives from the 10-m platform, videotaped records of 17 elite male divers performing in competitions between 1995 and 1999 were analyzed. Linear and angular momenta at last contact were similar for both dives. Although the lower extremity actions were comparable, they occurred significantly earlier (p < .05) in reverse triple takeoffs, allowing divers to enter the tuck more quickly. As divers lean, the moment arm of the vertical platform reaction force increases with respect to the CG. The vertical platform reaction force moment promotes back and opposes reverse somersaulting angular momentum. Meanwhile, the horizontal platform reaction force moment promotes reverse and opposes back somersaulting angular momentum. Consequently, divers performing reverse triples maintained a more vertical trunk position during the early part of the takeoff, while those executing back triples leaned further before initiating lower and upper extremity actions to exert force against the platform. Since the strategy for reverse rotation may result in the head passing close to the platform and there is very little to gain in degree of difficulty, it is recommended that competitors execute back rather than reverse somersaulting armstand dives.

scholarly journals Anatomo-physiological features of knee injuries and possibilities of conservative treatment

2021 ◽  
Vol 284 ◽  
pp. 02018
Author(s):  
Yulia Yurlova ◽  
Sergey Dianov
Keyword(s):  
Conservative Treatment ◽  
Knee Joint ◽  
Sports Injuries ◽  
Complex Structure ◽  
Knee Injuries ◽  
Lateral Collateral Ligament ◽  
Knee Joints ◽  
Specific Situation ◽  
Traumatic Injuries

The knee joint is a complex biomechanical system, where the complexity of structure determines pathology variety, difficulties in treatment and rehabilitation. The conservative treatment possibilities of the ligamentous apparatus injuries of a knee are the subject of our discussion. Purpose of the study is to analyze the prevalence of knee traumatic injuries and modern ideas about the conservative treatment possibility of these injuries. Ligamentous apparatus injury of a knee joint is a common one, especially among athletes, with different mechanisms of knee injuries characteristic of different sports. Injuries of the lateral collateral ligament must be diagnosed in a timely manner in order to determine the possibilities of conservative and / or surgical treatment. Failure to recognize the injury details can lead instability and poor results to a knee after ligament reconstruction. Proponents of conservative treatment tactics provide evidence that non-operative treating of the ligaments also gives good results. The complex structure of a knee joint and a large number of variants of its damage impose a special responsibility on traumatologists-rehabilitologists, who are engaged in the restoration of its functions. The question of the choice between surgical restoration or conservative treatment of acute BCS injuries of knee joints remains open and depends on the specific situation, but in each case, rehabilitation measures are required, on the timeliness and adequacy of which the patient's quality of life will depend on.

scholarly journals Robot-aided Training of Propulsion During Walking: Effects of Torque Pulses Applied to the Hip and Knee Joints During Stance

2020 ◽  
Author(s):  
Robert McGrath ◽  
Barry Bodt ◽  
Fabrizio Sergi
Keyword(s):  
Knee Joint ◽  
Opposite Direction ◽  
Single Pulse ◽  
Knee Extension ◽  
Biomechanical Study ◽  
Knee Joints ◽  
Application Range ◽  
After Effects ◽  
Pulse Experiment ◽  
Short Term Adaptation

AbstractThe goal of this study is to evaluate the effects of the application of torque pulses to the hip and knee joint via a robotic exoskeleton in the context of training propulsion during walking. Based on our previous biomechanical study, we formulated a set of conditions of torque pulses applied to the hip and knee joint associated with changes in push-off posture, a component of propulsion. In this work, we quantified the effects of hip/knee torque pulses on metrics of propulsion, specifically hip extension (HE) and normalized propulsive impulse (NPI), in two experiments. In the first experiment, we exposed 16 participants to sixteen conditions of torque pulses during single strides to observe the immediate effects of pulse application. In the second experiment, we exposed 16 participants to a subset of those conditions to observe short-term adaptation effects.During pulse application, NPI aligned with the expected modulation of push-off posture, while HE was modulated in the opposite direction. The timing of the applied pulses, early or late stance, was crucial, as the effects were often in the opposite direction when changing timing condition. Extension torque applied at late stance increased HE in both experiments range of change in HE: (1.6 ± 0.3 deg, 7.7 ± 0.9 deg), p < 0.001). The same conditions resulted in a negative change in NPI only in the single pulse experiment — change in NPI for knee torque: −2.9 ± 0.3 ms, p < 0.001, no significant change for hip torque. Also, knee extension and flexion torque during early and late stance, respectively, increased NPI during single pulse application — range of change in NPI: (3.4, 4.2) ± 0.3 ms, p < 0.001). During repeated pulse application, NPI increased for late stance flexion torque — range of change in NPI: (4.5, 4.8) ± 2 ms, p < 0.001), but not late stance extension torque. Upon pulse torque removal, we observed positive after-effects in HE in all conditions. While there were no after-effects in NPI significant at the group level, a responder analysis indicated that the majority of the group increased both NPI and HE after pulse application.

Refinement concept of the moment of force in mechanics

2018 ◽  
pp. 21-25
Author(s):  
Serhii Pozhidaev
Keyword(s):  
Work Force ◽  
System Of Units ◽  
Shoulder Strength ◽  
Force Moment ◽  
The Moment ◽  
Definition Of

A refined definition of the concept at the moment of force is obtained. Its application eliminates the contradiction existing in the Іnternational System of Units (SI). It is established that the unit of the force moment is N·m/rad, and the unit of the coefficient, which connects of force and torque, is m/rad. It is shown that the concept of “shoulder strength“ has no relation to the determination of the moment of force. Keywords: Іnternational System of Units (SI), energy, work, force moment, dimensional formula.

EFFECTS OF IMPACTS OF COVERING ROLLERS ON GENERAL FORCES OF SMALL-SIZED TILLAGE MACHINE

2021 ◽  
Vol 16 (3) ◽  
pp. 98-105
Author(s):  
Gubeydulla Yunusov ◽  
Nuriya Anderzhanova ◽  
Ayrat Valiev ◽  
Aleksey Aleshkin
Keyword(s):  
Rational Design ◽  
Classical Mechanics ◽  
Angular Speed ◽  
High Tech ◽  
Technological Parameters ◽  
Analytical Geometry ◽  
Generalized Force ◽  
Soil Preparation ◽  
The Difference ◽  
The Moment

Increasing the efficiency of agricultural production, in particular the production of crop products in personal subsidiary plots, depends on the development and implementation of high-tech machines and their working units. The need for small-sized tillage equipment is increasing from year to year. But in order to increase the functionality of the equipment and the quality of soil preparation for sowing, it is necessary to study the possibility of using various additional working units. The purpose of the work is theoretical studies of the movement and kinematic connection of a trailed slatted-spiral roller with a walk-behind tractor, which make it possible to substantiate rational design and technological parameters of a small-sized tillage tool. The study used the provisions of classical mechanics and analytical geometry, methods of equilibrium and motion of mechanical systems based on differential and integral principles of mechanics. The design of active and passive rollers for a walk-behind tractor is considered, which allows to qualitatively prepare the soil for sowing at the depth of seeding, the influence of potential and non-potential effects on their generalized forces is revealed, the angular velocity and their acceleration are determined, as well as the dynamic characteristics of the moment of inertia of the rollers relative to the axes of rotation X4 and Z4 and their frames relative to the axes of rotation X3 and Z3. The difference in the generalized force for a passive roller relative to the angle φ 5.49 N∙m was obtained. The angular speed of the active roller is 23.0 rad/s higher than that of the passive roller, and as a result of research it was revealed that the moments of inertia of the active roller and its frame relative to the axles are significantly higher than that of the passive roller. Generalized forces for an active roller relative to the angle q = 2.58 N∙m and relative to the angle φ = 1.98 N∙m, for a passive roller - relative to the angle q = 2.32 N∙m and relative to the angle φ = 7.47 N∙m. The generalized forces for the potential effects of an active roller are Qθa=1.58 N∙m, Qφa=2.26 N∙m, for a passive roller Qθn=1.32 N∙m, Qφn= 4.60 N∙m. Mθa = 1 N∙m, Mφa = 114.63 N∙m; passive roller - respectively Mθn = 1 N∙m, Mφn = 178.9 N∙m

Sign in / Sign up

Export Citation Format

Share Document