scholarly journals Effects of Side Load Chains of a Combine Harvester on Unbalanced Dynamic Vibrations of Its Threshing Drum

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yu Zhiwu ◽  
Li Yaoming ◽  
Wang Xinzhong ◽  
Tang Zhong ◽  
Jiahui Lu
Keyword(s):  
Dynamic Balance ◽  
Side Chain ◽  
Axial Distance ◽  
Chain Drive ◽  
Eccentric Load ◽  
Balance Test ◽  
Actual Measurement ◽  
Time Dynamic ◽  
Partial Load ◽  
Balance State

In order to study the influence of the side drive on the balance state of the threshing drum, this paper used the side eccentric load chain drive as the power on the threshing drum dynamic balance test bench. By analyzing the influence of different radial phases, different axial distances, and spiral combinations of the threshing drum on the counterweight, this paper studies the law of the effect of side partial load chain drive on the dynamic balance of the threshing drum and finds that the side chain drive has obvious influence on the unbalance phase of the threshing drum and the change of the axial distance of unbalance has little effect on the equilibrium state of the threshing drum. And from this, a vibration balance method based on the equivalent unbalance of the chain drive is proposed, which can predict and calculate the unbalance of the threshing drum. The unbalance of the threshing drum predicted by this method is smaller than the actual measured unbalance. The maximum error is 32.64% and the minimum error is 4.6%. In the two tests, the predicted unbalance is 1.24 mm/s in amplitude and 270 degrees in phase and amplitude 1.4 mm/s and phase 120 degrees, respectively. The measured unbalance is amplitude 1.587 mm/s and phases 286 degrees. The error between prediction and actual measurement is less than 32.64%, and the unbalance amplitudes that can be reduced by one-time dynamic balance are 0.856 mm/s and 0.674 mm/s, respectively. The research results in this paper provide an effective method for the balance state of the multidrum side chain transmission.

scholarly journals Effects of a 6-week core stabilization training program on dynamic balance and trunk stabilization endurance of horse riders

2021 ◽  
Author(s):  
Nicholas H. K. Lam ◽  
Wai Man Lau ◽  
Tin Lap Lau
Keyword(s):  
Training Program ◽  
Dynamic Balance ◽  
Measurement Tool ◽  
Balance Test ◽  
Core Stabilization ◽  
Balance Task ◽  
Postural Stabilization ◽  
Left And Right ◽  
Back Extensor ◽  
Swiss Ball

AbstractThe purpose of this study was to examine the effectiveness of a 6-week core stabilization training program (CSTP) in improving dynamic balance and back-extensor endurance of horse riders; and develop a measurement tool in assessing the dynamic postural stabilization endurance for horse riders. Twelve male horse riders (age: 23.58 ± 1.93 years; height: 165.09 ± 4.60 cm; weight: 56.53 ± 4.75 kg; experience in horse racing: 1.75 ± 0.34 years) completed 12 training sessions in 6 weeks. Subjects performed the CSTP with two progressions. CSTP started with the basic consciousness activation exercises, and then eliminated visual feedback in dynamic balance task on unstable surfaces and finished with switching the center of gravity. Moderate-to-large difference was demonstrated in the Y-Balance test scores for right leg (102.81 ± 8.32 vs 106.471 ± 4.35 cm, d = 0.55, 95% CL 0.00 to 1.08) and left leg (102.04 ± 3.20 vs 106.29 ± 3.62 cm, d = 1.25, 95% CL 0.41 to 2.05) following 6 weeks CSTP. However, trivial to small differences was reported between left and right leg in pre (d = 0.12, 95% CL − 0.49 to 0.73) and post 6-week CSTP (d = 0.04, 95% CL − 0.69 to 0.78). Biering–Sørensen test (BST) shows largely greater performance after 6-week CSTP (98.3 ± 30.1 vs 131.8 ± 19.0 s, d = 1.33, 95% CL 0.54–2.09). A novel measurement, Swiss ball four-point kneeling test was shown to be correlated with the change in BST (r = 0.633).

scholarly journals The Relationship between Dynamic Balance and Jumping Tests among Adolescent Amateur Rugby Players. A Preliminary Study

2021 ◽  
Vol 18 (1) ◽  
pp. 312
Author(s):  
Bartosz Wilczyński ◽  
Jakub Hinca ◽  
Daniel Ślęzak ◽  
Katarzyna Zorena
Keyword(s):  
Injury Risk ◽  
Dynamic Balance ◽  
Study Data ◽  
Balance Test ◽  
Risk Of Injury ◽  
Counter Movement Jump ◽  
Increased Risk ◽  
Positive Correlations ◽  
The Relationship ◽  
Rugby Players

Rugby is a demanding contact sport. In light of research, poor balance, reduced jumping ability, muscle strength, and incorrect landing patterns might contribute to the increased risk of injury in athletes. Investigating the relationship between tests assessing these abilities might not only allow for the skillful programming of preventive training but also helps in assessing the risk of injury to athletes. Thus, the main purpose of this study was to investigate the relationship between dynamic balance, vertical and horizontal jumps, and jump-landings movement patterns. Thirty-one healthy amateur adolescent rugby players (age: 14.3 ± 1.6 years, height 171.4 ± 9.7 cm, body mass 80 ± 26 kg) participated in the study. Data were collected by the Y-balance Test (YBT), Counter Movement Jump (CMJ), Single Leg Hop for Distance (SLHD), and Landing Error Score System (LESS). Significant positive correlations were found between SLHD both legs (SLHDb) and YBT Composite both legs (COMb) (r = 0.51, p = 0.0037) and between SLHDb and CMJ (r = 0.72, p < 0.0001). A relationship was also observed between the CMJ and YBT COMb test (r = 0.51, p = 0.006). Moderate positive correlations were found between the dominant legs in SLHD and the posterolateral (r = 0.40, p = 0.027), posteromedial (r = 0.43, p = 0.014), and composite (r = 0.48, p = 0.006) directions of the YBT. These results indicate that variables that are dependent on each other can support in the assessment of injury-risk and in enhancing sports performance of young athletes.

Comparison of Two Rehabilitation Protocols on Patient- and Disease-Oriented Outcomes in Individuals With Chronic Ankle Instability

2017 ◽  
Vol 22 (3) ◽  
pp. 57-65 ◽  
Author(s):  
Kyle Kosik ◽  
Masafumi Treada ◽  
Ryan McCann ◽  
Samantha Boland ◽  
Phillip A. Gribble
Keyword(s):  
Ankle Instability ◽  
Dynamic Balance ◽  
Controlled Trial ◽  
Intervention Programs ◽  
Foot And Ankle ◽  
Balance Test ◽  
Randomized Controlled ◽  
Rehabilitation Protocols ◽  
Main Effect ◽  
Ability Measure

Proximal neuromuscular alterations are hypothesized to contribute to the patient- and disease-oriented deficits observed in CAI individuals. The objective was to compare the efficacy of two 4-week intervention programs with or without proximal joint exercises. Twenty-three individuals with CAI completed this single-blinded randomized controlled trial. Outcome measures included the Star Excursion Balance Test (SEBT) and the Foot and Ankle Ability Measure (FAAM). A time main effect was observed for the FAAM-ADL (p = .013), FAAM-Sport (p = .012), and posteromedial (p = .04) and posterolateral (p = .003) SEBT reach directions. No group main effect or time by group interaction was found. Four weeks of supervised rehabilitation improved self-reported function and dynamic balance in people with CAI.

Comparison of the effect of foot orthoses on Star Excursion Balance Test performance in patients with chronic ankle instability

2018 ◽  
Vol 43 (1) ◽  
pp. 6-11 ◽  
Author(s):  
Faezeh Abbasi ◽  
Mahmood bahramizadeh ◽  
Mohammad Hadadi
Keyword(s):  
Ankle Sprain ◽  
Ankle Instability ◽  
Dynamic Balance ◽  
Chronic Ankle Instability ◽  
Textured Surface ◽  
Foot Orthoses ◽  
Textured Surfaces ◽  
Balance Test ◽  
Star Excursion Balance Test ◽  
Foot Orthosis

Background: Chronic ankle instability as a prevalent consequence of ankle sprain causes various impairments such as balance and postural control deficits. Foot orthoses are one of the common interventions for rehabilitation of patients with chronic ankle instability. Objectives: To investigate the effect of custom-molded foot orthoses with textured surfaces on dynamic balance of chronic ankle instability patients and to compare their effects with other types of foot orthoses. Study design: This is a repeated measure design. Methods: A total of 30 participants were recruited based on the guideline introduced by the International Ankle Consortium. The effect of prefabricated, custom-molded, and custom-molded with textured surface foot orthoses was evaluated on dynamic balance by the Star Excursion Balance Test. Normalized reach distances in anteromedial, medial, and posteromedial directions of the test were computed to be used for statistical analysis. Results: The foot orthoses increased reach distances compared to the no-orthosis conditions in all three directions. The custom-molded with textured surface foot orthosis has significant differences compared with prefabricated foot orthosis ( p = 0.001) in all measured directions and with custom-molded foot orthosis ( p < 0.01) in medial and posteromedial directions. Conclusion: Foot orthoses improve reach distances in patients with chronic ankle instability. Custom-molded with textured surface foot orthosis has a more pronounced effect compared with other foot orthoses. Clinical relevance The custom-molded foot orthosis with textured surface could be an effective device to improve dynamic balance in chronic ankle instability (CAI) patients. It may be considered as an efficient intervention to reduce ankle sprain recurrence in these individuals, although further research should be conducted.

Research on Control Power and Self-Sensing Technology for GMM Self-Sensing Actuator

2010 ◽  
Vol 34-35 ◽  
pp. 1314-1318
Author(s):  
Xin Hua Wang ◽  
Shou Qiang Hu ◽  
Qian Yi Ya ◽  
Shu Wen Sun ◽  
Xiu Xia Cao
Keyword(s):  
Real Time ◽  
High Speed ◽  
Dynamic Balance ◽  
The Self ◽  
Time Dynamic ◽  
Scheme Design ◽  
Control Power ◽  
Sensing Technology ◽  
The Cost ◽  
Micro Controller Unit

Structure and principle of a new kind of diphase opposition giant magnetostrictive self-sensing actuator (SSA for short) is introduced, for which a kind of double outputs high-precision NC stable voltage power is designed. With the method of combining with the hardware design and the software setting, the controllability and reliability of the actuator are greatly improved. And the whole design becomes more reasonable, which saves the cost and improves the practicability. In addition, based on the micro controller unit (MCU) with high-speed control, the scheme design of the real-time separation circuit for dynamic balance signal can effectively identify out and pick up the self-sensing signal which changes from foreign pressure feed back. Then the SSA real-time, dynamic and accurately control is realized. The experiment results show that the voltage power can high-speed and accurately output both output voltages with high current, and that the self-sensing signal decoupling circuit can isolate the self-sensing signals without distortion

scholarly journals Mathematical Model of the Dynamic Action of the Controlled Vibration Exciter on the Processed Medium of Mixer with Toroidal Working Container

2018 ◽  
Vol 7 (3.2) ◽  
pp. 478
Author(s):  
Serhii Zhyhylii ◽  
Maksym Kharchenko ◽  
Julia Katella
Keyword(s):  
Mathematical Model ◽  
Force Field ◽  
Dynamic Balance ◽  
External Action ◽  
Vibration Exciter ◽  
Turn Angle ◽  
Dynamic Action ◽  
Resonance Frequencies ◽  
Balance State ◽  
Intermediate Resonance

Vibration mixers are technological machines that are meant for mixing of different processed medium. A driving force in such machines is realizing by oscillation exciter. In this article, the constructive scheme of the vibration mixer is introduced. Such a mixer has the toroidal working container and is equipped with controlled mechanical centrifugal unbalanced exciters of oscillations with a vertically located unbalanced shaft. The work principle of one of the possible configurations in this exciter is considered and provided. One inflexible and two mobile unbalances are strengthen on its unbalanced shaft. The mobile unbalances by means of independent external action, that is caused by mechanism for managing of mobile unbalances, have an opportunity to change synchronously its positions on the unbalanced shaft directly in time of mixer’s work. The centrifugal inertia forces of inflexible and mobile unbalances make the dynamic wrench that consists of the main vector  and the main moment  and rotates with unbalanced shaft. It is determined that the value of the main vector  and the main moment  evaluate the dynamic action of this vibration exciter to the mixer’s working container. The mathematical model of the dynamic action of oscillator exciter on the processed medium of mixer with the toroidal working container is received. Depending on the value of turn angle of mobile unbalances from its starting positions exciter: a) staying in the dynamic balance state; b) is generating the translation force field; c) generates the wrench force field of this or that direction. These opportunities of controlled vibration exciter firmly provide anfractuous circulative motion of the processed medium on the volume of the mixer’s working container. Using of controlled exciter also leaves out the transfers through intermediate resonance frequencies. As its starting and stopping happen in a dynamic balance state, so it leaves out the possibility of manifestation of the “Sommerfeld’s effect” that is harmful for the driven motor, improves the constructive availability of the vibration mixer and increases its efficiency and life duration. 

scholarly journals Investigation of the Effect of Acute Muscular Fatigue on Static and Dynamic Balance Performances in Elite Wrestlers

2019 ◽  
Vol 8 (5) ◽  
pp. 179
Author(s):  
Ömer Özer
Keyword(s):  
Aerobic Power ◽  
Dynamic Balance ◽  
Muscular Fatigue ◽  
Static Balance ◽  
Muscular Endurance ◽  
Maximal Strength ◽  
Balance Test ◽  
Balance Exercise ◽  
Fatigue Exercise ◽  
Before And After

Maximal strength, muscular endurance, maximal aerobic power, and anaerobic capabilities, power are needed to have victory for wrestlers in a wrestling competition.The aim of the study is to investigate the effect of acute muscular fatigue on static and dynamic balance performances in elite wrestlers. Ten elite male wrestlers (25 &plusmn; 2.3 years, 181 &plusmn; 6.5 cm, 84 &plusmn; 4.2 kg) participated in the study voluntarily. Participants were undertaken dynamic and static balance test before fatigue exercise (in Cybex) and immediately after fatigue exercise, theywere undertaken dynamic and static balance test again. SPSS packet program was used to evaluate the data. There were no statistically significant differences in static and dynamic balance before and after fatigue. The results show that wrestlers&rsquo; balance is not affected by muscular fatigue, so there is no need for balance exercise after fatigue at least according to this study.

scholarly journals Effect of Exercises in Water and Land on Balance and Cognitive Functions in Elderly and Old Persons

2019 ◽  
Vol 1 (18) ◽  
Author(s):  
Remigija Dekaminavičiūtė ◽  
Vilma Dudonienė
Keyword(s):  
Cognitive Functions ◽  
Elderly Women ◽  
Dynamic Balance ◽  
Exercise Program ◽  
Static Balance ◽  
Trail Making Test ◽  
Exercise Programs ◽  
Balance Test ◽  
Trail Making ◽  
Better Than

Research background. Aging constantly manifests itself not only in physiological changes, but also in cognitive ones. Exercise programs for elderly have been created aiming at avoiding risk of falling, but there is little known about changes in cognitive functions under the effect of exercise. The aim was to evaluate the effect of water-based and land-based exercises on balance and cognitive functions in elderly women and men. Methods. The dynamic balance of study participants (n = 32) was evaluated using Timed Up & Go Test, the static balance was evaluated with a 4-position Static Balance Test and the cognitive functions were evaluated with Six-Item Cognitive Impairment Test, the Cognitive Failures Questionnaire and the Trail Making Test. The participants were randomly divided in two groups: water exercise and land-based exercise. Results. After 8 weeks of exercise in water and on land, static and dynamic balance and cognitive functions improved in both groups (p < 0.05), no statistically signifcant difference was found between the groups except for the trail making test, which was performed more quickly by subjects who attended exercise in water. After the exercise program, the men’s dynamic and static balance (while standing in the tandem position) were better than women’s, but women’s standing on one leg position was better than that of men’s (p < 0.05). Conclusion. There were no statistically signifcant differences in cognitive function between men and women after intervention. After both exercise programs, dynamic and static balance (in the tandem position) in men were better (p < 0.05) than those in women, standing on one leg but women’s position was statistically signifcantly better than that of men’s.Keywords: exercise program in water and land-based, static and dynamic balance, cognitive functions.

scholarly journals The effect of prophylactic knee bracing on proprioception performance in first division rugby union players

2004 ◽  
Vol 16 (1) ◽  
pp. 33 ◽  
Author(s):  
TH Kruger ◽  
MF Coetsee ◽  
S Davies
Keyword(s):  
South African ◽  
Sports Medicine ◽  
Dynamic Balance ◽  
Rugby Union ◽  
Knee Brace ◽  
Balance Test ◽  
Kwazulu Natal ◽  
Test Order ◽  
The University ◽  
Rugby Players

Objective. To investigate the effects of prophylactic knee bracing on proprioceptive performance among first division rugby union players during a 2-minute Wilknox Quad Time Logger balancing task. Design. Each subject performed a 2-minute balancing task on the Wilknox Quad Time Logger. Test order, left or right leg, and the sequence of brace or non-brace, were randomised. Subjects were placed on the balancing board and instructed to balance for 2 minutes. Subjects performed 6 trials. Two days elapsed between testing. Each testing day involved 2 trials, 1 trial with and 1 without the prophylactic knee brace. Settings. Testing took place at the biokinetics laboratory of the University of Zululand. Subjects. Thirty playing (not injured) male rugby players, aged 22 - 30 years, participating in the KwaZulu-Natal club championships (2000). Outcome measure. Performance was measured in terms of time that balance was lost in a dynamic balance test. Peak proprioception was the best balancing performance recorded, and average proprioception the average balancing performance for all trials. Results. The findings showed an improvement of 17.9% in average proprioception times and 19.1% in peak proprioception times with the application of a prophylactic knee brace (p < 0.01). Conclusion. Prophylactic knee bracing improved proprioception performance of playing (uninjured) rugby players, and therefore may be responsible for the improvement in knee injury statistics reported in some studies on knee bracing. South African Journal of Sports Medicine Vol.16(1) 2004: 33-36

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