• Title/Summary/Keyword: Muscle performance

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Effects of crude glycerin from waste vegetable oil in diets on performance and carcass characteristics of feedlot goats

  • Chanjula, Pin;Cherdthong, Anusorn
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.4
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    • pp.514-521
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    • 2018
  • Objective: This experiment was conducted to investigate the effects of crude glycerin from waste vegetable oil (CGWVO) on performance, carcass traits, meat quality, and muscle chemical composition. Methods: Twenty-four crossbred (Thai Native${\times}$Anglo Nubian) uncastrated male goats ($16.8{\pm}0.46kg$ body weight [BW]) were assigned to a completely randomized design and subjected to four experimental diets containing 0%, 2%, 4%, and 6% of CGWVO (63.42% of glycerol and 47.78% of crude fat) on a dry matter (DM) basis. The diets were offered ad libitum as total mixed rations twice daily. The feed intake, feeding behavior, growth performance, carcass and meat traits, and muscle chemical composition were evaluated. Results: Based on this experiment, there were significant differences (p>0.05) among groups regarding DM intake, growth performance, and carcass traits where goats receiving 6% of CGWVO had lower daily DM intake, growth performance, and carcass traits than those fed on 0%, 2%, and 4% of CGWVO. There were no effects of CGWVO on carcass length, carcass width, Longissimus muscle (LM) area, Warner-Bratzler shear force, pH and color of LM at 45 min after slaughter, as well as on other carcass cut and muscle chemical composition. Conclusion: In conclusion, the addition of up to 4% of DM in the diets for crossbred finishing goats seems to be the most interesting strategy, since it promotes greatest animal performance. Moreover, this study was a suitable approach to exploit the use of biodiesel production from waste vegetable oil for goat production.

A Relationship Between the EMG Silent Period and Muscle Fatigue of the Masticatory Muscle (저작근의 근전도 휴지기와 근육피로와의 관계)

  • Kim, Tae-Hoon;Yang, Deok-Jin;Kang, Byeong-Gil;Cho, Il-Jun;Lee, Jin;Kim, Sung-Hwan
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.50 no.5
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    • pp.247-254
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    • 2001
  • Silent period(SP) is transient stops of muscle activity that are induced by mechanical or electrical stimulus and the duration of silent period is a important parameter that have been associated with symptoms of masticatory dysfunction. Muscle fatigue is induced by sustained muscular contractions. It is associated with the external manifestations as the inability to maintain a desired force output, muscular tremor, and localized pain. Muscle fatigue is a parameter that have been measured or monitored the deterioration of a performance of muscles. On the study of relationship between SP and masticatory muscle fatigue, Nagasawa suggested that SP increases up to 3 min. from the beginning of clenching when the subjects performed sustained contractions at 50% maximum clenching level. In this paper, in order to evaluate a relationship between SP and muscle fatigue, 10 SPs per 1 minute are measured at 10%, 20%, 50% maximum clenching level. We used the median frequency in order to quantify the degree of muscle fatigue. However, the results shows that the duration of silent period was not significantly affected by differing levels of muscle fatigue. Therefore, we suggest that the SP is not increased or decreased as the results of muscle fatigue, also the origin of the SP generation mechanism is discussed.

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The Effects of Lumbar Stabilization Exercise on Muscle Activity and Isokinetic Muscle Strength of Female Patients with Chronic Low Back Pain (요부안정화 운동이 만성요통여성 환자의 근활성도와 등속성 근력에 미치는 영향)

  • 방현수
    • Journal of the Korean Society of Physical Medicine
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    • v.10 no.2
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    • pp.63-71
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    • 2015
  • PURPOSE: The purpose of this study to investigate the effects of exercise on lumbar stabilization in muscle activity and isokinetic muscle strength of female with chronic low back pain. METHODS: The candidates was chose to twenty women in their 30s and 40s complaining back pain for over 12 weeks and consist of 10 people for lumbar stabilization and general physical therapy group(PL group), another 10 people for general physical therapy group(GP group). Lumbar stabilization exercise was conducted for 8 weeks and was comprised of 60 minutes for two times a week. In order to examine the effects of lumbar stabilization, results in the present study were analyzed maximal voluntary isometric contraction (MVIC) using electromyogram to measure muscle activity and isokinetic performance including peak torque and average power at the pre to post. RESULTS: The following are results in this study. The MVIC and isokinetic muscle strength were gradually increased in all group. As the result of the test of the MVIC and isokinetic muscle strength, the difference of lumbar stabilization and general physical therapy group is statistically more significant than that of general physical therapy group. CONCLUSION: In the present study, results indicate that lumbar stabilization helps to improve the muscle activity and isokinetic muscle strength.

The Effects of Mental Practice about Leg Exercise Muscle Activities of the Rectus Femoris

  • Kim, Tae-Hoon;Kim, Kyung-Hun;Kim, Ju-O
    • Journal of Korean Physical Therapy Science
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    • v.24 no.3
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    • pp.39-47
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    • 2017
  • Purpose: This study aimed to investigate the effects of mental practice about leg exercise muscle activities of the rectus femoris. Method: 20 subjects were participated in this study. The values before the experiment were measured and those after the mental performance from the first experiment to the fifth experiment were measured. Electromyography (EMG) was used to measure the muscle activity of rectus femoris. Result: The muscle activity of the both rectus femoris after mental practice increased steadily and showed significant differences. Conclusion: In the present study, it was found that the muscle activity of both legs was increased during the mental practice. It can be seen that there was a difference before and after mental practice, and muscle activity of rectus femoris was increased.

The effects of cryotherapy on delayed onset muscle soreness (지연발생 근육통의 냉치료 효과에 대한 연구)

  • Kim, Sang-Yeob
    • Journal of Korean Physical Therapy Science
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    • v.8 no.2
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    • pp.1065-1071
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    • 2001
  • Delayed onset muscle soreness is a sensation of discomfort that occurs 24 h after exercise, and it is associated with the performance of unfamiliar and high force muscle work, such as eccentric contractions. The injury to the muscle has been well described but the mechanism underlying the injury is not fully understood. Although the pathophysiological processes underlying delayed onset muscle soreness are not completely understood, many researchers have investigated various treatments in a attempt to reduce the soreness. Physical therapy is the most importance techniques to reduce delayed onset muscle soreness. The purpose of this study is to investigate the effect of a cryotherapt on DOMS. Thirty subjects were randomly assigned to experimental group : control, cryotherapy, and placebo group. Elbow flexion range, mechanical pain threshold. and subjective pain were measured 30 min before DOMS was induced and 24, 48, 72 hours after DOMS was induced. The results of this study were as follows: 1. Elbow flexion range showed significant difference each time, especially at 48 and 72 hours 2. Mechanical pain thershold and subjectively pain showed no significant difference between group.

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Influence of Unilateral Muscle Fatigue in Knee and Ankle Joint on Balance and Gait in Healthy Adults

  • Lee, Na-Kyung;Kim, Young-Mi;Kim, Kyoung
    • The Journal of Korean Physical Therapy
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    • v.29 no.1
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    • pp.39-43
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    • 2017
  • Purpose: This study was to investigate the effects of unilateral muscle fatigue in knee and ankle joints on balance and gait in healthy adults. Methods: Exercise inducing muscle fatigue in the knee joint consisted of concentric and eccentric contraction of dominant knee extensors in healthy adults by using the Leg Extension Rehap exercise machine (HUR, Finland). Exercise inducing muscle fatigue in the ankle joint was composed of voluntary contractions and forced contractions of the dominant plantar flexors in healthy adults. Exercises to induce muscle fatigue in the knee and ankle joints were performed until the subject complained of fatigue or pain, the occurrence of muscle fatigue was confirmed by electromyography. We measured static and dynamic balance using the Good Balance system and gait performance by RS-scan. Results: Static and dynamic balance ability and spatial-temporal gait decreased significantly after muscle fatigue in knee and ankle joint. Conclusion: These results show that unilateral muscle fatigue of the lower extremities affected postural control and gait. Therefore, therapists and sport trainers should minimize the risks of fall and injuries related to unilateral muscle fatigue.

Comparison of Muscle Activity Between Handwriting and Touchscreen Use in Younger Adults and the Elderly

  • Min, Se-Ra;Jung, Young-Jin;Yoon, Tae-Hyung;Jung, Nam-Hae;Kim, Tae-Hoon
    • International Journal of Contents
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    • v.16 no.1
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    • pp.57-64
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    • 2020
  • We sought to compare upper extremity muscle activity between handwriting on paper and touchscreen with dominant and non-dominant hands in younger adults (age 23.90±1.12) and the elderly (age 75.55±5.76). Muscle activity (percent of maximum voluntary contraction) in the biceps brachii muscle, triceps brachii muscle, flexor carpi ulnaris muscle, and extensor carpi ulnaris muscle was measured using an electromyography device. As a result, our data indicate that muscle activity is lower in younger adults than the elderly. Besides, muscle activity is lower in the dominant versus non-dominant hand, and lower when writing using a touchscreen than on paper. These results can be used to support recommending touchscreens in the elderly. Also, they can be used as baseline data for comparing the performance of non-paretic side and paretic side in patients relative to the central nervous system.

Effect of Russian Current Stimulation on Muscular Performance and Muscle Activity of Quadriceps Femoris Muscle of Convalescent Patient after Leg Fracture (러시안 전류 자극이 하지 골절 후 회복기 환자의 넙다리네갈래근육의 근수행력과 근활성도에 미치는 영향)

  • Jung, Byeong-Ok;Bang, Hyun-Soo
    • Journal of Digital Convergence
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    • v.12 no.7
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    • pp.365-370
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    • 2014
  • The present study was aimed to comprehend the effect of the Russian current stimulation on the muscular performance and activity of quadriceps femoris muscle of the convalescent patient after the leg fracture.This study conducted test based on 20 patients after leg fracture. Russian current was applied for six weeks as three times in a week, between January 9, 2013 and 15 March 16, 2013. The electromyogram was used to measure the muscle activity of the quadriceps femoris, and the isokinetic equipment was used to measure the muscular performance. The muscular performance difference by duration depending on the application of the Russian current showed the significant increase in all muscular performances. The activity of all muscles of the quadriceps femoris muscle by duration showed significant increase. These results showed that the Russian current can be the effective treatment method for enhancing the muscular strength of the weakened lower limbs muscle due to the problem such as the leg fracture.

A Pilot Study on the Muscle Activities in Step Input Test as an Indicator of the Vehicle Characteristics

  • Kong, Yong-Ku;Jung, Myung-Chul;Lee, In-Seok;Hyun, Young-Jin;Kim, Chang-Su;Seo, Min-Tae
    • Journal of the Ergonomics Society of Korea
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    • v.32 no.3
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    • pp.217-227
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    • 2013
  • Objective: The purpose of this study was to analyze 'response time', 'peak response time' and 'overshoot value' for each muscle by applying the EMG signal to the vehicle response in ISO 7401 and to quantify the response of the driver according to vehicle characteristics by comparing vehicle characteristics and muscle responses of the driver. Background: The Open-loop test defined in international standards ISO 7401 is the only method for evaluating the performance of the vehicle. However, this test was focused only on mechanical responses, not driver's ones. Method: One skilled male driver(22 yrs. experience) was participated in this experiment to measure muscle activities of the driver in transient state. Then the seven muscle signals were applied to calculate 'response time', 'peak response time', and 'overshoot value'. Results: In the analyses of the EMG data, the effects of vehicle type and muscle were statistically significant on the 'response time' and 'peak response time'. Also, the effects of vehicle type, muscle, and lateral acceleration level were statistically significant on the 'overshoot value' in this study. According to the analyses of the vehicle motion data, vehicle motion variable(LatAcc, Roll, YawVel) was statistically significant on the 'response time' and vehicle type, vehicle motion variable, and lateral acceleration level were statistically significant on the 'peak response time', respectively. Conclusion: In the analyses of the 'response time' and 'overshoot value', the data of muscle activities(EMGs) was better index that could evaluate the vehicle characteristic and performance than the data of vehicle motion. In case of peak response time, both EMG and vehicle motion data were good index. Application: The EMGs data from a driver might be applicable as index for evaluation of various vehicle performances based on this study.

Focal Muscle Vibration Changes the Architecture of the Medial Gastrocnemius Muscle in Persons With Limited Ankle Dorsiflexion

  • Moon, Il-Young;Lim, Jin-Seok;Park, Il-Woo;Yi, Chung-Hwi
    • Physical Therapy Korea
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    • v.29 no.1
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    • pp.48-53
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    • 2022
  • Background: The gastrocnemius tightness can easily occur. Gastrocnemius tightness results in gait disturbance. Thus, various interventions have been used to release a tight gastrocnemius muscle and improve gait performance. Moreover, focal muscle vibration (FMV) has recently been extensively researched in terms of tight muscle release and muscle performance. However, no study has investigated the effects of FMV application on medial gastrocnemius architectural changes. Objects: In this study, we aimed to investigate the effects of FMV on medial gastrocnemius architecture in persons with limited ankle dorsiflexion. Methods: Thirty one persons with <10° of passive ankle dorsiflexion participated in this study. We excluded persons with acute ankle injury within six months prior to study onset, a history of ankle fracture, leg length discrepancy greater than 2 cm, no history of neurological dysfunction, or trauma affecting the lower limb. The specifications of the FMV motor were as follows: a fixed frequency (fast wave: 150 Hz) and low amplitude (0.3-0.5 mm peak to peak) of vibration; the motor was used to release the medial gastrocnemius for 15 minutes. Each participant completed three trials for 10 days; a 30-second rest period was provided between each trial. Medial gastrocnemius architectural parameters [muscle thickness (MT), fiber bundle length (FBL), and pennation angle (PA)] were measured via ultrasonography. Results: MT significantly decreased after FMV application (p < 0.05). FBL significantly increased from its baseline value after FMV application (p < 0.05). PA significantly decreased from its baseline value after FMV application (p < 0.05). Conclusion: FMV application may be advantageous in reducing medial gastrocnemius excitability following a decrease in the amount of contractile tissue. Furthermore, FMV application can be used as a stretching method to alter medial gastrocnemius architecture.