• Journal of Biomedical Engineering Research
• /
• v.38 no.6
• /
• pp.308-312
• /
• 2017

Skeletal muscle function plays a very important role in quality of life. However, skeletal muscle causes functional decline under aging or some diseases. Exercise and muscle training are good solutions to delay sarcopenia, but there are limitations to those who are uncomfortable in exercise. For this reason, alternative interventions for muscle sarcopenia are required, and many studies proved the increase of skeletal muscle mass by electrical stimulation. In conventional studies, however, mouse skeletal muscle cells have been mostly used in experiments to identify electrical stimulation conditions while human derived cells have not been frequently utilized in these studies. Stimulation used for rehabilitation has been uniformly treated without the consideration of aging. In addition, many studies have been used with conventional petri dish usually requiring many numbers of cells, which is not appropriate for rare. Moreover, they are not usually condition uniformity of electrical field. In this study, we have developed an electrical stimulation device which consumes a small amount of cells and can form a uniform electrical field. With the system, we analyzed the skeletal muscle differentiation and Myotube thickness depending on the electrical stimulation condition.

• The Journal of Korean Physical Therapy
• /
• v.25 no.2
• /
• pp.76-80
• /
• 2013

Purpose: The objective of this study was to offer primary clinical data examining whether change of imaging structure and quantitative evaluation of muscle activity on myofascial trigger points can lead to implementation of an analytical technique for evaluation of myofascial pain diagnoses. In addition, we examined the effect of a variety of mediation techniques, in order to examine neuromuscular physiological characteristics of myofascial trigger points muscle by comparing differences in pressure pain threshold and ultrasound imaging. Methods: Participants in the study included 30 adults in their twenties. The subjects were divided into the normal and myofascial trigger points groups. Clinical outcomes were evaluated by pressure pain threshold for pain and ultrasound imaging was performed for evaluation of the structural characteristics of muscle. Independent t-test was used for statistical analysis. Results: The two groups showed statistical significance in the change in pressure pain threshold (p<0.05). Findings of ultrasound imaging analysis showed no significant differences, increased muscle thickness was observed (p>0.05). Findings of ultrasound imaging analysis showed significant differences, increased muscle echodensity was observed (p<0.05). Findings on ultrasound imaging analysis showed significant differences, increased muscle white area index was observed (p<0.05). Conclusion: From these results, active myofascial trigger points muscle showed quality deterioration on ultrasound imaging. Thorough evaluation of imaging structure and physiological characteristics can be useful quantitative analytical techniques for diagnosis of myofascial pain syndrome and a primary factor reflected in physical therapy intervention.

• Journal of the Korean Academy of Clinical Electrophysiology
• /
• v.8 no.1
• /
• pp.23-29
• /
• 2010

Purpose : This study is to offer clinical primary data that examines the change of imaging structure and the quantitative evaluation of muscle activity on myofascial trigger points. This study examines neuromuscular physiological characteristic by comparing the differences in physical findings, pressure pain threshold, imaging, and electrophysiological characteristics in latent and active myofascial trigger points muscle and normal muscle through the following experimental procedures. Methods : The participants for the study were thirty-three adults in their twenties. We divided three groups into normal, latent and active myofascial trigger points groups by physical findings. We analyzed the results of measured pressure pain, threshold for pain, ultrasound imaging perform for structure characteristic of muscle, surface EMG according to type of muscle contraction for function of muscle contraction. Results : Significant differences were indicated in pressure pain threshold (p<0.05). Significant differences were discovered in the ultrasound imaging analysis. There were increases in muscle Echogenicity white area index (p<0.001). There were significant differences that decrease in %MVIC (p<0.05), increase in MDF (p<0.05). Conclusion : From these results, active rnyotascial trigger points muscle showed quality deterioration on ultrasound imaging and decreased function of muscle contraction, increased motor unit action potential of II type fiber, and electrophysiologically. Imaging structure and neuromuscular physiological characteristic can be diagnostic and quantitative analytical techniques for myofascial pain syndrome and a primary factor that reflected in physical therapy intervention.

• Nutrition Research and Practice
• /
• v.15 no.4
• /
• pp.528-540
• /
• 2021

BACKGROUND/OBJECTIVES: In a healthy person, from 35 years of age, there is an annual loss of muscle mass at the rate of 1-2% and is associated with a decline in the quality of life. This study aimed to identify the particular dietary patterns associated with the risk of lower lean muscle mass in Korean postmenopausal women. SUBJECTS/METHODS: The Korea National Health and Nutrition Examination Survey (KNHANES) is a population-based, continuous cross-sectional annual survey. The participants of the KNHANES IV (2008-2009) and V (2010-2011) were considered for this study. The study sample consisted of 1548 postmenopausal women, aged 45-86 years. Lower lean muscle mass was defined as having appendicular skeletal muscle mass corrected for body weight less than 1 standard deviation of the young reference group aged 20 to 39 years in KNHANES IV and V. To identify the dietary pattern using factor analysis, 24-h recall data was used. RESULTS: The prevalence of lower lean muscle mass was 31.3% in this study population. Four dietary patterns were identified by factor analysis; 'Diverse', 'Western', 'Traditional', and 'Snacks and beverages'. The 'Western' pattern, highest factor loadings for flour and bread, potatoes, red meat, processed meat, eggs, and cheese, was significantly associated with a high (60%) risk of lower lean muscle mass (odds ratio [95% confidence interval] = 1.60 [1.07-2.39], P for trend = 0.01) after adjustments for potential covariates. The other 3 dietary patterns were not associated with lower lean muscle mass. CONCLUSIONS: The study findings suggest that the 'Western' dietary pattern that includes flour and bread, potatoes, red meat, processed meat, eggs, and cheese, may be associated with a higher risk of lower lean muscle mass in Korean postmenopausal women.

• Exercise Science
• /
• v.26 no.2
• /
• pp.103-114
• /
• 2017

INTRODUCTION: Regulation of skeletal muscle protein mass is implicated not only in exercise performance but in metabolic health. Exercise in combination with nutrition, particularly dietary protein/amino acid intake, are the pragmatic approach that effectively induces muscle anabolic response (i.e., muscle hypertrophy) through regulating protein synthesis and breakdown. PURPOSE: The purpose of this review was to summarize available data on the effect of exercise intervention and amino acids intake on muscle protein synthesis and breakdown and provide an insight into development of an effective exercise intervention and amino acids supplements, applicable to training practice. METHODS: In this review, we have reviewed currently available data mainly from stable isotope tracer studies with respect to the effect of exercise intervention and protein or amino acid supplement on muscle protein anabolic response. CONCLUSIONS: Taken together, exercise alone may not be effective in achieving a positive net muscle protein balance due to the fact that protein breakdown still exceeds protein synthesis until nutrition intake such as protein/amino acids. It appears that muscle anabolic response increases in proportional to the amount of protein intake up to 20 - 35 g depending on quality of protein, age, differences on exercise intensity, duration, and frequency, and individual's training status

• Journal of Environmental Science International
• /
• v.24 no.1
• /
• pp.117-131
• /
• 2015

Purpose: In this study a pilates exercise program using self-efficacy sources was provided for women 65 years of age or older and the effects on physical fitness, body composition, depression, self-efficacy, and health-related quality of life were tested. Methods: A quasi-experimental study employing a nonequivalent control group, pre-post design was conducted. The subjects consisted of 30 older women in the experiment group and 30 in the comparison group. The intervention was conducted twice a week for a period of 12 weeks. During this period, the pilates exercise program using self-efficacy sources (health education, phone coaching, mentoring, checking homework, recreation) were provided in the experiment group and pilates exercise program were offered in the comparison group. Chi-square test, independent t-test, ANCOVA were used for data analysis. Results: Following completion of the program, upper muscle strength (F=4.131, p=.047), low muscle strength (F=5.558, p=.022), upper flexibility (F=5.252, p=.026), static balance (F=5.957, p=.018), dynamic body balance & agility(F=18.971, p<.001), endurance(F=10.058, p=.002), muscle mass (F=5.748, p=.020), depression (F=4.493, p=.038), Self-efficacy (F=33.853, p<.001), and Health-related quality of life(F=5.586, p=.022) were significantly better in the experimental group. Conclusion: Findings from this study indicate that the pilates exercise program using self-efficacy sources are effective in enhancing physical fitness, body composition, self-efficacy and health-related quality of life and in decreasing depression for female elders and could therefore be regarded as positive program for promotion of physical and mental health for older women.

• Animal Bioscience
• /
• v.34 no.4
• /
• pp.743-750
• /
• 2021

Objective: The objectives of this study were to explore the expression patterns of myosin heavy chain (MyHC) genes of different skeletal muscles from Chinese cattle, and to investigate the relationship between myofiber characteristics and meat quality of M. longissimus lumborum (LL), M. psoas major (PM), and M. semimembranosus (SM) from Chinese Luxi and Qinchuan cattle. Methods: Three major muscles including LL, PM, and SM from Chinese Luxi cattle and Chinese Qinchuan cattle were used in this study. The myofiber characteristics were measured by histochemical analysis. The MyHC isoforms expression was evaluated by real-time quantitative polymerase chain reaction. Quality traits including pH value, meat color, cooking loss, Warner-Bratzler shear force (WBSF) and sarcomere length were determined at day 5 postmortem. Results: PM muscle had higher pH value, a* value, sarcomere length and lower WBSF value compared to LL and SM muscles (p<0.05). Numbers of type I myofiber and the relative expression of MyHC I mRNA in PM muscle were higher than those of LL and SM muscles (p<0.05). Myofiber diameter of PM muscle was lower than that of LL and SM muscles, regardless of myofiber types (p<0.05). Conclusion: According to the stepwise linear regression analyses, tenderness was influenced by myofiber characteristics in all three examined muscles. Tenderness of beef muscles from Qinchuan and Luxi cattle could be improved by increasing numbers of type I myofiber.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.30 no.1
• /
• pp.61-73
• /
• 2024

Background: The purpose of this study is to investigate the effect of ankle strengthening and proprioceptor exercise, including gluteus-medius strengthening exercise, on ankle strength, dynamic and static balance, ankle function, and quality of life in 24 adults without ankle instability. Methods: After randomly classifying 12 people per group into the experimental group and the control group, Home-exercise rehabilitation program was conducted for a total of 2 weeks. The control group performed ankle strengthening and proprioceptor exercise 5 times a week for 15 minutes, and the experimental group was performed by adding 15 minutes of gluteus-medius strengthning exercise to the exercise performed by the control group. The SPSS 27.0 program was used for statistical analysis. Results: Both groups showed statistically significant differences in the plantar flexion muscle strength, Y-Balance test, side hop test, quality of life. But, only experimental group showed statistically significant differences dorsi-flexion muscle strength and hip abduction muscle strength. There was no statistical difference in comparison of difference values between groups. Conclusion: These exercises can provide useful home rehabilitation programs for sports populations seeking to prevent injury in sports.

• Journal of Animal Science and Technology
• /
• v.66 no.4
• /
• pp.645-662
• /
• 2024

Climate change, driven by the natural process of global warming, is a worldwide issue of significant concern because of its adverse effects on livestock output. The increasing trend of environmental temperature surging has drastically affected meat production and meat product quality, hence result in economic losses for the worldwide livestock business. Due to the increasing greenhouse gas emissions, the situation would get prolonged, and heat exposure-related stress is expected to worsen. Heat exposure causes metabolic and physiological disruptions in livestock. Ruminants and monogastric animals are very sensitive to heat stress due to their rate of metabolism, development, and higher production levels. Before slaughter, intense hot weather triggers muscle glycogen breakdown, producing pale, mushy, and exudative meat with less water-holding capacity. Animals exposed to prolonged high temperatures experience a decrease in their muscle glycogen reserves, producing dry, dark, and complex meat with elevated final pH and increased water-holding capacity. Furthermore, heat stress also causes oxidative stresses, especially secondary metabolites from lipid oxidation, severely affects the functionality of proteins, oxidation of proteins, decreasing shelf life, and food safety by promoting exfoliation and bacterial growth. Addressing the heat-related issues to retain the sustainability of the meat sector is an essential task that deserves an inclusive and comprehensive approach. Considering the intensity of the heat stress effects, this review has been designed primarily to examine the consequences of hot environment temperatures and related stresses on the quality and safety of meat and secondarily focus on cutting edge technology to reduce or alleviate the situational impact.

• Food Science of Animal Resources
• /
• v.38 no.3
• /
• pp.606-614
• /
• 2018

It is important to understand how marbling traits and tenderness differ among beef steaks from the carcass grading site and other regions within the longissimus thoracis (LT) muscle, as these characteristics are closely associated with consumer acceptability and willingness to purchase. Thus, the aim of this study was to compare the marbling fleck traits and objective tenderness parameters in the groups classified by the coarseness index (CI) of marbling fleck (high and low groups) at the carcass grading site ($13^{th}$ thoracic vertebra; 13T) and three different locations (13T, 9T, and 6T) within the LT muscle from well-marbled (marbling score 7 to 9) Hanwoo steer. Image analysis showed that the longitudinal locations had a significant effect on marbling fleck traits. The total area of large marbling fleck divided by the total marbling area (coarseness) was higher at the central region (13T to 12T) compared to the front thoracic region (6T to 5T) in the high CI group (0.23 vs. 0.17, p<0.05), whereas no significant differences were observed in the total number of marbling fleck within the LT muscle in the high or low CI groups (p>0.05). Location effect on objective tenderness parameters within the LT muscle was somewhat limited, although the high CI group had a lower Warner-Bratzler shear force (WBS) value than did the low group (p<0.05). Taken together, the degree of coarseness of marbling fleck decreased from the carcass grading site to the front thoracic site, whereas the objective tenderness parameters, including WBS and hardness, of the grading site did not differ from the other regions within the LT muscle.