• The Journal of the Korea Contents Association
• /
• v.11 no.12
• /
• pp.326-334
• /
• 2011

The aim of the study was to investigate the thickness of deep neck muscles during neck endurance tests using ultrasonography images to assess muscle sizes in persons with or without neck pain experience. Sixty-five university students volunteered for the study. The thicknesses of longus colli, longus capitis, semispinalis and cervical multifidus were assessed bilaterally using diagnostic ultrasound equipment during each endurance test. Participants were divided into two groups based on their Neck Pain(NP) experience; 45 subjects of those had no experience of NP (Group1) whereas 20 subjects of those reported NP experience sometime in their lives (Group2). Endurance time of both neck flexion and extension tests in Group1 showed significantly longer than Group's (p<0.01). The thicknesses of deep neck flexors and extensors were observed smallest at the terminal of endurance tests in general. Only left longus colli was found to be significantly smaller at rest in subjects of Group2 than Group 1's (P=0.02). The size difference between at contraction and the terminal of right longus capitis was observed bigger in subjects of group1 than subjects in group2. Future studies are needed to conduct with clinical subjects to assess contraction patterns of neck muscles.

• Journal of Digital Convergence
• /
• v.10 no.11
• /
• pp.551-558
• /
• 2012

Objectives: The purpose of this study was to determine whether the sacrooccipital category II blocking technique may improve abdominal muscle endurance and alleviate shoulder pain caused by pelvic tilting. Methods: A total of 50 subjects diagnosed with category II sacroiliac joint instability and lower back pain were randomly assigned to the control or treatment group. The sacrooccipital technique category II blocking procedure (2-min duration) was performed 3 times a week until the category II indicator of joint instability had subsided. The control subjects were subjected to a sham procedure of equal duration and frequency. We assessed abdominal muscle endurance using the partial curl-up test and shoulder pain using a visual analogue scale, before and immediately after the intervention and 2 weeks after the intervention. Results: On two-way analysis of variance with repeated measures on time factor, significant treatment and interaction effects on muscle endurance were found. A significant interaction effect, but not treatment effect, was found for shoulder pain. Post hoc test showed that the shoulder pain was reduced immediately after intervention (treated group) and 2weeks (control and treated group) after the intervention as compared to before the intervention. Conclusions: This study suggests that sacrooccipital category II blocking can be used to alleviate shoulder pain caused by pelvic instability. The mechanisms behind the long-term benefits may include an increase in abdominal muscle endurance.

• Korean Journal of Exercise Nutrition
• /
• v.24 no.2
• /
• pp.30-37
• /
• 2020

[Purpose] The present study investigated the effect of endurance exercise with blood flow restriction (BFR) performed at either 25% maximal oxygen uptake (${\dot{V}}O_2$ max) or 40% ${\dot{V}}O_2$ max) on muscle oxygenation, energy metabolism, and endocrine responses. [Methods] Ten males were recruited in the present study. The subjects performed three trials: (1) endurance exercise at 40% ${\dot{V}}O_2$ max without BFR (NBFR40), (2) endurance exercise at 25% ${\dot{V}}O_2$ max with BFR (BFR25), and (3) endurance exercise at 40% ${\dot{V}}O_2$ max with BFR (BFR40). The exercises were performed for 15 min during which the pedaling frequency was set at 70 rpm. In BFR25 and BFR40, 2 min of pressure phase (equivalent to 160 mmHg) followed by 1 min of release phase were repeated five times (5 × 3 min) throughout 15 minutes of exercise. During exercise, muscle oxygenation and concentration of respiratory gases were measured. The blood samples were collected before exercise, immediately after 15 min of exercise, and at 15, 30, and 60 minutes after completion of exercise. [Results] Deoxygenated hemoglobin (deoxy-Hb) level during exercise was significantly higher with BFR25 and BFR40 than that with NBFR40. BFR40 showed significantly higher total-hemoglobin (total-Hb) than NBFR40 during 2 min of pressure phase. Moreover, exercise-induced lactate elevation and pH reduction were significantly augmented in BFR40, with concomitant increase in serum cortisol concentration after exercise. Carbohydrate (CHO) oxidation was significantly higher with BFR40 than that with NBFR40 and BFR25, whereas fat oxidation was lower with BFR40. [Conclusion] Deoxy-Hb and total Hb levels were significantly increased during 15 min of pedaling exercise in BFR25 and BFR40, indicating augmented local hypoxia and blood volume (blood perfusion) in the muscle. Moreover, low-and moderate-intensity exercise with BFR facilitated CHO oxidation.

• 한국체육학회지인문사회과학편
• /
• v.55 no.3
• /
• pp.649-658
• /
• 2016

This study aimed to analyze PDH(Pyruvate dehydrogenase) and protein expression of PDK4(Pyruvate dehydrogenase kinase 4), PDP1(PDH phosphatase 1), enzymes that are involved in the activation of PDH, in skeletal muscle and to investigate the concentration of thiamine administration in liver and muscle following 4 weeks of endurance training. Methods : 6 weeks old male ICR mice were divided into two groups: sedentary group (CON, n=10; TH, n=10), and exercise group (EX, n=10, THEX, n=10). Thiamine(thiamine tetrahydrofurfuryl disulfide: TTFD) TTFD was orally administrated into TH and THEX groups in 50mg/kg body weight for 4 weeks. Treadmill training was performed in EX and THEX groups at about 70% of VO2max for 5 times a week for 4 weeks. Results : In this study, the concentration of glycogen was significantly increased following 4 weeks of endurance training, but a significant difference was not found following thiamine administration. Similarly, there was a significant effect of the training on PDH and the expression of PDK4 and PDP1 as PDH was increased by about 40% along with the increase in PDK4 and PDP1. However, there was no significant difference found between the groups following thiamine administration. Discussion : This result shows that there was no synergistic effect of thiamine administration, potentially due to adaptation of skeletal muscle from a long-term endurance training. Therefore, it will be necessary to consider the intake timing of thiamine and to analyze proteins that are related to PDH following the administration of complex carbohydrates.

• Korean Journal of Plant Resources
• /
• v.25 no.6
• /
• pp.657-663
• /
• 2012

Muscle strength and endurance activities of Korean ginseng (Panax ginseng C. A. Meyer; KG) were compared with those of wild simulated cultivation ginseng (WCG) in mice. Fifty male ICR mice were divided into five groups: A (vehicle); B (WCG 100 mg/kg); C (WCG 500 mg/kg); D (KG 100 mg/kg); E (KG 500 mg/kg). Subsequently, the mice were subjected to the forced swimming test (FST) and treadmill test at the $4^{th}$ and $7^{th}$ weeks. The glycogen content in the muscle and blood analysis (levels of glucose, triglyceride (TG), IGF-1) were also performed immediately after the last FST and treadmill test at the $7^{th}$ week. Immobility times in FST were shorter in WCG- than KG-treated groups, and the results of the treadmill tests were also significant except for KG-treated at 100 mg/kg. The glycogen content was increased in both groups with a peak at 500 mg/kg of WCG groups. Serum concentrations of TG and glucose were decreased by administration of KG and WCG and all treated groups showed increase in the level of IGF-1 in serum. These results suggest that KG and WCG supplementations are effective in escalating the muscle strength and endurance.

• PNF and Movement
• /
• v.17 no.3
• /
• pp.451-461
• /
• 2019

Purpose: This study identified the effect of abdominal muscle contraction using changes in waist circumference for healthcare workers with back pain due to inadequate posture during working hours. Methods: In this study, we provided educational training focused on posture alignment and utilized waist circumference change sensors to induce the contraction of abdominal muscles as a method to address low back pain in healthcare workers. All 32 participants received the same training and then were assigned to two groups: wearing the keeping core band (CB) and not wearing the keeping core band (NCB). For the CB group, the waist circumference change sensor was applied for 6 weeks during working hours. Wilcoxon's signed-ranks test and paired t-tests were used to compare the differences between the groups. All statistical significance levels were set to α=0.05. Results: Trunk muscle endurance increased significantly in the CB group. There was no significant difference in stability index to evaluate static postural control, but active hip abduction tests, which evaluate dynamic postural control, showed significant decrease in the CB group. Conclusion: These results suggest that the induction of abdominal contraction using the waist circumference change sensor may improve the trunk muscle endurance and the postural control ability of the hip and pelvis of healthcare workers.

• Korean Journal of Applied Biomechanics
• /
• v.15 no.3
• /
• pp.51-59
• /
• 2005

To examine the influence of aging on the mechanism of muscle fatigue, we compared the magnitude of central and peripheral fatigue in young and old women before, during and after a sustained submaximaI isometric contraction of elbow flexor muscles. Twelve women (6 young. $20.7{\pm}1.2$ years and 6 old, $68.8{\pm}29$ years) performed a contraction at 20% of maximal voluntary contraction (MVC) torque with their non-dominant arm. The old women were weaker than the young women, however their endurance time for the 20% contraction was longer compared with the young women ($1822{\pm}444$ vs. $1061{\pm}678$ sec, P <. 05). Both groups had a similar reduction in voluntary activation ratio (VA) during and after the fatiguing contraction. However, the old women showed much greater variability in VA before and after the contraction ($91.61{\pm}4.54%$ and $76.70{\pm}19.55\;%$ range of $79{\sim}99$ to $87{\sim}99%$ respectively) compared with the young women ($95.71{\pm}1.86\;%$ and $83.46{\pm}7.57\;%$ range of $39{\sim}75$ to $69{\sim}90%$, respectively). Furthermore, the EMG activity of the elbow flexor muscles and triceps brachii was greater for the old women compared with the young women throughout the fatiguing contraction, indicating different activation strategies with age. Indices of peripheral fatigue including twitch properties, showed that fatigue within the muscle was more rapid for the young women compared with the old women. These results suggest that although old women are weaker than young women, they have greater endurance due to mechanisms within muscle. Furthermore, old women showed great variability in their ability to optimally activate all muscle fiber compared with young women for an isometric contraction.

• Korean Journal of Exercise Nutrition
• /
• v.24 no.2
• /
• pp.11-21
• /
• 2020

[Purpose] Doxorubicin (DOX) is a potent anti-cancer drug that appears to have severe myotoxicity due to accumulation. The skeletal muscle has a regeneration capacity through satellite cell activation when exposed to extracellular stimulus or damage. Endurance exercise (EXE) is a therapeutic strategy that improves pathological features and contributes to muscle homeostasis. Thus, this study investigated the effect of EXE training in mitigating chronic DOX-induced myotoxicity. [Methods] Male C57BL/6J mice were housed and allowed to acclimatize with free access to food and water. All the mice were randomly divided into four groups: sedentary control (CON, n=9), exercise training (EXE, n=9), doxorubicin treatment (DOX, n=9), doxorubicin treatment and exercise training (DOX+EXE, n=9) groups. The animals were intraperitoneally injected with 5 mg/kg/week of DOX treatment for 4 weeks, and EXE training was initiated for treadmill adaptation for 1 week and then performed for 4 weeks. Both sides of the soleus (SOL) muscle tissues were dissected and weighed after 24 hours of the last training sessions. [Results] DOX chemotherapy induced an abnormal myofiber's phenotype and transition of myosin heavy chain (MHC) isoforms. The paired box 7 (PAX7) and myoblast determination protein 1 (MYOD) protein levels were triggered by DOX, while no alterations were shown for the myogenin (MYOG). DOX remarkably impaired the a-actinin (ACTN) protein, but the EXE training seems to repair it. DOX-induced myotoxicity stimulated the expression of the forkhead box O3 (FOXO3a) protein, which was accurately controlled and adjusted by the EXE training. However, the FOXO3a-mediated downstream markers were not associated with DOX and EXE. [Conclusion] EXE postconditioning provides protective effects against chronic DOX-induced myotoxicity, and should be recommended to alleviate cancer chemotherapy-induced late-onset myotoxicity.

• Journal of muscle and joint health
• /
• v.15 no.2
• /
• pp.155-165
• /
• 2008

Purpose: The purpose of this study was to develop a progressive exercise program based on clinical guidelines for exercise prescription for older adults with osteoarthritis, which was planned to improve the existing arthritis self-help program. Method: We analyzed the contents of the arthritis self-help program and closely reviewed the guideline of exercise prescription for elderly with osteoarthritis. Results: The major contents of the revised arthritis self-help program are as follows: 1) The weekly education is composed of one-hour exercise and one-hour health education about various subjects. 2) The weekly main exercise is composed of muscle strengthening and endurance exercise. 3) Endurance exercise consists of three steps. 4) Muscle strengthening exercise is performed by gravity at first, and then the Thera-Band muscle strengthening exercise is followed on the 4th week. Conclusion: It is necessary to verify the effect of the progressive exercise program for older adults with osteoarthritis. It is thought that this revised program could be adopted as a rehabilitation program for older adults with osteoarthritis.

• International journal of advanced smart convergence
• /
• v.11 no.3
• /
• pp.197-205
• /
• 2022

In order to investigate the effect of an 8-week elastic band exercise program according to age on the isokinetic strength and dynamic equilibrium of the knee, 10 women under 49 years old and 10 women over 50 years old were selected. Dynamic equilibrium was measured through Y-Balance test one week before the exercise program, and power and endurance were confirmed by measuring isokinetic muscle strength of the knee. After measurement, small tool exercise was performed for 8 weeks. After 8 weeks of exercise, isokinetic muscle strength and dynamic equilibrium were measured. As a result, isokinetic muscle strength, which checks muscle strength and muscular endurance, increased after measurement than before measurement regardless of age, and dynamic equilibrium increased after measurement rather than before measurement, and the group under 49 years of age was higher than the group over 50 years old. We think that small tool exercise improves isokinetic muscle strength and is effective in neuromuscular development, improving dynamic stability ability, which is an important factor in preventing falls.