Earticle

[PURPOSE] The purpose of this study was to assess the effect of swimming exercise in diabetic atrophy by monitoring changes in biomarkers associated with musculoskeletal growth and abnormalities. [METHODS] Ninety-two male Sprague-Dawley rats were randomly divided into four groups: control plus exercise group (CO+Ex), control and no exercise group (CO+No Ex), diabetes plus exercise group (DM+Ex) and diabetes and no exercise group (DM+No Ex). Swimming exercise was implemented for 60 min/day, 5 day/week for a total of eight weeks. Muscle strength and atrophy biomarkers as well as muscle morphology were compared at the first, second, fourth and eighth week of experimentation. [RESULTS] ACE levels were significantly higher in the DM groups (p<.05), however swimming exercise did not significantly affect ACE levels. Irisin levels were significantly higher in the DM and DM+Ex groups compared to the CON, in week one (p<.05), and greater in the DM+Ex group at week two compared to CON+Ex (p<.05), but swimming did not significantly affect irisin levels over the eight-week period in DM rats. In terms of muscle damage, Myl3 expression was unchanged in the CON groups, but significantly higher in the DM+Ex group compared to the CON+Ex group (p<.05). AST was found to be in higher levels in the DM+No Ex group, compared to CON and CON+Ex (p<.05); and DM+Ex group, compared to the CON+Ex group at weeks one, four and eight (p<.05). Tibialis anterior muscle fibers were thicker in the DM+Ex group compared to DM+No Ex, but only at week four (p<.05). Otherwise, no other notable differences were recorded in muscle morphology. [CONCLUSIONS] These results suggest that swimming exercise alone may not be sufficient to induce muscle strength and/or protective effects against muscle atrophy associated with diabetes mellitus. However, this mode of exercise may be considered safe by not compounding the deteriorative effects of this disease.

[PURPOSE] The purpose of this study was to compared cardiovascular disease risk factors and fitness components in obese middle aged men after Crossfit exercise in 2 weeks. [METHODS] All subjects were obese and middle aged men. Cardiovascular disease risk factors (body fat percent, waist circumference, body mass index, blood pressure, total-cholesterol, HDL-cholesterol, LDL-cholesterol, triglyceride, fasting glucose), and fitness components (muscle strength, muscle endurance, agility, flexibility) were measured and compared before and after 2 weeks. [RESULTS] First, waist circumference was significantly improved and diastolic blood pressure was significantly different after 2 weeks. Second, muscle endurance, agility, and flexibility were significantly improved after 2 weeks. [CONCLUSIONS] These results implies that short term participant of Crossfit exercise is time-efficient exercise to improve health and fitness in obese middle aged men.

[PURPOSE] The aim of this study was to suggested the best way of Squat by estimating and analyzing muscle activity in waist and lower limbs, the number of set repeat-count, and total momentum when we change the width of stance and the angle of knee joint in Squat. [METHODS] In this study, we recruited 10 subjects from the college of physical education, who had built a career at resistance exercise over 1 years. They were divided into five groups by way of Squat. The exercise was executed with 75% 1RM and estimated by randomized-crossover way. The speed of exercise was not limited, and in each set we counted the number of set repeat-count by estimating maximum repetition of each group. we estimated total momentum by multiplying maximum repetition and weight. We estimated an EMG at rectus femoris, vastus medialis, vastus lateralis, erector spinae, and calculate the result by iEMG. After analyzing by two-way ANOVA, We have some significant result from the study. [RESULTS] There was no difference in the number of repetitions and the total work during Squat according to stance width. The rectus femoris and erector spinae showed high iEMG in narrow stance squat and wide stance squat. The vastus lateralis showed high iEMG in narrow stance squat. The vastus medialis showed high iEMG in wide stance squat. The number of repetitions and total momentum in the squat exercise according to the knee angle were 45° harf squat, 90° standard squat, and 120° deep squat. The iEMG responses of quadriceps femoris and erector spinae were 90° standard squat and 120° deep squat higher than 45° harf squat. [CONCLUSION] The smaller the stance width at the squat, the higher the muscle activity of rectus femoris and erector spinae. As the knee angle increased during the squat, the number of repetitions decreased and the muscle activity of quadriceps femoris and erector spinae was higher. This requires attention to knee and back injuries when squatting with a narrow stance and a deep knee angle. In addition, there is a need to perform different exercise loads according to the knee angle during the squat exercise.

[PURPOSE] The purpose of the study was to investigate postural adjustments on effects of fear of falling and directional change during Gait Initiation(GI). [METHODS] Three groups are formed with fear of falling and the senior fitness test results, and they performed with gait in a forward direction and to the right direction(90°). In order to get the data, ten cameras, makers, and EMG were used. Two way ANOVA was used to compare kinematic, spatio·temporal parameters and EMG data. [RESULTS] The HO-TO duration in a GI to the right direction was shorter than in a straight ahead GI at left foot swing. The step width of left foot in TO-HS was significantly larger in the GI to the right direction. The medial·lateral of center of mass velocity in the GI to the right direction was slower than in a straight ahead GI. [CONCLUSIONS] There were significant differences of kinematic parameters in the straight ahead GI and the GI to the right direction, but fear of falling did not affect in the walking type. Further research would be suggested investigating the change of weight load and center of mass for elders with fear of falling during GI.

[PURPOSE] This study is a pilot study to investigate the possibility of kinect sensor based muscle strength test. [METHODS] Ten male subjects (age: 26.30±1.70 years, height: 176.88±2.89cm, weight: 73.40±4.03kg) were selected for the study. The exercise specialist and kinect sensor based muscle strength test program were evaluated at the same time. The items of evaluation were upper strength test (30 sec. arm curls) and lower strength test (30 sec. chair stands). Intraclass correlation coefficient (ICC) was calculated using a two-way mixed model to determine the reliability between the results measured by the exercise instructor and the results measured by the kinect sensor-based muscle strength test method. Bland-Altman plots were used to assess the differences between the two methods and to evaluate the agreement. To obtain the maximum and minimum values of the error intervals, mean + 1.96 × standard deviation and mean -1.96 × standard deviation were calculated. [RESULTS] As a result of upper strength test, ICC was 0.904 (95% CI: .614-.976), Bland-Altman analysis showed that the mean value of the result was 0.6 and the error interval was -3.44 to 4.64. As a result of the test of lower strength test, ICC was found to be 0.895 (95% CI: .576-.974), Bland-Altman analysis showed that the mean value of the result was -0.3 and the error interval was -3.50 to 2.90. [CONCLUSIONS] The ICC of the test showed very high inter - test reliability, showing no difference between the two methods. Therefore, kinect sensor-based muscle strength test may be recommended as a new objective method for testing the strength of the elderly.

[PURPOSE] The purpose of this study was to investigate the frequency and type of physical activity according to the difference of grip strength among Korean adults and to clarify the relationship between grip strength and prevalence of hypertension. [METHODS] We analyzed a secondary database, the 6th Korean National Health Nutrition Survey (2015), which examined the grip strength, frequency and type of physical activity, body composition, blood pressure, and biomakers of blood among Korean adults. The grip strength was divided 4 groups based on a quartile and 88.7% of participants mainly were using the right hand. Contingency table analysis was used to examine the differences of physical activity frequency and physical activity type among the 4 groups. Also, the logistic regression analysis was used to analyze the prevalence of hypertension according to the difference of grip strength. [RESULTS] The frequency of strength exercise, and flexibility exercise were significantly higher in the fourth group (4th Quartile) among four groups. When the first quartile group was as a reference (1), the prevalence of hypertension in female was significantly lower in the second quartile group at 60% (2nd Quartile, [0.40(0.18, 0.90)]), the third quartile group at 58% (3rd Quartile, [0.42(0.19, 0.90)]), and the fourth quartile group at 85% (4th Quartile, [0.15(0.06, 0.40)]). In male, the hypertension prevalence was significantly lower in the third quartile group at 60% (3rd Quartile, [0.40(0.18, 0.90)]), and the fourth quartile group at 69% (4th Quartile, [0.31(0.12, 0.81)]). The left grip strength in both female and male also showed a similar tendency in the relationship prevalence of hypertension and grip strength. [CONCLUSIONS] The grip strength can be used as an index for predicting the prevalence of hypertension. To reduce the prevalence of hypertension and improve grip strength, regular high intensity exercise, strength exercise, and flexibility exercise should be recommended.

[PURPOSE] This study aimed to investigate the associations of sarcopenia with rheumatoid arthritis and osteoarthritis in the general population of Korean adults. [METHODS] We analyzed the data for 11,466 adults aged ≥40 years from the Korea National Health and Nutrition Examination Survey 2008-2011. Dual-energy X-ray absorptiometry was used to measure the skeletal muscle mass. Sarcopenia was defined when the appendicular skeletal muscle index was less than the sex-specific average minus the two standard deviations in the young reference group(age, 20-39 years). Survey logistic regression analysis was used to assess the association of sarcopenia with rheumatoid arthritis and osteoarthritis. [RESULTS] Sarcopenia status was dose-dependently associated with a higher risk of rheumatoid arthritis, after adjustment for potential confounders(p-trend=.002, odds ratio [OR], 2.14; 95% confidence interval [CI], 1.13, 4.05 in sarcopenia group vs. high muscle mass group). However, a higher risk of osteoarthritis was observed in pre-sarcopenia group compared with the high muscle mass group(OR, 1.45; 95% CI, 1.03, 2.05), but not in sarcopenia group. [CONCLUSIONS] We found that sarcopenia status was associated with rheumatoid arthritis, and pre-sarcopenia status was associated with osteoarthritis. Our findings suggest that maintaining a skeletal muscle could be beneficial in preventing musculoskeletal disorders, including rheumatoid arthritis and osteoarthritis.

[PURPOSE] The study was aimed to identify the effects of Traf2 and SIRT1 on Akt aceytlation and autophagy in cardiac hypertrophy. [METHODS] We analyzed the effects of diet and exercise intervention on cardiac hypertrophy and the underlying mechanisms of TNF-α/Traf2/SIRT1 through Akt-FOXO pathway. [RESULTS] A significant up-regulation of Traf2 expression and down-regulation of SIRT1 were observed as the increase of TNF-α in cardiomyocytes. By the significant deacetylation of FOXO1 in 50 μM resveratrol treated group, we can suppose that FOXO1 is activated by SIRT1 in cardiomyocytes. Positive effects of exercise intervention remarkably inhibited the up-regulation of Traf2 expression and Akt acetylation in cardiac hypertrophy. However we could not confirm either a higher depression in Akt acetylation or the activation of FOXO1 by the SIRT1 activation. [CONCLUSION] The present study demonstrated that Traf2 served as an important mediator that enhanced cardiac hypertrophy by activating AKT pathway, and the positive effects of exercise training on the inhibition of Traf2 in cardiac hypertrophy.

PURPOSE] The purpose of this study was to investigate the correlation between leg length difference with pelvic and shoulder level, weight distribution, ankle muscle strength. [METHODS] The subjects were consisted of 49 female students whose leg length was 15mm or more among 90 female. The height of the pelvis and shoulder level were measured using the Global Posture System (GPS). The foot pressure was measured using a foot scan, and ankle muscle strength was measured using a Commander Muscle Tester. [RESULTS] There was a statistically significant positive correlation between structural leg length, pelvic height, shoulder height, and ankle instability(p<.05), while ankle dorsiflexion and inversion muscle strength were statistically significant negative correlation(p <.05). [CONCLUSION] The greater the difference in leg length, the greater the difference in pelvic level. The greater the difference in shoulder level, the greater the dorsiflexion strength of the ankle joint, especially the higher the shoulder height, the greater the ankle dorsiflexion strength. It was found that the greater the dorsiflexion strength of the ankle joint, the less the inversion strength. In conclusion, misalignment of the lower limb may cause back and neck and shoulder pain and ankle joint injury, so it is necessary to recognize the importance of proper posture and habit of the lower limbs.