• Physical Therapy Korea
• /
• v.18 no.1
• /
• pp.9-17
• /
• 2011

The purpose of this study was to assess visual biofeedback's influence on trunk muscles' (EMG) activity and endurance holding time for correct position during whole-body tilt exercise. For the study, we recruited 14 volunteers who showed no symptom of lumbar disease during medical tests. We measured the EMG activity of their rectus abdominis, external abdominal oblique, internal abdominal oblique and erector spinae muscles, and their endurance holding time for correct position during $40^{\circ}$ anterior and posterior whole-body tilt under two conditions: whole-body tilt with and without visual biofeedback. Resistance with gravitational force on the trunk during whole-body tilt was applied by using a device that had a monitor on which the subjects could check their alignment and that sounded an alarm if a subject's alignment collapsed. The study showed an increase in the EMG activity of external abdominal oblique, internal abdominal oblique/rectus abdominis ratio and endurance holding time for correct position during both $40^{\circ}$ anterior and posterior whole-body tilt with visual biofeedback compared with without visual biofeedback (p<.05). We suggest that the whole-body tilt exercise with visual biofeedback could be a beneficial strategy for selectively strengthening the internal abdominal oblique muscle and minimizing the rectus abdominis muscle's activity while maintaining correct alignment during whole-body tilt exercise.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.28 no.3
• /
• pp.75-86
• /
• 2005

To investigate the fatigue characteristic of upper limbs, this study analyzed RMS(root mean square) and MPF(mean power frequency) value between initial and terminal stages of each experiment condition. And the effect of intermittent endurance time was evaluated using the Borg's CR10 value that was measured for the parts of upper limb. According to the results of ANOVA on RMS value, there were significant difference on the %MVC about push, pull, and down force exertion. Particularly the ANOVA of up force exertion was significant difference on shoulder flexion, elbow flexion and rest time as well as %MVC. The results of ANOVA for MPF value were significant difference on the %MVC in regard of the push and up force exertion. In case of up force exertion, MPF value tended to shift low frequency at all of the experiment conditions. According to the analysis of duty cycle, RMS value considerably increased over 50% duty cycle and as the %MVC increased, the duty cycle affected the increase of RMS value. MPF value for up and down force exertion decreased at 33%, 50% and 67% duty cycle for all of %MVC. Borg CR10 value of hand and forearm were below the 3-point to the 40% of endurance time at 30%MVC and to the 20% of endurance time at 50%MVC with the exception of up force exertion. But Borg CR10 values of upper arm and shoulder at up force exertion were more than 3-point to the 20% of endurance time at 30%MVC and in the start point of endurance time at 50%MVC.

• Journal of Convergence for Information Technology
• /
• v.8 no.4
• /
• pp.81-86
• /
• 2018

The purpose of this study is to compare the difference between quadriceps strength and endurance on the degree of elasticity of convergent kinesio taping. Twenty-eight normal adults who voluntarily participated in this study were randomly assigned among 4 groups, that is, group without tape, group with tape elasticity of 0 %, group with tape elasticity of 25 %, or group with tape elasticity of 50 %. Quadriceps strength and endurance were measured using CSMI. Strength among the groups was significantly different (p<.001), and the greater the elasticity of the tape, the greater the muscle strength. However, endurance was't significantly different among the groups (p>.05). These findings suggest that convergent kinesio taping elasticity with 25% and 50% is effective for quadriceps strength in physical activity.

• Journal of The Korean Society of Integrative Medicine
• /
• v.9 no.1
• /
• pp.123-131
• /
• 2021

Purpose : The time spent using smart devices is constantly increasing, particularly in recent times. Using smart devices for a long time with an incorrect posture may lead to cerebral palsy (CP), instability, and abnormal muscle tone. Therefore, we aimed to investigate the relationships among cervical instability, deep neck flexor (DNF) activity, range of motion (ROM), and muscle tonus. Methods : Fifty subjects with CP participated in this study, and they were physiotherapists at W Hospital in Daejeon. Those who voluntarily participated in the research were selected as candidates who fulfilled the selection criteria. According to an instability test, 25 subjects were assigned to the instability and control groups. All subjects first underwent the instability test to be allocated to the appropriate group. Those in the instability group tested positive on the instability test. The Neck Disability Index (NDI), ROM, muscle tone, and DNF activity were measured to evaluate their relationships. The DNF strength and endurance were measured using a cranio-cervical flexion test. The upper trapezius (UT), sternocleidomastoid (SCM), and suboccipital (SO) muscle tones were measured using a contact soft tissue tone measuring instrument. The statistical significance level was set to .05. Results : There were significant differences in the flexion, extension, and rotation of the cervical ROM (CROM) between the two groups (p<.05). The SCM, UT, and SO muscle tones were significantly different between the two groups (p<.05). The DNF strength and endurance showed a significant difference between the two groups (p<.05). Conclusion : We found that there were significant increases in the CROM and muscle tone and decrease in the DNF strength and endurance in the instability group. This indicated that cervical instability is affected by the DNF strength and endurance. We may recommend DNF exercises in cases of cervical instability in clinical environments.

• Physical Therapy Korea
• /
• v.29 no.2
• /
• pp.156-164
• /
• 2022

Background: Low back pain (LBP) is a representative disease, and LBP is characterized by muscle dysfunction that provides stability to the lumbar spine. This causes physical functional problems such as decreased posture control ability by reducing the muscular endurance and balance of the lumbar spine. Pelvic compression using instruments, which has been used during recent stabilization exercises, focuses on the anterior superior iliac spine of the pelvis and puts pressure on the sacroiliac joint during exercise, making the pelvis more symmetrical and stable. Currently, research has been actively conducted on the use of pelvic compression belts and non-elastic pelvic belts; however, few studies have conducted research on the application effect of pelvic compression using instruments. Objects: This study aimed to investigate whether there is a difference in trunk muscular endurance and dynamic and static balance ability levels by applying pelvic stabilization through a pelvic compression device between the LBP group and the non-LBP group. Methods: Thirty-nine subjects currently enrolled in Daejeon University were divided into 20 subjects with LBP group and 19 subjects without LBP (NLBP group), and the groups were compared with and without pelvic compression. The trunk muscular endurance test was performed with 4 movements, the dynamic balance test was performed using a Y-balance test, and the static balance test was performed using a Wii balance board. Results: There was a significant difference the LBP group and the NLBP group after pelvic compression was applied to all tests (p < 0.05). In the static and dynamic balance ability test after pelvic compression was applied, there was a significant difference in the LBP group than in the NLBP group (p < 0.05). Conclusion: These results show that pelvic compression using instruments has a positive effect on both those with and without LBP and that it has a greater impact on balance ability when applied to those with LBP.

• Korean Journal of Exercise Nutrition
• /
• v.13 no.2
• /
• pp.161-167
• /
• 2009

The purpose of this study was to investigate whether two different exercises, acute exhaustive exercise and long-term endurance exercise training could affect to the expression of Mn-SOD, HSP70, and PPAR-γ protein in myocardium. The Wistar-Kyoto rats(n=24, 4 weeks) were used and randomly divided into 3 groups; endurance exercise training group (EET, n=8), acute exhaustive exercise group (AEE, n=8) or control group (CON, n=8). EET performed treadmill exercise for 12 weeks (5 days/week, 30~60 min/day). AEE exercised treadmill running (speed increased gradually to 14-26 m/min, 60 min ±10min) until exhausted when EET finished the program. Then, all the rats were sacrificed 48 hours rest at least after the last session of their own exercise program. Hearts were isolated and then the expression of Mn-SOD, HSP70, and PPAR-γ were analyzed by western blotting. One-way repeated ANOVA was used and p value under 0.05 was considered as statistical significance. The results were followed as; the expression of Mn-SOD of AEE was decreased compared with CON. However, the expression of Mn-SOD of EET was increased compared with CON. There was significant difference between AEE and EET in the expression of Mn-SOD. The expressions of HSP70 and PPAR-γ in the both AEE and EET were significantly increased compared with CON. In conclusion, acute exhaustive exercise might induce oxidative stress wheres endurance exercise training could ameliorate the oxidative conditions by increase of Mn-SOD, HSP70, and PPAR-γ. Therefore, we suggested that endurance exercise training could enhance the complementary antioxidant system and improve to prevent apoptosis. Further, a long-term moderat aerobic exercise program might play a important role in mitochondrial biogenesis in the heart.

• Journal of Korean Physical Therapy Science
• /
• v.30 no.3
• /
• pp.72-83
• /
• 2023

Background: Normal-weight obese women have a normal weight with relatively low muscle mass resulting from high body fat. We aimed to investigate the effects of core exercise on body composition, abdominal muscle thickness, trunk muscular endurance, and psychological factors in normal-weight obese women. Design: One group pre-, mid-, and post-test design. Methods: A total of 20 normal-weight obese women were recruited voluntarily. Core exercises were performed for 30 minutes, three times a week for 4 weeks. InBody measurements, ultrasound imaging, and clinical tests were used to assess body composition, abdominal muscle thickness, trunk and core muscular endurance, and psychological condition(satisfaction with appearance and self-esteem). The dependent variables were measured three times: before the intervention (pre-test), 2 weeks after the intervention (mid-test), and 4 weeks after intervention (post-test). One-way repeated measures ANOVA and Friedman test were used for statistical analysis. Results: Although there was no change in the body composition (p>0.05), thickness of the transversus abdominis and internal and external oblique muscles, endurance of the trunk flexors and extensors and core muscles, and psychological condition showed significant differences after the intervention (p<0.05). Conclusion: Our findings will help develop exercise programs for normal-weight obese individuals that utilize the beneficial effect of core exercises.

• Journal of Conservation Science
• /
• v.37 no.6
• /
• pp.689-700
• /
• 2021

This study aims to optimize the measurement conditions of handmade Hanji paper to reduce the time required for measurement while meeting folding endurance standards, for various basis weights. Thirteen types were selected, including 12 types of Hanji with grammages of 17 g/m², 30 g/m², and 45 g/m², and one type of 75 g/m² copy paper, and 24 sheets were prepared in the laid and chain directions. Subsequently, folding endurance experiments at different load (14.72 N, 9.81 N, 4.91 N) and specimen width conditions (15 mm, 10 mm, 5 mm) were performed, using a 4-MIT folding endurance tester. The results showed that, for specimen widths of 15 mm and 10 mm under a load of 4.91 N, the folding endurance falls within the reference range (10~10000 times). In particular, reduced folding endurance range and measurement time were observed at a width of 10 mm under a load of 4.91 N. Moreover, the endurance trend lines based on the average values of load and specimen width ranges enabled the prediction of the folding endurance within those ranges, according to the decreasing slope. Furthermore, for a specimen width of 15 mm under a load of 4.91 N, the folding endurance in the comparison group (35 to 17723 times) significantly exceeds the upper limit of the reference range (10~10000 times). Therefore, the measurement conditions of 4.91 N with a specimen width of 10 mm are proposed.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2002.10b
• /
• pp.413-414
• /
• 2002

An automotive wheel bearing is one of the most important components to guarantee the service life of a passenger car. The endurance life of a bearing is affected by many parameters such as material properties, heat treatment, lubrication conditions temperature loading conditions, bearing geometry, internal clearance and so on. In this paper, we calculate the endurance life of wheel bearing units and analyze the sensitivity of bearing geometric parameters on the life by using Taguchi method.

• Proceedings of the IEEK Conference
• /
• 2000.06b
• /
• pp.52-55
• /
• 2000

The temperature effects of programming speed and endurance characteristics in p-channel flash memory cell have been investigated. In the case of room temperature, the programming speed of p-channel flash memory by using BTB scheme is faster than that by using CHE scheme. However, endurance characteristics with BTB programming scheme is not better than that with CHE programming scheme. In the case of elevated temperature, CHE programming speed is reduced due the gate current degradation but BTB programming speed is enhanced due to the increasing of gate current. Finally, the endurance characteristics of both schemes are improved due to the reduction of gate oxide traps.