• Korean Journal of Applied Biomechanics
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• v.22 no.1
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• pp.35-42
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• 2012

The aim of the present study was to investigate effect of running speed conditions on the kinematic pattern of the metatarsus, mid-foot, calcaneus. Twenty-two healthy young adults were made to run on treadmill at three different running speeds(normal speed, 9.2; slow speed, 7.4; fast speed, 11.1km/hr.) and the trajectories of the 10 reflective markers for each subject were recorded by an eight-camera motion capture system at 200 Hz. Three-dimensional angles for the foot segment in the support phase during running were calculated according to Euler's technique. Results showed that running speed did not affect the peak of the dorsi/plantar flexion, inversion/eversion, and adduction/abduction or their range of motion for each foot segment. However, when the running speed was fast, significant differences were found in the peak of the plantar flexion, eversion, and adduction and ROM(range of motion) of the dorsi/plantar flexion, inversion/eversion, and adduction/abduction between the foot segments, metatarsus, mid-foot, and calcaneus. It was proposed that the foot segment should be analyzed from a multi-segment system point of view on the basis of anatomical reference during locomotion.

• Korean Journal of Applied Biomechanics
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• v.29 no.3
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• pp.167-172
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• 2019

Objective: The aim of this study was to investigate the effect of midsole hardness of running shoe on muscle fatigue and impact force during distance running. Method: Ten healthy college recreational runners who were performing distance running at least three times a week participated in this experiment. They were asked to run for 15 minutes in the treadmill at 10 km/h with running shoes having three different types of midsole hardness (Soft, Medium, Hard). EMG signal and insole pressure were collected during the first and last one minute for each running trials. Data were analyzed using a one-way analysis of variance (ANOVA) with repeated measures. Results: Midsole hardness did not affect the consistency of stride length. For the median frequency of the EMG signal, only VL was affected by midsole hardness; that of medium was greater than other midsoles (p<.05). The loading rate of impact forces increased by midsole hardness (p<.01). Conclusion: Although soft midsole could attenuate impact forces at heel contact, it might have a negative effect on the fatigue of muscle which could decelerate the body after heel contact. Therefore, it is necessary to select the optimum hardness of midsole carefully for both reduction impact forces and muscle fatigue.

• Korean Journal of Applied Biomechanics
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• v.17 no.4
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• pp.181-190
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• 2007

The purpose of this study was to analyze the muscle fatigue for lower limbs during the level and downhill running. The subjects were 6 males of twenties who have no experience to get the injury in the lower limbs and required to run on the level and downhill which was -7% grade treadmill at 8.3km/h. EMG signal was gained by ME3000P8 Measurement Unit and computed the Median Frequency(MF) with the power spectrum analysis in the Megawin software. Rectus femoris(RF), Vastus lateralis(VL), Gluteus medius(GLU), Biceps Femoris(BF), gastrocnemius medial head(GM), gastrocnemius lateral head(GL), Tibialis anterior(TA) were selected. The result of this study were as follows: The MF of RF decreased in the downhill running than level running in length of time but, the MF of VL was opposite. The MF of BF decreased in the level and downhill running, but, the MF of BF decreased much in the level than downhill running. The MF of GLU decreased much in the downhill running but, almost no change in the level running. The MF of TA decreased in the level running than downhill running. The MF of GL decreased in the level running but, the MF of GM decreased in the downhill running in length of time. This study analyzed the muscle fatigue of the lower limbs with the median frequency on the basis of an assumption that the impact force for the flexion and extension of the joint and the body mass may be much in the eccentric contraction such as the downhill running than level running. RF and GM showed the muscle fatigue in the downhill running than level running. BF and GL showed the muscle fatigue in the level running than downhill running.

• Journal of Korean Physical Therapy Science
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• v.19 no.3
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• pp.23-30
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• 2012

The purpose of this study was to apply treadmill training through motor learning to cerebral palsy children and examine its effects on their Gross Motor Functions. The subjects of this study were 13 spastic diplegia children who had difficulty in independent gait, and GMFCS level III, IV. We performed treadmill gait training using the principle of weight bearing, based on 4times a week for 30 minutes before and after each session physical therapy we gave weight bearing treadmill training 5 to 10 minutes, during 7 weeks(April 9, 2012~May 26, 2012) fittingly for the children's gait characteristics. In order to test how the weight bearing treadmill training affects spastic diplegia children's gross motor functions, we measured body mobility with Gross Motor Function Measure (GMFM). These data were collected before and after the experiment and analyzed through comparison. Data collected from the 13 spastic diplegia children the results were as follows. For evaluating with regard to change in body mobility, significant difference was observed between before and after the experiment in measured gross motor functions, which were crawling, kneeling, standing, walking, jumping and running(p<0.05). According to the results of this study, when gait training through motor learning was applied to spastic cerebral palsy children, it made significant changes in their body mobility. Accordingly, for the effective application of gait training through motor learning to cerebral palsy children, it is considered necessary to make research from different angle on how such training affects children's mobility, activity of muscles in the lower limbs, and gait characteristics.

• Journal of Nutrition and Health
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• v.34 no.7
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• pp.748-753
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• 2001

This study is to investigate the effects of capsaicin with high-fat diet on tissue glycogen contents in exercise-trained rats. Forty male Sprague-Dawley rats were offered a high-fat diet for 2 wks in individual cages and were exercise-trained by a animal treadmill running throughout the experimental period. After 2 wks of the prefeeding with high-fat diet, the rats were divided into two group: high-fat diet group(CON)and high-fat diet + capsaicin(0.014%) group(CAP). The rats were killed by decapitation at 10 hr(rest), 1 hr and 2 hr after treadmill running(27m/min, 6$^{\circ}$). Body weight and epididymal adipose tissure weight were significantly lower in CAP than in CON, but soleus muscle weight was not different between the two groups. Glycogen contents in liver, soleus and gastrocnemius white muscles were significantly lower in CAP than in CON at rest, 1 hr and 2 hr (p<0.05). However, glycogen content in gastrocnemius red muscle was significantly higher in CAP compared with CON at 2 hr after the exercise(p<0.05). These results indicate that capsaicin intake with high-fat diet would decrease glycogen contents in liver and muscle, however, this effect on glycogen metabolism could be changed by muscle type.

• The Korean Journal of Physiology
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• v.11 no.1
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• pp.33-36
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• 1977

The object of the present study is to examine the effect of physical training during early growth of life on body weight gain and physical performance. Early weaned (2 weeks after birth) male mice were divided into control and training group-and experimental period was divided into growing period (from 1st week to 6th weeks after weaning) and adult period (from 7th weeks to 9th weeks after weaning). Physical training was. given on a small animal treadmill with a speed of 34.3m/min and $19^{\circ}C$ slope and both groups of body weight gain and maximal running time on the treadmill were determined. The results obtained are summarized as follows; 1. Body weight gain was lesser in training group than control group and the difference was. statistically significant at 1, 2.5, 5.7 weeks of training period. 2. Maximal running time of training group was found to be longer than that of control group at 6th (p<0.01), 8th (p<0.001) and 9th weeks. (p<0.01). From the above results, it may be concluded that if physical training is started in early growth of life, there might be an improvement of physical performance.

• Korean Journal of Exercise Nutrition
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• v.23 no.2
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• pp.1-6
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• 2019

[Purpose] Strenuous exercise often induces skeletal muscle damage, which results in impaired performance. Sphingolipid metabolism contributes to various cellular processes, including apoptosis, stress response, and inflammation. However, the relationship between exercise-induced muscle damage and ceramide (a key component of sphingolipid metabolism), is rarely studied. The present study aimed to explore the regulatory role of sphingolipid metabolism in exercise-induced muscle damage. [Methods] Mice were subjected to strenuous exercise by treadmill running with gradual increase in intensity. The blood and gastrocnemius muscles (white and red portion) were collected immediately after and 24 h post exercise. For 3 days, imipramine was intraperitoneally injected 1 h prior to treadmill running. [Results] Interleukin 6 (IL-6) and serum creatine kinase (CK) levels were enhanced immediately after and 24 h post exercise (relative to those of resting), respectively. Acidic sphingomyelinase (A-SMase) protein expression in gastrocnemius muscles was significantly augmented by exercise, unlike, serine palmitoyltransferase-1 (SPT-1) and neutral sphingomyelinase (N-SMase) expressions. Furthermore, imipramine (a selective A-SMase inhibitor) treatment reduced the exercise-induced CK and IL-6 elevations, along with a decrease in cleaved caspase-3 (Cas-3) of gastrocnemius muscles. [Conclusion] We found the crucial role of A-SMase in exercise-induced muscle damage.

• Korean Journal of Applied Biomechanics
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• v.26 no.2
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• pp.167-174
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• 2016

Objective: The purpose of this study was to determine the interrelationship between ranges of motion of the knee and ankle joints on the sagittal plane and the attenuation magnitude of impact shock at high frequency (9~20 Hz) in the support phase during downhill running. Method: Fifteen male heel-toe runners with no history of lower extremity injuries were recruited for this study (age, $25.07{\pm}5.35years$; height, $175.4{\pm}4.6cm$; mass, $75.8{\pm}.70kg$). Two uniaxial accelerometers were mounted to the tuberosity of tibia and sacrum, respectively, to measure acceleration signals. The participants were asked to run at their preferred running speed on a treadmill set at $0^{\circ}$, $7^{\circ}$, and $15^{\circ}$ downhill. Six optical cameras were placed around the treadmill to capture the coordinates of the joints of the lower extremities. The power spectrum densities of the two acceleration signals were analyzed and used in the transfer function describing the gain and attenuation of impact shock between the tibia and the sacrum. Angles of the knee and ankle joints on the sagittal plane and their angle ranges were calculated. The Pearson correlation coefficient was used to test the relationship between two variables, the magnitude of impact shock, and the range of joint angle under three downhill conditions. The alpha level was set at .05. Results: Close correlations were observed between the knee joint range of motion and the attenuation magnitude of impact shock regardless of running slopes (p<.05), and positive correlations were found between the ranges of motion of the knee and ankle joints and the attenuation magnitude of impact shock in $15^{\circ}$ downhill running (p<.05). Conclusion: In conclusion, increased knee flexion might be required to attenuate impact shock during downhill and level running through change in stride or cadence while maintaining stability, and strong and flexible ankle joints are also needed in steeper downhill running.

• Korean Journal of Applied Biomechanics
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• v.17 no.2
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• pp.61-73
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• 2007

The purpose of this study was to investigate the influence of the muscular endurance on the kinematic factors during a prolonged run. Subjects, 12 males, who were divided into three groups(lower group, general group, and in higher group) after measuring the lower limb's muscular endurance previously. They were asked toe run on the treadmill at 7.4km/h of speed. To analyze the kinematics parameters of the trunk during running, the ProReflex MCU Camera(Qualisys, Sweden) were used. All parameters were sampled from 5 minute, 40 minute, and 60 minute moments during running. An ANOVA with Repeated Measure was used to test the statistic significance between and within groups for all parameters determined with SPSS 11.0. Significance was defined as p<.05. The conclusions were as follows; There was significantly difference within(lapse of running time) groups in the take-off and minimum knee angle event of swing phase of the trunk flexion and extension. In conclusion, the muscular endurance affected on movement of the trunk during a prolonged run. In addition, it showed that there was significant difference in the energy consumption by lapse of running time. Therefore, it seems to be relationships between the muscular endurance and running efficiency.

• YAKHAK HOEJI
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• v.57 no.5
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• pp.348-356
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• 2013

The present study investigated the effects of Hovenia Dulcis (HD) fruit extract powder on the improvement of physical activity, especially exercise capacity. Forty mice were divided into 4 groups including normal controls, negative controls, 100 (HD-100) and 200 (HD-200) mg/kg HD fruit extract powder groups for 5-times exercises using treadmill. Normal control did not performed treadmill running but others did 5-times for 10 days. HD fruit extract powders were administrated orally one-times per day for 10 days before treadmill exercise and normal and negative controls were fed with excipient water. After 5-times exercise, blood biochemical analysis showed that aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and creatine phosphokinase (CK) activities and blood lactate concentration were statistically increased in negative controls than in normal controls. They were decreased in HD fruit extract powder groups, compared with negative controls. These results were considered as the effects of HD fruit extract powders on reduced tissue damages during exercise. Other measured indices did not reveal remarkable differences. All together, these results suggest that HD fruit extract powders may enhance the exercise performance by recovering the exercise-fatigue via blood lactate concentration by reducing blood LDH activity and via reduction of blood CK and AST activity.