• Journal of the Korean Society of Physical Medicine
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• v.11 no.4
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• pp.33-39
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• 2016

PURPOSE: The purpose of this study was to investigate whether a circuit aerobic exercise program positively affects pulmonary function and gait endurance in chronic stroke patients. METHODS: Twenty-four chronic stroke patients were allocated equally and randomly to an experimental group (n=12) or a control group (n=12). All participants received 60 minutes of comprehensive rehabilitation treatment, the experimental group additionally performed a circuit aerobic exercise for 30 minutes, while the control group additionally performed a general aerobic exercise, i.e., gait training on the treadmill for 30 minutes. These 30-minute exercise sessions were held three times per week for six weeks. Pulmonary function was assessed using forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and maximal voluntary ventilation (MVV), and gait endurance was assessed using the 6-minute walk test (6MWT). RESULTS: In the both groups, FVC, FEV1, MVV, and 6MWT were significantly increased after training. Members of the experimental group showed significant improvements in FVC, FEV1, and MVV, and significantly greater improvements than controls (p<.05). However, 6MWT improvements were not significantly different in the two groups (p>.05). CONCLUSION: The devised circuit aerobic exercise program offers an effective rehabilitation aerobic exercise for improving pulmonary function and gait endurance in patients after chronic stroke.

• Journal of Nutrition and Health
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• v.35 no.8
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• pp.825-833
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• 2002

The effects of dietary supplementation of Eleutherococcus senticosus, taurine and carnitine on maximal endurance exercise performance along with other related parameters were evaluated in rats that underwent aerobic exercise training for 6 weeks. Thirty-two male rats (4 weeks old) were randomly divided into 4 groups, and fed experimental diets and/or aerobic exercise trained according to the protocol: SC (sedentary control group), EC (exercise-trained control group), EE (exercise-trained Eleutherococcus senticosus-supplemented group), and EETC (exercise-trained Eleutherococcus senticosus, taurine and carnitine-supplemented group). The food efficiency ratio of EC rats was significantly lower than the value for SC rats (p < 0.01). Exercise-trained control animals (92 $\pm$ 8.8 min) could run significantly longer until exhausted on the treadmill than sedentary control rats (11 $\pm$ 0.8 min) (p < 0.001). Animals fed an Eleutherococcus senticosus-supplemented diet, and an Eleuthherococcus sonticosus, taurine and carnitine- supplemented diet while undergoing aerobic exercise training for 6 weeks exhibited, respectively, 8 and 5 minutes longer running performance until exhausted than the rats fed the control diet. The gastrocnemius muscle glycogen concentration of the rats, measured at 48 hours post maximal exercise performance test, was 43% higher in EC rats than the value for SC rats (p < 0.05), but was not different among EC, EE, and EETC rats. The mitochondrial citrate synthase activity of the soleus muscle was significantly higher in EC rats compared to the value for SC rats (p < 0.01), and showed a tendency to increase, without statistical significance, in EE or EETC rats compared to the value for EC rats. These results indicate that aerobic exercise training for 6 weeks significantly improved maximal exercise performance, muscle glycogen content along with citrate synthase activity, which are important in the energy metabolism of muscle under aerobic exercise. Dietary supplementation of Eleutherococcus senticosus in rats while undergoing aerobic exercise training improved maximal endurance exercise performance without significantly affecting muscle glycogen content and enzyme activities involved in energy metabolism during exercise. Taurine and carnitine supplementation failed to show an additive effect on maximal endurance exercise performance when consumed along with Eleutherococcus senticosus.

• Korean Journal of Applied Biomechanics
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• v.27 no.1
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• pp.45-52
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• 2017

Objective: The aim of this study was to investigate the periodicity of the lower extremity joint flexion/extension angle to compare the local stability between young and elderly women during walking on a treadmill. Method: Eighteen young women (mean $age=21.2{\pm}1.6y$; mean $mass=57.1{\pm}6.1kg$; mean $height=1.61{\pm}0.04m$) and 18 elderly women (mean $age=66.4{\pm}1.2y$; mean $mass=55.4{\pm}8.3kg$; mean $height=1.56{\pm}0.04m$) participated in this study. Approximate entropy (ApEn) was used to determine the periodicity in the lower limb joint angles. Results: The ApEn values of the two groups were statistically greater in the surrogate data test than in the original time series data (p<.05). The periodicity of the hip and ankle flexion/extension angles decreased in the elderly women group compared with the young women group (p<.05). The periodicity of the lower extremity joint flexion/extension angle showed that the ankle joint increased dominatingly in both groups (p<.05); the hip joint decreased compared with the knee joint in the young women group; and the knee joint decreased compared with the hip joint in the elderly women group (p<.05). Conclusion: These results suggest that the lower extremity joint flexion/extension angles of the young and elderly women during walking contained random noises as well as biological signals. In addition, the differences in the periodicity in the lower extremity joint between the young and elderly women may provide some insight in predicting potential falls and be used as a characteristic indicator for determining local stability in elderly women during walking.

• Physical Therapy Korea
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• v.27 no.3
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• pp.185-190
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• 2020

Background: Backward walking exercise may offer some unique and potentially beneficial differences compared with forward walking exercise. There is still a lack of research on backward walking exercises and forward head posture. Objects: The purpose of this study was to determine the effect of backward walking exercise on college students forward head posture in their 20s. Methods: Twenty-one subjects participated in the experiment. The subjects were those with a craniovertebral angle (CVA) of 55 degrees or less who understood the purpose and method of this study and voluntarily agreed. A camera capable of taking pictures of the lateral plane was installed at a distance of 1.5 meters before exercising. Pictures were taken before walking backward, and after walking for 15 minutes on the treadmill, the images were taken in the same way. The composition of the backward walking exercise was walking at a rate of 1.0 for 5 minutes, and the remaining 10 minutes were walking at a rate of 1.5. Wilcoxon signed rank test was used to compare CVA and craniorotational angle (CRA) before and after exercise. Results: As a result of this study, there was a significant difference in CVA before and after exercise (p < 0.05). There was a significant difference in CRA before and after exercise (p < 0.05). Conclusion: The backward walking exercise and verbal command seems to have positively influenced the changes in CVA and CRA among college students in their 20s. It seems that studies to confirm balance or muscle activity as well as changes in forward head posture through the long-term intervention of the backward walking exercise should be conducted.

• Korean Journal of Applied Biomechanics
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• v.16 no.1
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• pp.65-79
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• 2006

The purpose of this study was firstly to investigate correctional function of custom semi-rigid foot orthotics for excessively pronated people during gait by observing comfort, navicular movement and leg muscles' activity according to short-term and mid-term wearing duration and secondly to understand positive and/or negative point of view of a recently proposed paradigm related to foot orthotics more profoundly. Sixteen subjects who showed excessive pronation at navicular drop test were recruited for this study. Custom semi-rigid foot orthotics were made fitting for foot characteristics of the subjects by podiatry division of Otto Bock Korea company. While wearing the foot orthotics for two months, comfort of wearing were questioned and vertical navicular movement and electromyography of leg muscles during gait were measured at the condition of both immediately after and 2 months after including a control condition, respectively. The subjects were required to walk on a treadmill at the speed of 1.5m/s and four digital video camera filmed the movement of navicular process at the speed of 60 frames/s. In conclusion, in excessively pronated group continuous increase of comfort from short-term to mid-term wearing of custom foot orthotics is assumed to be closely related with short-term and mid term correctional action, of which are consisted the decrease of the range of navicular drop and navicular raisins- the faster timing of minimum navicular position occurring, and the decrease of leg muscles' activities. This conclusion could lead to positively accept new paradigm related to foot orthotics suggested by Nigg and the author suggest that in the future study the variable which could observe navicular movement would be one of major variables to study preferred path of skeleton in the paradigm.

• Biomedical Science Letters
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• v.24 no.3
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• pp.245-252
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• 2018

Heart rate recovery (HRR) is simply an indicator of autonomic balance and is a useful physiological indicator to predict cardiovascular morbidity and mortality. The purpose of this study was to compare the differences in HRR between metabolically healthy obesity group and metabolically unhealthy obesity and to ascertain whether heart rate recovery is a predictor of metabolic syndrome. Metabolic syndrome was defined according to the standards of the National Cholesterol Education Program Adult Care Panel III. Obesity was assessed according to WHO Asian criteria. It was classified into three groups of metabolically healthy non-obesity group (MHNO, n=113), metabolically healthy obesity group (MHO, n=66), metabolically unhealthy obesity (MUO, n=18). Exercise test was performed with Bruce protocol using a treadmill instrument. There was no difference in HRR between MHO and MUO ($32.71{\pm}12.25$ vs $25.53{\pm}8.13$), but there was late HRR in MUO than MHNO ($25.53{\pm}8.13$ vs $34.51{\pm}11.80$). HRR in obese was significantly correlated with BMI (r=-0.342, P=0.004), waist circumference (r=-0.246, P=0.043), triglyceride (r=-0.350, P=0.003), HbA1c (r=-0.315, P=0.009), insulin (r=-0.290, P=0.017) and uric acid (r=-0.303, P=0.012). HRR showed a lower prevalence of abdominal obesity, hypertriglyceridemia, and low HDL-cholesterol in the third tertile than in the first tertile. In conclusion, MHO had no difference in vagal activity compared with MHNO, but MUO had low vagal activity. HRR is associated with metabolic parameters and is a useful predictor of abdominal obesity, hypertriglyceridemia, and low HDL-cholesterolemia.

• The Korean Journal of Physiology
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• v.2 no.2
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• pp.45-52
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• 1968

Maximal oxygen uptake was measured in twenty-eight middle-aged men aged 45.0 (range: 40.3-50.7) years and fourteen middle-aged women aged 40.5 (range: 34.3-47.5) years by means of a treadmill test. The physique of subjects were:mean skinfold thickness at 4 sites, namely, back, arm, waist and abdomen was 7.59 mm in men and 14.5 mm in women; total body fat estimated from the mean skinfold thickness, 11.9% fat in men and 25.5% fat in women. The detailed observations are as follows: 1. Maximal oxygen uptake expressed on any reference unit in men was greater than that of women. The values of men to women were: 2.61 to 1.92l/min., 45.1 to 37.0 ml/min./kg, 51.8 to 46.5 ml/min./kg lean body mass (LBM), 15.7 to 12.6 ml/min./cm body height. 2. Maximal pulmonary ventilation in men was 80.2 l/min. and 63.5 l/min. in women. 3. There was a correlation of fairly high degree between maximal oxygen uptake and body weight, namely, r=0.56 in men and r=0.79 in women. The correlation between maximal oxygen uptake and lean body mass also was fairly high, namely, r=0.58 in men and r=0.69 in women. 4. The correlation between maximal pulmonary ventilation and body weight or lean body mass was r=0.51 and r=0.25 in middle-aged men and r=0.41 and r=0.19 in middle-aged women, respectively. 5. Maximal heart rate in men was 176.4 beat/min. and it was 183.9 beat/min. in women. 6. Maximal oxygen pulse in men was 14.6 ml/beat and 9.5 ml/beat in women. 7. Aerobic work capacity of korean middle-aged men and women maintained the same level as that of young men and women, respectively, as shown by maximal oxygen uptake expressed ml/min./kg or ml/min./kg lean body mass.

• Korean Journal of Applied Biomechanics
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• v.30 no.2
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• pp.145-154
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• 2020

Objective: The purpose of this study was to determine the relationship between impact and shear peak force, and tibia-accelerometer variables during running. Method: Twenty-five male heel strike runners (mean age: 23.5±3.6 yrs, mean height: 176.3±3.3 m/s, mean mass: 71.8±9.7 kg) were recruited in this study. The peak impact and anteroposterior shear forces during treadmill running (Bertec, USA) were collected, and impact shock variables were computed by using a triaxial accelerometer (Noraxon, USA). One-way ANOVA was used to test the influence of the running speed on the parameters. Pearson's partial correlation was used to investigate the relationship between the peak impact and shear force, and accelerometer variables. Results: The running speed affected the peak impact and posterior shear force, time, slope, and peak vertical and resultant tibial acceleration, slope at heel contact. Significant correlations were noticed between the peak impact force and peak vertical and resultant tibia acceleration, and between peak impact average slope and peak vertical and resultant tibia acceleration average slope, and between posterior peak (FyP) and peak vertical tibia acceleration, and between posterior peak instantaneous slop and peak vertical tibial acceleration during running at 3 m/s. However, it was observed that correlations between peak impact average slope and peak vertical tibia acceleration average slope, between posterior peak time and peak vertical and resultant tibia acceleration time, between posterior peak instantaneous slope and peak vertical tibial acceleration instantaneous slope during running at 4 m/s. Conclusion: Careful analysis is required when investigating the linear relationship between the impact and shear force, and tibia accelerometer components during relatively fast running speed.

• The Korean Journal of Pain
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• v.34 no.4
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• pp.394-404
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• 2021

Background: We aimed to investigate the effect of epidural polydeoxyribonucleotide (PDRN) on mechanical allodynia and motor dysfunction in a rat model of lumbar foraminal stenosis (LFS). Methods: This study was conducted in two stages, using male Sprague-Dawley rats. The rats were randomly divided into eight groups. In the first stage, the groups were as follows: vehicle (V), sham (S), and epidural PDRN at 5 (P5), 8 (P8), and 10 (P10) mg/kg; and in the second stage, they were as follows: intraperitoneal PDRN 8 mg/kg, epidural 3,7-dimethyl-1-propargilxanthine (DMPX) (0.1 mg/kg), and DMPX (0.1 mg/kg). The LFS model was established, except for the S group. After an epidural injection of the test solutions, von Frey and treadmill tests were conducted for 3 weeks. Subsequently, histopathologic examinations were conducted in the V, S, P5, and P10 groups. Results: A total of 65 rats were included. The P8 and P10 groups showed significant recovery from mechanical allodynia and motor dysfunction at all time points after drug administration compared to the V group. These effects were abolished by concomitant administration of DMPX. On histopathological examination, no epineurial inflammation or fibrosis was observed in the epidural PDRN groups. Conclusions: Epidural injection of PDRN significantly improves mechanical allodynia and motor dysfunction in a rat model of LFS, which is mediated by the spinal adenosine A_2A receptor. The present data support the need for further research to determine the role of epidural PDRN in spinal stenosis treatment.

• Journal of Biomedical Engineering Research
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• v.40 no.1
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• pp.32-37
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• 2019

In this study, we designed a blending algorithm for rate adaptive pacing for cardiac pacemaker. Generally, rate adaptive pacing (RAP) is applied to patients whose heart rate does not rise during exercise for chronotropic incompetence (CI) patient. It is very important to develop an algorithm for RAP that can be properly applied to CI patients. In order to design an RAP algorithm we used dual sensors. Firstly, we designed a bio-signal measurement system based on the dual sensors, which are accelerometer and respiratory system. Secondly, we conducted treadmill test for the simulation experiment while using 3-lead ECG as reference. Finally, we designed a blending algorithm based on activation state of the dual sensors. The proposed blending algorithm was subdivided into three sections based on the accelerometer signal, which are rapidly increased section (W1), hardly changed section (W2), and decreased section (W3). Each weight is set aside for each section. To evaluate this algorithm, ten healthy adult males were participated. The correlation and Root Mean Square Error between the proposed algorithm and the reference were compared, and shown to be r=0.88 and 2.82 bpm, respectively. These results show that the proposed blending algorithm of dual sensors enables proper tracking of the heart rate during exercise. Also, it shows the possibility that the proposed blending algorithm can be applied to improve quality of life of the chronotropic incompetence patient.