• International Journal of Vascular Biomedical Engineering
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• v.3 no.1
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• pp.14-22
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• 2005

In the present study, our aim is to investigate whether responses to the head-up tilt (HUT) on nonlinear properties of heart rate variability (HRV) in young and elderly subjects are different or not. Thirteen young-healthy subjects ($24.5{\pm}3.7$ years) and 18 old-aged healthy subjects ($74.5{\pm}7.4$ years) participated in this study. An electrocardiogram (ECG) in the supine posture, at $0^{\circ}$, and in the standing posture, at $70^{\circ}$ of head-up tilt, was recorded. Detrended fluctuation analysis (DFA) and approximate entropy (ApEn), measures of short-/long-term correlation properties and overall complexity of heart rate (HR) respectively, along with spectral components of HR variability (HRV) were analyzed for both the supine and HUT postures. We observed that the short-term fractal exponent ${\alpha}_1$ increased during HUT posture (F(1, 29) = 39.79, P = 0.000), especially, the young subjects showed a significantly higher values compared to the elderly subjects. ApEn significantly decreased (F(1, 29) = 8.61, P = 0.006) during HUT posture. HUT posture decreased the complexity in HR dynamics and increased short-term fractal exponent values in young subjects but not in elderly subjects. These results imply that there are differences of response to HUT on nonlinear properties between young and elderly subjects.

• Journal of Biomedical Engineering Research
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• v.18 no.1
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• pp.37-44
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• 1997

In this paper, the power spectral analysis of heart rate variability(HRV) was performed to evaluate effects of orthostatic stress with head-up tiIt on autonomic nervous system(ANS) for 25 healthy male subjects(age : 24 $\pm$ 5 yr.) and a new method was proposed to assess the autonomic balance. The ECG and respiration signals were recorded at tiIt angles of $0^{\circ}$, $45^{\circ}$, $90^{\circ}$and $0^{\circ}$ successively for 10 minutes per each stage under the condition of frequency controlled respiration(0.25Hz). Heat rate(HR) gradually increased ils the angle increased Similarly, according to the increment of angle, normalized low frequency component(0.05-0.15Hz) gradually increased, whereas normalized high frequency component (0.20-0.30Hz) was reduce4 From these results it is speculated that orthostatic stress head-up tiLt, results in the prevalence of sympathetic tone in autonomic balance with the increment of sympathetic tone and the decrement of parasympathetic tone, which seems to meanthat autonomic nervous system plays a major role in compensating for disturbances of cardiovascular system due to it.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.21 no.2
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• pp.33-37
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• 2015

Background: The purpose of this study on the effects of deep cervical flexors strengthening exercise to forward head posture and pain of neck in patients with chronic neck pain. Method: We selected 30 subjects among neck pain patients and carried out measurements. The subjects' forward head posture was measured including head tilt angle (HTA), neck flexion angle (NFA) and forward shoulder angle (FSA), neck disability index (NDI), numeric rating scale (NRS). The subjects underwent deep cervical flexors muscle strengthening with pressure bio-feedback device for 4 weeks. Then, after intervention, the subjects' forward head posture was measured again. It was performed Wilcoxon signed-ranks test for confirming the effect of deep cervical flexor muscles strengthening exercise. Results: As a result of comparison of measurements before and after intervention, we found that there were statistically significant improvement in the subjects' NDI, NRS and forward head posture including head tilt angle, neck flexion angle and forward shoulder angle. Conclusion: We concluded that deep cervical flexors strengthening exercise has the effect of alleviation of neck pain patients and is effective for forward head posture.

• Aerospace Engineering and Technology
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• v.8 no.1
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• pp.207-214
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• 2009

The purpose of this study was to examine the influence of hypoxic exercise at head down tilt (HDT) on cardiovascular responses. Eight men ($23{\pm}2$ yrs, $176{\pm}4$ cm, and $75{\pm}8$ kg) underwent four separate exercise testing sessions; seated normoxia (SN), seated hypoxia (SH), HDT normoxia (HN), and HDT hypoxia (HH). Each participant performed the leg cycling at predetermined 40% of maximal aerobic capacity relevant to each posture for 15 min. Heart rate was higher in SH than SN and higher also in HH than SH (p<0.05). Blood oxygen saturation was lower in SH than SN (p<0.05). During resting, diastolic blood pressure and mean arterial pressure was significantly lower in HDT than seated posture (p<0.05). No differences were found between conditions in hemoglobin and hematocrit and electrolytes including, sodium, potassium, and chloride. Lactate was higher in SH than SN. In conclusion, there was no effect for cardiovascular responses to duplicate stimuli both hypoxia and posture.

• Anxiety and mood
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• v.16 no.2
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• pp.83-90
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• 2020

Objective : Heart rate variability (HRV) is known to reflect autonomic nervous system activity. Individuals with posttraumatic stress disorder (PTSD) are reported to have lower HRVs. We attempted to find HRV indices with head up tilt position that reflect the symptoms well in order to evaluate PTSD symptoms. Methods : Sixty-seven patients with PTSD and 72 patients without PTSD were assessed using the PTSD Checklist for DSM-5 (PCL-5), the Beck Depression Inventory, the Beck Anxiety Inventory and the Pittsburgh Sleep Quality Index. HRV was measured in the head-up tilt position. We collected data regarding heart rate (HR), standard deviation of the NN intervals (SDNN), the square root of the mean squared differences of successive NN intervals (RMSSD), log low-frequency (LNLF) and log high-frequency (LNHF). Results : The value of LNHF was different according to presence or absence of PTSD after head-up tilt position. In the findings of the association between PTSD symptoms and HRV indices as based on head-up tilt, LNHF had a significant correlation with the total score of PCL-5. Conclusion : The reduction of the high-frequency component of HRVs in the PTSD group might reflect more PTSD symptoms.

• The Journal of Korean Physical Therapy
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• v.35 no.6
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• pp.177-184
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• 2023

Purpose: The purpose of this study was to compare the concurrent validity and test-retest reliability of 'KPIMT Torticollis Protractor', a smart phone and I-pad application for convenient range of motion measurement, and 'Image J', an analysis software with high reliability and validity, according to head tilt and active cervical rotation angle. This was done to determine the clinical utility of 'KPIMT Torticollis Protractor'. Methods: Head tilt and active cervical spine rotation angles of 40 children with congenital muscular torticollis were measured using Image J and KPIMT Torticollis Protractor, respectively. The level of concurrent validity and inter-rater and intra-rater reliability between the two measurement methods were analyzed. Results: For forty participants, the concurrent validity between Image J and KPIMT Torticollis Protractor showed very high validity with ICC of ICC 0.977 (0.995-0.999), 0.994 (0.994-0.998), CV_ME% 0.71-0.72%, SEM% 0.31-0.34%, MDC% 0.86-0.94%. The test-retest intra-rater reliability showed very high reliability ICC 0.911 (0.911-0.966), CV_ME% 0.71%, SEM% 0.34-0.36%, MDC% 0.81-0.94%. The test-retest inter-rater showed very high reliability ICC 0.936 (0.933-0.957), CV_ME% 0.70%, SEM% 0.34-0.35%, MDC% 0.81-0.83%. Conclusion: The KPIMT Torticollis Protractor, a smart phone and IPD application, is a highly reliable and valid device for angle measurement in children with congenital myotonia and can be easily used in clinical practice.

• Korean Journal of Applied Biomechanics
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• v.29 no.4
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• pp.237-245
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• 2019

Objective: The purpose of this study was to investigate the effect of a 12-week Balanching Exercise on posture alignment, and foot plantar pressure balance in female middle students. Method: The subjects consisted of 26 female middle students, Among of 26 people exercise group is 13 persons (age: 14.69±0.48 yrs, height: 156.62±6.96 cm, weight: 50.72±9.94 kg) and control group is 13 persons (age: 14.85±0.38 yrs, height: 158.93±4.44 cm, weight: 54.25±6.60 kg) and they played Balanching Exercise for 12 weeks for 60 minutes a day, three times a week. Results: In this study, the changes of posture alignment of female middle students were analyzed. The results were as follows: head tilt, the shoulder tilt, the pelvis tilt in experimental group and there was statistically significant. Control group was head tilt, the shoulder tilt, the pelvis tilt but there was not statistically significant difference. The changes of foot pressure balance of female middle students were analyzed. The change of the foot pressure balance difference before and after the experimental group decreased by 29.3% from 6.69±3.86% to 4.73±3.57%, which was statistically significant. Control group was increased by 17.6% from 6.30±4.43% to 7.41±3.69% there was not statistically significant difference. Conclusion: The results of this study suggest that Balanching Exercise has a positive effect on improving the posture alignment and has a positive effect on foot pressure balance Research should be continued.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.406-409
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• 1997

In this paper, the power spectral analysis and fractral dimension analysis of heart rate variability(HRV) were performed to evaluate effects of orthostatic stress with head-up tilt on autonomic nervous system(ANS) for 24 young and healthy subjects(age: $24{\pm}5yr$.). The ECG and respiration signals were recorded at the tilt angle of $0^{\circ},\;15^{\circ},\;30^{\circ},\;45^{\circ},\;70^{\circ}$ and $90^{\circ}$ successively for 5 minutes per each stage under the condition of frequency controlled respiration (0.25Hz). Heart rate(HR) gradually increased as the angle increased. Similarly, according to the increment of angle, normalized low frequency(LF) component(0.05-0.15Hz) gradually increased, whereas normalized high frequency(HF) component (0.20-0.30Hz) was reduced. From these results it is speculated that orthostatic stress, head-up tilt, results in the prevalence of sympathetic tone in autonomic balance with the increment of sympathetic tone and the decrement of parasympathetic tone, which seems to mean that autonomic nervous system plays a major role in compensating for disturbances of cardiovascular system due to it.

• 대한방사선치료학회:학술대회논문집
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• 2004.06a
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• pp.14-14
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• 2004

• The Korean Journal of Physiology
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• v.12 no.1_2
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• pp.35-40
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• 1978

To evaluate orthostatic brain hypoxia from the passive tilt, anesthetized dogs were tilted from supine to $90^{\circ}C$ upright and $90^{\circ}C$ head down position. Blood pH, $Pco_2$ and $Po_2$ changes during tilt were measured on 8 dogs. Respiratory rate was decreased in upright position and increased in head down position comparing to that in rte horizontal position. pH in arterial blood was increased in upright position and decreased in venous blood comparing to that in the horizontal position. No significant changes were found in the head down position. $Pco_2$ of arterial and venous blood was decreased both in upright and head down. position A significant decrease was found in the head down position. $Po_2$ in arterial blood was increased both in the upright and head down position. However, it was decreased in the venous blood. The cause of increased $Po_2$ in arterial blood seemed to do due to hyperventilation and the cause of decreased $Po_2$ in venous blood was thought to be due to increased $O_2$ consumption of animals during the tilt.