• The Journal of Korean Physical Therapy
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• v.27 no.5
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• pp.320-324
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• 2015

Purpose: The purpose of this study was to provide methods for assessment of functional balance through study of correlation with the weight bearing ratio, functional balance, and functional gait on patients with stroke. Methods: Thirty-nine patients with stroke participated in this study. The timed up and go test was used to measure balance and the functional ambulation category test to measure functional gait. Weight bearing was measured in the quiet standing posture and weight bearing in the quiet standing posture immediately after performing the standing-task. Results: Both timed up and go test and functional ambulation category test showed significant correlation with balance in the quiet standing posture immediately after performing the standing task. Conclusion: Measurement of balance in the quiet standing posture immediately after performing the standing-task was considered a meaningful scale for measurement of both balance function and gait function of patients with stroke.

• Physical Therapy Korea
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• v.27 no.4
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• pp.241-249
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• 2020

Background: Prolonged standing during work causes a lower extremity pain and disorders. Patellofemoral pain syndrome (PFPS) is one of the common diagnoses of the knee pain. Although the etiology of PFPS is not completely understood, it is considered to be multifactorial. Objects: The purpose of this study was to investigate difference in strength of knee muscles, quadriceps:hamstring muscles strength ratio (Q:H ratio), asymmetry ratio of knee muscles strength and dorsiflexion range of motion (ROM) between standing workers with and without PFPS. Methods: Twenty-eight standing workers with PFPS and 26 age-, height-, and weight-matched standing workers without PFPS participated in this study. A tension sensor measured knee muscle strength, and motion sensor measured dorsiflexion ROM. The asymmetry ratio of knee muscles was calculated by a specific formula using the knee muscles strength of the dominant side and the sound side. An independent t-test was used to identify significant differences in the strength, ROM, Q:H ratio, and asymmetry ratio between the PFPS and normal groups. Results: The standing worker with PFPS have significantly lower dorsiflexion ROM (p < 0.000) and higher asymmetry ratio of the hamstring muscles strength (p < 0.000) compare to the standing worker without PFPS. No significant differences were seen in the strength of quadriceps muscle and hamstring muscles, Q:H ratio, and asymmetry ratio of quadriceps muscle strength. Conclusion: There was a significant difference in the asymmetry ratio of the isometric hamstring muscle strength. This finding suggests that the asymmetry ratio of isometric hamstring muscle strength may be more important than measuring only the hamstring muscle strength of the PFPS side. Furthermore, the results of this study showed a significant difference in dorsiflexion ROM between the standing industrial workers with and without PFPS. Dorsiflexion ROM and isometric hamstring muscle strength should be considered when evaluating the subjects with PFPS.

• Physical Therapy Korea
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• v.8 no.2
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• pp.55-63
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• 2001

For spinal flexibility measurements to be meaningful to clinicians or researchers, they must have a normative information and an understanding of how different variables affect spinal range of motion (ROM). Normal spinal ROM measurements are influenced to differing degrees by many factors. These factors include age, gender, time of day, leisure activities, previous history of low back pain, warming up, and the techniques with which normative data are collected. The additional variables of standing height, ratio of standing height to sitting height, and obesity had not been previously studied extensively and were shown to have a significant effect on flexibility in the sagittal plane. These relationship cannot be explained easily. Thus, the purpose of this study was to determine the relationship between spinal flexibility and individual factors (weight, standing height, and ratio of standing height to sitting height) that influence it. Fifteen healthy subjects between the ages of 20 and 27 years were studied. Two physical therapists measured independently the spinal forward bending ROM in the sagittal plane by Remodified Schober test and Finger-to-floor test. In order to determine the statistical significance of the result the Pearson's correlation was applied at the .05 level of significance. The results of this study were as follows: 1) Significant relationship was not identified between spinal flexibility and weight. 2) Significant relationship was not identified between spinal flexibility and standing height. 3) Significant relationship was not identified between spinal flexibility and ratio of standing height to sitting height.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.2
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• pp.16-23
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• 2013

An experimental study has been conducted to investigate the effects of equivalence ratio on the propagation characteristics of $CH_4$-air premixed flame intervened by an ultrasonic standing wave. A Schlieren photography was used for the flame structure visualization, and the flame propagation behavior was investigated in detail throughout the post-processing analysis. It is found that the structural variation of methane/air premixed flame caused by the intervention of ultrasonic standing wave give rise to the enhancement of combustion reaction and flame propagation velocity. Effectiveness of the standing wave on the flame velocity decreases as the equivalence ratio increases. Larger flame velocity with the standing wave becomes undistinguishable in a specific range of equivalence ratios.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.628-631
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• 2017

An experimental study of the combustion characteristics according to the equivalence ratio of hydrocarbon fuel/air premixture excited by ultrasonic standing wave are presented. The image of the propagating flame was acquired using a high-speed camera, and the combustion characteristics of each fuel were closely observed through image processing. it was conformed that ultrasonic standing wave has been found to stimulate the combustion reaction in the stoichiometric ratio.

• PNF and Movement
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• v.19 no.2
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• pp.215-223
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• 2021

Purpose: This study aimed to compare the contraction ratios of the abdominal muscles and the preferential activation ratios of the transversus abdominis muscle (TrA) during the abdominal drawing-in maneuver (ADIM) in the hook-lying, sitting, and standing positions. Methods: This study included 30 healthy participants. The thicknesses of the TrA, internal oblique muscle (IO), and external oblique muscle (EO) were measured at rest and during the ADIM in the hook-lying, sitting, and standing positions using B-mode ultrasound imaging. The contraction ratios of these muscles and the preferential activation ratios of the TrA were calculated for each position. Results: The contraction ratio of the TrA and preferential activation ratio of the TrA during the ADIM in the hook-lying position were significantly higher than those in the sitting and standing positions (p < 0.05). The contraction ratio of the TrA during the ADIM in the sitting position was significantly higher than that in the standing position (p < 0.05). Conclusion: The hook-lying position tended to facilitate TrA activity better than the sitting position. Furthermore, the sitting position tended to facilitate TrA activity better than the standing position. These findings suggest that the ADIM in the hook-lying position should be implemented before that in the sitting position and that the ADIM in the sitting position should be implemented before that in the standing position.

• The Journal of Korean Physical Therapy
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• v.24 no.2
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• pp.73-81
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• 2012

Purpose: The aim of the present study was to measure the standing balance symmetry of stroke patients using a force-plate with computer system, and to investigate the correlation between the standing balance symmetry and that of the walking function in stroke patients. Methods: 48 patients with stroke (34 men, 14 women, $56.8{\pm}11.72$ years old) participated in this study. Static standing balance was evaluated by the weight distribution on the affected and the nonaffected lower limbs, sway path, sway velocity, and sway frequency, which reflected the characteristic of body sway in quiet standing. Dynamic standing balance was evaluated by anteroposterior and mediolateral sway angle, which revealed the limit of stability during voluntary weight displacement. Symmetry index of static standing balance, (SI-SSB) calculated by the ratio of the affected weight distribution for the nonaffected weight distribution, and symmetric index of dynamic standing balance (SI-SDB) by the ratio of the affected sway angle for the nonaffected sway angle. Functional balance assessed by a Berg balance scale (BBS), and the functional walking by 10m walking velocity, as well as the modified motor assessment scale (mMAS). Results: Static balance scales and SI-SSB was the only correlation with BBS (p<0.05). Dynamic balance scales and SI-DSB, not only was correlated with BBS, but also with 10m walking velocity and mMAS (p<0.01). Additionally, there was a significant difference between SI-SSB and that of SI-DSB (p<0.01). Conclusion: The balance and the walking function relate to real life in the stroke showed strong relationships with the dynamic standing balance symmetry in the frontal plane and the ability of anterior voluntary weight displacement in sagittal plane.

• The Journal of Korean Medicine
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• v.37 no.1
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• pp.114-124
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• 2016

Objectives: The aim of this study is to find what effects both the posture of sitting and standing and the ratio of inhalation and exhalation (I/E) have on heart rate variability (HRV) Methods: We made two breathing sets with 4:6 or 6:4 ratios of I/E at 0.1 Hz of respiratory frequency and sitting or standing position. There was 20 minute-rest between sets. Each set include 5 minute-3 breathings as follows: 0.1Hz paced breath with sitting, usual breathing with standing and 0.1Hz paced breath with standing. Five minute-usual breathings with sitting as basal lines were exerted before and after these 3 breaths. Electrocardiogram-recording was exerted from 73 healthy participants (37 men and 36 women) who carried out two sets of breathings. Finally, HRV indices were analyzed of 62 participants (32 men and 30 women). Results: In 4:6 maintaining the same posture, SDNN were statistically increased, while mean heart rate(HR) were not changed. In 6:4, mean HR, SDNN were statistically increased. When changed from sitting to standing, in 4:6, SDNN were statistically decreased and mean HR was increased. However, in 6:4 during change of posture, SDNN were also statistically decreased and mean HR was statistically decreased. There was no statistical change of HF during 4:6 or 6:4 ratios of I/E moving from sitting to standing position. Conclusions: For increasing HRV, breathing in low respiratory rate with sitting was recommended regardless of ratio of I/E. In changing from sitting to standing, 4:6 may increase mean HR, and 6:4 may decrease mean HR.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.4
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• pp.45-51
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• 2015

An experimental study was performed for the analysis of frequency-equivalence ratio correlation in the methane-air premixed flame influenced by ultrasonic standing wave. The propagating flame was caught by high-speed Schlieren photography, and the variation of flame-behavior including the flame structure was investigated in detail employing a post-processing analysis of the high-speed images. It was found that a structural variation and propagation-velocity augmentation of the methane-air premixed flame by the intervention of ultrasonic standing wave were more caused off around the stoichiometry. Also, a dependency of the flame behaviors on the driving frequency and equivalence ratio of the reactants was confirmed.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.4
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• pp.360-364
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• 1996

Study on germination ratio and growth of lettuce affected by accumulated salt in vinyl house cultivation soils was investigated by pot test with EC 1.65. 3.50, 5.75. 7.15. 9.50 and 13.57 dS/m. (Germination rate of lettuce in different electric conductivity of 0, 2, 4, 6, 8 and 10 dS/m controlled with KCl were 96.7, 96.7, 87.8, 82.2, 52.2, and 27.8 % respectively. Standing ratio of lettuce in soil below 6 dS/m was more than 60% and in soils of 7.15, 9.50 and 13.57 dS/m they were 45, 32 and 31%, respectively. Growth and fresh weight of lettuces increased significantly in a low EC content soil. The fresh weight of lettuces in the soil of EC 3.50 dS/m was higher than that of the soil EC 1.65 dS/m by 22%, while another soils(EC: 5.75, 7.15, 9.50 and 13.57 dS/m) were decreased 3, 15, 60 and 62%, respectively. Relationship between soil EC and standing ratio of lettuce showed high correlation coefficient($r=-0.9057^{**}$). Therefore, in the field of vinyl houses concentrated salt, standing ratio of lettuce can be foreseen by soil EC [Y = -4.313x+ 82.95 (Y:standing ratio, x:soil EC)], also standing ratio and fresh weight of lettuce showed high correlation coefficient($r=0.8396^{**}$).