• Korean Journal of Applied Biomechanics
• /
• v.22 no.3
• /
• pp.285-293
• /
• 2012

The aim of this study is to identify the appropriate movement for maintaining postural balance during Front Kick and Turning Side Kick motions. To do so, ten Taekwondo athletes: five skilled players(S, body mass: $65.0{\pm}5.8kg$, height: $172.3{\pm}3.7cm$, age: $20.0{\pm}1.2yrs$, career: $9.0{\pm}1.9yrs$) and five less-skilled players(LS, body mass: $67.1{\pm}5.5kg$, height: $173.2{\pm}5.1cm$, age: $19.4{\pm}1.7yrs$, career: $9.6{\pm}1.7yrs$) participated in this study. A three-dimensional motion analysis was performed on the participants using eight infrared cameras and two force plate(sampling frequency of 200 Hz and 2000 Hz for S and LS players, respectively). The participants' motions were divided into: a front-kick phase(P1) and a turning-side-kick phase(P2). For P2(p<.05), the range and root mean square(RMS) of the ground reaction torque and the M-L mean velocity of COP were greater for LS than for S; similarly, for P2(p<.05), the M-L range, A-P range, and velocity of the COP were greater for LS than for S. Further, the M-L range and maximum velocity of the COP was greater for failure than for success(p<.05). The femoral biceps muscle for bending the knee joint was significantly stronger in S than in LS(p<.05). It is expected that these results will be useful in developing a training program for improving the balance and stability of Taekwondo poomsae athletes and improve their front-kick and turning-side-kick motions.

• PNF and Movement
• /
• v.15 no.1
• /
• pp.27-33
• /
• 2017

Purpose: This study examined the effects of upper- and lower-limb coordinated exercise with proprioceptive neuromuscular facilitation (PNF) on stroke patients' recovery of their balancing and walking abilities. Methods: This study was conducted with 30 patients aged at least 60 years and diagnosed with stroke. The patients were randomly assigned to either a PNF upper- and lower-limb coordinated exercise group of 15 patients or an aero-step balance exercise group of 15 patients. To test the subjects' balancing and walking abilities, balancing ability tests and 10-m walking speed tests were conducted before and after the interventions. The patients performed their respective exercises for 30 minutes per session, three times per week for four weeks. The PNF exercise group performed six stages of exercise consisting of a combination of PNF patterns such as sprinting, skating, and striking. The six stages (right striking, right skating, right sprinting, left striking, left skating, and left sprinting) were performed continuously with a rest period of 1 min. after training for 4 min. The exercises for the aero-step balance group consisted of balancing in a two-leg standing position, weight shifting in a two-leg standing position, one-leg standing, squat exercises, marching in place, and squatting on an aero step. Results: The PNF exercise group showed significant improvements in their balancing ability evaluations compared to the aero-step balance group and also showed significant improvements in their 10-m walking speed tests. Conclusion: Based on the results of this study, PNF upper- and lower-limb coordinated exercise resulted in clinical improvements of stroke patients' balancing and walking abilities. Therefore, this type of exercise is recommended as a clinical intervention for the recovery of stroke patients' lower-limb function. Future studies should be conducted with longer intervention periods and more subjects to generalize the study results.

• PNF and Movement
• /
• v.18 no.1
• /
• pp.11-22
• /
• 2020

Purpose: The purpose of this study was to investigate the effects of neck stabilization exercise with PNF for neck alignment, neck disability index, and sitting balance in adults with forward-head posture. Methods: Forty participants were randomly assigned to two groups. Patients in the neck stabilization exercise group (NSG, n = 20) and the proprioceptive neuromuscular facilitation neck pattern exercise group (PNFG, n = 20) were studied 30 minutes a day three times a week for four weeks. Outcomes were measured using cranial vertical angle (CVA), the Korean version of the neck disability index (KNDI), anterior limit of stability (ALOS), and posterior limit of stability (PLOS) before and after the intervention period. Results: There were significant effects in the CVA and the KNDI of both groups pre- and post-intervention. There were significant effects in ALOS and PLOS in the PNFG pre- and post-intervention compared with the NSG. Conclusion: The results of this study suggest that PNF with neck exercise could be beneficial to the static balance of adults with forward-head posture.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.05a
• /
• pp.14-17
• /
• 2008

A poppet type shutoff valve under the pneumatic control has been adapted for the MOV (Main Oxidizer shutoff Valve) for KSLV (Korea Space Launch Vehicle). The MOV controls the supply of liquid oxygen into the combustion chamber just by opening and shutting operations. The poppet part of the poppet valves is usually connected with the piston, but on the other hand that of the MOV is separated and just contacted with the piston in order to secure the flexibility of the valve design. For the prevention of the collision with valve body by an undesirable movement of the piston part, it is necessary to evaluate the force during the valve closing. The analysis of the force balance of the MOV at the moment of the valve closing have been performed and some important design parameters for the force balance control have been introduced.

• The Journal of Korean Physical Therapy
• /
• v.35 no.5
• /
• pp.156-161
• /
• 2023

Purpose: This study examined the effects of subjective visual vertical perception and head orientation on static balance control. Methods: The subjects were 25 young and healthy adults. The vertical perception was measured using a subjective visual vertical (SVV), and the Center of pressure (COP) parameter was analyzed by continuously measuring the movement of the COP to determine the changes in static postural control. The group was divided based on a deviation of 3° in SVV (11 of SVV≥3°, 14 of SVV<3°) and measured with different head orientations: front, up, down, left, and right in the upright and tandem positions, respectively. Results: In the upright position, the SVV≥3° group had significantly larger values for all COP parameters (Sway length, Surface, Delta X, Delta Y, and Average speed) compared to the SVV<3° group (p<0.05). In the tandem stance, only the Ellipse Surface value was significantly larger among the COP parameters in the group with SVV≥3° compared to the group with SVV<3°(p<0.05). In contrast, the other COP parameters were not significantly different (p>0.05). The effects of static balance control on the head orientation were not statistically significant (p>0.05), and the interactions between the subjective vertical perception and head orientation were not significant (p>0.05). Conclusion: These results suggest that pathological deviations in SVV are associated with impaired static balance performance. This study can provide a therapeutic rationale for using visuospatial cognitive feedback training to improve the static balance.

• Economic and Environmental Geology
• /
• v.45 no.5
• /
• pp.525-533
• /
• 2012

Snowmelt from seasonal snow covers can be significant in many environments of northern and alpine areas. Water flow and chemical transport resulting from snowmelt have been studied for an understanding of contributions to watersheds or catchments. A Mobile-Immobile water Model (MIM) was developed to describe the movement of ionic tracers through a snowpack by Lee et al. (2008a) and Lee et al. (2008b). To validate the model used in the studies, mass balance calculations of the model were conducted and comparisons were made between model results and analytical solutions in this work. Mass balance was calculated based on the fact that change in total mass within a snowpack with time is equal to sum of any change in the flux of water or ionic tracers into and out of the snowpack. Calculations of both water and ionic mass show almost perfect agreement between changes of two water and solute mass fluxes. Comparisons between model results and analytical solutions including wave velocity and effective saturation show almost perfect agreement.

• The Journal of Korean Physical Therapy
• /
• v.21 no.2
• /
• pp.39-45
• /
• 2009

Purpose: The purpose of this study was to determine correlations between the Berg Balance Scale (BBS), Functional Reach Test (FRT), Timed Up & Go (TUG), Motor-Free Visual Perception Reach Test Vertical format (MVPT-V), Functional Independence Measure (FIM). Methods: The subjects used in this study were 35 stroke patients from Cheongju ST. Mary's hospital. Balance was measured by BBS, FRT. Functional mobility was measured by TUG. Visual perception was measured by MVPT-V. FIM was used to evaluate the activities of daily living. Data was analyzed using pearson product correlation. The TUG and MVPT-V index were analyzed by linear regression. Results: There was a statistically significant difference between FRT and BBS (r=0.89, p<0.01), FIM (r=0.74, p<0.05), MVPT-V (r=0.40, p<0.05), and TUG (r=-0.36, p<0.05). There was significant statistical differences between TUG and MVPT-V (r=-0.64, p<.01). However, statistically significant differences were observed between BBS and FIM (r=0.79, p<0.01). The visual close item of the MVPT-V showed the strongest variance in predicting TUG. Conclusion: The use of both quantitative and qualitive scales was shown to be a good measuring instrument for the classification of general clinical performances of stroke patients. In particular, the results suggest that the visual perception test may be able to predict functional locomotion in stroke patients.

• The Journal of Korean society of community based occupational therapy
• /
• v.8 no.3
• /
• pp.91-106
• /
• 2018

The purpose of this paper is to review vestibulo-ocular reflex and vestibular rehabilitation for balace problem in elderly. Falling is a common problem associated with aging. Falling and the resulting consequences constitutes one of the most common and serious problems. Balance deficits are one of the top risk factors for falling. Three systems(visual, vestibular and somatosensory) need to be integrated and used to coordinate and control balance. During normal ambulation and head movement, the vestibulo-ocular reflex(VOR) stabilizes gaze, and helps to keep the image of the retina. There is a direct association between deficits in VOR and falls. Older adults have a decreased ability to enhance and suppress the VOR. Vestibular rehabilitation(VR) is an exercise-based group of approaches that began with the aim of central nervous system compensation. VR restores VOR gain and reduces error using repetitive movements of the head and eyes. Many researches showd balance and gait tests were superior in the VR group. It is considered this article helps to prevent elderly falling with vestibular rehabilitation.

• Physical Therapy Rehabilitation Science
• /
• v.12 no.3
• /
• pp.214-221
• /
• 2023

Objective: This study aimed to assess the impact of using the LED light electromyographyfeedback system (EMG-light) during Pilates exercises in women to maintain consistent muscle contraction in the abdominal external oblique muscles and reduce muscle contraction in the upper trapezius muscles. This study compared Pilates training using the EMG-light with Pilates training only in healthy women for 4 weeks. Design: This study was conducted as a cross-sectional study. Methods: A total of 17 healthy women were divided into an experimental group (n=9) and a control group (n=8). Both groups performed Pilates exercises as assigned, twice per week for four weeks, with each session lasting fifty minutes. The experimental group were used the EMG-light feedback system during pilates exercise while the control group did not use EMG-light. We used cervical vertebral angle (CVA), shoulder tilt angle to evaluate neck posture and standing balance with closed eye for 30s before and after exercise. Results: The control group exhibited a significant change in CVA (p<0.05). Both groups showed significant changes in shoulder tilt, center of pressure (COP) path-length, and COP velocity during eyes-closed conditions (p<0.05). However, there were significant differences between the experimental and control groups in terms of CVA, shoulder tilt, COP path-length, and COP velocity. Conclusions: This study demonstrated that Pilates exercises had positive effects on shoulder posture and balance. The use of EMG-light provided real-time visual feedback on muscle contraction during Pilates exercise. However, the experimental group did not show significant improvements compared to the control group, which performed Pilates exercises without feedback.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.2 no.1
• /
• pp.57-65
• /
• 1996

The latest date, No. 1 YouII was grounded and sunk into the sea at MAMHYUNGJEDO ( South brother Island) in Sep. 21. 1995, and M.V. Sea Prince of V.L.C.C also made a big oil poullution accident owing to Typhoon "Paei" at front sea of Yeu Choun on Jul. 25. 1995. The large or small scall scale of oil poullution accident frequently was occurred about 300-350 cases per ine(1) year. The countries advanced in marine relations like as, nited Kingdom and Japan, have perfect system The country of expert education, training and oil recovery equipments in oil poullution accidents. The large quantity oil skimming ship's basic condition need general skimming ship which was high speed and large quantity skimming ability , and hve to store the recovered oil into tanks This oil skimming shop are composit the skimmer whuch move up and down according to the wace movements, storage tank which storage the recovered oil in after side, transfer pump which transformed from flooding tank to separating tank and separating tank which separated the oil mixtures, Also there are cylindrical floated which keep the auto positing, gate which keep the auto positing, gate which protect and guide the recovering oil from sea and balance weight for skimmer balance. Also there are cylindrical floated which keep the auto positing, gate which protect and guide the recovering oil from sea and balance weight for skimmer balance. The important arrangement is twin arm which moved by two hinge and move te skimming unit by wave movement. In gate of inside, made long wear in the gate bellow position, there are also connected the flexible hose for oil mixtures drop. The separating tank composited with multi-divided bulkhead for ffective oil and sea water separating by settling and flotation principle. As use the above natural princile and equipment, we can remove the large quantity oil by developed oil skimming ship.ming ship.