• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.23 no.1
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• pp.63-72
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• 2017

Background: The purpose of this case study was to investigate into the effect of complex exercise program on the postural change, gait and balance ability in elementary school students with forward head posture. Methods: Four patients with forward head posture were recruited. They were evaluated pre-treatment, and after 6weeks, using neck disability index (NDI), numeric pain rating scale (NPRS), balance ability, foot pressure (fore foot/rear foot peak pressure ratio, F/R ratio), gait ability (cadence, toe out angle, stance phase). Results: First, the angle of forward head posture (craniovertebral angle; CVA and cranialrotation angle; CRA) was decreased in all subjects. The NPRS and NDI were decreased in all subjects. Also, The cadence, toe out angle and F/R ratio were increased in all subjects. The stance phase of gait cycle was positively change in all subjects. Lastly, the static balance ability improved in all subjects. Conclusion: According to the results above, the complex exercise program for students with forward head posture can help improve the postural change, gait and balance ability. Also, the complex exercise program was able to select interventions depending on the patient's condition and the desired goal.

• Physical Therapy Korea
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• v.14 no.4
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• pp.44-49
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• 2007

The purpose of this study was to investigate the effects of auditory cues in the form of a metronome on gait initiation (GI) in Parkinson's disease (PD). 2 patients (mean age: 54 yrs) with idiopathic PD participated in the study. All patients (Hoehn and Yahr disability score of 2.0) were tested in the "on" state approximately 1.5 hours following the administration and fully responding to their PD medications. Subjects first initiated walking at self-initiated speeds to determine their cadences. Then, subjects were asked to initiate gait along the walkway while keeping pace with a metronome. The metronome rate (in beats/min) was set at a cadence 85% (slow condition), 100% (normal condition) and 115% (fast condition) of gait for each subject. Subjects were able to increase the speed of GI with faster cadence, but the speed of GI for the slow condition was similar to that of the normal condition. Swing toe-off was 578.3 ms for the fast condition, 709.4 ms for the normal condition and 736.2 ms for the slow condition. Respective times for swing heel-strike were 894.3 ms, 1110.2 ms and 1119.1 ms, and stance toe-off were 1105.4 ms, 1338.5 ms, and 1343.1 ms. Except for stance unloading ground reaction forces were greatest for the fast condition and smallest for the slow condition. It appears that PD patients were able to modulate GRFs and temporal events in response to auditory cues to achieve the peak acceleration force of the swing and stance limb. The findings from this study provided preliminary data, which could be used to investigate how PD patients modulate GRFs and temporal events during GI in response to tasks.

• The Journal of Korean Physical Therapy
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• v.27 no.1
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• pp.43-49
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• 2015

Purpose: The aim of the current study was to examine the effects of hinged ankle-foot orthosis (HAFO) on walking function in children with spastic diplegic cerebral palsy (CP). Methods: Thirty-two children (mean age: $6.79{\pm}0.35years$, age range: 5-7 years) who were diagnosed with spastic diplegic cerebral palsy participated in the study. Each subject typically walked through 10 meters of a gait platform with markers on the subject's proper body segments and underwent 3-D motion analysis system with and without hinged ankle-foot orthosis. The HAFOs were all custom-made for individual CP children and had plantarflexion stop at $0^{\circ}C$ with no dorsiflexion stop. The interventions were conducted over three trials in each group, and measurements were performed on each subject by one examiner in three trials. 3-D motion analysis system was used to measure gait parameters such as walking velocity, cadence, step-length, step-width, stride-length, and double support period in two conditions. Results: The walking velocity, cadence, step-length, and stride-length were significantly greater for the HAFO condition as compared to the no HAFO condition (p<0.05). However, no significant difference in step-width and double support period was observed between two conditions. Conclusion: These findings suggest that using the HAFO during walking would suggest positive evidence for improving the spatiotemporal parameters of gait in children with spastic diplegic cerebral palsy.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.12
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• pp.58-65
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• 2009

In this paper, we designed high voltage gate drive IC including dead time circuit in which capacitors controlled rising time and falling time, and schimitt-triggers controlled switching voltage. Designed High voltage gate drive IC improves an efficiency of half-bridge converter by decreasing dead time variation against temperature and has variable dead time by the capacitor value. and its power dissipation, which is generated on high side part level shifter, has decreased 52 percent by short pulse generation circuit, and UVLO circuit is designed to prevent false-operation. We simulated by using Spectre of Cadence to verify the proposed circuit and fabricated in a 1.0um process.

• The Journal of Korean Physical Therapy
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• v.18 no.1
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• pp.95-106
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• 2006

Purpose: The aim of this study was to investigate the kinematics of young adults during ramp climbing at different inclinations. Methods: Twenty-three subjects ascended and descended four steps at four different inclinations(level, $8^{\circ},\;16^{\circ},\;24^{\circ}$). Temporal-spatial parameters were measured by GaitRite system(standard mat). Groups difference was analysed with on-way ANOVA and Student-Newman-Keuls test. Results: The different kinematics of ramp ascent and descent were analysed and compared to level walking patterns. In ascending ramps, step length and stride length decreased with $24^{\circ}$ inclination (p<.000). Stance duration increased with $24^{\circ}$, but swing duration decreased with $24^{\circ}$ inclination (p<.000). Step time and velocity decreased with $16^{\circ}C,\;24^{\circ}$ inclination (p<.000). Cadence decreased with all inclination($8^{\circ},\;16^{\circ},\;24^{\circ}$)(p<.000). In descending ramps, step length and stride length, velocity decreased with all inclination($8^{\circ},\;16^{\circ},\;-24^{\circ}$)(p<.000). Stance duration increased with all inclination($8^{\circ},\;-16^{\circ},\;-24^{\circ}$) and swing duration decreased with all inclination($-8^{\circ},\;-16^{\circ},\;-24^{\circ}$)(p<.000). But Step time was not differentiated with different inclinations. Cadence decreased with only. $8^{\circ}$ inclination(p<.05). Conclusion: These results suggest that there is a certain inclination angle or angular range where subjects do switch between level walking and ramp walking gait pattern. This shows their motor control strategy between level and ramp walking. Further studies are necessary to confirm and detect the ascent and descent ramp gait patterns.

• Physical Therapy Korea
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• v.9 no.1
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• pp.1-15
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• 2002

The purpose of this study was to compare the balance and gait between fallers and non-fallers in elderly. A brief questionnaire was used to obtain the fall history. Twenty-seven women subjects were evaluated in this study. Eleven subjects and a mean age of 84.5 years (SD=4.6) were designated as the faller group. Sixteen subjects and a mean age of 80.3 years (SD=5.3) were designated as the non-faller group. The fall-related factors (mental status, balance, range of motion and muscle strength of lower extremity, sensation of foot, and cadence, walking velocity, stride length) were compared between faller group and non-faller group and measured. The results showed that faller group had significantly less range of motion of the hip flexion and knee extension, and strength of the knee extensor and ankle dorsiflexor and plantar flexor than non-faller group. The scores of the Functional reach test and One leg standing were significantly less in faller group than in non-faller group. Faller group showed less walking velocity and stride length compared to non-faller group. However, there was no significant difference in cadence during comfortable waking and fast walking between two groups. There were no significant differences in pressure, position sensory between two groups. These results suggest that exercise for improving the flexibility, muscle strength of the lower extremity and balance may be useful strategies to prevent fall in elderly. Further studies are needed to identify which specific factors are related to fall in the elderly population.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.885-892
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• 2017

In this paper, we proposed a novel crowbar circuit for high-speed discharge charge switching to solve discharge charge-time delay of supply voltage in the conventional crowbar circuit. The proposed circuit is designed to increase the charge-speed after high-speed discharge of supply voltage, thereby reducing the time exposed to radiation damage and, the normal operation time of electronic system after passing the pulse radiation. The simulation of the discharge charge-times before the implement of the hardware is conducted using Cadence's pspice tool, and DUT (Device Under Test) board is fabricated in the device level. The comparison measurement of the crowbar circuits is performed on the satellite-electronic device for 24V. As the result, we confirmed the high-speed function of the proposed circuit by improvement of the discharge-speed 96.8% and the charge-speed 27.3% as compared with the conventional circuit.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.2
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• pp.59-66
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• 2017

PURPOSE: The purpose of this study was to determine the effects of postural control training on balance and walking ability in chronic stroke patients. METHODS: Eighteen chronic stroke patients were allocated equally and randomly to an experimental group (n=9) or a control group (n=9). All participants received 60 minutes of comprehensive rehabilitation treatment, the experimental group additionally received a postural control training for 30 minutes, while the control group additionally performed a treadmill training for 30 minutes. These 30-minute training sessions were held five times per week for three weeks. Balance was assessed using Berg balance scale (BBS) and walking ability (gait speed, cadence, step length, and double limb support) was assessed using the GAITRite system. RESULTS: Improvement on all outcome measures was identified from pre-to-post intervention for both groups (p<.05). Post-intervention, there was a significant between-group difference on measured outcomes (p<.05). The experimental group exhibited greater improvement in the gait speed (p=.01; 95% CI .08-.16), cadence (p=.04; 95% CI .34-4.79), step length (p=.02; 95% CI 1.50-5.17), double limb support period (p=.04; 95% CI -2.18 to -.14), and BBS (p=.01; 95% CI 1.04-6.74) compared to the control group. CONCLUSION: The findings of this study suggest that postural control training may be beneficial for improving balance and walking ability of patients with chronic stroke.

• The Journal of Korean Physical Therapy
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• v.12 no.1
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• pp.41-47
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• 2000

BACKGROUND AND PURPOSE. The purpose of this study is to investigate the effect of the disturbed vision on the gait distance parameters on the healthy young population. SUBJECTS. Twenty four healthy college aged individuals are randomly assigned to both a condition with a strobe light and the other condition without a strobe light. METHODS. The instrumentation used for gait analysis is the GaitRite electronic walkway system with a personal IBM computer. The examiner naked all the subjects to walk 6 times on the gait mat without the strobe light and. 6 times on the mat with the strobe light. The first 4 trials were practice and the last two trials were recorded in both conditions. The gait parameters analyzed were as follows : velocity, cadence, step length, and heel to heel base of support. RESULTS. Paired samples t-test used for this study did not found any significant differences between the two conditions because the p-values that were analyzed on the experiment were Utter than 0.05. The gait parameters that were analyzed included cadence, velocity, left and right heel to heel base of support, and left and right step length. DISCUSSION AND CONCLUSION. Based on this population, the condition of disturbed vision via the effect of the strobe light was not significantly challenging to compromise the body's sensory systems. However, in the elderly population, these systems can undergo age related changes. Visual changes rapidly decline in people 60 to 80 years of age and changes in the vestibular system include $20-40\%$ reduction in hair cells.

• The Journal of Korean Physical Therapy
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• v.23 no.3
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• pp.21-27
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• 2011

Purpose: The purpose of the present study was to examine, in stroke patients, differences between backward walking training applied on a treadmill and the same training applied on the ground. Methods: Twenty seven stroke patients were divided into a treadmill backward walking group of 14 patients and a ground backward walking group of 13 subjects. Each group performed their respective training method for 8 weeks (15 min per day, 4 days a week). Walking ability was measured using a 10 m MWS (Maximal Walking Speed) test and the GAITRite system to examine changes in walking. Cadence, stridelength, step time, step length and symmetry index of the less affected side were measured to examine changes in stance phase of the lower extremity of the more affected side. Results: 10 m MWS, cadence, stride length, step time and step length of the less affected side significantly increased and symmetry index significantly decreased after training in both groups. The treadmill backward walking group experienced a significantly greater increase in step time and step length and a significantly greater decrease in symmetry index than the ground backward walking group. Conclusion: The two walking training methods were effective for improving stability in stance phase of the lower extremity of the more affected side, but the treadmill method was more effective. The present study is meaningful in that it analyzed the effects of backward walking training methods on walking and the differences of the training methods to provide information necessary for effective treatment of stroke patients.