• Korean Journal of Applied Biomechanics
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• v.22 no.4
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• pp.413-419
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• 2012

The purpose of this study was to investigate the effects of increased saddle height on the length and activity pattern of vastus lateralis (VL) and biceps femoris (BF) muscle. To compare the effects of increased saddle height, Preferred (self-selected height of subject) and High saddle height (approximately 5% higher saddle height than self-selected) were used. Seven elite cyclists (career: $16.1{\pm}8.5years$) participated in 3 min. sub-maximal pedaling tests under the same cadence (90 RPM) and pedaling power (150 W). Hip and knee joint angles, and the length and activity of VL and BF were compared by measuring 3D motion and electromyography (EMG) data. Results showed that there were significant differences in peak extension timing of the hip joint angle and the range of motion of the hip and knee joint between different saddle heights. Although there were significant differences in muscle length of both muscles with increasing saddle height, the timing and amount of muscle activity differed only at the BF. These findings suggest that the timing and amount of bi-articular muscle activity (i.e. BF) can be altered by changing the saddle height. For practically applying these results, further study is necessary to evaluate the effects of various cadence and the pedaling power with various saddle heights.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3610-3617
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• 2012

This study was to evaluate the effects of an action observation to improve on gait in stroke patients. Participants were randomly allocated to two groups: experimental (n=10) and control (n=10). Both groups were trained for 60 minutes, 6 times a week during 6 weeks by neuro-development treatment. Experimental group practiced additional action observation for 3 session 10 minutes per week 6 weeks. Both groups were evaluated by gait velocity, affected step length, non affected step length, affected stride length, non affected stride length, double support time, cadence, and timed up and go to test. There were significantly increased by action observation in outcomes of the gait performance from the gait velocity, affected side step length, affected side stride length, cadence, timed up and go test. In conclusion, the action observation improves gait performance in stroke patients. The results suggest that action observation training is feasible and suitable for individuals with hemiparesis patients.

• Journal of Korea Multimedia Society
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• v.14 no.5
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• pp.614-621
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• 2011

This paper presents design of a wide tuning range digitally controlled oscillator(DCO) for Mobile-DTV applications. DCO is the key element of the ADPLL block that generates oscillation frequencies. We proposed a binary delay chain(BDC) structure, for wide tuning range DCO, modifying conventional fixed delay chain. The proposed structure generates oscillation frequencies by delay cell combination which has a variable delay time of $2^i$ in the range of $0{\leq}i{\leq}n-1$. The BOC structure can reduce the number of delay cells because it make possible to select delay cell and resolution. We simulated the proposed DCO by Cadence's Spectre RF tool in 1.8V chartered $0.18{\mu}m$ CMOS process. The simulation results showed 77MHz~2.07GHz frequency range and 3ps resolution. The phase noise yields -101dBc/Hz@1MHz at Mobile-DTV maximum frequency 1675MHz and the power consumption is 5.87mW. The proposed DCO satisfies Mobile-DTV standards such as ATSC-M/H, DVB-H, ISDB-T, T-DMB.

• Journal of International Academy of Physical Therapy Research
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• v.10 no.4
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• pp.1914-1920
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• 2019

Background: Mobilization and cranio-cervical flexion exercise has been reported in reducing pain from cervical part and improving its motor function; also, has been represented that alleviate of neck pain and recover of neck muscles improve the normal gait performance. However, few studies have identified the effects of mobilization and exercise on pain and gait parameters with preceding issues. Objective: To examine the effects or changes of pressure pain threshold (PPT) and gait parameters in patients with chronic neck pain. Design: Cross-Sectional Clinical Trials Methods: Twenty patients with the history of neck pain (>3 months) performed the cervical mobilization and cranio-cervical flexion exercise. Gait parameters were assessed with wireless device and collected data were transmitted to the personal computer via Bluetooth. The PPT was measured posteroanterior direction at the prone position and the mean of subsequent three PPT measurements was used for the final analysis. Results: Both cervical central posteroanterior mobilization (CCPAM) (p<.000) and sling-based cranio-cervical flexion exercise (SBCCFE) (p<.000) group showed a significant increase in the PPT and the gait parameters, cadence (p<.023), was significantly increased in the CCPAM group, however slightly increased in the SBCCFE group. The comparison between the CCPAM and the SBCCFE groups after treatment did not show significant differences for the score on the PPT and gait parameters. Conclusions: This study suggests that CCPAM and SBCCFE increase PPT, cadence, and gait speed.

• Physical Therapy Rehabilitation Science
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• v.3 no.1
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• pp.43-48
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• 2014

Objective: The purpose of this study was to examine the influences on gait features during mobile phone use while ramp walking. Design: Cross-sectional study. Methods: Thirty-three healthy adult subjects performed four walking conditions on an outside ramp with a 5 m length, 1.5 m width, and a $5^{\circ}$ angle. All participants were touch screen mobile phone users. Four walking conditions were used: 1) ramp ascent, 2) ramp descent, 3) texting during ramp ascent, and 4) texting during ramp descent. In conditions 3) and 4), subjects texted the words of "Aegukga"-the song of patriotism-while walking. Upon the signal of start, the subjects walked the ramp during texting. Gait parameters were measured at the length of 3 m excluding 1 m of the start and end of the total length. Each situation was repeated three times for each subject, and mean values were calculated. For gait examination, a gait analyzer was used (OptoGait). Results: Subjects ranged in age from 23 to 38 years (mean age, 27.73). Eighty-three percent of subjects in our study had experienced an accident during mobile phone use. Texting on a mobile phone while walking significantly decreased ramp gait, speed, cadence, stride length, step length, and single support (p<0.05) and significantly increased stride time, step time, gait cycle, and double support (p<0.05). There was a significant difference in cadence, step length, stride time, step time, and single support during ramp ascent and descent (p<0.05). Conclusions: Texting on a mobile phone while walking significantly decreased gait quality.

• Physical Therapy Rehabilitation Science
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• v.3 no.1
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• pp.7-12
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• 2014

Objective: The purpose of this study was to investigate the effects of a three dimensional balance trainer in combination with a video-game system and visual feedback on balance recovery and gait function in subacute stroke patients. Design: Randomized controlled trial. Methods: Twenty-three subacute stroke patients were assigned to either an experimental (n=12) or a control group (n=11) using a random permuted block design and sealed envelopes. The experimental group received additional 3-dimensional balance training combined with visual feedback and a game program for 30 min/day, 5 days/week for 4 weeks. Both groups received 30-min of conservative physical therapy sessions based on neurodevelopmental therapy. Before and after the 20 sessions, walking abilities were evaluated by the the GaitRite system and balances were evaluated using the Berg Balance Scale (BBS). The Trunk Impairment Scale (TIS) was used to assess trunk muscle performances. Results: After the 4-week intervention, BBS and TIS scores were significantly increased in both groups (p<0.05), and increases in these scores were significantly greater in the experimental group (p<0.05). After the 4-week intervention, gait speed and cadence were significantly increased in both groups (p<0.05), and as was observed for BBS and TIS scores, changes of gait speed and cadence were significantly greater in the experimental group (p<0.05). Conclusions: The study shows that the 3-dimensional balance trainer combined with visual biofeedback and a video-game system provides a therapeutic means for improving balance and gait ability in subacute stroke patients.

• Physical Therapy Rehabilitation Science
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• v.3 no.2
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• pp.77-85
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• 2014

Objective: In the present study, the effects of progressive body weight support treadmill forward & backward walking training (FBWT), progressive body weight support treadmill forward walking training (FWT), and progressive body weight support treadmill backward walking training (BWT), and on stroke patients' ambulatory abilities were examined. Design: Randomized controlled trial. Methods: A total of 36 chronic stroke patients were divided into three groups with 12 subjects in each group. Each of the groups performed one of the progressive body weight supported treadmill training methods for 30 minute, six times per week for three weeks, and then received general physical therapy without any other intervention until the follow-up tests. For the assessment of the step length, total double support, cadence, gait were measured using optogait and the 10-m walk test (10MWT), 6 minutes walk test (6MWT). Results: In the within group comparisons, all the three groups showed significant differences between before and after the intervention (p<0.05). In the comparison of the three groups, there were significant differences among the three groups in stride length, double limb support stance, cadence, 10MWT, and 6MWT in the third week, and only in stride length, 10MWT, and 6MWT test in the sixth week (p<0.05). Conclusions: This study verified that progressive body weight-supported treadmill gait training positively affected the gait ability of stroke patients in an actual gait environment. It also showed that FBWT group was more effective than FWT group and BWT group training.

• Physical Therapy Rehabilitation Science
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• v.7 no.2
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• pp.49-53
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• 2018

Objective: This study was performed to examine differences in the association between straight and curved walking abilities of inpatients in the subacute phase and walking independence level. Design: Cross-sectional study. Methods: Subjects were divided into an independent group and a supervised group (n=10 each) by walking independence level within the ward decided by physical therapists. Inclusion criteria comprised the ability to ambulate independently within the ward, regardless of the use of walking aids. Straight walking abilities (walking velocity, stride length, and cadence) were evaluated using the 5-meter walk test. Curved walking abilities were evaluated using the Figure-of-8 Walk Test (F8W) and the 3-meter zigzag walk test (3ZW). Differences in associations between straight and curved walking abilities of inpatients were examined by calculating correlation coefficients between straight and curved walking abilities. Results: Age, walking velocity, stride length, F8W and 3ZW varied markedly between independent and supervised groups. In the independent group, F8W and 3ZW correlated significantly with walking velocity and cadence (p<0.05). In the supervised group, F8W correlated significantly with walking velocity and stride length (p<0.05), but 3ZW did not correlate significantly with straight walking abilities. Conclusions: The association between straight and curved walking abilities varied between inpatients who could ambulate independently and inpatients requiring supervision for ambulating. These differences may depend on skill on straight and curved walking abilities. There is a possibility that curved walking exercise is necessary for supervised group.

• The Journal of Korean Physical Therapy
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• v.33 no.4
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• pp.202-209
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• 2021

Purpose: This study examined whether various lower extremity exercises using a Swiss ball in the standing position could improve balance, muscle strength, gait, and fall efficacy in stroke patients. Methods: Twenty-one stroke patients were randomly divided into three groups, each with seven participants. For four weeks, experimental group 1 performed various lower extremity exercises using a Swiss ball, while experimental group 2 executed the same exercises without a Swiss ball, and the control group underwent general physical therapy. The subjects' knee extensor muscle strength, balance, gait, and fall efficacy were evaluated before and after the intervention using portable muscle strength measurement, the Berg Balance Scale (BBS), G-walk, and the Korean Falls Efficacy Scale (K-FES). Results: Knee extensor strength increased significantly in all three groups after the intervention; in particular, a significant increase was seen in experimental groups 1 and 2 compared to the control group. Moreover, all three groups had significantly better BBS scores and higher cadence after the intervention; notably, experimental group 1 had better scores and increased cadence than the control group. Additionally, gait speed was significantly increased in the experimental group 1 than in the control group. The step length of the non-affected leg was also significantly higher in the same group. The K-FES score improved significantly in all three groups, but there was no significant difference between the groups. Conclusion: This study suggests that lower extremity exercises with or without a Swiss ball could be effective interventions to improve muscle strength, balance, gait, and fall efficacy in stroke patients.

• PNF and Movement
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• v.17 no.2
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• pp.237-243
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• 2019

Purpose: The purpose of the present study was to investigate the effects of toe wedges on the gait ability of adolescents with spastic diplegic cerebral palsy. Methods: Six adolescents with spastic diplegic cerebral palsy participated in this study. During the participants walked with- and without toe wedges, the gait ability was analyzed using the electronic walkway system. Gait parameters, including velocity, cadence, step length, stride length, single support time, and double support time, were collected and analyzed. Results: When the participants walked with toe wedges, there were significant improvements in gait velocity, cadence, and double support time compared to those without toe wedges (p<0.05). However, there were no significant differences in step length, stride length, and single support time. Conclusion: Toe wedges may have a positive effect on the gait ability of adolescents with spastic diplegic cerebral palsy. However, it is necessary to conduct high-quality studies to identify the effects of toe wedges.