• 대한통합의학회지
• /
• 제11권2호
• /
• pp.207-219
• /
• 2023

Purpose : This study was conducted to investigate the changes in trunk movement and ground reaction during sit to stand motion using visual feedback. Methods : Fifteen adults (average age: 23.53±1.77 years) participated in this study. An infrared reflective marker was attached to the body each participant for motion analysis, and the participants performed sit to stand motion while wearing a hat attached with a laser pointer, which provided visual feedback. First, the sit to stand action was repeated thrice without obtaining any visual feedback, followed by a three minute break. Next, the laser pointers attached to hats were irradiated on a whiteboard, located at a distance of 5 m in front of the chairs, on which the participants sat; a baseline was set, and the participants performed stand up movements three times under this condition. A visual feedback was provided to the participants to prevent the laser pointers from crossing the set baseline. During each stand-up movement, the position of the reflective marker attached to the subject's body was recorded in real time using an infrared camera for motion analysis. The trunk movement and ground reaction force were extracted through recorded data and analyzed according to the presence or absence of visual feedback. Results : The results indicated that in the presence of a visual feedback during the sit-to-stand movements, the range of motion of the trunk and hip joints decreased, whereas that of the knee and ankle joints increased in the sagittal plane. The rotation angle of the trunk in the horizontal plane decreased. The left and right movement speed of the center of pressure increased, the pressing force decreased, and the forward and backward movement speed of the trunk decreased. Conclusion : The results suggest that the efficiency and stability of the stand up movement of a body increase when a visual feedback is provided.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2016년도 춘계학술발표대회
• /
• pp.162-165
• /
• 2016

본 논문은 윗몸 일으키기를 측정하는 타이젠 웨어러블 디바이스용 웹 어플리케이션의 정확도 개선에 대한 연구를 수행한다. 본 연구에서 사용하는 어플리케이션은 디바이스의 Accelerometer 센서를 이용하여 사용자의 윗몸 일으키기 자세를 측정한다. 올바른 윗몸 일으키기 자세에 대한 Accelerometer 데이터를 분석한 후 이를 토대로 운동역학적 데이터를 이용한 알고리즘을 구현하여 어플리케이션을 제작하고, 이를 기존에 존재하는 윗몸 일으키기 측정 앱과 비교했을 때 9.25%의 정확도를 개선할 수 있다.

• 운동과학
• /
• 제26권1호
• /
• pp.61-68
• /
• 2017

PURPOSE: To examine the cumulative (7 days) effect of breaking up prolonged sitting on systemic endothelial function in sedentary men. METHODS: Thirty sedentary men ($33.93{\pm}5.72years$) participated in two randomized 7 days sitting trial (Sit group (control) vs. Breaks group). The protocol of Breaks group is as follows: 4-minute of moderate-intensity marching in place (walking) every 1 hour during business hour (total: 8 breaks/day). Assessment of brachial artery endothelial function using flow-mediated dilation (FMD) and arterial stiffness indices (augmentation index, arterial pressure and pulse wave velocity) were measured before and after 7 days treatment. RESULTS: Brachial artery FMD significantly increased after 7 days breaking up prolonged sitting treatment (Breaks groups, $9.65{\pm}2.61$ to $9.62{\pm}2.6%$) compared with 7 days prolonged sitting (Sit group, $8.37{\pm}3.41$ to $10.11{\pm}3.75%$) (interaction effect, p=.004). Arterial pressure (AP) significantly increased after treatment (Breaks group, $2.75{\pm}2.19$ to $2.38{\pm}1.63mmHg$, p=.002) in Sit group but there was no change (Sit group, $1.00{\pm}3.18$ to $2.50{\pm}9.23mmHg$) in Breaks groups (interaction effect, p=.008). CONCLUSIONS: These finding show that 7 days regular breaking up prolonged sitting improve in FMD, compared with prolonged sitting. Therefore, regular breaking up prolonged sitting may improve systemic endothelial function in sedentary men.

• The Journal of Korean Physical Therapy
• /
• 제25권5호
• /
• pp.303-310
• /
• 2013

Purpose: The purposes of this study were to evaluate the correlation of clinical tools for assessment of balance and ability of gait, in order to discriminate the phases of sit-to-walk movement of patients with stroke using the motion analysis system, and to investigate the reliability of the phase of sit-to-walk movement according to functional ability of patients with stroke. Methods: Twenty -one patients participated (men 17, women 4) in this study. Sit-to-walk movement of all patients was recorded by the motion analysis system. Berg Balance Scale, Timed Up and Go test, Functional Reach Test, 10 meter Walk Timed Test, and Performance-Oriented Mobility Assessment were used as functional assessment tools. Results: The results of this study showed significant correlation between the phase I, II, IV and total phase duration of sit-to-walk movement and functional assessment tools. In addition, the intraclass correlation coefficient (ICC) showed high reliability in accordance with the functional ability of patients with stroke (Pearson's r 0.93 to 1.00). Conclusion: In conclusion, there is high reliability between measures of the phase of sit-to-walk movement of chronic stroke patients and the clinical assessment tool. Results of this study suggest that measurement of the phase of sit-to-walk movement can be used significantly as an intervention and a clinical tool for patients with stroke.

• 한국운동역학회지
• /
• 제16권2호
• /
• pp.121-134
• /
• 2006

The purpose of this study was to analyze the effect of different types of rehabilitation training program on the kinetic and kinematic parameters during sit-to-stand movement(STS) in chronic stroke patients. Two groups of hemiparetic patients, experimental and control, participated in the study. The experimental group participated in a 10-week training program (three sessions/wk, $1{\sim}1.5\;hr/session$) consisting of a warm-up, aerobic exercises, lower extremity strengthening. and a cool-down. The control group participated in an aerobic exercise. Three dimensional kinematic analysis and force platform; were used to analyze the duration of STS, lower extremity angle, and weight bearing ability. The experimental group which had more strength of lower extremity displayed decrease in duration of STS. However, the control group showed increases in duration during sit-to-stand movement. The control group flexed their trunk more than the group did Therefore, it took more time to extend their trunk during STS. The duration in sit-to-stand was affected by the strength of lower extremity and the angle of trunk movement. The angles of ankle and knee joint had an influenced on duration of STS. The post experimental group performed with their feet near the front leg of the chair during sit-to-stand, therefore the duration was decreased. The repetitive sit-to-stand movements as a resistance exercise was effective to hemiparetic patients in learning mechanism of sit-to-stand. The control group showed decreased differences in the vertical ground reaction forces between paretic and non-paretic limbs. Their training program included strengthening exercise that may help improving weight bearing ability. The control group showed increases in the center of pressure in the anteroposterior and mediolateral displacement. This means that the stability of movement was low in the control group. Their training program which combined aerobic and strengthening exercises that are more effective to improve the stability of movement.

• 조명전기설비학회논문지
• /
• 제12권1호
• /
• pp.51-57
• /
• 1998

본 논문은 구동신호 위상제어 기능을 갖는 SIT고주파공진 인버터를 제안하였다. SIT를 이용한 위상제어형인버터는 낮은 스위칭 손실로서 높은 스위칭 주파수의 전력변환을 실현시킬 수 있다. 특히 2단위 인버터의 출력전압을 직렬로 연결하여 높은 출력을 얻을 수 있다. 과전류에 대해서 보호회로를 이용한 시스템의 안정성과 그리고 PLL에 의해 부하변화에 따른 자동추종제어를 실현하였다. 특히 제안된 인버터는 고주파에서도 거의 정현파에 가까우며, 스위칭 주파수 범위는 180∼220〔kHz〕이고, 2〔kW〕의 유도가열에 응용하였다. 본 인버터의 동작 특성에 대해서 이론과 실험결과를 비교 검토하였다.

• The Journal of Korean Physical Therapy
• /
• 제27권3호
• /
• pp.169-173
• /
• 2015

Purpose: This study aimed to improve the asymmetrical weight-bearing ratio, by applying different repetitive sit-to-stand training methods to the paretic-side foot of hemiplegic patients, as well as to provide the necessary information for applying balance training with hemiplegic patients. Methods: The subjects were divided into two groups: a spontaneous foot group and an asymmetrical foot group. They all performed repetitive sit-to-stand training five times a week for a total of six weeks. The sit-to-standing movement was studied using standardized clinical tests. The Biodex Balance System, Time up and go test (TUG), 5 times sit-to-stand test (5XSST), and functional reach test (FRT) were used to measure the static and dynamic standing balance of the patients. Results: In the balance system measurement, the results for the overall index, ant-post index, med-lat index, fall risk index, 5XSST, and FRT after the training differed significantly between the comparison groups (p<0.05). In the evaluation of dynamic balance, the differences in TUG did not differ significantly between the comparison groups after the training (p>0.05). Conclusion: The study found that the asymmetrical group showed significant increases in static and dynamic balance in comparison to the spontaneous group after repetitive sit-to-stand training. Based on this result, it is clear that training in an asymmetrical position with the paretic foot back can increase the left-right stability limit and the anterior-posterior stability limit, thus improving balance control.

• 대한임상검사과학회지
• /
• 제52권1호
• /
• pp.36-44
• /
• 2020

With the advent of westernized diet and a lack of exercise, young female college students are paying more attention to their bodyweight and health. Whole-body vibration has been demonstrated to be a suitable training method for improving knee extension maximal strength in young female athletes, as well as the gait performance in elderly women. This study aimed to evaluate the effects of a vertical vibration intervention on the physical fitness and postural balance in young females. Fifty-four young women were recruited; all subjects were randomly assigned to the intervention group and control group. The intervention group underwent vertical vibration with a platform for 12 weeks. The results showed that body mass index and body fat percentage had decreased (P<0.05). In addition, their muscle endurance as indicated by a sit-up test and their flexibility as indicated by a sit-and-reach test were both increased. With regard to postural balance, their 30-second sit-to-stand and timed up and go test results were improved. At the same time, their mean single-leg stance with eyes closed time increased (P<0.05). However, there were no significant differences, meanwhile, for the control group. Overall, the results showed that the whole body vibration (WBV) intervention had some beneficial effects on physical fitness and postural balance in young women.

• The Journal of Korean Physical Therapy
• /
• 제27권6호
• /
• pp.413-418
• /
• 2015

Purpose: This study was performed to examine the effect of action observation training on sit to-walk times in chronic stroke patients. Methods: Twelve stroke patients were randomly allocated to two groups, as follows: an action observation training (AOT) group and a scenery picture observation (SPO) group. The AOT group was engaged in video observation for 2 minutes 30 seconds with 12 ADL functional activities related to the sit-to-walk task: physical training was carried out in two repetitions lasting 2 minutes 30 seconds. The landscape imagery control group observed landscape picture for 2 minutes 30 seconds and then carried out the same physical training. The intervention involved a total of 12 sessions over 4 weeks, and each session lasted 30 minutes. The pre and post-tests measured the timed up and go test (TUG), Sit to stand test (STS), and Dynamic gait index (DGI). The Wilcoxon signed ranks test was used to compare pre-test and post-test result, and the Mann-Whitney U test was employed for comparison between groups. Results: The TUG time was significantly different between the AOT group and the SPO group. According to the findings, the experimental group's TUG was significantly decreased (p<0.05). In comparison of the two groups, there was no significant in STS or DGI between the AOT group and SPO group. Conclusion: This study showed that the intervention can be used to decrease TUG time. Our research suggests that action observation training has a positive effect on sit-to-walk times in patients with chronic stroke.

• PNF and Movement
• /
• 제15권1호
• /
• pp.77-84
• /
• 2017

Purpose: This study aimed to investigate the effect of visual feedback training-for gradual weight shift in sit-to-stand training-on the balance and walking abilities of chronic hemiplegia patients. Methods: Twenty patients with chronic hemiplegia volunteered to participate in this study. The experimental group received visual feedback for gradual weight shift in the sit-to-stand training, while the contrast group followed the standard process for the sit-to-stand training. The evaluation of the balance and walking ability was conducted with the functional reach test (FRT), Berg balance scale (BBS), five time sit-to-stand (FTSTS) test, timed up and go (TUG) test, 10 m walk test (10MWT), balancia, activities-specific balance confidence (ABC) scale, and falls efficacy scale (FES). Results: In the results before and after intervention, there was a significant difference in TUG, 10MWT, ABC, and FES in the visual feedback training group (p < 0.05). In the control group, there was a significant difference in the 10MWT and ABC (p < 0.05). Also, in the evaluation of the postural fluctuations, the control group data showed a significant increase in Covar. The visual feedback group showed a significant difference in the W average. Conclusion: The visual feedback training group showed some improvement in terms balance and walking ability and on the ABC scale and FES. Therefore, if the diagonal progressive weight bearing exercise is combined with the various patterns and basic principles of PNF, it may be a more efficient intervention method.