• 제어로봇시스템학회논문지
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• 제9권11호
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• pp.943-951
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• 2003

A strategy for fault-tolerant gaits of autonomous legged robots is proposed. A legged robot is considered to be fault tolerant with respect to a given failure if it is guaranteed to be capable of walking maintaining its static stability after the occurrence of the failure. The failure concerned in this paper is a locked joint failure for which a joint in a leg cannot move and is locked in place. If a failed joint is locked, the workspace of the resulting leg is constrained, but legged robots have fault tolerance capability to continue static walking. An algorithm for generating fault-tolerant gaits is described and, especially, periodic gaits are presented for forward walking of a hexapod robot with a locked joint failure. The leg sequence and the formula of the stride length are analytically driven based on gait study and robot kinematics. The transition procedure from a normal gait to the proposed fault-tolerant gait is shown to demonstrate the applicability of the proposed scheme.

• 한국정밀공학회지
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• 제22권5호
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• pp.197-204
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• 2005

In this study, ground reaction force(GRF), absolute symmetry index(ASI) and coefficient of variation(CV) of fixed, single-axis and multi-axis prosthetic ankle assemblies were investigated to show the biomechanical evaluation for above knee amputees. In the experiments, 37 normal male volunteers, two male and two female AK amputees were tested with fixed, single-axis and multi-axis prosthetic ankle assembly. A gait analysis was carried out to derive the ratio of GRF to weight as the percentage of total stance phase for ten points. The results showed that fixed-axis ankle was superior to the other two ankle assemblies for the characteristic of forwarding and breaking forces. Multi-axis ankle was relatively superior to the other two ankle assemblies for gait balancing and movement of the center for mass. single-axis ankle was relatively superior to the other two ankle assemblies for CV and ASI of GRF.

• 한국콘텐츠학회논문지
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• 제15권6호
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• pp.259-266
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• 2015

본 연구는 비만인의 보행과 관련된 근거자료를 제시하고 근골격계 질환 예방을 위한 임상적 자료로 활용하고자 시행하였다. 신체 건강한 여대생 40명을 정상체중집단(20명), 비만집단(20명)으로 분류하여 보행패턴(smartstep), 균형지수(biodex balance SD), 근활성도(surface EMG)를 정량적으로 측정하여 비교하였다. 연구결과, 정상체중집단에 비해 비만집단의 경우 체중으로 인한 압력과 부하를 이겨내고, 체중 증가로 인한 신체 불균형 상태에서 발목관절 움직임을 증가시켜 보행함으로써 발목 움직임에 작용하는 근육의 활성도가 더 높아짐을 알 수 있었다. 따라서 비만인의 하지 근골격계 질환예방을 위해서는 하지 근육의 근력강화 및 지속적인 균형훈련과 보행 훈련이 필요할 것으로 생각된다.

• 한국운동역학회지
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• 제31권2호
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• pp.95-103
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• 2021

Objective: The aim of this study was to investigate the differences in spatiotemporal gait performance, function, and pain of lower-extremity according to foot morphological characteristics. Method: This case-control study recruited 42 adults and they were classified into 3 groups according to foot morphology using navicular-drop test: pronated (≥ 10 mm), normal (5~9 mm), and supinated (≤ 4 mm) feet. Spatiotemporal gait analysis and questionnaires including Foot and Ankle Ability Measure activities of daily living / Sports, Western Ontario and McMasters Universities Osteoarthritis Index, Lower Extremity Functional Scale, International Physical Activity Questionnaire, and Tegner activity score were conducted. One-way analysis of variance was used for statistical analysis. Results: The pronated feet group showed longer loading response and double limb support in both feet and increased pre-swing phase in non-dominant feet. The supinated feet group demonstrated a longer swing phase in non-dominant feet and single limb support in dominant feet. However, there was no significant group difference in function and pain of knee joint and lower-extremity between groups. Conclusion: Our results indicated that abnormal spatiotemporal gait performance according to foot morphology. Although there was no difference in lower extremity dysfunction and pain according to the difference in foot morphology, they have the possibility of symptom occurs as a result of continuous participation in activities of daily living and sports. Therefore, individuals with pronated or supinated foot should be supplemented by utilizing an orthosis or training to restore normal gait performance.

• 한국정밀공학회지
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• 제29권11호
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• pp.1199-1206
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• 2012

Recently, technologies to help the elderly or disabled people who have difficulty in walking are being developed. In order to develop these technologies, it is necessary to construct a system that gathers the gait data of people and analysis of these data is also important. In this research, we constructed the development of sensor system which consists of pressure sensor, three-axis accelerometer and two-axis gyro sensor. We used k-means clustering algorithm to classify the data for characterization, and then calculated the symmetry index with histogram which was produced from each cluster. We collected gait data from sensors attached on two subjects. The experiment was conducted for two kinds of gait status. One is walking with normal gait; the other is walking with abnormal gait (abnormal gait means that the subject walks by dragging the right leg intentionally). With the result from the analysis of acceleration component, we were able to confirm that the analysis technique of this data could be used to determine gait symmetry. In addition, by adding gyro components in the analysis, we could find that the symmetry index was appropriate to express symmetry better.

• PNF and Movement
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• 제16권1호
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• pp.67-73
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• 2018

Purpose: Smartphones, which are widely used worldwide to detect acceleration and position, have been used in the area of rehabilitation medicine in recent clinical research studies and tests. The aim of the present study was to determine the feasibility of using a smartphone application based on center of movement (COM) displacement to measure gait parameters in stroke patients in the clinical field of rehabilitation medicine. Methods: The study consisted of 30 stroke patients. The COM was measured using a smartphone application, Gait Analysis Pro, during a 6-m walk. Each patient performed three 6-m walking trials, and the smartphone application measured gait duration, gait speed, step length, cadence, and vertical and lateral displacement of the COM. The Kolmogorov-Smirnov test was conducted to determine the normality in gait parameters, and a repeated one-way analysis of variance (ANOVA) was performed to determine the consistency among the three trials. A p value of 0.05 was considered statistically significant in all the tests. Results: In all the measured parameters, the smartphone application showed a normal distribution, as shown by the results of the Kolmogorov-Smirnov test. There were no significant differences among the three repetitive walking trials. Conclusion: These results suggest that the smartphone application can be used for evaluating gait in stroke patients, as well as in healthy adults. However, prior to using the smartphone application in the clinical field, further research involving three-dimensional gait analysis is needed to enhance the confidence level of the findings.

• Physical Therapy Rehabilitation Science
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• 제4권1호
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• pp.32-37
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• 2015

Objective: This study was conducted to test the effects of mobile texting and gaming on gait with obstructions under different illumination levels. Design: Cross-sectional study. Methods: Twelve healthy adults aged 20 to 36 years (mean 23.5 years) were tested under six different conditions. All participants used touchscreen smartphones. Testing conditions included: 1) Walking with an obstruction under a bright illumination level; 2) walking with an obstruction with a low level of illumination; 3) walking with an obstruction while texting under a bright illumination level; 4) walking with an obstruction while texting with a low level of illumination; 5) walking with an obstruction while gaming under a bright illumination level; and 6) walking with an obstruction while gaming with a low level of illumination. All participants were asked to text the Korean national anthem by their own phone and play Temple Run 2 using an iPhone 5. Gait variances were measured over a distance of 3 m, and the mean value after three trials was used. A gait analyzer was used to measure the data. Results: Compared to normal gait with obstruction, gait speed, step length, stride length, step time, stride time, cadence while texting and gaming showed significant differences (p<0.05). Differences between the illumination levels included gait speed, step length, stride length, and step time (p<0.05) with no significant differences in stride time and cadence. Conclusions: Dual-tasking using a smartphone under low levels of illumination lowers the quality of gait with obstructions.

• 국제물리치료학회지
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• 제10권4호
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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.

• 대한물리의학회지
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• 제17권3호
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• pp.59-67
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• 2022

PURPOSE: This study examined the effectiveness of task gait exercise combined with self-observation training to provide basic clinical data by analyzing the factors that task gait exercise combined with self-observation training has on the leg muscle activity and gait improvement in stroke patients. METHODS: The subjects were assigned randomly to experimental Group I, which mediated task gait exercise combined with self-observation training, and experimental Group II, which mediated task-walking movement. They received 30-minute interventions three times a week for four weeks. The leg muscle activity and 10 m walking test (10MWT) were conducted as pre-intervention tests, and they underwent a post-test four weeks later in the same manner as the pre-test. RESULTS: A statistically significant difference was observed in all muscles and 10MWT (p < .01) in experimental group I (p < .05), while there were significant differences only in the rectus femoris, biceps femoris, and 10MWT (p < .05). In a comparison of the changes between groups, there were statistically significant differences only in the tibialis anterior, soleus muscle, and 10MWT (p < .05). CONCLUSION: Self-observation training in experimental group I was effective in increasing the leg muscle activity and improving walking speed by discovering and correcting incorrect movements and following a normal gait pattern using the ankle joint. Therefore, the task gait exercise combined with self-observation training should be introduced and actively utilized for the rapid social recovery of stroke patients.

• 대한중풍순환신경학회지
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• 제14권1호
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• pp.1-7
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• 2013

The following study reviewed the walking patterns of stroke patients with hemiplegia, which is called hemiplegic gait of stroke patients. Focusing is given to the changes in the distance and temporal factors of walking, which is called spatiotemporal characteristics, throughout the walking cycle. First, we introduced the definitions of essential terms related to gait and its measure. Second, we reviewed the spatiotemporal characteristics of hemiplegic gait. A main issue was that hemiplegic gait showed significant deviations from normal healthy gait. Although hemiplegia is primarily associated with unilateral motor disorder, changes in almost all spatiotemporal parameters used to assess walking were evident on both the involved and uninvolved sides of the body. Last, we reviewed the changes of spatiotemporal parameters of hemiplegic gait according to the prognosis or status of stroke patients, which may help to give a specific intervention for rehabilitation of stroke.