• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.199-205
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• 2013

The purpose of this study was to analyze the changes in gait according to four style of bag's carryied method and three different bag's weights. Twenty healthy adults participated in four conditions. The first condition, they wearing a bag on one side shoulder and walked. The second condition, they carried a bag sling across on shoulder and walked. The third condition, they carried a bag on a back using both shoulders and walked. The fourth condition, they hold a bag in their right hand and walked. During all four conditions participants wore a SmartStep insole in their right shoe and had a pressure control device strapped to their right ankle. Each participant walked 10 meters carrying a 2.5 kg, 5 kg and 7.5 kg bag under all four conditions. There were significantly differents in stance phase rate; swing phase rate and walking speed according to bag weight of 2.5 kg, 5 kg, 7.5 kg.

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.317-325
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• 2011

This study aims to develop the stance-control typed 4-bar linkage orthotic knee joint that replace the locked orthotic knee joint for the disabled with poliomyelitis and muscle weakness of lower limb. Unlike the existing stance-control orthotic knee joint, there are no needs of electric power, connecting circuit, bulky compomnets, etc, because this 4-bar linkage orthotic knee joint is controled by geometric locking. To evaluate the 4-bar linkage orthotic knee joint, a subject participated in this study who has been diagnosed with lower limb poliomyelitis and have used locked type orthotic knee joint. In the results of analysis of subject's gait using 3-dimentional motion analysis system, this 4-bar linkage orthotic knee joint provide the stability during stance phase and knee flexion during swing phase.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.132-135
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• 2002

In the present study, an electro-mechanical KAFO (knee-ankle-foot orthosis) which satisfies both the stability in stance and the knee flexion in swing was developed and evacuated in eight polio patients. A knee joint control algorithm suitable for polio patients who are lack of the stability in pre-swing was also developed and various control systems and circuits were also designed. In addition, knee flexion angles and knee moments were measured and analyzed for polio patients who used the developed KAFO with the three-dimensional motion analysis system. Energy consumption was also evaluated for the developed KAFO by measuring the movement of the COG (center of gravity) during gait. From the present study, the designed foot switch system successfully determined the gait cycle of polio patients and controlled knee joint of the KAFO, resulting in the passive knee flexion or foot clearance during swing phase. From the three-dimensional gait analysis for polio patients, it was found that the controlled-knee gait with the developed electro-mechanical KAFO showed the knee flexion of 40$^{\circ}$∼45$^{\circ}$ at an appropriate time during swing. Vertical movements of COG in controlled-knee gait (gait with the developed electro-mechanical KAFO) were significantly smaller than those in looked knee gait(gait with the locked knee Joint). and correspondingly controlled-knee gait reduced approximately 40% less energy consumption during horizontal walking gait. More efficient gait patterns could be obtained when various rehabilitation training and therapeutic programs as well as the developed electro-mechanical KAFO were applied for polio patients.

• The Journal of Korea Robotics Society
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• v.12 no.2
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• pp.124-131
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• 2017

This paper present a novel approach to control the lower body power assistive exoskeleton system of a HEXAR-CR35 aimed at improving a muscular strength. More specifically the control of based on the human intention is crucial of importance to ensure intuitive and dexterous motion with the human. In this contribution, we proposed the detection algorithm of the human intention using the MCRS which are developed to measure the contraction of the muscle with variation of the circumference. The proposed algorithm provides a joint motion of exoskeleton corresponding the relate muscles. The main advantages of the algorithm are its simplicity, computational efficiency to control one joint of the HEXAR-CR35 which are consisted knee-active type exoskeleton (the other joints are consisted with the passive or quasi-passive joints that can be arranged by analyzing of the human joint functions). As a consequence, the motion of exoskeleton is generated according to the gait phase: swing and stance phase which are determined by the foot insole sensors. The experimental evaluation of the proposed algorithm is achieved in walking with the exoskeleton while carrying the external mass in the back side.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.6
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• pp.518-523
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• 2015

This paper proposes a gait phase classifier using a Recurrent Neural Network (RNN). Walking is a type of dynamic system, and as such it seems that the classifier made by using a general feed forward neural network structure is not appropriate. It is known that an RNN is suitable to model a dynamic system. Because the proposed RNN is simple, we use a back propagation algorithm to train the weights of the network. The input data of the RNN is the lower body's joint angles and angular velocities which are acquired by using the lower limb exoskeleton robot, ROBIN-H1. The classifier categorizes a gait cycle as two phases, swing and stance. In the experiment for performance verification, we compared the proposed method and general feed forward neural network based method and showed that the proposed method is superior.

• The Journal of Korean Physical Therapy
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• v.26 no.3
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• pp.136-139
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• 2014

Purpose: The purpose of this study will demonstrate that relationship between scoliosis and gait factor and foot weight bearing in ambulation. Methods: Subjects were 40 elementary students. A normal control group consisted of a total of 20 children without any known musculoskeletal disorders and an AIS group of 20 children with mild AIS (defined by a Cobb angle between 10 and $25^{\circ}$) were recruited. Measurements were scoliometer screening test, Cobb angle, gait parameter (rate of swing/stance phase, gait velosity), foot weight bearing (entire, fore, hind). Results: Scoliometer screening test (P = 0.000) and X-ray Cobb angle (P = 0.000) significant difference of group which was significantly higher in the AIS group. Gait parameter not showed significant difference. Forefoot weight bearing was significantly higher in the AIS group than more normal group. Conclusion: It seems that the results of weight bearing analysis in ambulation may be used in modifying rehabilitation programs for individual needs of patients with idiopathic scoliosis.

• The Journal of Korean Physical Therapy
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• v.21 no.2
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• pp.79-85
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• 2009

Purpose: This study examined the characteristics of gait in patients with chronic low back pain. Methods: The subjects were out-patients suffering from chronic low back pain at the department of physical therapy, B hospital in Seoul. Gait analysis was performed by dividing the subjects into two groups. The study and control group comprised 15 chronic low back pain patients and 14 healthy people, respectively. Gait analysis was performed using a VICON 512 Motion Analysis System to obtain the spatio-temporal and kinematic parameters. Results: First, there was a significant difference in the spatio-temporal parameters between the two groups (p<0.05). Second, the study group showed significant differences in the kinematic parameters during the stance phase (p<0.05). Third, there were significant differences in kinematic parameters in the study group during the swing phase (p<0.05). Conclusion: The gait pattern of patients with chronic low back pain is characterized by more rigid patterns. Compared to the control group, there was a decrease in the spatio-temporal parameters and kinematic parameters in patients with chronic low back pain. These findings are expected to play a role as basic data and to form a rehabilitation program for low back pain patients.

• Physical Therapy Korea
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• v.20 no.1
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• pp.18-27
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• 2013

The purpose of this study was to compare the ring lock type knee-ankle-foot orthosis (KAFO) with newly developed 4-bar linkage KAFO on the gait characteristics of persons with poliomyelitis clinically. This 4-bar linkage is the stance control type KAFO which provide the stability during stance phase and knee flexion during swing phase. Two subjects participated in this study voluntarily. We provided the customized 4-bar linkage KAFO then asked the subjects to walk in level surface and stairs under the two different KAFO conditions. The characteristics of gait in the persons with poliomyelitis were evaluated using a 3D motion analysis system and force plate. Additionally 6 minute walk test for physiological cost index were conducted using pulse oximeter to measure the energy consumption. In the results of this study, the differences of 4-bar linkage KAFO compared with ring lock type KAFO are as follows: (1) Walking speed, stride length, and step length on level increased in subjects, (2) The gait symmetry was improved by generated knee flexion and decreased pelvic external rotation on level and stairs walking, (3) Decreased vertical excursion of center of mass and pelvic elevation during swing phase was decreased on level, (4) Knee extension moment, hip flexion moment, hip and knee internal rotation moment of non-braced limb were decreased on level walking, (5) Walking speed in 6-minute walk test was increased and physiological cost index was decreased. These findings indicate that 4-bar linkage KAFO compared with ring lock type KAFO is effective in enhancing pattern, endurance, and energy consumption in level surface and stairs walking.

• Journal of Wellbeing Management and Applied Psychology
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• v.5 no.1
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• pp.1-7
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• 2022

Purpose: This study aimed to investigate spatial and temporal features of motor control in an individual with hemiparesis during the curvilinear gait (CG) and proposed an exercise guideline. Research design, data and methodology: An individual aged 63 with hemiparesis by stroke disease was participated in the study. Autoencoder (AE) was used to extract four motor modules from eight muscle activities of the paretic leg during CG. After extraction, each module of four modules was operationally defined by numbering from M1 to M4 according to spatial and temporal features and compared with results reported in a previous study. Results: As a result, an individual with hemiparesis had motor module problems related to difficulty of weight acceptance (module 1), compensation for the weakness of ankle plantar flexor (module 2), a spastic synergistic pattern (module 3) and difficulty with transition from the swing to stance phase (module 4) in terms of spatial features. Also, a delayed activation timing of temporal motor module (module 2) related to the forward propulsion during CG was observed. Conclusions: Gait rehabilitation for the stroke will need to consider clinical significances in respect of the deterioration of motor module and provide the tailored approaches for each gait phase.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.22 no.1
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• pp.9-15
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• 2016

Background: This study was conducted to investigate the effects of unstable modified wall squat exercises accompanied by abdominal drawing-in on the gait variables of healthy adults. Methods: The total number of subjects was 30, and 15 were randomly placed in the training group (TG) and 15 in the control group (CG). To determine the gait variables of TG and CG, step length difference (SLD) stance phase difference (STPD), swing phase difference (SWPD), single support difference (SSD), and step time difference (STD) were measured using OptoGait, a gait analysis system. Results: When the pre-intervention and post-intervention results of TG and CG were compared, statistically significant differences in SLD, STPD, SWPD, SSD and STD of TG were seen. Conclusion: Unstable modified wall squat exercises accompanied by abdominal drawing-in might help reduce the deviation between left and right gait variables during walking.