• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.446-452
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• 2002

This paper Presents a 3-D design and a Vibration control of a new walking R.G.O.(Robotic Gait Orthosis) and would like to develop a simulation by this walking system. The vibration control and evaluation of the new knee joint mechanism on the biped walking R.G.O.(Robotic Gait Orthosis) was a very unique system and was to obtain by the 3-axis accelerometer with a low frequency vibration for the paraplegia It will be expect that the spinal cord injury patients are able to recover effectively by a biped walking R.G.O.. The new knee joint system of both legs were adopted with a good kinematic characteristics. It was designed attached a DC-srevo motor and controller, with a human wear type. It was able to accomodate itself to a environments of S.C.I. Patients. It will be expect that the spinal cord injury patients are able to recover effectively by a new walking R.G.O. system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.814-817
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• 2004

It is a challenging task to make the paraplegic to walk with out the assist of the caregiver. So, we have developed various type of gait orthosis for paraplegic during the five years lately. The purpose of this study ultimately is energy consumption test of serveral type gait orthosis for developing the high efficiency gait orthosis. From the experimental results, the oxygen consumption rate were 6.9$\pm$3.3ml/kg in RGO gait, 5.3$\pm$1.3ml/kg in PGO, and 6.2$\pm$3ml/kg in HGO gait. The maximum hip flexion angle were 16$^{\circ}$ in RGO , 15$^{\circ}$ in PGO, and 47.5$^{\circ}$. in HGO. As a result It was found that. Hybrid Gait Orthosis need high energy consumption more than PGO for walking, but it is small weight and strengthened muscle.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.8
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• pp.104-110
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• 2008

The aim of this study ultimately is verifying that PGO gait is more efficient than RGO fur paraplegics because the air muscle assists hip flexion power in heel off movement. The gait characteristics of the paraplegic wearing the PGO or RGO are compared with that of a normal person. PGO with air muscles was used to analyze the walking of patients with lower-limb paralysis, and the results showed that the hip joint flexion and pelvic tilt angle decreased in PGO. In comparison to RGO gait, which is propelled by the movements of the back, PGO uses air muscles, which decreases the movement in the upper limb from a stance phase rate of 79$\pm$4%(RGO) to 68$\pm$8%. The energy consumption rate was 8.65$\pm$3.3 (ml/min/Kg) for RGO, while it decreased to 7.21t2.5(ml/min/Kg) for PGO. The results from this study show that PGO decreases energy consumption while providing support for patients with lower-limb paralysis, and it is helpful in walking for extended times.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.1
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• pp.10-18
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• 2003

This paper presented a design and control of a biped walking RGO(robotic gait orthosis) and its simulation. The biped walking RGO was distinguished from the other one by which had a very light-weight and a new RGO system will be made of 12-servo motors and 12-controllers. The vibration evaluation of the dynamic PLS(posterior leaf splint) on the biped walking RGO was used to access by the 3-axis accelerometer with a low frequency vibration of less than 30 Hz. The galt of the biped walking RGO depends on the constrains of mechanical kinematics and the initial posture. The stability of dynamic walking was investigated by analyzing the ZMP (zero moment point) of the biped walking RGO. It was designed according to the human wear type and was able to accomodate itself to the environments of S.C.I. Patients. The Joints of each leg were adopted with a good kinematic characteristics. To analyse joint kinematic properties. we made the strain stress analysis of the dynamic PLS and the analysis study of FEM with a dynamic PLS.

• Journal of International Academy of Physical Therapy Research
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• v.11 no.1
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• pp.1992-1998
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• 2020

Background: The foot drop stimulator is designed to improve the walking ability of foot drop in patients after stroke, however, studies on clinical effects are still lacking. Objective: To investigate the effect of a foot drop stimulator on the walking and balancing abilities of foot drop patients after a stroke. Design: One-Group (Pretest-Posttest) Design. Methods: All subjects walked in all three conditions: foot drop stimulator (FDS) ankle foot orthosis (AFO) and barefoot. Primary outcome measures were assessed for walking and balance using a 10-m walking test (10MWT) and a timed up and go test (TUG). Secondary outcome measures consisted of a brief user interview, and the patients recorded the advantages and disadvantages of each condition. Results: FDS, AFO, and barefoot conditions showed a statistically significant difference in 10MWT and TUG (P<.001) as a result of comparing three conditions. FDS and AFO were significantly different from the barefoot condition as post-hoc results; however, there was no significant difference between the two conditions (P>.05). Conclusion: In this study, the foot drop stimulator contributed to improving the balance ability, and the walking ability was similar to the effect of the ankle-foot orthosis.

• Physical Therapy Korea
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• v.20 no.1
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• pp.64-73
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• 2013

The purposes of this study were to develop a new orthosis controlling ankle and knee joint motion during the gait cycle and to identify the effects of the newly designed orthosis on gait kinematics and tempospatial parameters, including coordination of the extremities in stroke patients. Fifteen individuals who had sustained a stroke, onset was 16 months, participated in this study. Before application of the measurement equipment the subjects were accustomed to walking on the ankle-foot orthosis (AFO) or stance control knee with knee flexion assisted-oil damper ankle-foot orthosis (SCKAFO) for 5 minutes. Fifteen patients were investigated for 45 days with a 3-day interval between sessions. Measurements were walking in fifteen stroke with hemiparesis on the 3D motion analysis system. Comparison of AFO and SCKAFO are gait pattern. The difference between the AFO and SCKAFO conditions was significant in the gait velocity, step length of the right affected side, stance time of both legs, step-length asymmetry ratio, single-support-time asymmetry ratio, ${\phi}$-thigh angle and ${\phi}$-shank angle in the mid swing (p<.001). Using a SCKAFO in stroke patients has shown similar to normal walking speeds can be attained for walking efficiency and is therefore desirable. In this study, the support time of the affected leg with the SCKAFO was longer than with the AFO and the asymmetry ratio of single support time decreased by more than with the AFO. This indicates that the SCKAFO was effective for improving gait symmetry, single-support-time symmetry. This may be due to the decrease of gait asymmetry. Thus, the newly designed SCKAFO may be useful for promoting gait performance by improving the coordination of the extremity and decreasing gait asymmetry in chronic stroke patients.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.8
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• pp.814-823
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• 2011

Nowadays many neurological diseases such as stroke and Parkinson diseases are continually increasing. Orthotic devices as well as exoskeletons have been widely developed for supporting movement assistance and therapy of patients. Robotic knee orthosis can compensate stiff-knee gait of the paralyzed limb and can provide patients consistent assistance at wearable environments. With keeping a robotic orthosis wearable, however, it is not easy to develop a compact and safe actuator with fast rotation and high torque for consistent supports of patients during walking. In this paper, we propose a novel kinematic model for a robotic knee orthosis to drive a knee joint with independent actuation during swing and stance phases, which can allow an actuator with fast rotation to control swing motions and an actuator with high torque to control stance motions, respectively. The suggested kinematic model is composed of a hamstring device with a slide-crank mechanism, a quadriceps device with five-bar/six-bar links, and a patella device for knee covering. The quadriceps device operates in five-bar links with 2-dof motions during swing phase and is changed to six-bar links during stance phase by the contact motion to the patella device. The hamstring device operates in a slider-crank mechanism for entire gait cycle. The kinematics and velocity/force relations are analyzed for the quadriceps and hamstring devices. Finally, the adequate actuators for the suggested kinematic model are designed based on normal gait requirements. The suggested kinematic model will allow a robotic knee orthosis to use compact and light actuators with full support during walking.

• Physical Therapy Korea
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• v.27 no.4
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• pp.227-232
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• 2020

Background: Hallux valgus (HV) is a foot deformity developed by mediolateral deviation of the first metatarsophalangeal joint. Although various foot-toe orthoses were used to correct the HV angle, verification of the effects of kinetics variables such as ground reaction force (GRF) through three-dimensional (3D) gait analysis according to the various type of orthoses for HV is insufficient. Objects: This study aimed to investigate the effect of soft and hard types of foot and toe orthoses to correct HV deformity on the GRF in individuals with HV using 3D motion analysis system during walking. Methods: Twenty-six subjects participated in the experiment. Participants had HV angle of more than 15° in both feet. Two force platforms were used to obtain 3D GRF data for both feet and a 3D motion capture system with six infrared cameras was used to measure exact stance phase point such as heel strike or toe off period. Total walk trials of each participant were 8 to 10, the walkway length was 6 m. Two-way repeated measures ANOVA was used to determine the effects of each orthosis condition on the various GRF values. Results: The late anteroposterior maximal force and a first vertical peak force of the GRF showed that the hard type orthosis condition significantly increased GRF compared to the other orthosis conditions (p < 0.05). Conclusion: There were significant effects in GRF values when wearing the hard type foot orthosis. However, the hard type foot orthosis was uncomfortable to wear during walking. Therefore, it is necessary to develop a new foot-toe orthosis that can compensate for these disadvantages.

• Physical Therapy Korea
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• v.21 no.1
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• pp.29-36
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• 2014

The purpose of this study was to investigate the immediate effect of fabric ankle-foot orthosis on spatiotemporal gait parameters, compared to a barefoot condition in children with spastic cerebral palsy. Eleven children with spastic cerebral palsy participated in this study. Spatiotemporal gait parameters were measured with the GAITRite system. Fabric ankle-foot orthosis significantly improved Timed Up and Go test time and gait velocity. There was no significant difference in cadence. The step time significantly improved in both the more and less affected foot compared to the barefoot condition. The step length of the affected foot also significantly improved, but there was no significant difference in the step length of the less affected foot. There was significant improvement in the stride length of both the affected and less affected foot, but no significant difference in single stance or double stance. The fabric ankle-foot orthosis could improve stability, and selective control of the joint and promote better walking in children with cerebral palsy. Consequently, the fabric ankle-foot orthosis might be an alternative assistive device for neurological populations as a primary role instead of the typical ankle-foot orthosis.