• Journal of Institute of Control, Robotics and Systems
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• v.21 no.6
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• pp.503-509
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• 2015

In this paper, we designed and tested an ankle joint mechanism for a gait rehabilitation robot. Gait rehabilitation programs are designed to improve the natural leg motion of patients who have lost their walking capabilities by accident or disease. Strengthening the muscles of the lower-limbs and stimulation of the nervous system corresponding to walking helps patients to walk again using gait assistive devices. It is an obvious requirement that the rehabilitation system's motion should be similar to and as natural as the normal gait. However, the system being used for gait rehabilitation does not pay much attention to ankle joints, which play an important role in correct walking as the motion of the ankle should reflect the movement of the center of gravity (COG) of the body. Consequently, we have designed an ankle mechanism that ensures the safety of the patient as well as efficient gait training. Also, even patients with low leg muscle strength are able to operate the ankle joint due to the direct-drive mechanism without a reducer. This safety feature prevents any possible adverse load on the human ankle. The additional degree of freedom for the roll motion achieves a gait pattern which is similar to the normal gait and with a greater degree of comfort.

• Annals of Rehabilitation Medicine
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• v.42 no.6
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• pp.872-883
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• 2018

Objective To replace camera-based three-dimensional motion analyzers which are widely used to analyze body movements and gait but are also costly and require a large dedicated space, this study evaluates the validity and reliability of inertial measurement unit (IMU)-based systems by analyzing their spatio-temporal and kinematic measurement parameters. Methods The investigation was conducted in three separate hospitals with three healthy participants. IMUs were attached to the abdomen as well as the thigh, shank, and foot of both legs of each participant. Each participant then completed a 10-m gait course 10 times. During each gait cycle, the hips, knees, and ankle joints were observed from the sagittal, frontal, and transverse planes. The experiments were conducted with both a camera-based system and an IMU-based system. The measured gait analysis data were evaluated for validity and reliability using root mean square error (RMSE) and intraclass correlation coefficient (ICC) analyses. Results The differences between the RMSE values of the two systems determined through kinematic parameters ranged from a minimum of 1.83 to a maximum of 3.98 with a tolerance close to 1%. The results of this study also confirmed the reliability of the IMU-based system, and all of the variables showed a statistically high ICC. Conclusion These results confirmed that IMU-based systems can reliably replace camera-based systems for clinical body motion and gait analyses.

• Physical Therapy Rehabilitation Science
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• v.1 no.1
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• pp.22-27
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• 2012

Objective: Falls are defined as contact of the body with the floor after losing balance during activities of daily living. Falls commonly occur among the elderly, and stroke patients in particular are at a high risk of falling. The purpose of this study was to investigate the changes of temporal and spatial gait parameters and gait symmetry according to experience falls in post-stroke patients. Design: Cross-sectional study. Methods: Fifty three patients with stroke were recruited on a voluntary basis from the rehabilitation unit, who currently undergoing physical therapy. All participants were asked to answer questions regarding the frequency of falls in the past 1 year. Fifty-three patients with stroke were allocated 2 groups according to experienced falls: stroke with falls (n=26) during past 1 year and stroke without falls (n=27). The spatial and temporal gait parameters and gait symmetry ratio were measured using GAITRite system. Results: The spatial gait parameters and the temporal gait parameters were significantly different between the stroke with falls group and the stroke without falls group (p<0.05). Furthermore, step length was the only significantly different among symmetry ratio (p<0.05). Conclusions: Experience of falls can lead to impairment of gait ability in stroke patients. This result is expected to be used as a basic data for rehabilitation program development to prevent a fall of post-stroke patients.

• The Journal of Korean Physical Therapy
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• v.32 no.3
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• pp.185-190
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• 2020

Purpose: Gait and cognitive impairment in stroke patients exacerbate fall risk and mobility difficulties during multi-task walking. Virtual reality can provide interesting and challenging training in a community setting. This study evaluated the effect of community-based virtual reality gait training (VRGT) using a 360-degree image on the gait ability of chronic stroke patients. Methods: Forty-five chronic stroke patients who were admitted to a rehabilitation hospital participated in this study. Patients meeting the selection criteria were randomly divided into a VRGT group (n=23) and a control group (n=22). Both these groups received general rehabilitation. The VRGT group was evaluated using a 360-degree image that was recorded for 50 minutes a day, 5 days per week for a total of 6 weeks after their training. The control group received general treadmill training for the same amount of time as that of the VRGT group. The improvement in the spatiotemporal parameters of gait was evaluated using a gait analyzer system before and after training. Results: The spatiotemporal gait parameters showed significant improvements in both groups compare with the baseline measurements (p<0.05), and the VRGT group showed more improvement than the control group (p<0.05). Conclusion: Community-based VRGT has been shown to improve the walking ability of chronic stroke patients and is expected to be used in rehabilitation of stroke patients in the future.

• Journal of the Korean Society of Clothing and Textiles
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• v.44 no.6
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• pp.1107-1119
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• 2020

This study analyzed a subject's body reaction and subjective sensation when wearing a gait-assistive rehabilitation robot. The research method measured skin and clothing surface temperatures for 'seating-standing' and 'walking in place' exercises after wearing a gait-assistive rehabilitation robot. In addition, subjective sensation and satisfaction were evaluated on a 7-point Likert scale. The study results showed that the average skin temperature during exercise while wearing the gait-assistive rehabilitation robot was within a comfortable range. However, during the 'seating-standing' exercise, the skin temperature was slightly lowered. Additionally, the clothing surface temperature tended to be lower than the pre-exercise temperature after all exercises. The subjective sensation evaluation results showed that the wear comfort of the waist part was low during mobility/activity. In addition, an overall improvement in the wear comfort of the robot is necessary. The short-time movement of wearing and walking in the gait-assistive rehabilitation robot did not interfere with the thermal comfort of the body. However, the robot needs to be ergonomically improved in consideration of the long wearing time along with improved material that to satisfy overall wearing comfort.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.331-334
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• 1996

The present study was performed to investigate gait characteristics of 30-39 year-old normal adults and 9-10 year-old children. The results focused on joint motions in the sagittal plane and ground reaction forces. The results will play an important role as a valuable data to determine normal and abnormal gait patterns as well as gait characteristics of Korean people.

• Journal of Biomedical Engineering Research
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• v.28 no.2
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• pp.218-228
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• 2007

Modem concepts of gait rehabilitation after stroke favor a task-specific repetitive approach. In practice, the required physical effort of the therapists limits the realization of this approach. Therefore, a mechanized gait trainer enabling nonambulatory patients to have the repetitive practice of a gait-like movement without overstraining therapists was constructed. In this study, we developed an active gait training system for patients with gait disorder. This system provides joint movements to patients who cannot carry out an independent gait. It provides a normal stance-swing ratio of 60:40 using an eccentric configuration of two gears. Joint motions of the knee and the ankle were evaluated with using the 3D motion analysis system and compared with the results from the multi-body dynamics simulation. In addition, clinical investigations were also performed for low stroke patients during the 6-week gait training. Results from the dynamics simulation showed that joint movements of the knee and the ankle were affected by the gear size, the step length and the length of the foot plate, except the radius of curvature of the foot guide plate. Also, the 6-week gait training revealed relevant improvements of the gait ability in all low subjects. Functional ambulation category levels of subjects after training were 2 in three patients and 1 in a patient. The developed active gait trainer seems feasible as an adjunctive tool in gait rehabilitation after stroke.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.3
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• pp.315-322
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• 2009

This paper explains a control and navigation algorithm of a 6-DOF gait rehabilitation robot, which can allow a patient to navigate in virtual reality (VR) by upper and lower limbs interactions. In gait rehabilitation robots, one of the important concerns is not only to follow the robot motions passively, but also to allow the patient to walk by his/her intention. Thus, this robot allows automatic walking velocity update by estimating interaction torques between the human and the upper limb device, and synchronizing the upper limb device to the lower limb device. In addition, the upper limb device acts as a user-friendly input device for navigating in virtual reality. By pushing the switches located at the right and left handles of the upper limb device, a patient is able to do turning motions during navigation in virtual reality. Through experimental results of a healthy subject, we showed that rehabilitation training can be more effectively combined to virtual environments with upper and lower limb connections. The suggested navigation scheme for gait rehabilitation robot will allow various and effective rehabilitation training modes.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.2
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• pp.126-132
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• 2009

This study examined the differences in spatio-temporal parameters, joint angle, ground reaction force (GRF), and joint power according to the changes of gait speed for trans-tibial amputees to investigate the features of the energy-storing foot for sports. The subjects walked at normal speed and at fast speed, wearing a single-axis type foot (Korec) and an energy-storing foot for sports (Renegade) respectively. The results showed that Renegade yielded faster gait speed as well as more symmetric gait pattern, compared to Korec. However, as gait speed was increased, there was no significant difference in kinematics, ground reaction force, and joint power between two artificial foots. This was similar to the results from previous studies regarding the energy-storing foot, where the walking velocity and gait symmetry have been improved. Nevertheless, the result of this study differed from the previous ones which reported that joint angle, joint power, and GRF increased as the gait speed increased except spatio-temporal parameters.

• Journal of the Korean Society of Physical Medicine
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• v.19 no.1
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• pp.155-164
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• 2024

PURPOSE: The purpose of this study was to evaluate the effects of simultaneous application of gaze stabilization exercise and cognitive training on the balance and gait ability in subacute stroke patients. METHODS: Thirty-five patients diagnosed with stroke within 3-6 months were randomly assigned, and the experimental group (n = 18) to which both gaze stabilization exercise and cognitive training were applied and the control group (n = 17) to which only gaze stabilization exercise was applied were targeted. It was performed for 30 minutes at a time, three times a week, for a total of 4 weeks. Berg Balance Scale, Timed Up and Go test, 10Meter Walking Test, and Walking symmetry were evaluated. RESULTS: In the comparison of changes between Berg Balance Scale, Time Up and Go test, 10 Meter Walking Test, and Gait symmetry, both experimental and control groups showed significant differences before and after the intervention, and in the evaluation of Gait symmetry, significant differences between groups. CONCLUSION: As a result of this study, when gaze stabilization exercise and cognitive training were allied simultaneously, it was possible to improve the balance and gait ability of subacute stroke patients, and had a more significant effect on gait ability. In considered that training that simultaneously applies gaze stabilization exercise and cognitive training can be presented as a balance and gait rehabilitation for stroke patients on the future.