• Journal of the Ergonomics Society of Korea
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• v.26 no.2
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• pp.131-136
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• 2007

In this study, we developed an active ankle-foot orthosis(AAFO) which can control dorsi/ plantar flexion of the ankle joint to prevent foot drop and toe drag during walking. 3D gait analyses were performed on five healthy subjects under three different gait conditions: the normal gait without AFO, the SAFO gait with the conventional plastic AFO, and the AAFO gait with the developed AFO. As a result, the developed AAFO preeminently induced the normal gait compared to the SAFO. Additionally, AAFO prevented foot drop by proper plantarflexion during loading response and provided enough plantarflexion moment as a driving force to walk forward by sufficient push-off during pre-swing. AAFO also could prevent toe drag by proper dorsiflexion during swing phase. These results indicate that the developed AAFO may have more clinical benefits to treat foot drop and toe drag, compared to conventional AFOs, and also may be useful in patients with other orthotic devices.

• Physical Therapy Korea
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• v.10 no.3
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• pp.81-90
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• 2003

This study was conducted to assess the effects of the gait training method in incomplete spinal cord injured persons using an auto-walking machine. Persons with incomplete spinal cord injury level C or D on the American Spinal Injury Association impairment scale participated for eight weeks in an auto-walking training program. The gait training program was carried out for 15 minutes, three times per day for 8 weeks with an auto-walking machine. The foot rests of the auto-walking machine can be moved forward, downward, backward and upward to make the gait pattern with fixed on crank. The patient's body weight is supported by a harness during waking training. We evaluated the gait speed, physiologic cost index, motor score of lower extremities and the WISCI (walking index for spinal cord injury) level before the training and after the forth and eighth week of walking training. 1. The mean gait speed was significantly increased from .22 m/s at pre-training to .28 m/s after 4 weeks of training and .31 m/s after 8 weeks of training (p=.004). 2. The mean physiologic cost index was decreased from 4.6 beats/min at pre-training to 3.0 beats/min after 4 weeks and 2.0 beats/min after 8 weeks of training, but it was not statistically significant (p=.140). 3. The mean motor score of lower extrernities was significantly increased from 29.8 to 35.8 after 8 weeks of training (p=.043). 4. The mean WISCI level was significantly increased from level 10 to level 19 after 8 weeks of training (p=.007). The results of this study suggest that the gait training program using the auto-walking machine increased the gait speed, muscle strength and galt pattern (WISCI level) in persons with incomplete spinal cord injury. A large, controlled study of this technique is warranted.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.1153-1160
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• 2012

This study was intended to implement ankle joint dorsi flexion training against ankle muscule strength weakening that erodes stroke patients' gait performance to examine the effect of the training on stroke patients' plantar pressure and gait ability. In this study, 36 stroke patients diagnosed with stroke due to cerebral infarction or cerebral hemorrhage were divided to measure 10MWS which are stroke patients' gait variables maximum plantar pressure by area of the sole by collecting data using an F-scan system during gait. Given these results of the study, compared to other training groups, the ankle muscule strength reinforcing training group showed statistically significant increases of maximum plantar pressure in the great toe, the toe and the first metatasal areas too and thus it can be said that this training increases forward thrust during stroke patients' foot end taking off and positively affects stroke patients' ability to perform gait.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.1
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• pp.45-52
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• 2016

PURPOSE: The purpose of this study was to determine the effects of balance training on balance pad and sand on balance and gait ability in stroke patients. METHODS: Sixty stroke patients were divided into a Balance Pad group(BPG, N = 20), a Sand group (SG, N = 20) and a Hard Ground group (HGG, N = 20) randomly. The subjects in the Hard Ground group stood in a comfortable position, faced a therapist, then threw a Swiss ball back and forth. They then performed balance training in which they raised and lowered their ankles while facing forward or moved objects from one table to another. The BPG performed same tasks in HGG, on an unstable surface using a balance pad. The SG performed same tasks on sand ground. All groups received training 30min per day, five times per week, for eight weeks. RESULTS: After intervention, all groups showed significant increases balance and gait components. And the BPG and the SG showed significant increase in weight distribution rate, Sway length and BBS compared with the HGG, but there was no significant difference in Cadence, Stride length among three groups. CONCLUSION: According to the results of this study, balance training on unstable surface using balance pad and sand was more effective in improving balance in stroke patients.

• Journal of Multimedia Information System
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• v.8 no.2
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• pp.121-130
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• 2021

Foot bionic robot could be supported and towed through a series of discrete footholds and be adapted to rugged terrain through attitude adjustment. The vibration isolation of the robot could decouple the fuselage from foot-end trajectories, thus, the robot walked smoothly even if in a significant terrain. The gait programming and foot end trajectory algorithm were simulated. The quadruped robot of parallel five linkages with eight degrees of freedom were tested. The kinematics model of the robot was established by setting the corresponding coordinate system. The forward and inverse kinematics of both supporting and swinging legs were analyzed, and the angle function of single leg driving joint was obtained. The trajectory planning of both supporting and swinging phases was carried out, based on the control strategy of compound cycloid foot-end trajectory planning algorithm with zero impact. The single leg was simulated in Matlab with the established kinematic model. Finally, the walking mode of the robot was studied according to bionics principles. The diagonal gait was simulated and verified through the foot-end trajectory and the kinematics.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.3 s.303
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• pp.1-10
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• 2005

This paper proposes a novel fault-tolerant gait planning of a hexapod robot considering kinematic constraints. 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. It is shown that the conventional fault-tolerant gait of a hexapod robot for forward walking on even terrain may be fallen into deadlock, depending on the configuration of the failed leg. For coping with such deadlock situation, a novel fault-tolerant gait planning is proposed. It can avoid deadlock by adjusting the position of the foot trajectory, and has the same leg sequence and stride length as those of the conventional fault-tolerant gait. To demonstrate the superiority of the proposed scheme, a case study is presented in which a hexapod robot, having walked over even terrain before a locked joint failure, could avoid deadlock and continue its walking by the proposed fault-tolerant gait planning.

• Physical Therapy Korea
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• v.21 no.3
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• pp.80-88
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• 2014

Previous studies have reported that decreased cognitive ability has been consistently associated with significant declines in performance of one or both tasks under a dual-task walking condition. This study examined the relationship between specific cognitive abilities and the dual-task costs (DTCs) of spatio-temporal gait parameters in stroke patients. The spatio-temporal gait parameters were measured among 30 stroke patients while walking with and without a cognitive task (Stroop Word-Color Task) at the study participant's preferred walking speed. Cognitive abilities were measured using Computerized Neuropsychological Testing. Pearson's correlation coefficients (r) were calculated to quantify the associations between the neuropsychological measures and the DTCs in the spatio-temporal gait parameters. Moderate to strong correlations were found between the Auditory Continuous Performance test (ACPT) and the DTCs of the Single Support Time of Non-paretic (r=.37), the Trail Making A (TMA) test and the DTCs of Velocity (r=.71), TMA test and the DTCs of the Step Length of Paretic (r=.37), TMA test and the DTCs of the Step Length Non-paretic (r=.36), the Trail Making B (TMB) test and the DTCs of Velocity (r=.70), the Stroop Word-Color test and the DTCs of Velocity (r=-.40), Visual-span Backward (V-span B) test and the DTCs of Velocity (r=-.41), V-span B test and the DTCs of the Double Support Time of Non-paretic (r=.38), Digit-span Forward test and the DTCs of the Step Time of Non-paretic (r=-.39), and Digit-span Backward test and the DTCs of the Single Support Time of Paretic (r=.36). Especially TMA test and TMB test were found to be more strongly correlated to the DTCs of gait velocity than the other correlations. Understanding these cognitive features will provide guidance for identifying dual- task walking ability.

• Physical Therapy Rehabilitation Science
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• v.9 no.3
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• pp.155-164
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• 2020

Objective: This study aimed to compare muscle structure, balance, and gait parameters between healthy adults and persons with stroke and to analyze the correlation among these variables. Design: Cross-sectional study. Methods: Twenty persons with stroke (11 male, 9 female) and twenty healthy participants (9 male, 11 female) were included. Ultrasound images of the triceps surae and the tibialis anterior were acquired in sitting resting, sitting co-contraction, and standing resting positions and also during the functional reach test (FRT) and single leg anterior reaching test (SLART). Muscle thickness and fascicle length were measured. Spatiotemporal parameters of gait were measured using a pressure walkway. Gait speed, cadence, step length, stride length, stance time, and swing time were measured. Results: Changes in percent fascicle length were significantly greater in the gastrocnemius and soleus (SOL) muscles of healthy adults in the sitting co-contraction position (p<0.05). The percent fascicle length of the SOL in FRT and SLART were significantly greater in healthy adults (p<0.05). The mid-stance phase of stroke patients was shorter than healthy adults (p<0.05). A negative correlation was observed between percent fascicle length of the SOL in the sitting co-contraction position and the proportion of the mid-stance phase (p<0.05). Conclusions: The function of the triceps surae is affected in persons with stroke when compared with healthy adults. This can lead to difficulty in performing tasks that involve forward transfer of weight. If the triceps surae is not sufficiently secured, the possibility of compensation in the stance phase increases during gait.

• Journal of The Korean Society of Integrative Medicine
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• v.8 no.3
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• pp.21-31
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• 2020

Purpose : The purpose of this study was to determine the effects of a cognitive-exercise program using step on the cognitive function, gait, and depression of elderly with mild cognitive impairment. Methods : The subjects comprised 30 elderly people with mild cognitive impairment who used elderly welfare centers in the provinces A, B, and C between March 21 and June 7, 2019. They were divided into an experimental group (n=15) and a control group (n=15) before undergoing an experiment based on a pretest-posttest control group design. The lowenstein occupational therapy cognitive assessment-geriatric population was used to assess the subjects' cognitive function, while the 4-stage balance test, 30-second chair-stand test, timed up & go test, and functional reach test were employed to evaluate their gait. In addition, the beck depression inventory was used to measure their levels of depression. Results : The cognitive-exercise program using step enhanced the subjects' cognitive function and gait and reduced their levels of depression. Furthermore, statistically significant differences were found between the experimental group and the control group. Conclusion : The cognitive-exercise program using step promoted the process of sensorimotor and cognition through the learning process of various steps taking left and right steps and cognitive activities. It improves gait by activating the coordination of the musculoskeletal and nervous systems of the body and positively affecting posture control, balance, flexibility, and lower extremity muscles. It also relieved depression by performing successful step learning and cognitive activities with forward-looking (doing) that leads to pleasure and achievement. The present study confirmed the value of a cognitive-exercise program using step to treat multiple domains of functional decline in elderly patients with mild cognitive impairment. This is therefore proposed as an intervention program for this patient group.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.5
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• pp.471-478
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• 2012

A foot motion is estimated using an inertial sensor unit, which is installed on a shoe. The inertial sensor unit consists of 3 axis accelerometer and 3 axis gyroscopes. Attitude and position of a foot are estimated using an inertial navigation algorithm. To increase estimation performance, a smoother is used, where the smoother employs a forward and backward filter structure. An indirect Kalman filter is used as a forward filter and backward filter. A new combining algorithm for the smoother is proposed to combine a forward indirect Kalman filter and a backward indirect Kalman filter. Through experiments, the estimation performance of the proposed smoother is verified.