• Journal of Institute of Control, Robotics and Systems
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• v.17 no.10
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• pp.1029-1036
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• 2011

An energy-efficient reference walking trajectory generation algorithm is suggested utilizing allowable ZMP (Zero-Moment-Point) region, which maxmizes the energy efficiency for cyclic gaits, based on three-dimensional LIPM (Linear Inverted Pendulum Model) for biped robots. As observed in natural human walking, variable ZMP manipulation is suggested, in which ZMP moves within the allowable region to reduce the joint stress (i.e., rapid acceleration and deceleration of body), and hence to reduce the consumed energy. In addition, opimization of footstep planning is conducted to decide the optimal step-length and body height for a given forward mean velocity to minimize a suitable energy performance - amount of energy required to carry a unit weight a unit distance. In this planning, in order to ensure physically realizable walking trajectory, we also considered geometrical constraints, ZMP stability condition, friction constraint, and yawing moment constraint. Simulations are performed with a 12-DOF 3D biped robot model to verify the effectiveness of the proposed method.

• Annals of Rehabilitation Medicine
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• v.42 no.6
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• pp.854-862
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• 2018

Objective To investigate the effect of treadmill training with eyes open (TEO) and closed (TEC) on the knee joint position sense (JPS), functional balance and mobility in children with spastic diplegia. Methods Forty-five children with spastic diplegia aged 11-13 years participated in this study. They were randomly assigned to three groups of equal number. The control group (CON) underwent designed physical therapy program whereas, the study groups (TEO and TEC) underwent the same program, in addition to treadmill gait training with eyes open and closed, respectively. Outcome measures were the degree of knee joint position error, functional balance and mobility. Measurements were taken before and after 12 weeks of intervention. Results After training, the three groups showed statistically significant improvement in all measured outcomes, compared to the baseline with non-significant change in the knee JPS in the CON group. When comparing posttreatment results, the TEC group showed greater significant improvement in all measured outcomes, than the TEO and CON groups. Conclusion Treadmill training with eyes open and closed is effective in rehabilitation of children with diplegia, but blocked vision treadmill training has more beneficial effect.

• Korean Journal of Applied Biomechanics
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• v.33 no.3
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• pp.94-100
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• 2023

Objective: Few studies have investigated alterations of ground reaction force (GRF) in individuals with chronic ankle instability (CAI) compared with lateral ankle sprain (LAS) copers and healthy controls during walking. This study aimed to investigate differences in GRF variables among the CAI, LAS coper, and control groups. Method: Eighteen individuals with CAI, 18 LAS copers, and 18 healthy controls were recruited for this study. All participants walked on 8-m walkway with a force plate three times. GRF data during stance phase were extracted and analyzed. The analysis of variance and ensemble curve analysis were used for statistical analyses of discrete points and time-series data respectively. Results: The CAI group showed a greater loading rate (LR) and a shorter time to impact peak force than the other groups, as well as decreased vGRF from 56% to 65% in the stance phase than the control group. No significant differences were noted in the other variables. Conclusion: Based on these findings, individuals with CAI should enhance their ability to create propulsion during the push-off phase and spend more time absorbing GRF to decrease the LR, which is considered one of risk factors for overuse injury and ankle osteoarthritis.

• Physical Therapy Rehabilitation Science
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• v.11 no.4
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• pp.391-399
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• 2022

Objective: This study aimed to investigate the effects of fall-prevention exercise programs on fall efficacy, depression and health-related quality of life in elderly. Design: a randomized controlled trial Methods: A total of 57 participants over 65-years-old have been allocated to control and experimental groups. The experimental group received 8 weeks of fall-prevention exercises that included strengthening of lower extremities, balance and gait training. They received the exercises twice a week for 50 minutes as a group.Both groups were assessed using Modified Falls Efficacy Scale (MFES), Geriatric Depression Scale (GDS), and 36-Item Short-Form Health Survey (SF-36) prior and post to the intervention. The control group also received the same exercise program after the post evaluation. Results: The experimental group showed overall improvement in MFES, GDS, and physical components of SF-36 (p<0.05). The MFES was significantly increased in the experimental group after the intervention (p<0.05). The GDS was significantly decreased in the experimental group after the intervention (p<0.05). The SF-36, only physical Function, Role limitations due to physical health, general health, and energy and fatigue categories were improved in the experimental group after the intervention (p<0.05). Conclusions: The results showed 8 weeks of fall-prevention exercise programs can increase fall efficacy and physical related quality of life while reducing depression of elderly over 65.

• Physical Therapy Rehabilitation Science
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• v.6 no.2
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• pp.77-82
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• 2017

Objective: Swimming and water-based exercise (WE) programs can provide vigorous physical activity in a fun and a motivating environment. The properties of water, may make it easier for children with cerebral palsy (CP) to move and to participate in an WE program. The aims of this study was to evaluate the effect of WEs on postural control in children with spastic CP. Design: Quasi-experimental design (one group pretest-posttest design). Methods: Twenty preschoolers with spastic CP participated in this study. Prior to the application, sufficient warm-up training was performed to allow the subjects to adapt to the water. Afterwards, three different types of underwater leg exercises for the flexor, extensor, and adductor/abductor of muscles of the lower limb were performed. The WE program lasted during 8 weeks, with one-40 minute sessions per week (8 training session). The usual care was performed during the training session. The Korean-trunk control measurement scale (K-TCMS) and weight distribution variability (difference of both Fz) were measured before and after training session. Results: According to the results, the K-TCMS scores of the three sub-levels, including static sitting, dynamic sitting, and dynamic reaching, was significantly increased after the training session (p<0.05). Also, the weight distribution variability was significantly decreased after 8 weeks (p<0.05). Conclusions: We suggest that WEs may improve the postural control ability in children with spastic CP. Furthermore, we support the need for additional research on the effect of WE on gait or activity of daily living performance with a control group included.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.424-431
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• 2020

The purpose of this study was to investigate the effects of the Otago exercise program on physical function and risk of falling in elderly who have experienced falls. Thirty-six elderly people who had experienced falls more than once were randomly classified into an experimental group and control group. Each group exercised 30 minutes three times per week for a total of 8 weeks. Measurements were made using Tetrax to assess risk of falls. In addition, to measure physical function, static balance was measured using Biorescue, dynamic balance was measured using TUG, walking ability was measured using 10 MWT, and lower extremity strength was measured using FTSST. A paired t-test was conducted to verify the difference between before and after exercise in each group, and an independent t-test was performed for comparison between the groups. Regarding the experimental and control groups, static balance ability and dynamic balance ability increased significantly after exercise, and risk of falls decreased (p<.05). Lower extremity strength and gait ability increased significantly after exercise only in the experimental group (p<.05). Based on these results, the Otago exercise program is effective in improving physical function and reducing risk of falls in elderly people who have experienced falls.

• Physical Therapy Korea
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• v.15 no.2
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• pp.64-72
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• 2008

The purpose of this study was to determine the differences in joint moment in the intact limb of uni-transfemoral amputees and to identify the implications of knee osteoarthritis. As an experimental method, three-dimensional gait analysis was performed on 10 uni-transfemoral amputees and 10 healthy males. Kinematics and kinetics at the hip, knee, and ankle joint were calculated. As a statistical method, independent t-tests were conducted to perform a comparison between the transfemoral amputee group and the control group. The results showed that the external knee adduction moment increased in the transfemoral amputee group (.22 Nm/kg) compared with that of the control group (.13 Nm/kg) at terminal stance (p=.008). External knee flexion moment also increased in the transfemoral amputee group (.24 Nm/kg) but this difference was not statistically significant. External hip flexion moment increased in the transfemoral amputee group (1.35 Nm/kg) compared with that of the control group (.45 Nm/kg) at initial stance, and external hip extension moment decreased in the transfemoral amputee group (-.26 Nm/kg) compared with that of the control group (-.76 Nm/kg) at terminal stance. Although external ankle plantarflexion moment of the transfemoral amputee group increased, it was not found to be statistically significant. The results suggest that the intact limb joint moment of the uni-transfemoral amputees during walking can be different from that of healthy subjects. In conclusion, it was found that there is a link between the increase of external knee adduction moment and the prevalence of knee osteoarthritis in uni-transfemoral amputees. This result is expected to provide some objective data for rehabilitation programs related to knee osteoarthritis in transfemoral amputees.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.1
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• pp.1-9
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• 2013

PURPOSE: This study compared the effects of dual motor task training and simple task training on the balance of subacute stroke patients. METHODS: A total of 23 subacute stroke patients participated in the study. The subjects were allocated randomly to two groups: an experimental group and a control group. Both groups received conventional treatment for 50 minutes, 5 times per week for 6 weeks. In addition, the experimental group stacked blocks, moved catch cups, and moved rings while standing and gait. To evaluate the effects of the exercises, subjects were evaluated by using the balance system and the timed get up and go test(TUG) for balance measurement. The data was analyzed using a paired t-test and independent t-test to determine the statistical significance. RESULTS: The experimental group showed a significant decrease on the medial-lateral and anterior-posterior stability index compared to the control group (p<.05) for the simple task and a significant decrease on the medial-lateral and anterior-posterior stability index compared to the control group for the dual task. In addition, the experimental group showed a significant increase in TUG time compared to the control group (p<.05). CONCLUSION: These results support the perceived benefits of dual motor task training to augment the balance of subacute stroke patients. Therefore, dual motor task training is recommended for subacute stroke patients.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.1
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• pp.203-209
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• 2009

The purpose of this study is to develop a minimally constraint joint angle measurement system for the feedback control of FES (functional electrical stimulation) locomotion. Feedback control is desirable for the efficient FES locomotion, however, the simple on-off control schemes are mainly used in clinic because the currently available angle measurement systems are heavily constraint or cosmetically poor. We designed a new angle measurement system consisting of a magnet and magnetic sensors located below and above the ankle joint, respectively, in the rear side of ipsilateral leg. Two magnetic sensors are arranged so that the sensing axes are perpendicular each other. Multiple positions of sensors attachment on the shank part of the ankle joint model and also human ankle joint were selected and the accuracy of the measured angle at each position was investigated. The reference ankle joint angle was measured by potentiometer and motion capture system. The ankle joint angle was determined from the fitting curve of the reference angle and magnetic flux density relationship. The errors of the measured angle were calculated at each sensor position for the ankle range of motion (ROM) $-20{\sim}15$ degrees (dorsiflexion as positive) which covers the ankle ROM of both stroke patients and normal subjects during locomotion. The error was the smallest with the sensor at the position 1 which was the nearest position to the ankle joint. In case of human experiment, the RMS (root mean square) errors were $0.51{\pm}1.78(0.31{\sim}0.64)$ degrees and the maximum errors were $1.19{\pm}0.46(0.68{\sim}1.58)$ degrees. The proposed system is less constraint and cosmetically better than the existing angle measurement system because the wires are not needed.

• Journal of International Academy of Physical Therapy Research
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• v.6 no.1
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• pp.795-801
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• 2015

The purpose of this study was to find out an inspiratory muscles training program's therapeutic effects on stroke patients' respiratory function. For the purpose, this study targeted 20 stroke patients being hospitalized in K hospital in Daegu, and diveded the patients into the both groups of Inspiratory muscle training(IMT) group and control group, randomization. The 10 patients in the IMT group was applied the inspiratory muscles training. The control group was composed of other 10 patients. IMT group was given a inspiratory muscle training program for 30 minutes per times, 5 times a week for 6 weeks. The investigator measured the patients' respiratory function compared changes in the function and ability before and after the IMT. The results of this study are as follows. Investigating the inspiratory muscle training group's lung functions, there appeared some significant differences in the tests the FVC(Forced vital capacity), FEV1(Forced expired volume in one second) before and after the training(p<.05), but the control group had no significant in the same tests before and after(p<.05). The differences in the both groups after depending the inspiratory muscles training were significantly found in the tests of FVC, FEV1, FEV1/FVC(p<.05). The maximum inspiratory pressure showed some significant differences in the inspiratory muscle training group(p<.05), but didn't show any significant difference in the control group(p>.05). Conclusionally, it will be judged that the inspiratory muscles training program will improve stroke patients' respiratory function, and it is considered that will move up stroke patients' gait and body function.