• Journal of Korean Neurosurgical Society
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• v.58 no.2
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• pp.131-136
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• 2015

Objective : To investigate the incidence of corpus callosum injury (CCI) in patients with mild traumatic brain injury (TBI) using brain MRI. We also performed a review of the clinical characteristics associated with this injury. Methods : A total of 356 patients in the study were diagnosed with TBI, with 94 patients classified as having mild TBI. We included patients with mild TBI for further evaluation if they had normal findings via brain computed tomography (CT) scans and also underwent brain MRI in the acute phase following trauma. As assessed by brain MRI, CCI was defined as a high-signal lesion in T2 sagittal images and a corresponding low-signal lesion as determined by axial gradient echo (GRE) imaging. Based on these criteria, we divided patients into two groups for further analysis : Group I (TBI patients with CCI) and Group II (TBI patients without CCI). Results : A total of 56 patients were enrolled in this study (including 16 patients in Group I and 40 patients in Group II). Analysis of clinical symptoms revealed a significant difference in headache severity between groups. Over 50% of patients in Group I experienced prolonged neurological symptoms including dizziness and gait disturbance and were more common in Group I than Group II (dizziness : 37 and 12% in Groups I and II, respectively; gait disturbance : 12 and 0% in Groups I and II, respectively). Conclusion : The incidence of CCI in patients with mild TBI was approximately 29%. We suggest that brain MRI is a useful method to reveal the cause of persistent symptoms and predict clinical prognosis.

• Physical Therapy Rehabilitation Science
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• v.5 no.3
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• pp.113-119
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• 2016

Objective: The effect of abdominal expansion maneuver (AEM) and abdominal draw-in maneuver (ADIM) on postural control in an unsupported position in stroke patients. Design: Randomized controlled trial. Methods: A total of 36 persons with hemiplegic stroke participated in this study. The subjects were randomly divided into an AEM experimental group (n=12), an experimental ADIM group (n=12), and a control group (n=12). We collected the general characteristics of all subjects and the pre-test results before the intervention and after 4 weeks of the intervention. The trunk stabilization training of the ADIM and AEM group were performed 15 minutes a day, 3 times a week for 4 weeks, and general physical therapy was performed 2 times a day, 30 minutes per session, 5 times a week for all three groups. The control group received joint mobilizations, muscle strengthening, endurance strengthening, and gait exercises along with treatment of the central nervous system, such as neuro-developmental treatment, mat, and gait training. The AEM is an inspiratory phase of tidal breathing expanding the lateral lower ribcage in a lateral direction with minimal superior movements of the chest. Then the lower abdomen expands and the navel moves in an anterior-caudal direction. The ADIM is a repeated contraction and relaxation of the anal sphincter during inspiration. The navel pulls the lower abdomen to the direction of the spine without the movement of the trunk and pelvis. Results: Before and after the interventions, medial-lateral axis movement distance, anterior-posterior axis movement distance, sway mean velocity, and sway area 95% was a statistically significant change in all three groups (p<0.05). The post-hoc test showed a significant improvement in medial-lateral axis movement distance, anterior-posterior axis movement distance, sway mean velocity, and sway area in the AEM group compared with the control group, and in the ADIM group compared with the control group (p<0.05). Conclusions: In conclusion, both AEM training and ADIM training are necessary interventions to maintain the independent sitting position according to the characteristics of the patient.

• Journal of Biomedical Engineering Research
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• v.34 no.2
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• pp.80-90
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• 2013

Recently, functional insoles of wedge-type it is for the young to raise their height inserted between insole and heel cause foot pain and disease. Additionally, these have a problem with stability and excessively load-bearing during gait like high-heel shoes. In this study, we compared the changes in biomechanical characteristics of foot with different insole thickness then we will utilize for the development of the insole with the purpose of relieving the pain and disease. Subjects(male, n = 6) measured COP(center of pressure) and PCP(peak contact pressure) on the treadmill(140cm/s) using F-scan system and different insole thickness(0~50 mm) between sole and plantar surface during gait. Also, we computed changes of stresses at the foot using finite element model with various insole thickness during toe-off phase. COP moved anterior and medial direction and, PCP was increased at medial forefoot surface, $1^{st}$ and $2^{nd}$ metatarsophalangeal, ($9%{\uparrow}$) with thicker insoles and it was show sensitive increment as the insole thickness was increased from 40 mm to 50 mm. Change of the stress at the soft-tissue of plantar surface, $1^{st}$ metatarsal head represents rapid growth($36%{\uparrow}$). Also, lateral moments were increased over the 100% near the $1^{st}$ metatarsal as the insole thickness was increased from 0 mm to 30 mm. And it is show sensitive increment as the insole thickness changed 10 mm to 20 mm. As a result, it was expected that use of excessively thick insoles might cause unwanted foot pain at the forefoot region. Therefore, insole thickness under 30 mm was selected.

• Korean Journal of Applied Biomechanics
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• v.24 no.3
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• pp.287-293
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• 2014

The purpose of this study was to investigate the effects of Hoehn-Yahr scale on the activation of lower-extremity muscles during walking. Electromyography (EMG) analysis was carried out on 36 patients with Parkinson's disease in the off phase of the medication cycle. We recorded EMG signals of the tibialis anterior (TA), medial gastrocnemius (MG), lateral gastrocnemius (LG), soleus (SOL), rectus femoris (RF), vastus lateralis (VL), semitendinosus (ST) and biceps femoris (BF) using Noraxon 16 channels EMG system during walking at preferred speed. Rectified EMG signals were normalized to reference voluntary contractions (RVC) over a gait cycle at the preferred speed, allowing for an assessment of how the activity was distributed over the gait cycle. Compared to the H & Y Scale 1, H & Y Scale 3 exhibited greater activation of the vastus lateralis during mid-stance and greater activation of the medial gastrocnemius during terminal swing. Compared to the H & Y Scale 1, H & Y Scale 2 and 3 exhibited less activation of the tibialis anterior during initial swing. We conclude that the more Hoen & Yahr Scale increase, the more abnormal lower-extremity muscles activation.

• Journal of IKEEE
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• v.24 no.1
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• pp.9-18
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• 2020

The pattern recognition or fuzzy inference, which is mainly used for the development of the automatic walking mode change of the above knee prosthesis, has a disadvantage in that it is difficult to estimate with the immediate change of the walking environment. In order to solve a disadvantage, this paper developed an algorithm that automatically converts the walking mode of the next step by estimating the walking environment at a specific gait phase. Since the proposed algorithm should be implanted and operated in the microcontroller, it is developed using the random forest base in consideration of calculation amount and estimated time. The developed random forest based gait and environmental estimation model were implanted in the microcontroller and evaluated for validity.

• Journal of Korean Physical Therapy Science
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• v.4 no.1
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• pp.303-313
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• 1997

We developed the shoes which is specially designed to decrease the leg's fatness during walking and to improve the body figure. The analysis of the gait cycle and the shoes gave changes at the swing phase. We examined the results to 30 girl students of Yeong Dong Junior College for 5 weeks from 27, October to 29, Nobember in 1996, and the results were also obtained in decrease of their thigh's size in circumference. The results of the analysis are as followings; 1) After experiment circumference of the right thigh was decreased 0.04cm in noncontrol group and significantly decreased 1.04 cm in control group(p<0.01). 2) After experiment circumference of the left thigh was decreased 0.27 cm in noncontrol group and significantly decreased 1.17cm in control group(p<0.01). 3) After experiment circumference of the right calf of the leg decreased 0.09 cm in noncontrol group and significantly decreased 0.54 cm in control group(p<0.01). 4) After experiment circumference of the left calf of the leg decreased 0.21 cm in noncontrol group and significantly decreased 0.47 cm in control group. 5) After experiment body weight were not changed significantly in both group. In these results, if the people want to exercise the analysis of fat in the thigh, put on the shoes which improves the body figure and do daily work, and it will be naturally decreased the fat in thigh and they will maintain the beauty lines of the legs. There weren't any changes in the body weight while the fat of thigh in circumsference was analysed and decreased. It means that because the weight of the fat is very light, there weren't any changes in body weight.

• Korean Journal of Applied Biomechanics
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• v.34 no.2
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• pp.81-92
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• 2024

Objective: The purpose of this study was to analyze the impact acceleration, shock attenuation and biomechanical variables at various running speed. Method: 20 subjects (height: 176.15 ± 0.63 cm, weight: 70.95 ± 9.77 kg, age: 27.00 ± 4.65 yrs.) participated in this study. The subjects ran at four different speeds (2.5 m/s, 3.0 m/s, 3.5 m/s, 4.0 m/s). Three-dimensional accelerometers were attached to the distal tibia, sternum and head. Gait parameters, biomechanical variables (lower extremity joint angle, moment, power and ground reaction force) and acceleration variables (impact acceleration, shock attenuation) were calculated during the stance phase of the running. Repeated measures ANOVA was used with an alpha level of .05. Results: In gait parameters, decreased stance time, increasing stride length and stride frequency with increasing running speed. And at swing time 2.5 m/s and 4.0 m/s was decreased compared to 3.0 m/s and 3.5 m/s. Biomechanical variables statistically increased with increasing running speed except knee joint ROM, maximum ankle dorsiflexion moment, and maximum hip flexion moment. In acceleration variables as the running speed increased (2.5 m/s to 4.0 m/s), the impact acceleration on the distal tibia increased by more than twice, while the sternum and head increased by approximately 1.1 and 1.2 times, respectively. And shock attenuation (tibia to head) increased as the running speed increased. Conclusion: When running speed increases, the magnitude and increasing rate of sternum and head acceleration are lower compared to the proximal tibia, while shock attenuation increases. This suggests that limiting trunk movement and increasing lower limb movement effectively reduce impact from increased shock. However, to fully understand the body's mechanism for reducing shock, further studies are needed with accelerometers attached to more segments to examine their relationship with kinematic variables.

• Journal of Mechanical Science and Technology
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• v.19 no.spc1
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• pp.237-254
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• 2005

The vast mechanical systems could be classified as closed loop system, open loop system and open & closed (switching) system. In the closed loop system, the kinematics and dynamics of 3-D mechanisms will be reviewed and closed form solutions using the direction cosine matrix method and reflection transformation method will be introduced. In the open loop system, kinematic & dynamic analysis methods regarding the redundant system which has more degrees of freedom in joint space than those of task space are reviewed and discussed. Finally, switching system which changes its phase between closed and open loop motion is investigated with the principle of dynamical balance. Among switching systems, the human gait in biomechanics and humanoid in robotics are presented.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.523-528
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• 2000

In this paper, the new type biped walking robot which is composed of the minimum number or links just for walking and its appropriate gaits are proposed. The proposed new gaits for this robot are four-crossing, crawling, standing and turning gait. In designing the biped robot we propose the Performance Index which means the needed torque per a moving distance and generate foot trajectories by $3^{rd}$ order spline Interpolation. Among those, numerically we find the optimal conditions which minimize the Performance Index. Dynamically stable walking of the biped robot is realized by satisfying the stability condition of ZMP(zero moment point), which is related to maintaining the ZMP within the region of the supporting foot during the s1n91e leg support phase. We determine the region of mass center from the stability condition of ZMP and plan references which track the mass conte. trajectory of constant velocity. Finally we implement the gaits statically tracking the planned trajectories using PD control method.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.244-244
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• 2000

We proposed the above-knee prosthesis using rotary MR damper in which knee joint is semi-actively controlled by microprocessor. Dissipation torque in the knee joint can be controlled by the magnetic field which is induced by applying current to a solenoid, Tracking control of knee joint angle was tested by 3-DOF Leg simulator. The experimental results show that the proposed above-knee prosthesis system had good performance in swing phase tracking and repetitive controller in conjunction with a computed control law and PD control law, reduced RMS tracking error as the repetitions of tracking. Moreover, desired knee angle trajectory was generated based on the estimation of gait period with the gyro signal and the tracking control was performed.