• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.05a
• /
• pp.132-135
• /
• 2002

In the present study, an electro-mechanical KAFO (knee-ankle-foot orthosis) which satisfies both the stability in stance and the knee flexion in swing was developed and evacuated in eight polio patients. A knee joint control algorithm suitable for polio patients who are lack of the stability in pre-swing was also developed and various control systems and circuits were also designed. In addition, knee flexion angles and knee moments were measured and analyzed for polio patients who used the developed KAFO with the three-dimensional motion analysis system. Energy consumption was also evaluated for the developed KAFO by measuring the movement of the COG (center of gravity) during gait. From the present study, the designed foot switch system successfully determined the gait cycle of polio patients and controlled knee joint of the KAFO, resulting in the passive knee flexion or foot clearance during swing phase. From the three-dimensional gait analysis for polio patients, it was found that the controlled-knee gait with the developed electro-mechanical KAFO showed the knee flexion of 40$^{\circ}$∼45$^{\circ}$ at an appropriate time during swing. Vertical movements of COG in controlled-knee gait (gait with the developed electro-mechanical KAFO) were significantly smaller than those in looked knee gait(gait with the locked knee Joint). and correspondingly controlled-knee gait reduced approximately 40% less energy consumption during horizontal walking gait. More efficient gait patterns could be obtained when various rehabilitation training and therapeutic programs as well as the developed electro-mechanical KAFO were applied for polio patients.

• Physical Therapy Korea
• /
• v.30 no.2
• /
• pp.110-119
• /
• 2023

Background: Osteoarthritis is a common condition with an increasing prevalence and is a common cause of disability. Osteoarthritic pain decreases the quality of life, and simple gait training is used to alleviate it. Knee osteoarthritis limits joint motion in the sagittal and lateral directions. Although many recent studies have activated orthotic research to increase knee joint stabilization, no study has used patellar tendon straps to treat knee osteoarthritis. Objects: This study aimed to determine the effects of patellar tendon straps on kinematic, mechanical, and electromyographic activation in patients with knee osteoarthritis. Methods: Patients with knee osteoarthritis were selected. After creating the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), leg length difference, Q-angle, and thumb side flexion angle of the foot were measured. Kinematic, kinetic, and muscle activation data during walking before and after wearing the orthosis were viewed. Results: After wearing the patellar tendon straps, hip adduction from the terminal stance phase, knee flexion from the terminal swing phase, and ankle plantar flexion angle increased during the pre-swing and initial swing phases. The cadence of spatiotemporal parameters and velocity increased, and step time, stride time, and foot force duration decreased. Conclusion: Based on the results of this study, the increase in plantar flexion after strap wearing is inferred by an increase due to neurological mechanisms, and adduction at the hip joint is inferred by an increase in adduction due to increased velocity. The increase in cadence and velocity and the decrease in gait speed and foot pressure duration may be due to joint stabilization. It can be inferred that joint stabilization is increased by wearing knee straps. Thus, wearing a patellar tendon strap during gait in patients with knee osteoarthritis influences kinematic changes in the sagittal plane of the joint.

• Physical Therapy Korea
• /
• v.20 no.1
• /
• pp.18-27
• /
• 2013

The purpose of this study was to compare the ring lock type knee-ankle-foot orthosis (KAFO) with newly developed 4-bar linkage KAFO on the gait characteristics of persons with poliomyelitis clinically. This 4-bar linkage is the stance control type KAFO which provide the stability during stance phase and knee flexion during swing phase. Two subjects participated in this study voluntarily. We provided the customized 4-bar linkage KAFO then asked the subjects to walk in level surface and stairs under the two different KAFO conditions. The characteristics of gait in the persons with poliomyelitis were evaluated using a 3D motion analysis system and force plate. Additionally 6 minute walk test for physiological cost index were conducted using pulse oximeter to measure the energy consumption. In the results of this study, the differences of 4-bar linkage KAFO compared with ring lock type KAFO are as follows: (1) Walking speed, stride length, and step length on level increased in subjects, (2) The gait symmetry was improved by generated knee flexion and decreased pelvic external rotation on level and stairs walking, (3) Decreased vertical excursion of center of mass and pelvic elevation during swing phase was decreased on level, (4) Knee extension moment, hip flexion moment, hip and knee internal rotation moment of non-braced limb were decreased on level walking, (5) Walking speed in 6-minute walk test was increased and physiological cost index was decreased. These findings indicate that 4-bar linkage KAFO compared with ring lock type KAFO is effective in enhancing pattern, endurance, and energy consumption in level surface and stairs walking.

• Journal of the Korean Society of Physical Medicine
• /
• v.6 no.2
• /
• pp.127-133
• /
• 2011

Purpose: 본 연구는 단하지 보조기를 사용하는 뇌졸중환자의 시-거리 보행변수에 대한 청각신호 효과에 대한 알아보고자 하는 것이다. Methods: 9명의 뇌졸중환자가 본 연구에 참여하였으며 대상자는 보조기 착용이 없는 경우, 기존 보조기 착용의 경우 그리고 청각신호 보조기 착용의 경우에 각각 시-거리 보행 변수에 대해 측정하였다. 8대의 동작분석 카메라 시스템(Motion Analysis Corporation, Santa Rosa, USA)을 사용하여 시-거리 보행 변수를 측정하였으며 Wilcoxon rank sum test을 이용하여 양하지의 대칭성을 분석하였고 Friedman test를 사용하여 다른 보조기 사용에 따른 효과를 알아보았다. Results: 청각 신호 보조기의 경우, 손상측과 비손상측의 보행속도, 활보장 그리고 분속수가 대칭적으로 되었다. 손상측의 경우, 단하지 보조기를 착용하였을 때가 착용하지 않았을 때보다 대체적으로 보행 변수들이 증가하였다. 청각 신호 단하지 보조기를 착용하였을 때 손상측 하지의 보행 속도, 활보장, 보장, 양하지 지지 시간이 증가하였고 단하지 지지 시간은 감소하였다. Conclusion: 청각 신호 단하지 보조기 착용 시 보행 속도, 활보장, 보장은 보조기를 착용하지 않았을 때보다는 증가하였으나 청각 신호 단하지 보조기와 기존 단하지 보조기 착용 사이에는 차이가 없었다. 하지만, 본 연구의 결과는 청각 신호 단하지 보조기가 뇌졸중 환자의 시-거리 보행 변수를 개선할 수 있음을 보여주었고 앞으로 다양한 보행 변수들에 대한 연구가 필요하다고 생각한다.

• The Journal of Korean Physical Therapy
• /
• v.30 no.5
• /
• pp.199-203
• /
• 2018

The number of reported cases with dual disability is increasing for the past few decades. Currently, dual disability of lower limb amputation and motor weakness after stroke became a strong issue in public concern. The functional levels of patients have shown in the wide range from independent community ambulation to non-ambulation. Thus, it indicates that favorable outcomes for dual disability may depend upon adopted rehabilitative strategies. We present the case of a man with left below-knee amputation and severe right-sided weakness following a huge putaminal hemorrhage. He had suffered from extreme pain and misfit of the prosthetic socket and the complicated residual limb for three years prior to the stroke. Forty days post-stroke, we performed a revision surgery to resolve the complications of bony overgrowth, verrucous hyperplasia, and neuroma and applied an ankle foot orthosis (AFO). Two years post-stroke, he was able to ambulate outside his home and negotiate stairs using a cane. This is the first case with the dual disability of lower limb amputation and contralateral hemiplegia to undergo revision surgery. The results suggest that an early revision surgery and use of an AFO are crucial for achieving a higher level of mobility in such cases.

• Journal of International Academy of Physical Therapy Research
• /
• v.7 no.2
• /
• pp.1037-1040
• /
• 2016

This study aims to investigate the effects of ankle foot orthosis(AFO) on the activities of tibialis anterior(TA), soleus(Sol), rectus femoris(RF) and biceps femoris(BF) during stairs descending. The activities of TA, Sol, RF and BF were initially measured while descending 4 stairs without using AFO. The activities of the same muscles were then measured again while descending 4 stairs while using AFO. Wilcoxon signed-rank tests were used to analyze the results in order to examine the differences between the with using AFO and without using AFO. Although the activities of TA, Sol and RF were relatively lower while using AFO than without using AFO, only the differences in Sol and RF activities were significant(p<0.05). The activity of BF was relatively higher while using AFO compared to the activity of BF observed without using AFO. However, difference was not significant(p>0.05). Conclusion of this study was observed since AFO's ground reaction force absorption during stairs descending reduced the need to use So and RF that is related to shock absorption. BF activity was increased with AFO than without during standing forward to correct the trunk stability.

• Korean Journal of Applied Biomechanics
• /
• v.21 no.4
• /
• pp.487-494
• /
• 2011

The purpose of this study was to evaluate the effects of metatarsal pad (MP) compared with barefoot and MP with using different insoles on gait. 15 healthy females who had no history of injury in the lower extremity with an average age of 22.7 year(SD=1.35), height of 160 cm(SD=3.4), weight of 48.8 kg(SD=5.52) and average foot size of 232.5 mm(SD=6.8) participated in this study as the subjects. The subjects walked on a treadmill under four different experimental conditions: 1) walking with barefoot, 2) walking wearing MP 3) walking wearing a soft insole with MP(SIMP), 4) walking wearing a rigid insole with MP(HIMP). During walking, foot pressure data such as force, contacting area, peak pressure, and mean pressure was collected using Pedar-X System(Novel Gmbh, Germany) and EMG activity of lower limb muscles such as tibialis anterior(TA), lateral gastrocnemius(LG), rectus femoris(RF), and musculus biceps femoris(MBF) was gathered using Delsys EMG Work System(Delsys, USA). Collected data was then analyzed using paired t-test in order to investigate the effects of each of experimental conditions. As a result of the analysis, when MP and HIMP were equipped, overall contacting area was increased while the force, peak pressure and the mean pressure were decreased. Especially, when the SIMP was equipped, every data were significantly decreased. In case of EMG, wearing MP, SIMP and HIMP made three muscles(TA, LG, RF)'s activity decrease. A result of the analysis will be able to apply for manufacturing functional shoes, diabetes shoes, senior shoes and lower extremity orthosis. Significance of the study due to a metatarsal pad and the insole is to analyze the changes in muscle strength.

• Journal of Korean Foot and Ankle Society
• /
• v.6 no.2
• /
• pp.181-189
• /
• 2002

Purpose: We try to evaluate the functional outcomes of the ankle with isokinetic plantaflexion torque for acute achilles tendon rupture cases those treated by primary repair with the Krackow suture technique and early rehabilization. Materials and Method: The authors studied retrospectively, 15 patients of acute achilles tendon rupture treated and followed over six months, from July 1997 to May 2001. There were 12 men and 3 women, and mean age was 39.6year. The repair method of ruptured tendon was single or double Krackow suture technique. One week(5days-2weeks) after operation, early ROM with ankle-foot orthosis was started. We used Arner-Lindholm Scale for the clinical evaluation and analyzed patient's satisfaction and subjective strength deficit. We analyzed the dorsiflexion peak torque and plantarflexion peak torque of the ankle statistically with strength test with Cybex dynamometer. Result: In clinical results, we had 11 excellent cases(73%) and 3 good cases(20%). In patients satisfaction degree, 11 excellent cases(66.6%), 3 good cases(20%) and 2 fair cases(13.4%). And in strength deficit, 3 none deficit (20%), 9 minimal deficit(60%). We evaluated the isokinetic plantar flexion torque in 3months or 6months after operation. After 3 months, isokinetic test showed the mean functional deficits, 32% and 25% at $30^{\circ}$ and $120^{\circ}/sec$, in 7 cases(46.6%) of 15 cases respectively. After 6 months, the mean deficits were in 21%, 24% at 30. and $120^{\circ}/sec$, respectively. At 3 and 6 months' follow up, absolute value of isokinetic test showed increase of 25. 31bs to 421bs and 19.61bs to 271bs at $30^{\circ}$ and $120^{\circ}/sec$, respectively. Conclusion: We had good result for acute achilles tendon rupture treated by Krakow suture technique and early range of motion exercise of the ankle. After 6 months, strength deficit was 21% in all of cases but were able to return pre-injured state. This study shows Krakow suture technique was recommended method for primary repair and early rehabilization of achilles tendon ruptue.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.9 no.4
• /
• pp.323-329
• /
• 2016

This paper describes an insole FFO(Functional Foot Orthosis) model for comfortable walking by considering weight distribution. There are many ways to make an insole FFO model such as using 3D computer graphics, or plaster manually. Thus, we proposed a standardized way to make an insole model, specifically called, robust and automatically personalized deformable insole model. Our proposed method showed 0.8cm average error compared between our proposed auto-deformable insole model and the other insole model manually deformed by experts. Therefore, our proposed method can be an efficient way to make a customized insole model with small error compared to the manually customized insole model.

• Physical Therapy Korea
• /
• v.9 no.3
• /
• pp.77-91
• /
• 2002

Asymmetrical stance posture, balance, and gait disturbance are common problems in hemiplegic patients. Posterior leaf springs (PLS) are frequently prescribed to correct these problems. Recently, anterior leaf springs (ALS) have also been prescribed, but only limited studies have been performed to investigate the effects of ALS. The purpose of this study was to compare the effects of three conditions, i.e., wearing an ALS, wearing a PLS, and not wearing an AFO (ankle foot orthosis),: on 1) the distribution of weight bearing on the affected side, 2) standing balance, and 3) the gait patterns of hemiplegic patients. Eleven hemiplegic patients (10 men and 1 woman) participated in this study. The data were analyzed by the Friedman test. The results were as follows: 1) More weight bearing on the affected leg was observed in the ALS and PLS conditions than in the condition without an AFO. No significant difference between the ALS and PLS conditions was found. 2) There were statistically significant differences in the composite equilibrium scores (CES) among the three conditions. The CES in the PLS condition was significantly higher than in the ALS condition or the condition without an AFO. 3) Gait patterns improved significantly in the ALS and PLS conditions. No statistically significant difference between the ALS and PLS conditions was found. These results suggest that both ALS and PLS effectively improve the distribution of weight bearing on the affected side, standing balance, and gait patterns of hemiplegic patients. Further study using three-dimensional kinematic analysis and dynamic electromyography is needed to support these findings.