• Journal of Biomedical Engineering Research
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• v.33 no.4
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• pp.184-193
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• 2012

Many studies have reported that housework done using household appliances may affect biomechanical characteristics of the musculoskeletal system. The purpose of this study was to investigate the effects of housework done using a pulsator washing machine on joints and muscles. We calculated joint torques and muscle strengths on the basis of an experimental/virtual three-dimensional motion analysis for six healthy females using the pulsator washing machine at different heights (H) and depths (D) of the inside drum (H (mm){\times}D (mm), Trial1: $962.5{\times}609.4$, Trial2: $962.5{\times}624.4$, Trial3: $982.5{\times}644.4$, Trial4: $995.5{\times}642.4$, Trial5: $1015.5{\times}677.4$). The joint torques and muscle strengths tended to be considerably different during torso flexion in the sagittal plane for all the trials. The maximum joint torques for the thoracic vertebra, left ankle, and right shoulder measured in Trial4 were significantly higher than those measured in the other trials (p < 0.05); in addition, those for the thoracic vertebra and both ankles measured in Trial5 were significantly higher than those measured in the other trials (p < 0.05). The maximum muscle strengths for the left trapezius muscle and both tibialis anterior muscles measured in Trial5 were significantly higher than those measured in the other trials (p < 0.05). These results indicate that housework done using a pulsator washing machine may affect joint torques and muscle strengths, and these effects are dependent on the height and/or depth of the inside drum of the pulsator washing machine.

• 한국체육학회지인문사회과학편
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• v.57 no.3
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• pp.345-356
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• 2018

Objective: The purpose of this study was to investigate the local stability of the lower extremity joints and muscle activation patterns of the lower extremity during walking between falling and non-falling group in the elderly women. Method: Forty women, heel strikers, were recruited for this study. Twenty subjects (age:72.55±5.42yrs; height:154.40±4.26cm; mass:57.40±6.21kg; preference walking speed:0.52±0.17m/s; fall frequency=1.70±1.26 times) had a history falls(fall group) within two years and Twenty subjects (71.90±2..90yrs; height:155.28±4.73cm; mass:56.70±5.241kg; preference walking speed: 0.56±0.13m/s) had no history falls(non-fall group). While they were walking on a instrumented treadmill at their preference speed for a long while, kinematic and EMG signals were obtained using 3-D motion capture and wireless EMG electrodes, respectively. Local stability of the ankle and knee joint were calculated using Lyapunov Exponent (LyE) and muscles activation and their co-contraction index were also quantified. Hypotheses were tested using one-way ANOVA and Mann-Whitey. Spearman rank was also used to determine the correlation coefficients between variables. Level of significance was set at p<.05. Results: Local stability in the knee joint adduction-abduction was significantly greater in fall group than non-fall group(p<.05). Activation of anterior tibials that acts on the foot segment dorsal flexion was greater in non-fall group than fall group(p<.05). CI between gastrocnemius and anterior tibials was found to be significantly different between two groups(p<.05). In addition, there was significant correlation between CI of the leg and LyE of the ankle joint flexion-extention in the fall group(p<.05). Conclusion: In conclusion, muscles that act on the knee joint abduction-adduction as well as gastrocnemius and anterior tibials that act on the ankle joint flexion-extention need to be strengthened to prevent from potential fall during walking.

• Journal of Korean Foot and Ankle Society
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• v.1 no.1
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• pp.59-64
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• 1997

The aims of free tissue transplantation to the injured foot are to cover the exposed blood vessels, nerves, muscles, tendons and bones, to clear up infection, to lessen the morbidity, to shorten the hospitalization, and to prepare for further surgical procedures when no local or transpositioning flaps are available. Authors have carried out free flap transplantation in 13 cases of crushing injury, osteomyelitis and electrical burn in the foot at Chonbuk National University Hospital from June 1992 through May 1996. The results were as follows : 1. 9 cases of 13 (69%) were sustained from the traffic accident. 2. The dorsalis pedis free flap transplantation has been performed most frequently in 5 cases (38.5%), followed gracilis muscle flap in 4 cases(30.7%), rectus abdominis muscle flap in 2 cases(15.4%), latissimus dorsi muscle flap and upper arm flap in 1 each. 3. 6 muscle flaps were covered with split thickness skin graft 20 days after microsurgical anastomosis. 4. All of 13 cases were survived after microsurgical procedure and showed excellent coverage in the foot.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.137-148
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• 2006

The purpose of this study was to compare muscle activity in the lower extremity during walking wearing jogging and roller shoes. Twelve male middle school students (age: 15.0 yrs, height 173.7 cm, weight 587.7 N) who have no known musculoskeletal disorders were recruited as the subjects. Seven pairs of surface electrodes (QEMG8, Laxtha Korea, gain = 1,000, input impedance >$1012{\Omega}$, CMMR >100 dB) were attached to the right-hand side of the body to monitor the rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF), tibialis anterior (TA), and medial (GM) and lateral gastrocnemius (GL) while subjects walked wearing roller and jogging shoes in random order at a speed of 1.1 m/s. An event sync unit with a bright LED light was used to synchronize the video and EMG recordings. EMG data were filtered using a 10 Hz to 350 Hz Butterworth band-passdigital filter and further normalized to the respective maximum voluntary isometric contraction EMG levels. For each trial being analyzed, five critical instants and four phases were identified from the recording. Averaged IEMG and peak IEMG were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between shoe conditions (p<.05). The VM, TA, BF, and GM activities during the initial double limb stance and the initial single limb stance reduced significantly when going from jogging shoe to roller shoe condition. The decrease in EMG levels in those muscles indicated that the subjects locked the ankle and knee joints in an awkward fashion to compensate for the imbalance. Muscle activity in the GM for the roller shoe condition was significantly greater than the corresponding value for the jogging shoe condition during the terminal double limb stance and the terminal single limb stance. Because the subjects tried to keep their upper body weight in front of the hip to prevent falling backward, the GM activity for the roller shoe condition increased. It seems that there are differences in muscle activity between roller shoe and jogging shoe conditions. The differences in EMG pattern may be caused primarily by the altered position of ankle, knee, and center of mass throughout the walking cycle. Future studies should examine joint kinematics during walking with roller shoes.

• Journal of Biomedical Engineering Research
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• v.20 no.2
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• pp.183-190
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• 1999

The purpose of this study was to develop a portable and convenient closed-loop contrel type electrical stimulator for patients with foot drop. This system restores walking movement as well as prevents from atrophy or necrosis of lower limb muscles and increases blood circulation in hemiplegic patients caused by traffic accident, industrial disaster or stoke. This system detects the changes of the ankle joint angle during walking, and then controls the stimulus intensity automatically to maintain the programmed level of the ankle joint angle. Also, this automatic system controls the stimulus intensity which is affected by increased electrode impedance resulting from long time use. The system detects the joint angle by an optical sensor and includes modified PID control which adjusts the stimulus intensity if the joint angle deviates from the preset value. Stimulus parameters are 30~80 volt, 40 Hz, and 0.2 ms. The system was applied to five hemiplegic patients for 42 days. Duration of stimulation was 15 min/day for the first week and then the duration was gradually increased to 30, 60, 90 and 120 min/day. The muscle force was increased up to 29.7%, muscle fatigue was decreased compared with the level before stimulation and the pattern of locomotion was improved. These results suggest that the electrical stimulator with closed-loop control type is more convenient and effective in restoration of locomotion of patients with foot drop than open-loop system.

• Journal of Korean Society of Transportation
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• v.34 no.5
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• pp.409-420
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• 2016

Korea is expected to enter 'Super Aged Society' in 2026. However, as walking is the very basic human right of mobility, securing safe and convenient moving of elderly people comprising the majority of transportation vulnerable is thought to be the most basic welfare, which can be easily neglected. From this perspectives, this study provides the walking characteristics of elderly people to be used in design of pedestrian facilities. The analysis of the measurements using Motion Analysis Systems shows that all walking factors of elderly people is 75% level of the younger group. Elderly group shows slower movement, reduced shoulder movement and increased ankle movement compared to the others. Also, foots are risen less and ground repulsive force is increased. Cluster analysis shows that the group of the elderly shows high variability inside the group, and 2 or 3 clusters can be formed with factors of Walking, Balance and Muscles. These walking characteristics can be used in designing pedestrian road, slope and step height of roadway facilities.

• Journal of Convergence for Information Technology
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• v.10 no.12
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• pp.132-139
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• 2020

The purpose of this study is to analyze the effect of the height and insole height upon landing on the lower limb joint angle and muscle activity during maximum ground repulsion in young men. For a male in their twenties, a landing motion was performed with a force plate on a 40cm-high platform by wearing one of 0, 3, 5cm polyurethane insoles per week for a total of 3 weeks. During the landing motion, the joint angle of the lower extremities and the muscle activity of the rectus femoris, biceps femoris, anterior tibialis and calf muscles were measured during the maximum ground repulsion. In order to compare the changes in the joint angle and muscle activity of the lower limbs according to the height of the insole, a one-way ANOVA with repetitive factors was performed. As a result of the analysis of the lower limb joint angle, the higher the height of the insole affected the angle of the left ankle joint. As a result of the muscle activity analysis, the higher the height of the insole affected the right anterior tibialis muscle and biceps femoris. It is thought that it is possible to protect the body when landing through sufficient muscle strength increase of the lower limb muscles. As the angle of the affected muscle and lower limb joint may be different depending on the type of insole, it is considered necessary to study it.

• Korean Journal of Applied Biomechanics
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• v.21 no.3
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• pp.297-308
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• 2011

The purpose of this study was to investigate the relationship among isometric and isokinetic muscle strength, lean body mass(LBM) and bone mineral density(BMD) in the elderly. Eleven males(age, 70.27${\pm}$5.78yr; height, 167.36${\pm}$6.68 cm; weight, 68.34${\pm}$8.23 kg) and thirteen female(age, 69.77${\pm}$4.13yr; height, 152.80${\pm}$4.45 cm; weight, 56.86${\pm}$7.40 kg) participated in this study. In all subjects, LBM and BMD segments was measured by using Dual-energy x-ray absorptiometry(DEXA, Lunar DPS-DM, U.S.A.). Maximum isometric and isokinetic muscle strength of flexion and extension at the knee and elbow, ankle, trunk joints were measured by using an isokinetic dynamometer(CON-TREX(R) Multi Joint Testing Module, Switzerland). The results of this study showed that isometric and isokinetic muscle strength was significantly higher in extension than flexion. In the male and female, hamstring to quadriceps strength ratio(H:Q ratio) was increased as contraction velocity increased. BMD was correlated significantly with trunk extension in the male, but not in the female. LBM was correlated significantly in the male and female with knee extension strength. This study suggests that in the elderly muscle strength training program should put more weight on extensor muscles of the body.

• The Journal of the Korean bone and joint tumor society
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• v.17 no.2
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• pp.100-105
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• 2011

Vascular malformations may typically present with palpable mass that can be either asymptomatic or can present with symptoms including swelling and pain. On rare occasions, vascular malformation of muscle may produce joint deformities caused by contracture of the involved muscle. When vascular malformation involves the flexor muscle of the leg, ankle equinus deformity may occur. However, there are no reports of toe deformities secondary to intermuscular or intramuscular vascular malformations of flexor muscles of toe. Thus, we report a case of vascular malformation of flexor hallucis longus muscle with flexion contracture of toes in a 40-years-old woman who was treated with surgical excision.

• Journal of Korean Neurosurgical Society
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• v.41 no.1
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• pp.22-26
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• 2007

Objective : Cerebral palsy may induce harmful spastic hip adduction. We report the result of microsurgical selective obturator neurotomy, performed on 12 spastic hip adductions of 6 patients, followed clinically for at least 26 months postoperatively. Methods : Microsurgical selective obturator neurotomies, involving microsurgical resection of the anterior obturator nerve branches were performed on 6 patients from January 2000 through June 2003. All patients presented with the inability to sit and 2 patients complained of persistent, intractable pain. We used intraoperative bipolar stimulation to identify selected motor branches. Results : The procedure was performed bilaterally in all patients. In the 3 patients in whom contractures were present, microsurgical selective obturator neurotomies were accompanied by an additional tenotomy of the adductor muscles. Selective tibial neurotomy was performed on three of six patients who originally presented with a spastic ankle. Postoperatively, all spastic hip adductions were corrected more than 60 degrees in passive abduction-adduction amplitude. However, one patient who did not receive active postoperative physiotherapy demonstrated a decreased passive abduction-adduction amplitude upon follow-up. There were no surgical complications. Conclusion : We think microsurgical selective obturator neurotomy may be an effective procedure in the treatment of localized, harmful spastic hip adduction after failure of well conducted conservative treatment. As muscular contractions are often associated with spasticity of the hip adductors, an adjunctive tenotomy may be an option. Comprehensive postoperative physiotherapy is essential to improve long-term results.