• Journal of Institute of Control, Robotics and Systems
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• v.13 no.9
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• pp.843-850
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• 2007

This paper proposes a somatosensory stimulation system for the improvement of postural stability using vibration as somatosensory stimulation. This system consists of vibratory stimulation and postural response measurement. To evaluate this system, the center of pressure(COP) was closely observed in turn with simultaneous or separate mechanical vibratory stimulations to flexor ankle muscles (tibialis anterior, triceps surae) and two plantar zones on both feet while standing on a stable and an unstable support. The simultaneous vibratory stimulations cleared influenced postural stability and the effects of vibrations were higher with the unstable support. In separate vibratory stimulations, the extent of the COP sway reduced when the direction of the vibratory stimulations and that of the inclination of body coincided for flexor ankle muscle stimulations. In the contrary, the extent of the COP sway increased when the direction of the stimulations and that of body inclination coincided for plantar zone stimulations. These results can be useful for the development of rehabilitation systems that utilizes somatosensory inputs for postural balance.

• Journal of Korean Foot and Ankle Society
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• v.17 no.4
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• pp.294-301
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• 2013

Purpose: To report the clinical outcomes and complications of flexor hallucis longus (FHL) tendoscopy using 3 portals. Materials and Methods: Between January 2012 and April 2013, 10 patients (10 ankles) received tendoscopic surgery for the treatment of FHL tenosynovitis. Patients complaining of pain and tenderness along the course of FHL despite over 6 months of conservative treatments were indicated for surgery. The mean age was 41.7 years (range: 18-57) and the follow up period was 12.7 months (range: 6-20). Tendoscopy was performed using posteromedial, posterolateral, and plantar portals. Clinical evaluations included preoperative and postoperative visual analogue scale (VAS), American orthopaedic foot and ankle society (AOFAS) score, and patients' satisfaction. Results: Tendoscopic findings included tenosynovitis in 10 cases, degenerated vinculae in 6 cases, stenosis of the tendon at its entrance into the fibro-osseous tunnel in 5 cases, and degenerative partial tendon tear in 3 cases. Two cases had associated symptomatic os trigonum and 3 cases had posterior ankle impingement syndrome. Preoperative pain decreased from median VAS 6 (range: 4-10) to 2.1 (range: 1-5) at the last follow up and AOFAS score improved from 50.1 (range: 36-63) to 82.1 (range: 61-89) (p<0.05). Nine patients were satisfied or very satisfied with the outcome. Injury of the lateral plantar nerve occurred in one case. Conclusion: FHL tendoscopy using 3 portals is a feasible and useful minimal invasive surgical technique for the management of FHL tenosynovitis.

• Korean Journal of Acupuncture
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• v.29 no.2
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• pp.239-249
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• 2012

Objectives : This study was investigated to observe Foot Soeum Meridian Muscle in human. Methods : In order to expose components related to Foot Soeum Meridian Muscle, cadaver was dissected in the order of their depth; being respectively divided into superficial, middle, and deep layer. Results : Anatomical components related to Foot Soeum Meridian Muscle in human are composed of muscles such as flexor digitorum brevis tendon, abductor hallucis muscle, psoas major m., erector spinae m., and flexor retinaculum, fascia such as plantar aoneurosis, ligament such as sacrotuberal ligament, sacrospinous lig., nuchal lig., nerves such as plantar cut. br. of med. plantar nerve, med. crural cut. br. of saphenous n., br. of tibial n., post. femoral cut. n., spinal n.(dorsal rami of C4-6, T7-12, L1-3, and S1-3), and autonomic nervous system(sacral plexus, pelvic splanchnic n., etc.), and etc. Conclusions : This study shows comparative differences from established studies on anatomical components related to Foot Soeum Meridian Muscle, and the methodical aspects of analytic process. In addition, Foot Soeum Meridian Muscle in human is a comprehensive concept including the relevant nerves, but it remains questionable.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.3
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• pp.477-485
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• 2010

Purpose : The clinical scale to assess spasticity of muscle was wildly used the modified Ashworth scale (MAS). But reliability of the MAS has been controverted for ambiguity among the grades. The purpose of this study was to establish the inter-rater reliability of the modified MAS (MMAS) translated into Korean in stroke patients. Methods : Twenty-five patients (sixteen men and nine women) with hemiplegia (ten right and fifteen left) were measured by two raters who were physical therapist in the rehabilitation hospital. The raters assessed spasticity of shoulder adductor, elbow flexor, wrist flexor, hip adductor, knee extensor, and ankle plantar flexor in the same patients according to ratings criteria of the MAS and the MMAS. Results : For the inter-rater reliability of the MAS, two raters agreed on 57.3% and the Kappa values were moderate ($\kappa$=0.41) between two rater. The inter-rater reliability of the MAS was fair for the wrist flexor and the hip adductor and moderate for the other muscles. The intra-rater reliability was good for the shoulder adductor and the knee extensor and moderate for the other muscles. For the inter-rater reliability of the MMAS, two raters agreed on 84.7% and the Kappa values were good ($\kappa$=0.78) between two rater. The inter-rater reliability of the MMAS was moderate for the hip adductor, and good for the shoulder adductor and the wrist flexor, and very good for the other muscles. The intra-rater reliability was good for the wrist flexor and the hip adductor and very good for the other muscles. Conclusion : This study suggests that the MMAS translated into Korean is reliable test scale for the spasticity with stroke patients in the clinical field.

• Journal of Mechanical Science and Technology
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• v.20 no.8
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• pp.1183-1194
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• 2006

The aim of this study was to identify the characteristics of the flexion withdrawal reflex modulated by the hip angle and hip movement in spinal cord injury (SCI). The influence of the hip position and passive movement were tested in 6 subjects with chronic SCI. Each subject placed in a supine position and lower leg was fixed with the knee at 5 -45 degree flexion and the ankle at 25-40 degree plantar flexion. A train of 10 stimulus pulses were applied at 200 Hz to the skin of the medial arch to trigger flexion reflexes. From results of the regression analysis, static properties of normalized muscle activation of flexor muscles have the linear relationship with respect to hip angle (P< 0.05). In order to verify the neural contribution of flexion reflex, we compared the static and dynamic gains of estimated muscle activations with measured EMG of ankle flexor muscle. Form this study, we postulate that the torque and muscle response of flexion withdrawal reflex have linear relationship with hip angle and angular velocity.

• Journal of Korean Academy of Nursing
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• v.36 no.2
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• pp.341-352
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• 2006

Purpose: This study was conducted to develop & to determine the effect of an tailored falls prevention exercise for older adults. Method: Subjects consisted of 59 older adults (experimental group : 29, control group : 30) living at nursing homes. Experimental group participated in tailored falls prevention exercise for 16 weeks(3 times a week, 50 min every session). Data were collected before the exercise, 16 weeks & 24 weeks after the beginning of exercise. Results: 1) the experimental group significantly improved the muscle strength of hip extensor & flexor, knee extensor & flexor, ankle dorsiflexor, & plantar flexor compared to the control group. 2) the experimental group significantly decreased the mean time for 10 times chair stand. 3) the experimental group significantly increased the standing time on one leg and the number of heel raise for 30 seconds compared to the control group. In addition more older adults in the experimental group completed the tandem stance & semi-tandem stance for 10 seconds than the control group. 4) The experimental group significantly decreased the mean time of 6m walk and the fall frequency compared to the control group. Conclusions: This results suggest that tailored falls prevention exercise for older adults can improve muscle strength, static & dynamic balance and decrease the fall frequency of older adults.

• Physical Therapy Korea
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• v.28 no.2
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• pp.132-137
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• 2021

Background: Flat feet can be identified by assessing the collapse of the medial longitudinal arch (MLA) and these conditions can trigger epidemiological changes in the feet. Many of previous studies compared the muscle activity of lower body in terms of intervention and dynamics to treat the structural defect of flat feet. However, few studies have investigated or analyzed the muscle activity of gastrocnemius muscle in the subjects with flat feet. Objects: This study investigated the differences in changes of medial and lateral plantar flexors in subjects with flat feet during bipedal heel-rise (BHR) task and analyzed the differences in muscle activity between two groups by measuring the electromyography (EMG) of abductor hallucis (AH), tibialis anterior (TA), medial gastrocnemius (MG), lateral gastrocnemius (LG). Methods: A total of Twenty one adult females participated in this experiment. Subjects were assigned to groups according to the navicular drop test. The task was applied to the leg, where the heel lifting action prevailed. The muscle activity of the medial and lateral feet plantar flexors was evaluated, and the % maximum voluntary isometric contractions (%MVIC) of these were compared. Results: For the difference between groups the muscle activity (%MVIC) of LG muscle was statistically significantly low in flat feet group compared to healthy feet group (flat feet: 64.57, healthy feet: 90.17; p < 0.05). Conclusion: The results of this study will contribute to identifying the muscle activities of medial and lateral feet plantar flexors among subjects with flat feet, which can cause abnormal epidemiological changes in the feet.

• Korean Journal of Applied Biomechanics
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• v.34 no.2
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• pp.45-52
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• 2024

Objective: The purpose of this study was to measure the morphological characteristics of the foot and biomechanical variables of the lower extremity joints during vertical jump and investigate the relationship between foot morphology and biomechanics of vertical jump. Method: 24 men in their 20s (age: 22.42 ± 1.41 yrs, height: 173.37 ± 4.61 cm, weight: 72.02 ± 6.21 kg, foot length: 251.70 ± 8.68 mm) participated in the study. Morphological characteristics of the foot included the length of the first toe, the length of the second toe, and the horizontal length from the center of ankle joint to the achilles tendon (Plantar Flexion Moment Arm [PFMA]). Biomechanical variables were measured for plantar flexor strength of the ankle joint and peak angular velocity, moment, and power of the lower extremity joint during vertical jump. Results: There was a significant correlation between the length of the first toe and plantar flexion strength at 30°/s [r=.440, p=.016], the angular velocity of the metatarsophalangeal [MTP] joint [r=-.369, p=.038] while significant correlations between PFMA and the angular velocities of the knee joint [r=.369, p=.038] and ankle joint [r=.420, p=.021] were found. There were also significant correlations between the length of the first toe and the maximum moment of the hip joint [r=.379, p=.034], and the length of the second toe and the power of the hip joint [r=-.391, p=.029]. Finally, significant correlations between PFMA and the power of the ankle joint [r=.424, p=.019] and MTP joint [r=.367, p=.039] were found. Conclusion: Based on the results of this study, the length of the toe and PFMA would be related to the function of the lower extremity joint. Therefore, this should be considered when designing the functional structure of a shoe. Furthermore, this relationship can be applied to intensive training for the plantar flexors and toe flexors to improve power in athletic performance.

• Korean Journal of Applied Biomechanics
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• v.24 no.1
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• pp.35-42
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• 2014

Tendon elasticity is an important factor affecting muscle function and thus human movements. It has been reported that the mechanical properties of tendon are adaptable to external loading condition. Based on the adaptability of muscle and tendon to external loading conditions, one can assume that there might be an optimum ratio between muscle strength and tendon stiffness. The present study aimed to investigate whether there is correlation between plantar flexor muscle strength and stiffness of the achilles tendon (AT). Twenty two male subjects (age: $23.2{\pm}1.5yrs$, height: $175.5{\pm}6.2cm$, weight: $75.4{\pm}9.8kg$) performed maximum voluntary isometric plantarflexion on a custom-built dynamometer and muscle-tendon junction of the medial gastrocnemius muscle was simultaneously monitored using a real-time ultrasound imaging machine. The averages of muscle force and tendon stiffness were $366.38{\pm}79.37N$, $35.34{\pm}10.42N/mm$, respectively. Significant positive correlation was observed between muscle strength and tendon stiffness (r=0.8507), indicating that the muscle force is proportional to tendon stiffness. The results might have been used in computational modeling and criterion of training progress level in the fields of training and rehabilitation.

• The Journal of Korean Physical Therapy
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• v.19 no.1
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• pp.79-90
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• 2007

Purpose: We investigated how nerve mobilization influence ankle plantar flexor muscles of the affected lower extremity on the spasticity in stroke patients. Method: Total 12 patients were recruited, who had spasticity on ankle of the affected lower extremity, and applied nerve mobilization on the sciatic and tibial nerves in supine position. H-reflex was measured using EMG equipment, detected the ratio of maximum H/M and H-reflex latency, and compared the changes before, during, right after, 5 minutes after and 10 minutes after the application of nerve mobilization. The data were analyzed using repeated measure ANOVA to compare the changes in length of time. Results: In comparison with the ratio before nerve mobilization, the ratio of maximum H/M was significantly decreased during nerve mobilization(p<0.05), and it tended toward recovery right after, 5 minutes after and 10 minutes after applying nerve mobilization, there was no statistically significant difference(p>0.05). In comparison with the ratio before nerve mobilization, the ratio of maximum H/M was most significantly decreased during the first 10 seconds after nerve mobilization and it tended toward recovery gradually(p<0.05). In comparison with the H-reflex latency before nerve mobilization, it was significantly increased during nerve mobilization(p<0.05) and it was decreased right after nerve mobilization, After 5 and 10 minutes, it had a tendency toward recovery but it revealed no statistically significant difference (p>0.05). Conclusion: It is considered that nerve mobilization could contribute to initial rehabilitation with stroke patients for relieving spasticity and nerve contracture.