• 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.

• The Korean Journal of Physiology
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• v.26 no.2
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• pp.151-157
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• 1992

In urethane anesthetized cats, each vestibular semicircular canal nerve was electrically stimulated, and reflex responses of the cervical extensor and flexor (the splenius capitis and sternomastoid muscles) were recorded by means of electromyography. Stimulation of a unilateral (anterior, horizontal or posterior) canal nerve elicited excitation of the contralateral cervical muscles and inhibition of the ipsilateral ones; during the canal nerve stimulation, the two muscles in one side of the neck revealed synergistic responses. Based on these experimental results, we formulated a diagram showing the functional connections between the vestibular semicircular canals and the cervical muscles in the vestibulocollic reflex.

• Proceedings of the ESK Conference
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• 1994.04a
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• pp.49-51
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• 1994

The aims of this study were first to determine the influence of vibration displacement amplitude $(200{\mu}m, 300{\mu}m peak-to-peak)$ at selected frequencies (40-200Hz) on a commonly observed but often undesired motor response elicited bylocal vibratory stimulation, the Tonic Vibration Reflex (TVR). Second, to determine the degree of synchronization of motor unit (MU) activity with vibratory stimuli. Vibration was applied to the distal tendons of the hand flexor muscles. Changes in root- mean-square electromyographic (EMG) activity of the finger and wrist flexor muscles were analyzed both as a function of their initial contraction level (0%, 10%, 20% of the maximal voluntarycontraction: MVC) and as a function of the vibration parameters. The results indicate that the TVR increased with the initial muscle contraction up to 10% MVC: The TVR increased with vibration frequency up to 100-150 Hz and decreases beyond; A significant increase of the TVR with vibration displacement amplitude was observed only for the wrist flexor muscle; MU synchronization at vibration frequency (VF) was found more often in the low frequency range $(f{\leq}100 Hz)$ and tended todecrease beyond; In the high frequency range $(f{\geq}120 Hz)$, MU activity at subharmonic frequency was predominant; The "cut-off" frequency of the synchronization with VF was neither affected by the vibration displacement amplitude nor initial muscle contraction level. The surface EMG turned out to be a useful means to analyze MU synchronization since it is noninvasive, and it can be easily used for analysis of different muscle contraction levels, while single MU technique might have some difficulties at high muscle contraction levels. Furthermore, these results indicate that high frequencyvibration (f>150 Hz) tends to induce less muscle/tendon stress and MU synchronization. Such remarks are of importance for the design of hand-held vibrating tools.ing tools.

• 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.

• Annals of Clinical Neurophysiology
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• v.1 no.2
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• pp.126-146
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• 1999

In clinical neurology various different electrophysiological tests are widely used to demonstrate the unsuspected malfunctioning in the nervous system and to monitor over time the clinical status of patients. In addition clinical neurologists and neurosurgeons take advantage of the intraoperative monitorings to increase the quality of neurosurgical operations in the posterior fossa, in the spinal cord, or in visual pathways. In the field of movement disorders, elecrophysiolgical tests provide neurologists with making accurate differential diagnoses with useful therapeutic stratergies as well as with investigating the pathophysiological machanisms. By using the electromyographic tests it could be possible for us to evaluate the types of blephalospasm, the extent of hemifacial spasm, the level of myoclonus, and the prime muscles of torticollis etc. Sometimes the myographic guidance may be critical for choosing the exact injecting site of botulinum toxin. These several decades various electroencephalographic and evoked potential tests has been utilized in the electrophysiological laboratories to understand the basic pathophysiology of myoclonus, spasticity and other central motor dysfunctions. It could be one of the breakthroughs in the area of behavorial neurology that the brain function can be mapped by the spontaneous or evoked electrical activities of nervous system since the movement related potentials (MRPs) had been studies for several decades. Various reflex tests such as masseter reflex, blink reflex, click evoked vestibulocollic reflex, facial reflex, stretch reflex, flexor reflex, H-reflex, H-reflex recovery curve, vestibular inhibition of H-reflex, reciprocal inhibition, recurrent or Renshaw reflex, Ib inhibition, cutaneous reflex have been also used to understand normal or abnormal physiology in movement disorders. Polysomnography, posturography and gait studies are also applied in clinical neurology in association with with movement disorders which are useful in deciding the treatment regimen.

• The Journal of Korean Physical Therapy
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• v.32 no.6
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• pp.325-328
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• 2020

Purpose: This study examined the effects of the directions of neck rotation position on the muscle activity and strength of the elbow flexor and extensor muscle. Methods: Forty-one healthy adults participated in this study. The subjects were asked to their elbow 90° flexion in three different neck rotations (neutral, ipsilateral, and contralateral) in the sitting position. The muscle activities of the biceps and triceps brachii muscle were measured using surface electromyography. And the muscle strength of the elbow flexor was measured using dynamometer. One way repeated measures ANOVA was used to compare the muscle activity and strength of the elbow flexor and extensor depending on the different neck turning directions. Results: There were significant differences between contralateral neck rotation and ipsilateral neck rotation, contralateral neck rotation and neutral position. But, there was no significant difference in the triceps brachii muscle activity in comparison with the neck rotation. There were significant differences between contralateral neck rotation and ipsilateral neck rotation, contralateral neck rotation and neutral position. Conclusion: To summarize this study, the elbow flexor and extensor muscle activity and strength was highest in the contralateral neck rotation position. In other words, it was possible to confirm the effect of Asymmetrical Tonic Neck Reflex in healthy adults whose primitive reflexes were inhibition, and head and neck positions should be considered during clinical evaluation and treatment.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.394-398
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• 1994

The aim of the present study was to determine the influence of vibration frequency and muscle contraction level at constant vibration displacement amplitudes on a commonly observed motor response elicited by local vibratory stimulation, i.e., the Tonic Vibration Reflex (TVR). Vibration was applied to the distal tendons of the hand flexor muscles. Changes in activity of the hand flexor and extensor muscles were analyzed as a function of the vibration frequency (40-200 Hz), displacement amplitude(200.mu.m and 300.mu.m peak-to-peak), and the initial contraction level of the flexor muscles (0%, 10%, and 20% of the maximal voluntary contraction: MVC). The main results indicate that the TVR increases with vibration frequency up to 100-150 Hz and decreases beyond, and the TVR attains its maximum at 10% MVC. It appears that high frequency vibration tends to induce less muscle/tendon stress. Such a result is of particular importance for the design of handheld vibrating tools.

• Journal of Acupuncture Research
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• v.17 no.2
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• pp.231-246
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• 2000

Acupuncture has been used for treatment of numerous diseases, especially for pain control in the oriental culture. However, the mechanism of pain control by acupuncture was not clear so far. The present study was examined that the effects of electro-acupuncture (EA) applied to the acu-point of extra-segmental area on modulation of formalin induced pain in Sprague - Dawley rats. In order to apply EA to acu-points in the plantar area of right fore paws, a pair of teflon - coated stainless steel wires were implanted in HT 7 (shin-mun) and PC 7 (dae-neong) 5 days before behavioral test. A behavioral test was performed by means of video camera after injection of 5% formalin ($50{\mu}l$) into the lateral plantar region of left hind paw. EA was delivered by a constant current stimulator at 4~5 mA, 2 ms, and 10 Hz for 30 min. The electromyographic activities were recorded in the biceps femoris muscle under chloral hydrate anesthesia. Test stimuli with 1~9mA were applied to the sural nerve territory including the medial portion of the 4th toe and the lateral portion of the 5th toe. Behavioral responses including favoring, flinching and bitting were occured in the biphasic pattern, such as the lst phase (0~5 min) and the 2nd phase (20~45 min) after formalin injection. However, EA (4~5 mA, 2 ms, 10 Hz) significantly inhibited Che behavioral responses. EMG activities of flexor reflex had a latency of 100~300 ms and thresholds of test stimuli for EMG were 4~5 mA in normal rats. Injection of formalin decreased threshold of test stimuli and increased EMG activities for 2hrs after injection. However, EA significantly inhibited EMG activities of flexor reflex increased by formalin and recovered EMG evoked thresholds. These results suggest that contralateral extra-segmental EA inhibits the first and second phases of formalin induced pain but their mechanism be needed to examine additionally.

• The Korean Journal of Pain
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• v.6 no.2
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• pp.261-264
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• 1993

A 26 year old male patient had admitted to the department of plastic surgery for the treatment of skin defect of forearm and spastic contracture of right hand, attributable to burn injury following carbon monoxide intoxication. After receiving skin graft the patients tenotomy of flexor tendons, the patients was consulted to pain clinic for further evaluation and treatment of allodynia, hyperalgesia, and hyperpathia with marked emotional insufficiency. The patient was treated with stellate ganglion blocks, intermittent or continuous epidural blocks, and intermittent brachial plexus blocks for 3 months. with this treatment the patient's pain level improved to(VAS 10 to 4~5) and was discharged. The patient was readmitted 3 months later, due to the aggrzvation of pain. Brachial plexus blocks were given again by interscalene, supraclavicular, or axillary route, sometimes using a catheter, together with cervical epidural blocks. Tricyclic antidepressant was also prescribed. The results were remarkably good(VAS 2~3) and the patient did not require any further analgesic medication.

• Journal of Yeungnam Medical Science
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• v.14 no.1
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• pp.111-122
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• 1997

H-reflex is a kind of late respons which can be used for the proximal nerve conduction study. Also it is a useful and widely used nerve conduction technique es to look electrically at the monosynaptic reflex. Although recordable from all muscles theoretically, H-reflexes are most commonly recorded from the calf muscles following stimulation of the tibial nerve in the popliteal fossa. But in this study, We tried to establish the normal data and to evaluate the significance of the H-reflex study in cervical radiculopathy. H-reflexes were recorded from flexor carpi radialis (FCR) muscle, extensor carpi radialis (ECR) muscle, brachioradialis (BR) muscle, and abductor digiti minimi (ADM) muscle in 31 normal adults (62 cases) and 12 patients with cervical radiculopathy. The mean values of H-reflex latency in normal control group were $16.16{\pm}1.65$ msec in FCR; $15.99{\pm}1.25$ msec in ECR; $16.47{\pm}1.59$ msec in BR; $24.46{\pm}1.42$ msec in ADM. And the mean values of side to side difference of H-reflex latency were $0.47{\pm}0.48$ msec in FCR; $0.68{\pm}0.72$ msec in ECR; $0.63{\pm}0.43$ msec in BR; $22.31{\pm}1.24$ msec in ADM. Mean values of side to side differences of interlatency time were $0.49{\pm}0.47$ msec in FCR; $0.73{\pm}0.62$ msec in ECR; $0.79{\pm}0.71$ msec in BR; $0.69{\pm}0.44$ msec in ADM. Also, there were no significant differences in H-reflex latency between right and left side. H-reflex tests in patient group with cervical radiculopathy revealed abnormal findings in 11 out of 12 patients. These results suggest that H-reflex in the upper extremity would be helpful in the diagnosis of the cervical radiculopathy.