• Journal of The Korean Society of Integrative Medicine
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• v.10 no.4
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• pp.137-143
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• 2022

Purpose : The purpose of this study was to evaluate the reliability analysis of the deep tendon reflex by using electromyography (EMG). Methods : The study was tested on 30 volunteers who are women in their 20s. Using an electronic reflective hammer of EMG, deep tendon reflex was measured on all subjects with the participation of three trained physical therapists as raters. First, the subjects were comfortably seated on a table with their knees bent at 90 °. The three raters tapped the electric hammer at intervals of 10 seconds to avoid habituation until a total of 10 compound muscle action potential records were collected. Intraclass correlation coefficients (ICCs) were calculated to assess the inter-rater reliability of the deep tendon reflex with the use of EMG. The items of analysis included amplitude (mV), latency (ms), duration (ms), and area (mV × ms) of the compound evoked potentials. Results : Based on the average records of 10 compound muscle action potential, excellent reliability (ICC: .912) was achieved in terms of area, and there was good reliability in terms of latency (ICC: .795) and duration (ICC: .800). In the shortest latency of the compound muscle action potential, good reliability was achieved in terms of amplitude (ICC: .865), duration (ICC: .781), and area (ICC: .832). In the amplitude of peak-to-peak of compound muscle action potential, excellent reliability was recorded in terms of amplitude (ICC: .924), and good reliability was recorded in terms of duration (ICC: .801) and area (ICC: .874). Conclusion : The findings in this study indicate that electromyography via an electric hammer is a reliable method of assessing and measuring deep tendon reflexes. Especially, it may be an excellent gauge in the area of average values of the compound muscle action potentials and the amplitude of peak-to-peak of compound muscle action potentials.

• Physical Therapy Korea
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• v.5 no.4
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• pp.41-51
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• 1998

The right hip abductor musculature has been reported to demonstrate "stretch weakness" attributable to chronic elongation imposed by standing posture common to right-handed healthy persons. Kendall and associates have described the concept of "stretch weakness",. The purpose of this study was to assess isometric hip abduction torque and surface electromyographic activity (using MYOMED 432) in a sample of 40 healthy right-handed persons (20 male, 20 female), all of whom agreed to participate in the study, and compare side difference in the hip abductor musculature. In order to assure the statistical significance of the results, the paired t test was applied at the .05 level of significance. The results were as follows: 1) The difference in apparent leg length of right and left legs was significant at the .05 level. 2) There was a significant difference between right and left pelvic height (standing position) at the 05 level measurements, and scapula height at the .05 level. 3) Power measurements and action potentials of right hip abductor were greater than the left hip abductor regardless of the range of joint motion (inner range, outer range) 4) The difference in muscle power and action potentials according to inner or outer range of both hip abductor were significant at the .05 level. 5) In supine during active left hip abduction, the appearance of action potentials in the right hip abductors is indicative of contra-lateral effect (p<.05) These results suggest: In healthy right-handed persons, the apparent leg length on the right is longer than on the left, and pelvic height is elevated on the right side. Muscle those and muscle action potentials of the right hip abductor are higher than those of the left hip abductor in the lengthened position. Therefore, the results in this study are contrary to Kendall's. This type of study should be carried out in many physical therapy departments.

• The Journal of Korean Physical Therapy
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• v.2 no.1
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• pp.35-46
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• 1990

The right hip adbuctor musculature has been reported to demonstrate 'stretch weakness' attributable to chronic elongation imposed by standing posture common to right-handed healthy persons. Kendall and associates have described the concept of 'stretch weakness'. The purpose of this study was to assess isometric hip abduction torque and surface electro-myographic activity (using MYOMED 432) in a sample of 40 healthy right-handed persons (20 male, 20 female), all of whom agreed to participate in the study, and compare side difference in the hip abductor musculature. In order to assure the statistical significance of the results, the paired t-test was applied at the .05 level of significance. The results were as follows : 1. The difference in apparent leg length of right and left legs was significant at the .05 leve1. 2. There was a significant difference between right and left pelvic height (standing position) at the .005 level measurements, and scapula height at the .05 level. 3. Power measurements and action potentials of right hip adbuctor were greater than the left hip adbuctor regardless of the range of joint motion (inner range, outer range). 4. The difference in muscle power and action potentials according to inner or outer range of both hip abductor were significant at the .05 level. 5. In supine during active left hip abduction, the appearance of action potentials in the right hip abductors is indicative of contra-lateral effect (p<.005). These results suggest : In healthy right-handed persons. the apparent leg length on the right is longer than on the left, and pelvic height is elevated on the right side. Muscle torque and muscle action potentials of the right hip adbuctor art higher than those of the hip abductor in the lengthened position. Therefore, the results in this study are contrary to Kendall's. This type of study should be carried out in many physical therapy departments.

• The Korean Journal of Physiology
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• v.15 no.1
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• pp.3-8
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• 1981

Studies have been conducted to test the effect of Ginseng alcohol extract on the membrane potentials of frog skeletal muscle. The gastrocnemius muscle was isolated and placed in a chamber containing the Clark-frog Ringer solution. Membrane potentials were recorded using microelectrodes filled with 3 M KCI and muscle was electrically stimulated to obtain action potential. Changes in both the action potential and the resting membrane potential were observed after adding an appropriate amount of Ginseng alcohol extract in the perfusing Ringer solution. The results obtained from 346 muscle cells are summarized as follows : 1) The average resting membrane potential of the normal frog gastrocnemius muscle cell was -92.8 mV and the peak of the action potential reached at 29.8 mV. 2) Both the resting membrane potential and the peak of the action potential decreased by Ginseng alcohol extract, the effect being proportional to the dose of Ginseng alcohol extract. 3) The resting membrane potential and the peak of the action potential continuously decreased until about 40 min after Ginseng addition and leveled off thereafter. The potentials recovered to its original value after Ginseng was washed out. 4) The resting membrane potential was more sensitive to the Ginseng alcohol extract than was the action potential. These results strongly suggest that Ginseng alcohol extract increases both the $Na^+$ and $K^+$ permeability in the skeletal muscle cell membrane.

• The Korean Journal of Pharmacology
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• v.27 no.2
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• pp.99-108
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• 1991

The effect of racemic Ketamine HCl was observed on excitable membranes of sciatic nerve fibres and toe muscles from frog. Ketamine significantly depressed the amplitude of the action potential, maximum rate of rise and that of fall of action potentials of sciatic nerve by dose-dependent and time-course manner, and also it produced the inhibition of $K^+-contracture$ in toe muscle. We used two different ways of sucrose gap method to to obtain the better results from sciatic nerve. We observed and compared the effect of ketamine on sciatic nerve with naloxone, 4-AP (4-aminopyridine) and TEA (Tetraethylammonium). Naloxone significantly but not totally blocked the effect of ketamine both on nerve and on skeletal muscle. 4-AP or TEA by itself had a significant depressant effect on the action potentials on nerve by central perfusion (extracellular perfusion), but both of these drugs did not much affect the action of Ketamine on nerve. The reversibility of effect of Ketamine (10 mM) was observed both on nerve and on skeletal muscles when exposed to drug for short duration. The effects of racemic ketamine described may provide to support that one of the mechanisms of the action of Ketamine on nerve and on muscles of frog might be related to non-specifically effect on receptors within the ion channels $(K^+-channel,\;Na^+-channel\;or\;slow\;Ca^{++}\;channel)$ at higher dose which produces anesthetic effect and also it interacts specifically with one of the opioid receptors or subtype of these receptors which is sensitive to Naloxone at lower dose which produces analgesia.

• The Korean Journal of Pharmacology
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• v.8 no.2
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• pp.63-69
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• 1972

The effects of omission of buffers from Krebs-Ringer medium on contractile activity, membrane potentials and ATP content of electrically stimulated isolated rat atria were investigated. 1) Contractile status: A rapid and marked depression of the contractile activity of atria occurred when buffer-free medium was substituted for the normal Krebs-Ringer medium. 2) Electrical status: The omission of buffers from medium did not alter the resting or action potential magnitudes of atria. However, the action potential duration was on initial increase followed by a decrease in the buffer-free medium. 3) ATP concentration: The omission of buffers from medium resulted in a marked decrease in the ATP levels of atria. It has been also found in the present study that bicarbonate buffer plays an important role for the maintenance of the contractility and ATP levels of the heart. The contractile depression by the omission of buffers was not directly associated with electrical alterations in resting or action potentials of the heart. In the absence of bicarbonate-buffer, glucose no longer plays to maintain the contractile activity and the ATP levels of rat atria.

• Journal of IKEEE
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• v.24 no.4
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• pp.1039-1049
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• 2020

Neural decoding is important to recognize the user's intention for controlling a neuro-prosthetic hand. This paper proposes a real-time decoding method for multi-channel peripheral neural activity. Peripheral nerve signals were measured from the median and radial nerves, and motion artifacts were removed based on locally fitted polynomials. Action potentials were then classified using a k-means algorithm. The firing rate of action potentials was extracted as a feature vector and its dimensionality was reduced by a self-organizing feature map. Finally, a multi-layer perceptron was used to classify hand motions. In monkey experiments, all processes were completed within a real-time constrain, and the hand motions were recognized with a high success rate.

• Journal of Biomedical Engineering Research
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• v.16 no.1
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• pp.77-84
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• 1995

Nl and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. Nl -N2 audiograms were made by means of regulating stimulant intensities in order to produce constant Nl -N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip 15 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both nonlinear and active functions of the Cochlea can be monitored by Nl -N2 audiograms. Key words : Guinea Pig, Cochlea, Wl and N2 Gross Neural Action Potential, Nl -N2 audiogram.

• Proceedings of the PSK Conference
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• 2002.04a
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• pp.131.1-131.1
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• 2002

• Archives of Pharmacal Research
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• v.22 no.4
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• pp.335-339
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• 1999

The oxidation-reduction potentials of cosmetic raw materials, showing tyrosinase inhibitory action, and phenolic compounds structurally similar to L-tyrosine were determined by cylcic voltammetry. The voltammograms obtained could be classified ito 4 patterns (patterns 1-4). Patterns 1, characterized by oxidation and reduction peaks as a pair, was observed with catechol, hydroquinone or phenol, and pattern 2 exhibiting another oxidation peak in addition to oxidation and reduction peaks as a pair was found with arbutin, kojic acid, resorcinol, methyl p-hydroxybenzoate and L-tyrosine as the substrate of tyrosinase. Pattern 3 with an independent oxidation peak only was expressed by L-ascorbic acid, and pattern 4 with a reduction peak only at high potentials, by hinokitiol. The tyrosinase inhibitory activity of these compounds was also evaluated using the 50% inhibitory concentration ($IC_{50}$) and the inhibition constant (Ki) as parameters. Hinokitiol, classified as patterns 4, showed the highest inhibitory activity (lowest $IC_{50}$ and Ki). Hydroquinone showing the second highest activity belonged to pattern 1, which also included compounds exhibiting pattern 2 was relatively low with Ki values being in the order of 10-4 M. Although there was no consistent relationship between oxidation-reduction potentials and tyrosinase inhibitory action, the voltammetry data can be used as an additional index to establish the relationship between the structure and the tyrosine inhibitory activity.