• Annals of Clinical Neurophysiology
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• v.3 no.2
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• pp.168-171
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• 2001

It has been said that variable anatomical structures and neural circuits are related to the generation of tremor. There are cerebral cortex, thalamus, basal ganglia, inferior olivary nucleus, midbrain tegmentum, stretch reflex, and musculoskeletal structures. The stretch reflex is related with the physiologic tremor and various peripherally originated tremors. We experienced a case with the post-stroke resting tremor which was induced and aggravated by mechanical stretching stimulation. In the present case, stretch reflex has a major role in the generation and exacerbation of tremor. It is presumed that the development of tremor is attributed to the increased rhythmicity of ventral intermedius nucleus of thalamus. The enhancement of thalamic rhythmicity may be due to the increasement of long latency reflex by post-stroke rigidity. This case suggests that stretch reflex may have a major role in the pathophysiologic mechanisms of a certain centrally originated tremor.

• PNF and Movement
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• v.5 no.1
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• pp.57-66
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• 2007

This review discusses the development of muscle receptors, in particular, that of muscle sensory neurons and monosynaptic stretch reflex circuit. The development of muscle sensory neurons and monosynaptic stretch reflex requires a series of steps including expression of neurotrophic transcriptional factors and their receptor. The monosynaptic stretch reflex circuit is unique neuronal circuit system, and highly precise synaptic connection systems. Thus, coordination of sensory-motor function in muscle receptors depend on the expression of distinct classes of molecular cues, and on the formation of selective synaptic connections between sensory-motor neurons and their target muscle. Recent neurotrophic and transcription factor expression studies have expanded our knowledge on how muscle sensory neuron is formed, and how sensory-motor system is developed.

• PNF and Movement
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• v.1 no.1
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• pp.19-25
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• 2003

Objectives: The purpose of this article is to summarize the effect of stretch stimulus on muscle contraction facilitation. Methods : Some studies of the stretch reflex. ${\gamma}-motor$ system, and the effect of stretch stimulus on muscle activation were reviewed. Results : To facilitate muscle contraction, before the movement is started, the prime mover is in stretched position. The patient must be instructed to occur voluntary muscle contraction after quick stretching. It elicits the functional stretch reflex to produce a more powerful and functional contraction. The intensity of muscle contraction depends on two ways. One is firing rate of ${\alpha}-motor$ neuron by sensory information from the periphery induced in stretched position and stretch reflex. The other is excitation level of the cortical motor area and the corresponding motor neurons. Conclusions: To activate central nervous system and to increase firing rate of ${\alpha}-motor$ neuron. the therapist should apply quick stretch for the patient with stretched position and the patient should make voluntary muscle contraction.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.1 no.2
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• pp.39-48
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• 2003

The purpose of this study was to describe the alteration of stretch reflex and electrical activity of lower leg muscle in cerebral palsy by the water temperature. We used ten cerebral palsy. Participants classified according to each group in $29^{\circ}C$, $32^{\circ}C$, $35^{\circ}C$ by the water temperature. All subjects participated 3 session, which at least 1 week between session. The test was measured continuously pre test, post-test by thermometer and surface electromyography(sEMG). The following results were obtained; 1. Superficial temperature were significantly decreased in $29^{\circ}C$(p<0.001) group but were significantly increased $32^{\circ}C$, $35^{\circ}C$ group(p<0.001). 2. Muscle stretch reflex were significantly decreased in $32^{\circ}C$(p<0.05) and $35^{\circ}C$(p<0.001) group. 3. Stretch-evoked EMG were significantly increased in $29^{\circ}C$ group(p<0.01). These results lead us to the conclusion that changes of stretch reflex and electrical activity of lower leg muscle in cerebral palsy were influenced by the water temperature. Therefore, a further direction of this study will be to provide more evidence that a moderate water temperature have an effect on muscle tonus in a patient with cerebral palsy.

• The Korean Journal of Physiology
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• v.4 no.2
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• pp.19-24
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• 1970

Since the discovery of the muscle spindle by Hassall (1831), an intensive studies of its anatomical and physiological characteristics had been undertaken. Recent morphological studies of Boyd (1962) demonstrated that the muscle spindles have two different intrafusal muscle fibers, nuclear bag and nuclear chain fiber, and these intrafusal fibers are under independent motor innervation by ${\gamma}_1$ and ${\gamma}_2$ motor neurone. Neurophysiological studies of Hunt and Kuffler (1951) showed regulatory effect of ${\gamma}$ motor neurone upon the excitability of the spindle afferents. Harvey and Mathews (1961) observed the dynamic and static characteristics of the two different spindle afferents, the primary and secondary ending. Furthermore, Mathews (1962) postulated the functional existance of two kind of ${\gamma}$ motor neurones, namely, the dynamic and static fusimotor fiber. Recent report of Kim and Partridge(1969) pointed out that the descending vestibular signals had increased the slope of the length-tension relationship in stretch reflex; Kim (1967) demonstrated that the descending vestibular impulses act upon the stretch reflex loop through the ${\gamma}$ motor pathway. These experimental evidences from the morphological and neurophysiological studies on the muscle spindles support the concept that the stretch reflex action of the skeletal muscle operates as a negative feedback control system. The author had discussed the way by which the f system participates in the control of stretch relfex feed back system. that was taken for a prototype of posture and movement.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.63-72
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• 2008

The purpose of this study was to compare and analyze the effects of exercise types on lower extremity muscle activity in stroke patients. For the purpose, the subjects of this study were classified into three groups such as therapeutic exercise group(n=7), elastic band group(n=7), and stretch reflex group(n=7). The three exercise programs were 5 times a week for 8 weeks. The stretch reflex group revealed higher in iliopsoas and biceps femoris %MVIC than the therapeutic exercise group and elastic band group, whereas elastic band group revealed lower in tibialis anterior %MVIC than therapeutic exercise group in the primary single-limb support. The stretch reflex group revealed higher in iliopsoas %MVIC than the therapeutic exercise group and elastic band group, whereas stretch reflex group revealed lower in medial gastrocnemius %MVIC than therapeutic exercise group in the secondary double support phase.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.7 s.184
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• pp.152-158
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• 2006

The objective of this work is to develop the knee joint model for representing various pendulum motions and quantifying the spasticity. Knee joint model included the extension and flexion muscles. The joint moment consists of both the active moment from the stretch reflex and the passive moment from the viscoelastic joint properties. The stretch reflex was modeled as nonlinear feedback of muscle length and the muscle lengthening velocity, which is Physiologically-feasible. Moreover, we modeled the spastic reflex as having dynamic threshold to account far the various pendulum trajectories of spastic patients. We determined the model parameters of three patients who showed different pendulum trajectories through minimization of error between experimental and simulated trajectories. The simulated joint trajectories closely matched with the experimental ones, which show the proposed model can predict pendulum motions of patients with different spastic severities. The predicted muscle force from spastic reflex appeared more frequently in the severe spastic patient, which indicates the dynamic threshold relaxes slowly in this patient as is manifested by the variation coefficient of dynamic threshold. The proposed method provides prediction of muscle force and intuitive and objective evaluation of spasticity and it is expected to be useful in quantitative assessment of spasticity.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.3
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• pp.215-221
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• 2015

The elbow reflex, a principal reflex in the upper extremity, plays an important role in the diagnosis of cervical spine syndromes. In this study, the muscle activations of brachial biceps and triceps, and the kinematics of upper extremities were predicted using an activation model for the stretch reflex. The muscle activations that equated the simulation results estimated by the analysis model with the experimental results were obtained first, and the activations obtained from the simulations were compared with the electromyography signals obtained from the experiments, for model validation. The root mean squares error of the joint angles (obtained from experiments and simulation using the suggested model) was 0.056, a value that is half of that obtained using the previous model. This demonstrates that the suggested model corresponded well with the actual reflex.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.1
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• pp.217-219
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• 2010

Spasticity is a motor disorder characterized by a velocity dependent increase in muscle tone with exaggerated tendon jerks, resulting from hyper-excitability of the stretch reflex. The aim of this study is to develop a portable system for quantifying the grade of spasticity which could calculate the biomechanical as well as neurophysiologic parameters, and for determining the relationship between the Tonic Stretch Reflex Threshold (TSRT) and Modified Ashworth Scale (MAS). Eleven patients with stroke participated in the study (6 males and 5 females, the average age of $64.5\pm16.0$ years). As a results, the mean and standard deviation values of the TSRT were $129.8\pm4.2$, $123.4\pm5.2$ and $119.1\pm2.6$ in the MAS 1, MAS 1+ and MAS 2 groups, respectively. Also, there was a negative correlation between the TSRT and MAS (rho=-0.72, p<0.05). This demonstrated that the TSRT could be made clinically available for the more objective and reliable evaluation of the spasticity, instead of using the conventional clinical scales and an isokinetic dynamometer.

• The Journal of Korean Physical Therapy
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• v.5 no.1
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• pp.109-114
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• 1993

The originator of the proprioceptive neuromuscular facilitation method was Dr. Herman Kabat, a man who received the bachelor of science degree from New York University in 1932. In 1936 he moved to the University of Minnesota where he served as instructor in physiology and also studies medicine. He received his medical doctorate in 1942. When Dr. Karbat meet Sister Kenny suggested that certain change. She does not receptive his ideas. So that he decided to pursure the treatment of patients. Upon the establishment of the Karbat- kaiser Institute to be opened in 1946. Margaret Knott, the first physical therapist to be employed by him and to become his head physical therapist. In 1948 Vallejo center was opened. Dr. Kabat developed the PNF method combined motions to ascertain the effectiveness of maximal resistance and stretch in facilitating the response of a weak distal muscle. He identified mass movement patterns that were spiral and diagonal in character in 1965. Margaret Knott presented lecture at tile APTA Annual Conference in Las Vegas. The title was In the groove. On December 18, 1978 she passed away at her home in Vallejo. Marie-Louise Mangold is director of the Kaiser Foundation Rehabilitation Center now. She is the Vice President of International Proprioceptive Neuromuscular facilitation Association. About 20 physical therapist working teaching and study at KFRC in Vallejo. PNF neuromuscular mechanism becomes integrated and efficient without awareness of individual muscle action, reflex and a multitude of other neurophysiological reactions. The principles of PNF are visual consideration, verbal consideration, and proprioceptive input consideration with tactile stimulation, joint receptors, appropriate facilitation, stretch reflex normal timing, irradiation, pattern of movement.