• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.1
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• pp.13-19
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• 2013

The aim of this study was to investigate difference of the muscle activation patterns of the upper body during wheelchair cycle ramps ascent of different slopes for disabled with spinal cord injury. Three subjects who is disabled with spinal cord injury participated in this study. Surface electromyography (EMG) data (reaction time [RT], onset-offset time, and peak value of muscle activation) were collected biceps, triceps, upper trapezius, anterior deltoid, latissimus dorsi, and upper rectus abdominal muscles during wheelchair cycle ramps ascent ($0^{\circ}$, $3^{\circ}$, and $6^{\circ}$). For latissimus dorsi muscle, RT and peak value of muscle activation was were increased and offset time was delayed as the slope increased (p < 0.05). These results indicate that wheelchair cycle ramps ascent might cause excessive overuse of latissimus dorsi muscle.

• Physical Therapy Rehabilitation Science
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• v.9 no.2
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• pp.113-119
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• 2020

Objective: The vibration device is one of the most commonly used warm-up devices not only for healthy athletes but also for healthy individuals. Therefore, this study aimed to investigate the immediate effects of local vibration on ankle plantar flexor muscle activation and peak torque in healthy adults. Design: One-group pretest-posttest design. Methods: This was a single-group study comprising a total of 36 (16 males and 20 females) participants. The average age of the 36 participants was 22.3 years. All the participants' concentric and eccentric peak torques of the gastrocnemius lateralis muscle were measured using an isokinetic device. Simultaneously, the participants' muscle activity was measured by surface electromyography. After the pre-experimental data were collected, the participants comfortably sat on the prepared chair with their hips and knees flexed to 90°. While in sitting position, local vibration was applied for 10 minutes using a 1:1 ratio intermittent pulsing mode device based on a previous study. Then, the post-experimental data were collected immediately after the local vibration by performing a similar process performed during the pre-experimental data collection. Results: The results showed a significant difference in muscle activity and eccentric peak torque (p<0.05). On the contrary, concentric peak torque values showed an insignificant difference with pre- and post-value. Conclusions: The results of this study demonstrated that local vibration can be possibly considered as one of the effective ways to increase ankle plantar flexor muscle activity and muscle performance, specifically the eccentric peak torque, in healthy adults.

• Journal of International Academy of Physical Therapy Research
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• v.12 no.2
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• pp.2338-2344
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• 2021

Background: The therapeutic exercise method using kinesiology taping (KT) has been reported to be effective in activating the suprahyoid muscle in healthy adults. However, its applicability and effectiveness are not known to the physically vulnerable elderly. Objectives: To investigate the effects of kinesiology taping on the activity of suprahyoid muscles in community-dwelling elderly people. Design: Repeated measure design. Methods: We enrolled 23 healthy elderly adults (age range 60-75 years) with no history of neurologic disease. Participants performed five consecutive spontaneous swallowing actions at 5-second intervals under three conditions (KT with 80% stretch, placebo-KT, and non-KT. Activation of the suprahyoid muscles during swallowing in the three conditions was measured using surface electromyography (sEMG). In addition, a 0-10 numerical rating self-report scale was used to evaluate the required effort and the resistance felt during swallowing. Results: KT with 80% stretch were significantly higher in sEMG mean value, peak value, required effort, and resistance felt during swallowing compared to other two conditions (P<.05, all). KT with 80% stretch required the most effort during swallowing and, consequently, has a positive effect on increasing suprahyoid muscle activation. Conclusion: Our results could be taken into consideration in therapeutic exercise method for suprahyoid muscle in dysphagia rehabilitation.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.2
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• pp.53-57
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• 2017

PURPOSE: The purpose of study was to clear up the environmental risk factor that can be easily occurred unstability of hip during gait and one leg standing at various ramp angle. METHODS: Twenties healthy males of 69 subjects is participated in this study. Participants was measured activation on gluteus medius muscle during both conditions (walk across the ramp and one leg stand in the transverse direction) of seven different angle. The measured data were analyzed using one-way ANOVA to investigate the effect of muscle activation on the each condition. The statistical analyses were performed using SPSS ver. 18.0 and p-value less than .05 were considered significant for all cases. A post-hoc test was performed by Bonferoni method. RESULTS: The study showed that more muscle activities on gluteus medius is increased by increasing the ramp angle. Post-hoc analysis demonstrated that the peak and mean of muscle activity increased significantly with a ramp angle of $15^{\circ}$ and $25^{\circ}$ during gait and one-leg stand. CONCLUSION: According to the study results, impaired balance can be easily occurred when cross walk and one-leg stand on a ramp from higher than $15^{\circ}$, and highest risk was angle of $25^{\circ}$ or more. As a people with gluteus medius muscle weakness walks a ramp, the ramp angle has a cross relationship with the impaired balance. If people with gluteus medius weakness walk on the more than $10^{\circ}$ of ramp angle, they will need a lot of attention for prevent impaired balance.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1991.06a
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• pp.15-15
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• 1991

한국어 자음에 대한 생리적인 분류는 조음점 및 조음발법에 따라 다시 세분화할 수 있는데 그중에서 조음발법에 따라 파열음, 마찰음, 파찰음 및 비음들 여러가지로 분류할 수 있다. 그중 특히 파열음은 그 개방하는 방법에 따라 연음(lenis), 경음(glottalized) 및 기식음(aspirated)등으로 구분하는데 이러한 각음을 육안으로 확인하면 모음이 발성되기 위한 성대진동이 있기전의 자음을 위한 성대의 운동의 현상을 보면 기식음에서는 성대열림이 가장 크고 연음에서도 열림이 크지만 기식음보다는 적고 경음에서는 성대의 열림이 가장 작았다. 이러한 현상은 후두내시경에 의해 쉽게 확인할 수 있었는데 이것을 과학적으로 규명하기 위해서는 여러연구에 의해 가능하나 흔히 후두근전도 검사에 의한 성대내전근과 외전근의 역할의 차이를 비교함으로서 가능해지리라 예상되어 본 연구를 시행하였다. 사용된 문형 또는 단어는 한가지를 제외하고는 모두 의미있는 단어를 사용하였으며 EMG recording을 위해 사용된 근육은 후두내전근인 Vocalis muscle과 후두외전근인 Posterior cricoarytenoid muscle이 사용되었고 전기신호는 computer data processing system에 의해 분석되어졌다. 결과는 내시경에 의한 성대열림의 거리측정 결과를 분석함과 동시에 후두내근에 대한 근전도검사에 의한 분석을 토대로 하였으며 이를 간단히 설명하면 이제까지 많은 사람들은 한국어 자음에 대한 각각의 특징적인 현상들을 주로 성대내전근의 역할에 의해 규명하였으나 본 결과로는 성대내전근의 역할도 중요하지만 성대외전근의 역할 또한 상호 연관성을 가지면서 매우 중요한 역할을 한다는 점이다.for the Isotropic plates can be used. Use of some coefficients can produce "exact" value for laminates with such configuration.trap with 2.88[eV] deep of injected space charge from the chathode in the crystaline regions. The origin of ${\alpha}$$_2$ peak was regarded as the detrapping process of ions trapped with 0.9[eV] deep originated from impurity-ion remained in the specimen during production process of the material, in the crystalline regions. The origin of ${\beta}$ peak was concluded to be due to the depolarization process of "C=0"dipole with the activation energy of 0.75[eV] in the amorphous regions. The origin of ${\gamma}$ peak was responsible to the process combined with the depolarization of "CH$_3$", chain segment, with the activation energy of carriers from the shallo

• Journal of the Ergonomics Society of Korea
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• v.30 no.6
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• pp.689-694
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• 2011

Objective: The aim of this study is to evaluate the fluctuation of signal amplitude during repetitive dynamic contraction based on surface electromyography(EMG). Background: The most previous studies were considered isometric muscle contraction and they were difference to smoothing window length by moving average filter. In practical, the human movement is dynamic state. Dynamic EMG signal which indicated as the nonstationary pattern should be analyzed differently compared with the static EMG signal. Method: Ten male subjects participated in this experiment, and EMG signal was recorded by biceps brachii, anterior/posterior deltoid, and upper/lower trapezius muscles. The subject was performed to repetitive right horizontal lifting task during ten cycles. This study was considered three independent variables(muscle, amplitude processing technique, and smoothing window length) as the within-subject experimental design. This study was estimated muscular activation by means of the linear envelope technique(LE). The dependent variable was set coefficient of variation(CV) of LE for each cycle. Results: The ANOVA results showed that the main and interaction effects between the amplitude processing technique and smoothing window length were significant difference. The CV value of peak LE was higher than mean LE. According to increase the smoothing window length, this study shows that the CV trend of peak LE was decreased. However, the CV of mean LE was analyzed constant fluctuation trend regardless of the smoothing window length. Conclusion: Based on these results, we expected that using the mean LE and 300ms window length increased reproducibility and signal noise ratio during repetitive dynamic muscle contraction. Application: These results can be used to provide fundamental information for repetitive dynamic EMG signal processing.

• The Korean Journal of Physiology
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• v.14 no.2
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• pp.7-16
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• 1980

The effects of various inotropic interventions on the shape of the steady state length tension relation and the length-dependent activation process in cardiac muscle were studied. The influence of inotropic interventions upon the action potential was also observed. The range of varying muscle length was from the optimal length$(l_{max})$, where the active tension production is maximal, to 0.85 $l_{max}$. Changes in stimulus frequency or in external bathing Ca concentration constituted the inotropic interventions in this experiment. The papillary muscles were isolated from the rabbit right ventricles and perfused with $HCO-_3\;-buffered$ normal Tyrode solution which was aerated with $3%\;CO_2-97%\;O_2$ mixed gas and kept at $35^{\circ}C$. Resting Passive tension at $l_{max}$ was approximately 30% of the total tension and appeared from the muscle length of 0.90 $l_{max}$. The effect of stimulus frequency on the steady state level of developed tension was: As the stimulus frequency was increased from 0.1 to 0.5 Hz, there was little change in developed tension. As the frequency was increased further, to a value of about 3 Hz, tension increased steeply. Further increase of the frequency to 5 Hz had little additional effect on the developed tension. The length-tension curves for isometric peak tension became more steeper with the degree of potentiation by inotropic interventions. The relative steepness of the normalized length-tension curves where tension production was expressed as a percentage of maximal tension developed at $l_{max}$, varied inversely with the level of inotropic state and these curves were not superimposable one another. Thus at the stimulus frequency of 2 Hz or at the external Ca concentration of 8 mM, the relative decline in the developed tension for a given change in muscle length was considerably less than the decline observed at the frequency of 0.5 Hz or at the concentration of 2 mM Ca. Action potential duration was prolonged significantly as the frequency increased from 0.2 to 2 Hz, and this change in action potential duration was not observable on the changes in muscle length. There was a tendency of the hyperpolarization of membrane potential when the muscle length was shortened from $l_{max}$ to 0.95 $l_{max}$. These results support the hypothesis that there is a length-dependence of the activation process.