• PNF and Movement
• /
• 제19권1호
• /
• pp.1-8
• /
• 2021

Purpose: The purpose of this study was to determine how the position of tibial rotation affects peak force and hamstring muscle activation during isometric knee flexion in healthy women. Methods: Seventeen healthy women performed maximum isometric knee flexion at 30˚ with three tibial rotation positions (tibial internal rotation, neutral position, and tibial external rotation). Surface electromyographic (EMG) activity was recorded from the medial hamstring (MH) and lateral hamstring (LH) muscles. The strength of the knee flexor was measured with a load-cell-type strength-measurement sensor. Data were analyzed using one-way repeated analysis of variance. Results: The results showed that MH and LH activities and peak force were significantly different among the three tibial rotation conditions (p < 0.01). The post-hoc comparison revealed that the MH EMG activity in tibial neutral and internal rotation positions were significantly greater than tibial external rotation (p < 0.01). The LH activity in tibial external rotation was significantly greater than the tibial neutral position and internal rotation (p < 0.01). The peak force of the knee flexor was also greater in the external tibial rotation position compared with the tibial neutral and internal rotation positions (p < 0.01). Conclusion: Our findings suggest that hamstring muscle activation could be changed by tibial rotation.

• 대한인간공학회:학술대회논문집
• /
• 대한인간공학회 1996년도 추계학술대회논문집
• /
• pp.21-25
• /
• 1996

The Electomyographic (EMG) signals of flexor-extensor muscle pairs were investigated to identify the neural excitation pattern of low-back pain (LBP) patients during a repetitive bending motion. New parameters and EMG normalization technique were developed to quantitatively represent the difference of temporal EMG patterns between ten healthy subjects and ten LBP patients. Flexor-extensor muscle pairs such as rectus abdominis(RA)-erector spinae (ES at LS), external oblique(EO)-internal oblique(IO), rectus femois (quadriceps: QUD)-biceps femoris(hamstrings:HAM), and tibialis anterior(TA)-gastrocnemius(GAS) pairs of muscles were selected in this study. Results indicated that the temporal EMG pattern such as the peak timing difference of QUD-HAM muscle pair and the duration of coexcitation of ES-RA muscle pair showed a statistically isgnificant difference between healthy subjects and LBP patients. These results indicated that the new technique and parameters could be used as a diagnostic tool especially for LBP patients with soft tissue injuries that are rarely dentified by traditional imaging techniques such as X-ray, CT scan or MRI. Improtantly, the new EMG technique did not require the maximal volutary contraction(MVC) measure for normalization that helped patients minimize the pain experience during and after the session. Further study needs to be made to validate and refine this method for clinical application.

• Korean Journal of Acupuncture
• /
• 제29권2호
• /
• pp.239-249
• /
• 2012

본 연구는 족소음경근의 구성요소에 대하여 문헌 해석과 인체의 층별 해부를 통하여 해부학적 관점에서 관찰해 보기 위하여 수행되었다. 그리하여 다음과 같은 결론을 얻을 수 있었다. 1. 본 연구 결과 족소음경근의 구성요소와 분석방법에 있어서 기존의 연구와 다소 차이를 보여준다. 2. 족소음경근의 경로와 병증 증상 등을 고려할 때 족소음경근은 근육, 근막, 인대, 그리고 관련 신경을 포함하는 포괄적 개념으로 보인다. 3. 족소음경근의 분포는 경락과 밀접한 관련성이 있으나 일치하지는 않는 것으로 보이며 특히 치골부위 이상의 부위에선 그러할 것으로 사료된다. 4. 이론적으로 MPS와 Anatomy train 같은 가설과는 약간의 차이가 있어 보이며 굳이 관련시켜 생각할 이유가 없다고 생각한다.

• 대한정형도수물리치료학회지
• /
• 제21권1호
• /
• pp.1-4
• /
• 2015

Background: This study was conducted in order to see if muscle strength is different according to fall experience in female elders by comparing their muscle strength of waist and knee, which is one of factors inducing fall. Method: For this study, 22 female elders aged over 65 sampled from senior centers in D City were surveyed on their fall experiences using a questionnaire asking clinical history. Then, 8 elders with fall experience (FE) and another 8 without (NFE) were selected and participated in the research. Isokinetic muscle strength was measured with isokinetic equipment BIODEX SYSTEM 3 PRO, and the peak torque was obtained from the highest of 9 measurements at angular velocity $60^{\circ}/sec$ according to the method recommended in the manual. Measured items were waist flexion and extension, and knee flexion and extension. Results: The FE group showed higher extensor and flexor muscle strength of the waist, but the difference was not significant (p<.05). In addition, no difference was observed in extensor muscle strength of the knee (p<.05). In flexor muscle strength, however, the FE group was significantly higher than the NFE group (p<.05). Conclusion: The application of regular exercise programs for improving muscle strength, endurance, etc. to those with fall experience will be effective in preventing falls among them.

• 한국전문물리치료학회지
• /
• 제13권1호
• /
• pp.38-46
• /
• 2006

The purposes of this study were to investigate the median frequency (MDF) between initiation and termination of muscle contraction through surface electromyographic (sEMG) analysis and to propose the basis of clinical treatment for movement problems in early hemiparetic upper limbs. Thirteen patients who had stroke with onset less than 3 months prior to the study and seven control subjects participated in the study. The median frequency in initiation and termination of muscle contraction was recorded from wrist flexor and extensor muscles using the sEMG, with 3 second beeper signals, during maximal isometric wrist flexion and extension. Flexion and extension must be done as quickly and forcefully as possible. The results of the study were as follows: 1. The MDF of the onset and offset sections were significantly lower on the paretic than the nonparetic and control sides. 2. The MDF of the offset section significantly decreased on the paretic and nonparetic sides. Consequently, this study showed that the lowering of the MDF was due to the hemiparetic wrist motor impairment and muscle weakness. These results are also related to Fugl-Meyer motor assessment (FMA) scores in hemiparetic upper limbs. This study also suggests that since muscle weakness of early stroke patients affects the functional decrease of upper limbs, further studies must focus on the treatment to improve muscle agility and muscle fiber recruitment efficiency that can induce the functional recovery correlated to motor control.

• 한국철도학회논문집
• /
• 제10권5호
• /
• pp.576-581
• /
• 2007

본 연구는 기관사가 지하철 가/감속 장치인 마스콘을 구동 할 때의 시간에 따른 근피로도 변화를 근전도를 이용하여 측정 및 분석하였다. 기관사들은 대부분 하루에 평균 4시간 정도를 상지를 이용하여 마스콘을 구동한다. 4개의 근전도 채널을 상지의 어깨세모근(deltoid muscle), 위팔노근(brachioradialis muscle), 위팔 두갈래근(biceps brachii muscle) 그리고 자쪽 손목 굽힘근(flexor carpi ulnaris muscle)에 부착하여 각 상황에 따른 근전도 신호를 중앙주파수(MF)를 구하여 그 피로도를 분석하였다. 분석결과, 운행 30분 후 10명의 피험자(실제 기관사)의 80%이상의 중앙주파수 값이 유의하게 감소하였다. 이 결과는 30분의 마스콘 구동만으로도 기관사의 상지 근육에 피로를 유발함을 의미한다.

• 한국전문물리치료학회지
• /
• 제29권3호
• /
• pp.180-186
• /
• 2022

Background: The craniocervical flexion test (CCFT) was developed for the activation and endurance of deep cervical flexors. However, the muscle thickness and muscle thickness changing ratio of the sternocleidomastoid (SCM) and deep cervical flexor (DCF) muscles in subjects with and without forward head posture (FHP) have not been reported. Objects: To determine the difference in thickness of the SCM and DCF muscles and the difference in the muscle thickness changing ratio between SCM, DCF, and DCF/SCM 20 mmHg and DCF/SCM 30 mmHg between subjects with and without FHP. Methods: Thirty subjects with and without FHP were enrolled. The muscle thickness of the SCM and DCF was measured when maintained at a baseline pressure of 20 mmHg and a maximum pressure of 30 mmHg using a pressure biofeedback unit during the CCFT. Ultrasonography was used to capture images of SCM and DCF muscle thickness during the CCFT, which was calculated using the picture archiving and communication system (PACS). Results: We observed a significant difference within the pressure main effect between SCM and DCF at a baseline pressure of 20 mmHg and a maximum pressure of 30 mmHg (p < 0.05). However, there was no significant difference in the muscle thickness and muscle thickness changing ratio for SCM and DCF during CCFT between subjects with and without FHP. Conclusion: There was no significant difference in the muscle thickness recruitment pattern during CCFT in posture changes between subjects with and without FHP.

• The Korean Journal of Physiology
• /
• 제26권2호
• /
• pp.151-157
• /
• 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.

• Annals of Clinical Neurophysiology
• /
• 제8권1호
• /
• pp.16-22
• /
• 2006

Sporadic inclusion body myositis (s-IBM) is an aquired slowly progressive inflammatory myopathy with unknown etiology. Although light microscopic abnormalities and characteristic histopathology on muscle biopsy distinguishes from other inflammatory myopathies, vacuolated muscle fibers, intracellular amyloid deposits or tubulofilaments in electromicroscopic findings are not definite in some patients. This review shows the prominently involved muscles in s-IBM and specific or nonspecific electrophysiologic manifestations from reported data for helping the diagnosis of definite-or probable-IBM patients. In lower limbs, the quadriceps is predominantly involved, as is iliopsoas, and tibialis anterior is common. In the upper limbs, the greatest weakness is in forearm finger flexors. Finger extensors, biceps and triceps also are moderately to prominently involved. The majority of patients demonstrate polyphasic MUAPs that are short in duration. An additional striking feature is the concomitant documentation of long-duration, large-amplitude, polyphasic MUAPs. In spite of the frequent mixed myopathic-neurogenic electromyographic findings of IBM, just like that of chronic myositis, asymmetric, slowly progressive weakness of flexor digitorum profundus or quadriceps femoris muscles after age of 50 is very necessary condition for the diagnosis of IBM.

• 대한인간공학회지
• /
• 제18권1호
• /
• pp.55-69
• /
• 1999

It is very common to use the powered hand tools to enhance the productivity in various types of industry. But the use of the powered hand tools could cause health problems such as cumulative trauma disorders and vibration white fingers. In this study. the effects of hand-arm vibration and anatomical hand position on localized muscle fatigue were analyzed. Eight healthy male subjects volunteered for the study. Vibration frequencies of 0, 40, 80, 100, 150, and 200Hz and hand position of flexion and ulnar deviation were selected for the independent variables of the experiment. Median frequency shifting was used as a dependent variable. The results indicated that at the vibration frequency of 40Hz and accelation of 2g, the muscle fatigue was the greatest. For the hand position. there was significant difference between neutral and flexion. and neutral and ulnar deviation, but no difference between flexion and ulnar deviation. These results could be applied in designing powered hand tools to minimize the health problems.