• Physical Therapy Korea
• /
• v.22 no.1
• /
• pp.103-109
• /
• 2015

Although the relationship between temporomandibular disorder and forward head posture (FHP) is controversial, it is generally accepted that altered head posture can affect mandible position and masticatory muscles activity. Because suprahyoid (SH) and infrahyoid (IH) muscles are stretched by increased passive tension in FHP, this study investigated their activity during mouth opening in FHP compared to neutral head posture (NHP). Twenty healthy subjects (10 males and 10 females) participated in this study. Head postures were evaluated with a cervical range of motion instrument. Electromyography (EMG) activity of bilateral SH and IH muscles was measured while an open mouth was maintained at each head posture. Paired t-test was used to identify significant differences in normalized EMG activity between head postures. Statistical significance was set at .01. Results showed the normalized EMG activity of SH and IH muscles were significantly lower in FHP compared to NHP. This finding indicates that FHP affects the EMG activity of hyoid muscles when they are stretched.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.2
• /
• pp.139-143
• /
• 2010

Whiplash injuries often occur in motor vehicle collision accidents. This injury frequently occurs in the cervical region. However, the reason for this has not yet been clarified. In this study, a multi-body neck model with muscles was designed. Some muscles in the model were preloaded; these were previously determined using the concept of the follower load. Cervical spinal vertebrae, discs, and muscles were designed in accordance with the human cervical spine. The purpose of this study was to investigate the effect of preloads on muscles. The results imply that the whiplash model with preloaded muscles simulates practical situations more closely than models without preloads.

• PNF and Movement
• /
• v.15 no.3
• /
• pp.381-387
• /
• 2017

Purpose: Although some studies indicate that the Sorensen test may not be used to examine back muscles such as the erector spinae, alternatives to the back-extension test are rarely suggested. Therefore, the purpose of the present study was to investigate an effective way to stimulate the erector spinae muscles by adding a component of trunk rotation and lateral bending to general back extensions. Methods: A total of 18 healthy, physically active participants performed simple trunk extension, extension with trunk rotation, and extension with lateral bending. Surface electromyography responses of the latissimus dorsi, thoracic, and lumbar levels of the erector spinae; the gluteus maximus; and the biceps femoris muscles were investigated during these 3 conditions of modified back extension tests. Results: The simple trunk extension exercise caused significant increases in activity of the gluteus maximus and biceps femoris muscles as compared to the extension with rotation and lateral bending exercises. The extension with trunk rotation exercise showed significantly greater activation in the thoracic and lumbar levels of the erector spinae and in the latissimus dorsi as compared to the other exercises. The index measuring subjective difficulty was significantly lower in the simple trunk extension exercise as compared to the extension with trunk rotation and extension with lateral bending exercises. Conclusion: The present study suggests that extension with trunk rotation has the advantage of stimulating the para-spinal muscles, while simple trunk extension may not be adequate to selectively simulate the para-spinal muscles but may be appropriate for examining global trunk extensors.

• Journal of the Korean Society of Physical Medicine
• /
• v.9 no.3
• /
• pp.271-278
• /
• 2014

PURPOSE: This study researched the effects of different types of high heels on the muscles surrounding the cervical spine, the thoracic spine, and the lumbar spine by analyzing muscle activation of the paraspinal muscles during walking while wearing high heels. The high heels were all of the same height: 8cm. METHODS: The 28 subjects in this experiment were females in their 20s with a foot size of 225-230mm. To measure the muscle activation of the paraspinal muscles, EMG electrodes were attached on the paraspinal muscles around C6, T7, and L5. The muscle activation during walking while wearing 8cm high wedge heels, setback heels, and french heels was measured. The measurements were performed 3 times each and the mean value of the result was used for analysis. Two kinds of velocity were used in this study. One of the velocity was 2.5 m/s. The other was 3.5 m/s. RESULTS: The muscle activation of paraspinal muscles increased significantly according to increase of walking velocity. But there was no significant difference according to the heel types. CONCLUSION: In view of the results, the height of heels and the velocity of walking are more convincing variables than the width of the heels on the muscle activation of paraspinal muscles. So wearing high heels is not recommended for those who have pain or functional problem of cervical and lumbar vertebrae.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.1 no.1
• /
• pp.49-55
• /
• 1974

Electromyographic studies were performed on the action of the masseter muscles. Among the children aged from 6 to 8 years, ten children with normal occlusion and another ten with space maintainer were selected. The children were divided into 3 groups. They were: 1) A group: Children who removed space maintainer 2) B group: Children who inserted space maintainer 3) C group: Children with normal occlusion. The electromyogram was recorded with 4 channel polygraph. (Grass model VII) Electrodes which were cup-typed gold disks, 9 millimeters in the diameter, were located on the superficial layer of masseter muscles. The electromyogram was recorded in the physiologic rest position, molar occlusion, chewing movement, protraction, left lateral movement, and right lateral movement. The conclusions were as follows. 1. In the physiologic rest position, lateral movement, the electrical potentials of the masseter muscles were not changed clearly in each groups. 2. In molar occlusion, chewing movement, The electrical potentials of the masseter muscles of the B group were almost 10% higher than those of A group, and were almost 60-70% in comparision with C group. 3. In protraction, the electrical potentials of the masseter muscles of the B group were almost 40% higher than those of A group, and were almost equal to C group. 4. The electrical activities of the masseter muscles in the mandibular movements were in the following order: (1) Molar occlusion (2) Chewing movement (3) Protraction (4) Lateral movement.

• Korean Journal of Acupuncture
• /
• v.25 no.4
• /
• pp.17-29
• /
• 2008

Objectives : This study was carried out to investigate the correlation of meridian system in oriental medicine and muscular system in western medicine. Methods : Muscles were assigned to meridians by their main functions and the acupoints on them. New mutual relationships between meridians in lower limb were studied based on the muscular function. Results : In gluteal & femoral region, iliopsoas & quadratus femoris are assigned to spleen & stomach meridians, gluteus maximus & hamstrings to urinary bladder & kidney meridians, adductor muscle groups to liver meridian, gluteus medius & minimus & iliotibial tract to gall bladder meridian. In crural region, anterior crural muscles are assigned to stomach meridian, lateral crural muscles to gall bladder meridian, suferficial posterior crural muscles to urinary bladder (& kidney) meridian, deep posterior crural muscles to liver, spleen, kidney meridians. In lower limb, urinary bladder meridian and stomach meridian lead the muscular functions and correspond to each other, while spleen meridian assists stomach meridian, and kidney meridian assists urinary bladder meridian. Conclusions : Muscles may be assigned to meridians by their functions and the acupoints on them. From the view of muscular function, Yang meridians lead Yin meridians in lower limb.

• Korean Journal of Veterinary Service
• /
• v.25 no.3
• /
• pp.285-294
• /
• 2002

The present studies were carried out to determine antibiotics residues in pork and beef muscles by EEC-4-plate and HPLC. A total of 2,534 samples of pork muscles and 1,070 samples of beef muscles from slaughter houses were collected in Gyeongnam area from January to December, 2001. The results were summarized as follows; 1. Recovery rates of TCs, Sulfa drug, Penicillin G from fortified pork and beef muscles ranged as 68.79～98.24%, 78.21～94.58% and penicillin G 63.35～67.24% respectively, by HPLC. 2. Antibiotics residues were detected in 36 sample(1.42%) of pork muscles, 29 sample (2.71%) of beef muscles by EEC-4-plate. 3. Detection rate of antibiotic residues 14 samples(0.55%) and 26 samples(2.43%), in pork and beef muscles, respectively by HPLC. Concentration of residues in 22 sample(2.06%) of beef muscle were higher than tolerance level in korea. 4. Antibiotics detected were sulfamethazine(47.37%), tetracycline(15.79%), oxytetracycline (15.79%), penicillin G(15.79%), sulfamerazine(5.26%) in pork muscle samples and oxyteracycline (37.21%), penicillin G(30.23%), sulfamethazine(20.93%), tetracycline(4.65%), sulfamerazine (2.33%), sulfadimethoxine(2.33%), sulfaquinoxine(2.33%) in beef muscle samples.

• Journal of Korean Neurosurgical Society
• /
• v.62 no.1
• /
• pp.90-95
• /
• 2019

Objective : Anomalous muscles of the wrist are infrequently encountered during carpal tunnel surgery. Anatomic variants of the palmaris longus (PL), flexor digitorum superficialis, lumbricalis and abductor digiti minimi (ADM) have been reported but are usually clinically insignificant. Anomalies of the wrist muscles, encountered during endoscopic carpal tunnel surgery have rarely been described. I conducted this study to evaluate muscular anomalies of the volar aspect of the wrist, encountered during endoscopic carpal tunnel surgery. Methods : I studied a consecutive series of 1235 hands in 809 patients with carpal tunnel syndrome who underwent single-portal endoscopic carpal tunnel release (ECTR) from 2002 to 2014. Nine hundred seventy-three hands in 644 patients who had minimal 6-month postoperative follow-up were included in the study. The postoperative surgical outcome was assessed at least 6 months after surgery. Results : In eight patients, anomalous muscles were found under the antebrachial fascia at the proximal wrist crease and superficial to the ulnar bursa, passing superficial to the transverse carpal ligament. Those anomalous muscles were presumed to be variants of the PL or accessory ADM muscle, necessitating splitting and retraction to enter the carpal tunnel during the ECTR procedure. Other muscle anomalies were not seen within the carpal tunnel on the endoscopic view. The surgical outcome for all eight wrists was successful at the 6-month postoperative follow-up. Conclusion : Carpal tunnel surgeons, especially those using an endoscope should be familiar with unusual findings of anomalous muscles of the wrist because early recognition of those muscles can contribute to avoiding unnecessary surgical exploration and unsuccessful surgical outcomes.

• PNF and Movement
• /
• v.9 no.3
• /
• pp.1-9
• /
• 2011

Purpose : The purpose of this study was to find the effects of the transverse abdominis/internal abdominal oblique (TrA/IO), multifidus (MF) muscles while stabilization exercise was performed in a four-point kneeling position on the unstable surface. Methods : Twenty healthy adults volunteered to participate in this study. Each subject was instructed regarding maximum voluntary isometric contractions (MVIC) and stabilization exercise in four-point kneeling on the unstable surface. While MVIC and stabilization exercise of individual muscles were being performed, activation of the muscles was measured using surface electromyography (EMG). Activation of the muscles while performing stabilization exercise in four-point kneeling on the unstable surface was normalized to a percentages of the MVIC. Results : TrA/IO, MF muscles showed no significant differences among the surfaces. Conclusion : Activation of the trunk muscles while performing stabilization exercise in four-point kneeling does not effect on the surface.

• Journal of Oral Medicine and Pain
• /
• v.48 no.4
• /
• pp.159-168
• /
• 2023

Purpose: Coordinated activity between the jaw and neck muscles is important in oral motor tasks such as chewing. This study examined coherence between the jaw and neck muscles during chewing in healthy adults. Methods: A total of 12 healthy adults underwent electromyography (EMG) of the jaw and neck muscles during right-sided chewing at a frequency of 1 Hz. Surface electrodes were placed over the temporalis (TA), masseter (MS), anterior digastric (DA), and sternocleidomastoid (SM) muscles on the right side. EMG signals were processed for coherence and phase analysis using advanced signal processing techniques. Results: The MS and TA muscle pair exhibited high synchronization when chewing (median coherence=0.992). Contrarily, the coherence values between the MS and DA, as well as the MS and SM muscle pairs, were relatively low (median coherence=0.848 and 0.957, respectively). Phase analysis revealed minimal temporal differences between the MS and TA muscle pair and the MS and SM muscle pair, whereas substantial phase shifts were observed between the MS and DA muscle pair. Conclusions: During chewing in healthy adults, the TA muscle works synergistically whereas the DA muscle antagonistically with the MS muscle, and the SM muscle supports the activity of the MS muscle. The observed synchrony and coordination provide insights into the intricate interplay among these muscles during oral motor tasks.