• Journal of The Korean Society of Integrative Medicine
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• v.4 no.4
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• pp.101-108
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• 2016

Purpose : The purpose of this study was to determine the effect of selective thoracic extensor strengthening exercises in the sitting position using a foam-roller by investigating the electromyographic(EMG) activities of the thoracic and lumbar extensors. Methods : Eighteen healthy subjects with no medical history of back pain were recruited. EMG activity was recorded from thoracic extensor(TE) and lumbar extensor(LE) while subjects performed three thoracic extension exercises: prone thoracic extension(PTE), prone thoracic extension with abdominal draw-in maneuver(PTE-ADIM), and sitting thoracic extension using a foam-roller(STE). TE and LE EMG activity, and TE/LE EMG activity ratio were analyzed by one-way repeated-measures analysis of variance(ANOVA). Where a significant difference was identified, a Bonferroni correction was performed(p<.017, .05/3). Results : TE and LE EMG activity, and TE/LE EMG activity ratio differed significantly among the three exercises(p<.05). Post hoc pair-wise comparison with Bonferroni correction showed that TE muscle activity in the STE exercise was significantly different from PTE and PTE-ADIM exercises(p<.017). There was no significant difference between TE muscle activity for PTE and PTE-ADIM exercises(p>.017). LE muscle activity and TE/LE ratios were significantly different among the three exercises p<.017). Conclusion : TE/LE ratio showed superior selective thoracic extensor strengthening for the STE exercise than PTE and PTE-ADIM exercises. Therefore, we recommend STE exercise for selective thoracic extensor strengthening.

• The Journal of Korean Physical Therapy
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• v.34 no.5
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• pp.278-281
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• 2022

Purpose: This study sought to compare the muscle activity of the deltoid muscle according to the range of motion during the proprioceptive neuromuscular facilitation (PNF) upper extremity D2 pattern exercise performed with an isokinetic exercise device. The aim was to provide basic data for selecting an exercise for the relevant segment of the range of motion to enhance function in clinical practice. Methods: In this study, the relevant measurements of the anterior and middle trapezius of 25 healthy adults were taken using a surface electromyography system. The upper extremity pattern exercise was performed in three ranges (0% to 50%, 50% to 100%, and 25% to 75%) using the upper extremity isokinetic device. Results: There was a statistically significant difference in the muscle activity ratios of the anterior and middle deltoid muscles according to the measurement conditions (p<0.05). There was a statistically significant difference in the activity ratio of the middle deltoid muscle according to the measurement conditions in the ratio from the start range to the end range (p<0.05). There was no significant difference in the muscle onset time difference according to the measurement conditions (p>0.05). Conclusion: The muscle activity of the anterior and middle deltoid muscles was analyzed according to the range of motion during the PNF upper extremity pattern exercise performed with an isokinetic device. The results could be used as a basis for selecting exercises for the relevant segment of the range of motion according to the function to be emphasized.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.1
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• pp.53-71
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• 1991

This study was performed to investigate the muscular activity of the complete denture wearers compare with subjects with natural teeth. For the study, 10 subjects with natural dentition and 18 upper and lower complete denture wearers selected and the Bio-electric Processor EM2(Myo-tronics Reaserch, Inc., U.S.A.) with the surface electrodes was used to record electromyographic activity from the right and left middle of masseter and anterior temporal muscles of each subject during mandibular postural rest position, tapping of teeth from postural rest position, maximal clench, and right and left gum and raw carrow chewing. This results of this study were as follows : 1. In mandibular postural rest position, the denture wearers produces high muscular activity in contrast to natural objects(P<0.05) but, there was no difference between the state of denture removal and insertion, and the muscle activity of the anterior temporal muscle was high than the middle of masseter muscle in natural objects and denture wearers. 2. In tapping of teeth, there was no difference in muscle activity between natural objects and the state of denture removal of denture wearers. 3. In maximal clench, there was markedly lower denture wearers than natural objects in muscle activity, and the ratio of mean voltages was about 36 percentages. 4. In gum and raw carrow chewing, the activity was lower than natural object, the ratio was about 59 percentages. 5. In chewing, the mean voltages of the middle of masster muscle on the chewing side was highest, followed by the anterior temporal on the chewing side, the anterior temporal and masster muscles on the non-chewing side.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.3
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• pp.11-20
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• 2020

PURPOSE: Excessive activity of the upper trapezius (UT) muscle contributes to a rounded shoulder posture (RSP) through abnormal rotation of the scapula that weakens the lower trapezius (LT) and serratus anterior (SA) muscles. This study compared the effects of two arm-lifting exercises with and without the use of a Thera-band on the activities of LT, SA, and UT muscles, and the LT/UT and SA/UT activity ratio in subjects with a rounded shoulder posture. METHODS: Sixteen subjects with RSP participated in this study. All subjects performed arm-lifting (AL), diagonal arm-lifting (DAL), arm lifting with isometric adduction (ALIA), and diagonal arm-lifting with isometric adduction (DALIA) exercises. The surface electromyography data, LT, SA, UT, and the LT/UT and SA/UT activity ratios were measured. A paired t-test was used to compare the differences between two arm-lifting exercises and two arm lifting with isometric adduction exercises. RESULTS: In ALIA and DALIA exercises, the UT muscle activity decreased significantly, whereas the LT/UT, SA/UT activity ratio increased significantly. The activity of SA muscle increased significantly more with DALIA than that with DAL. CONCLUSION: Arm-lifting exercises using a Thera-band can be implemented as an effective way to reduce the UT overactivity and increase the SA activity and LT/UT, SA/UT activity ratio in subjects with RSP.

• Physical Therapy Korea
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• v.30 no.1
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• pp.8-14
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• 2023

Background: Excessive hamstring (HS) activation due to the weakness of the gluteus maximus (GM) causes pain in the hip joint. A single-leg deadlift is a hip extensor exercise, especially GM, that includes functional movements in daily life and complex multi-joint training. In single-leg deadlift, the muscle activity depends on the forward trunk lean angle, and it's necessary to study which muscles are used dominantly depending on the angle. Objects: The purpose of this study was to compare the effect on the muscle activity of the GM and HS during single-leg deadlift according to different forward trunk lean angles and the ratio of the GM vs HS (GM/HS). Methods: Twenty-one healthy female participants were recruited. The muscles activities of the GM, HS and the GM/HS ratio were measured through electromyography during single-leg deadlift according to three condition of forward trunk lean angles (30°, 60°, and 90°). Results: The GM and HS activities significantly differed among three conditions (p < 0.05). GM/HS ratio was significantly higher at 30° and 60° of forward trunk lean compared to 90°. Moreover, the GM activity was significantly higher at 60° of forward trunk lean than at 30° (p < 0.05). Conclusion: The single-leg deadlift at 60° of forward trunk lean is a proper GM muscle strengthening exercise.

• PNF and Movement
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• v.14 no.1
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• pp.1-6
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• 2016

Purpose: The purpose of this study was to analyze the effects of proprioceptive neuromuscular facilitation (PNF) patterns on electromyography (EMG) activity in the rectus abdominis, internal abdominal oblique, external abdominal oblique, and erector spinae according to position changes. Methods: Ten healthy adults volunteered to participate in the study. The subjects were required to complete exercises that followed two PNF extremity patterns, namely, an upper extremity extension-adduction-internal rotation pattern and a lower extremity flexion-adduction-external rotation pattern. The exercises were applied in the supine, side-lying, and sitting positions. Repeated measure one-way ANOVA and post-hoc Bonferroni correction were used to determine the influence of the patterns on muscle activity for each muscle, and descriptive statistics were then used to determine the local/global muscle ratios. Results: The upper extremity pattern had a significant effect on the rectus abdominis and erector spinae in the supine position, and on the internal oblique and external oblique in the sitting position (p<0.05). The median value for the internal oblique/rectus abdominis showed a high ratio of 2.05, and a high ratio of 1.01 was shown for the internal oblique/external oblique in the sitting position. The lower extremity pattern had a significant effect on the rectus abdominis in the side-lying position and on the internal oblique, external oblique, and erector spinae in the sitting position (p<0.05). The median value for the internal oblique/rectus abdominis showed a high ratio of 2.83 in the sitting position and a high ratio of 1.30 for the internal oblique/external oblique in the side-lying position. Conclusion: The PNF pattern increases local muscle activation in an unstable position. Therefore, when the pattern is used for intervention purposes, trunk stability and varied position changes should be taken into account.

• Journal of Korean Physical Therapy Science
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• v.21 no.1
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• pp.13-20
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• 2014

Purpose : The purpose of this study was to analyze and compare the surface electromyography(EMG) activity of trunk region muscle between normal subjects and chronic low back pain(CLBP) patients during one leg stance. Methods : The subjects were 27 people, were consisted of 12 subjects who don't have low back pain and 15 subjects who have low back pain from 19 to 28 year of age(mean age 22.22). We used surface EMG to evaluate the activity of the Rectus abdominis, External abdominal oblique, Quadratus lumborum, Gluteus medius muscle. We used independent two samples t-test for statistical data. Results : The result of this study showed that the maximal voluntary isometric contraction(%MVIC) ratio of the trunk muscles was higher in patients with CLBP than in normal subject. But there were no statistically significant differences. There were statistically significant differences of the activity of the Quadratus lumborum, Gluteus medius muscle(p<0.05).

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.1
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• pp.40-47
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• 2018

This study was conducted to examine changes in the muscle activity of the triceps surae, specifically the gastrocnemius and the soleus, depending on the angle of the knee joint during the manual muscle test (MMT) of the plantar flexion of the ankle. The muscle activity of the medial and lateral heads of the gastrocnemius was statistically significantly reduced when the angle of the knee joint was $15^{\circ}$, $30^{\circ}$, and $45^{\circ}$ compared to when the angle was $0^{\circ}$. However, there was no statistically significant difference in muscle activity at the angles of $15^{\circ}$ and $30^{\circ}$ or $45^{\circ}$. There was no statistically significant difference in the muscle activity of the soleus depending on the angle of the knee joint. The ratio of the muscle activity of the soleus to that of the triceps surae showed a statistically significant increase when the angle was $15^{\circ}$, $30^{\circ}$ and $45^{\circ}$ compared to when the angle was $0^{\circ}$. However, there was no statistically significant difference in muscle activity at the angles of $15^{\circ}$ and $30^{\circ}$ or $45^{\circ}$. When the angle of the knee joint was $15^{\circ}$ or higher during the test of the isolated soleus, the muscle activity of the gastrocnemius was reduced. These results indicate that the angle is suitable for the test of the isolated soleus, but there was no statistically significant difference in the muscle activity of the gastrocnemius when the angle was higher than $15^{\circ}$. Therefore, it can be concluded that the most suitable angle of the knee joint for the isolated MMT test of the soleus is $15^{\circ}$.

• Journal of muscle and joint health
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• v.17 no.2
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• pp.142-150
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• 2010

Purpose: The purpose of this study was to examine EMG activities and VMO/VL ratio of the vastus medialis oblique, vastus lateralis, and rectus femoris during squat exercise (knee angle: 15, 45, and 60 degrees; tibial rotation: internal rotation, neutral, and external rotation). Methods: Twelve subjects performed squat exercise at each knee angle and tibial rotation while electromyographic (EMG) activity was collected. Statistical analysis consisted of two-way repeated measures analysis of variance with post hoc analysis. Results: There were significant main effects of knee angles and foot positions and interaction effect on EMG activities of vastus medialis oblique and vastus lateralis. VMO/VL ratios were significantly different by tibial rotations and there was an interaction effect. A neutral position produced significantly more VMO/VL activity ratio than that from internally rotated position and externally rotated position at 60 degrees. Conclusion: Considering the interaction effects for EMG activity across quadriceps muscles tested, the 60 degrees knee angle with a neutral foot position may provide the most effective condition for patients with acute patellofemoral syndrome.

• Physical Therapy Korea
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• v.11 no.3
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• pp.1-9
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• 2004

Most exercise for Patellofemoral pain syndrome (PFPS) has focused on selectively strengthening the vastus medialis oblique muscle (VMO). Although open chain knee extension exercises are effective for increasing overall quadriceps strength, they are not always indicated for PFPS rehabilitation. This study was designed to identify the effect of combined posture of lower extremity on Electromyographic (EMG) activity of the vastus lateralis muscle (VL) and VMO during static squat exercises. The subjects were twenty young adult males who had not experienced any knee injury and their Q-angle was within a normal range. They were asked to perform static squat exercises in five various postures using their lower extremities. The EMG activity of the VL and VMO were recorded in five exercises by surface electrodes and normalized by %MVC values derived from seated, isometric knee extensions. The normalized EMG activity levels (%MVC) of the VL and VMO for the five postures of the lower extremities were compared using one way ANOVA with repeated measures. Results of repeated measures of ANOVA's revealed that exercise 3 and exercise 5 produced significantly greater EMG activity of VMO/VL ratios than exercise 1 (p<.05). When the static squat exercise was combined with hip adduction and toes pointed outwardly, the EMG activity of VMO/VL rates was increased. The EMG activity of VMO/VL ratio was highest during static squat exercises performed on a decline squat. These results haveimportant implications for progressive and selective VMO muscle strengthening exercises in PFPS patients.