• Journal of the Korean Society of Safety
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• v.16 no.2
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• pp.117-120
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• 2001

Low back pain has been known as the most frequent musuculoskeletal disorders in modern industrial society and cost by low back pain is increasing mon and more. The asymmetric lifting has been identified as a major risk factor of low back pain. In this study, the muscle activity and muscle exertion level during asymmetric load handling (without trunk flexion) was estimated. The results of normalized MVC measurement were decreased about 16％, 24％, 34％ respectively as the asymmetric angle was $30^{\circ}$, $60^{\circ}$, $90^{\circ}$. From the results of EMG measurement contralateral muscles were more active than ipsilateral muscles. RMSEMG values of right erector spinae muscles were decreased as the work posture went to 90$^{\circ}$ and those of left erector spinae muscles were increased until the asymmetric angle was 40$^{\circ}$ but decreased continually over 40$^{\circ}$. And for seven of subjects, activities of left and right latissimus dorsi muscles were maintained constantly, while for remainer, those were irregular.

• Physical Therapy Korea
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• v.20 no.1
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• pp.1-9
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• 2013

The purpose of this study was to determine the effect of the pelvic compression belt (PCB) on the electromyography (EMG) activities of trunk muscles during sit-to-stand (SitTS), and stand-to-sit (StandTS) tasks. Twenty healthy subjects (7 men and 13 women) were recruited for this study. The subjects performed SitTS, and StandTS tasks, with and without a PCB. Surface EMG was used to record activity of the internal oblique (IO), external oblique (EO), rectus abdominis (RA), erector spinae (ES), and multifidus (MF) of the dominant limb. EMG activity significantly decreased in the RA (without the PCB, $8.34{\pm}6.04$ %maximal voluntary isometric contraction [%MVIC]; with the PCB, $7.64{\pm}5.11$ %MVIC), EO (without the PCB, $14.83{\pm}11.82$ %MVIC; with the PCB, $11.98{\pm}7.60$ %MVIC), MF (without the PCB, $21.74{\pm}7.76$ %MVIC; with the PCB, $18.50{\pm}8.04$ %MVIC), and ES (without the PCB, $18.39{\pm}7.16$ %MVIC; with the PCB, $16.63{\pm}6.31$ %MVIC) during the SitTS task and in the IO (without the PCB, $20.58{\pm}15.60$ %MVIC; with the PCB, $17.27{\pm}12.32$ %MVIlC), RA (without the PCB, $8.04{\pm}5.68$ %MVIC; with the PCB, $7.40{\pm}4.71$ %MVIC), EO (without the PCB, $13.29{\pm}8.80$ %MVIC; with the PCB, $11.24{\pm}6.14$ %MVIC), MF (without the PCB, $18.59{\pm}7.64$ %MVIC; with the PCB, $15.86{\pm}6.48$ %MVIC), and ES (without the PCB, $17.14{\pm}6.44$ %MVIC; with the PCB, $15.46{\pm}5.62$ %MVIC) during the StandTS task when a PCB was used (p<.05). In men the EMG activity of the MF significantly decreased during the SitTS task when a PCB was used (p<.05): in women, the EMG activity of the RA, EO, MF, and ES during the SitTS task and that of the EO, MF, and ES during the SitTS task significantly decreased when a PCB was used (p<.05). In addition, the rates of change in the EMG activity of each muscle differed significantly during the SitTS and StandTS tasks before and after the use of the PCB. However, the EMG activity did not significantly differ between the male and female subjects. These findings suggest that the PCB may contribute to the modification of activation patterns of the trunk muscles during SitTS, and StandTS tasks.

• Physical Therapy Korea
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• v.25 no.3
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• pp.1-11
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• 2018

Background: Lumbopelvic stability is highly important for exercise therapy for patients with low back pain and shoulder dysfunction. It can be attained using a pelvic compression belt. Previous studies showed that external pelvic compression (EPC) enhances form closure by reducing sacroiliac joint laxity and selectively strengthens force closure and motor control by reducing the compensatory activity of the stabilizer. In addition, when the pelvic compression belt was placed directly on the anterior superior iliac spine, the laxity of the sacroiliac cephalic joint could be significantly reduced. Objects: This study aimed to compare the effects of EPC on lumbopelvic and shoulder muscle surface electromyography (EMG) activities during push-up plus (PUP) and deadlift (DL) exercise, trunk extensor strength during DL exercise. Methods: Thirty-eight subjects (21 men and 17 women) volunteered to participate in this study. The subjects were instructed to perform PUP and DL with and without the EPC. EMG data were collect from serratus anterior (SA), pectoralis major (PM), erector spinae (ES), and multifidus (MF). Trunk extensor strength were tested in DL exercise. The data were collected during 3 repetitions of all exercise and the mean of root mean square was used for analysis. Results: The EMG activities of the SA and PM were significantly increased in PUP with pelvic compression as compared with PUP without pelvic compression (p<.05). In DL exercise, a significant improvement in trunk extensor strength was observed during DL exercise with pelvic compression (p<.05). Conclusion: The results of this study indicate that lumbopelvic stabilization reinforced with external pelvic compression may be propitious to strengthen PUP in more-active SA and PM muscles. Applying EPC can improve the trunk extensor strength during DL exercise. Our study shows that EPC was beneficial to improve the PUP and DL exercise efficiency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.934-939
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• 2014

The purpose of this study unit a Quadrupedal position of limbs due to changes in the thickness of the trunk muscles to find out, by comparing the difference in muscle activity fours spinal stabilization devices do you need to choose an effective stance is to provide the data. The subjects C # 29 University students healthy adults were recruited. The Rectus abdominis muscle and the transversus abdominis and internal oblique abdominal muscle, external oblique abdominal muscle should be measured. The results of this study Lt. IO, EO, TrA, Rt. TrA, Muscle showed significant differences among the positions. The study reveals that the exercises in Quadrupedal position can activate trunk muscles and the degrees of muscle activities can vary according to the angle.

• Journal of Biomedical Engineering Research
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• v.29 no.6
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• pp.484-492
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• 2008

Sit to stand(STS) movement is one of the most common activity in daily life. In addition, Korean traditionally stand up from various sitting heights in one's daily life compared to other foreigners. As Korea enter rapidly to the aging society, needs of the elderly's independent life are increasing. Therefore the importance of research about the analysis of elderly's activity in daily life is rapidly increasing. In this study, we analyzed joint movements and changes of muscle length during STS(sit-to-stand) at various sitting heights(table seat, bath seat, bottom) in the Korean elderly's daily life by using the motion analysis and musculoskeletal modeling. Ten Korean elderly and young were participated in this experiment. Three heights of sitting posture which could represent typical sitting in Korean daily life were chosen as table seat(42cm), bath seat(21cm) and bottom(0cm). As the results, the elderly showed both smaller knee/hip flexion and larger trunk flexion relatively in comparison to the young during table seat STS. The elderly also showed larger dorsiflexion and smaller ROM of knee, hip, trunk compared to the young during bath seat STS. Additionally, the elderly showed larger plantarflexion, hip flexion, smaller knee flexion and trunk flexion during the first half of bottom STS and larger knee flexion, hip flexion and trunk flexion during the second half of bottom STS. In addition, we could know contraction and relaxation characters of major muscles in lower limb during various STS through the analysis of changes in muscle length by musculoskeltal modeling.

• Physical Therapy Korea
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• v.19 no.4
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• pp.38-45
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• 2012

The aim of this study is to compare the effect of abdominal drawing-in maneuver (ADIM) on lower trapezius (LT), serratus anterior (SA), and erector spinae (ES) muscle activity during arm lifts in prone and standing positions. Twenty healthy subjects were recruited, and NoraxonTeleMyo 2400T was used to collect electromyographic signals from the LT, SA, and ES muscles. A two-way repeated analysis of variance (ANOVA) used a significance level of .05. If a significant interaction was found, pairwise comparisons were performed with a Bonferroni adjustment (.05/4=.013). The results of the study were as follows: 1) In LT, no significant ADIM by position interaction was found ($F_{1,19}$=.356, p=.558). There was a significant main effect for ADIM. LT muscle activity with ADIM was significantly greater compared with muscle activity without ADIM ($F_{1,19}$=82.863, p<.001). There was also a significant main effect for position. LT muscle activity in the prone position was greater compared with muscle activity in the standing position ($F_{1,19}$=116.401, p<.001). 2) In SA, significant ADIM by position interaction was found ($F_{1,19}$=8.687, p=.008). There were significant differences in all pairwise comparisons. The greatest SA muscle activity was observed in the standing position with ADIM. 3) In ES, significant ADIM by position interaction was found ($F_{1,19}$=122.473, p<.001). The lowest ES muscle activity was elicited in the standing position with ADIM. Based on these results, ADIM is advocated in the prone position to increase LT muscle activity. In addition, it is concluded that arm lifts in the standing position with ADIM offer the most favorable combination for reducing ES muscle activity and increasing SA muscle activity.

• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.67-74
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• 2005

The purpose of this study is to compare and analyze the muscle activations between the professional golfers without low back pain symptom and the professional golfers with low back pain symptom, and so identify the stress related to golf swings, and provide the basic data to minimize the low back pain and the injury risk. Using surface electrode electromyography, we evaluated muscle activity in 6 male professional golfers during the golf drive swing. Surface electrodes were used to record the level of muscle activity in the Abdominal Oblique, Elector Spinae, Rectus Abdominis, Gluteus Maximus muscles during the golfer's swing. These signals were compared with %RVC(Reference voluntary contraction) which was normalized by IEMG(Integrated EMG). The golf swing was divided into five phases: take away, forward swing, acceleration, early follow through, late follow through. we observed patterns of trunk muscle activity throughout five phases of the golf swing. The results can be summarized as follows: RES(Right Elector Spinae) had statistically significant difference in take away phase, LGM(Left Gluteus Maximus), LRA(Left Rectus Abdominis), LOA(Left Oblique Abdominal) had statistically significant difference in forward swing phase, RES(Right Elector Spinae), RGM(Right Gluteus Maximus), ROA(Right Oblique Abdominal) had statistically significant difference in acceleration phase, RES(Right Elector Spinae), RGM(Right Gluteus Maximus) had statistically significant difference in early follow-through phase, LES(Left Elector Spinae), RGM(Right Gluteus Maximus) had statistically significant difference in late follow through phase.

• PNF and Movement
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• v.17 no.3
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• pp.401-409
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• 2019

Purpose: This study investigated the muscular activity of abdominal muscles during a variety of plank exercises following changes in the leg and head positions. Methods: Thirty healthy individuals participated in this study. They performed six variations of plank exercises, including three changes in head position and two changes in leg position. Each plank was defined as head neutral-leg neutral, head up-leg neutral, head down-leg neutral, head neutral-leg wide, head up-leg wide, and head down-leg wide. During the plank excises, the muscle activities of the rectus abdominis, internal oblique, erector spinae, and upper trapezius were measured. Results: The head down position significantly increased the rectus abdominis activity compared to other head positions (p<0.05). On the other hand, the upper trapezius muscle activity was significantly higher with the head up position compared to other head positions (p<0.05). Regardless of head positions, both the rectus abdominis and internal oblique muscles were significantly activated with leg wide position compared to the leg neutral position (p<0.05). Conclusion: Head and leg positions could change the muscular activities of abdominal muscles during plank exercises. For example, the head down position is effective for activating the rectus abdominis while the leg wide position could be advantageous for enhancing the internal oblique and rectus abdominis.

• Physical Therapy Rehabilitation Science
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• v.9 no.3
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• pp.201-208
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• 2020

Objective: This study aimed to identify the effects of performing shoulder and hip abduction during the V-sit exercise on abdominal muscle activity. Design: Cross-sectional study. Methods: Thirty healthy adults volunteered for this experiment. The participants randomly performed 6 types of V-sit exercises, including V-sit alone (hip 0°, shoulder 0°), V-sit with hip abduction 0° and shoulder abduction 15°, V-sit with hip abduction 0° and shoulder abduction 30°, V-sit with hip abduction 15° and shoulder abduction 0°, V-sit with shoulder and hip abduction 15°, and V-sit with shoulder abduction 30° and hip abduction 15°. EMG data were recorded from the rectus abdominis (RA), external oblique (EO), and internal oblique (IO) muscles of both sides. All abdominal EMG data during the six types of V-sit exercises were measured for 5 seconds, three times, and recorded for the middle 3 seconds excluding the 1 second at the start and end. Results: V-sit with shoulder abduction 30° resulted in significantly greater muscle activity of both RA, EO compared to shoulder abduction 0°, shoulder abduction 15° (p<0.05) and V-sit with shoulder abduction 15° showed significantly greater muscle activation of the RA compared with shoulder abduction 0° (p<0.05). The muscle activity of both EO and IO in the V-sit with hip abduction 15° was significantly greater than hip abduction 0° in all shoulder conditions (p<0.05). Conclusions: Greater angles of shoulder and hip abduction produced more abdominal muscle activity increases during the V-sit exercises. Shoulder abduction affected the RA, EO muscle activation and hip abduction affected the EO, IO muscle activation. This study showed that shoulder and hip abduction during V-sit exercises enabled effective activation of the trunk muscles.

• Journal of The Korean Society of Integrative Medicine
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• v.7 no.4
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• pp.33-41
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• 2019

Purpose : The muscle strength of iliopsoas (IL) was measured commonly in sitting position with hip and knee flexed 90°. However, there is no study to determine the muscle strength of IL in various test positions. Therefore, the purpose of this study was to compare the muscle strength of IL and muscle activity of rectus femoris (RF) according to test position and knee flexion angle. Methods : Twenty healthy subjects were participated for this study. The muscle strength of IL and muscle activity of RF were measured by hand-held dynamometer and surface electromyography during maximum voluntary isometric contraction (MVIC) of IL, respectively. The muscle strength of IL and muscle activity of RF was measured in 4 conditions as follows; 1) knee flexion angles 90 ° in supine, 2) 130 ° in supine position, 3) 90 ° in sitting, 4) 130 ° in sitting. Each condition were performed randomly by three repetitions. Results : The muscle strength of the IL was the main effect on the test position and knee flexion angle (p<.05), and the muscle activity of RF was the main effect only on the knee flexion angle (p<.05). There was also no interaction between the factors (p>.05). In supine position, the muscle strength of IL in knee flexion 130 ° was significantly less than that in knee flexion 90 ° (p<.0125). In knee flexion 90 °, the muscle strength of IL in supine position was significantly greater than that in sitting position (p<.0125). The muscle activity of RF in knee flexion 130 ° was significantly less than that in knee flexion 90 ° in supine and sitting positions (p<.0125). Conclusion : When the muscle strength of IL was measured in clinic and sports fields, the supine position with knee flexion 130 ° was recommended to prevent the muscle activation of RF and to maintain the trunk stability.