• 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.

• Korean Journal of Applied Biomechanics
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• v.25 no.3
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• pp.353-361
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• 2015

Objective : The aim of this study was to develop the non-powered horse riding device and was to evaluate the elaborate its applicability throughout static structural and transient structural analysis of the outdoor core strength exercise equipment. Method : Fifteen college students (mass: $69.55{\pm}13.38kg$, height: $1.69{\pm}5.61m$, age: $21.42{\pm}1.83yrs$) rode the powered horse riding device and 14 college students (mass: $71.12{\pm}9.74kg$, height: $1.73{\pm}3.31m$, age: $22.50{\pm}1.47yrs$) rode the non-powered horse riding device for the comparison. All motion capture data was collected at 100 Hz using six infrared cameras and the muscular activities were collected using a Delsys Trigno wireless system. The peak forward/backward lean angle, range of motion anter/posterior and vertical COM(Center of mass) movement of trunk and pelvis segment, and muscle activities of six muscles were compared between the two devices by using independent t-test (p<.05). Results : Several kinematic variables (peak forward-backward lean angle and vertical COM movement of trunk and pelvis segment, range of motion of trunk) significantly different between non-powered and powered horse riding device. The muscle activities of Rectus abdominis and External oblique of abdomen on the non-powered horse riding device were significantly greater than those of the powered device. Conclusion : It was concluded that non-power horse riding device could give the effect of core strength exercise as well as the body motion which can simulate the powered horse riding device.

• Journal of muscle and joint health
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• v.21 no.2
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• pp.97-105
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• 2014

Purpose: The purpose of this study was to identify the effects of an aquatic exercise program on physical fitness, body composition, and gait characteristics using trunk and pelvic angle in women living in urban fringe area. Methods: An aquatic exercise program consists of exercise in a swimming pool and self-help group activity with 16 women living in urban fringe (mean age: 63 years) for 8 weeks (twice a week for 2 hours). Physical fitness, body composition, trunk and pelvic angle using 2D video motion analyzer, and a questionnaire including socio-demographic variables were measured from July to August, 2013. Data were analyzed using a paired t-test with the SPSS/WIN 18.0 program. Results: At the end of 8 weeks intervention, there were significant decreases on body weight (p=.025), body fat (p=.030) and BMI (p=.011). There were significant increases on muscle strength (p=.001) and flexibility (p=.015). Trunk angle was significantly improved, which means participants less moved their body from side to side when they walked (p=.001). Conclusion: From this results, the aquatic exercise program could be an effective nursing intervention to improve physical fitness, body composition, and gait ability for women living in urban fringe area.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.3
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• pp.91-98
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• 2023

Purpose : The purpose of this study was to investigate the effect of the posture holding band on muscle activity of the rectus femoris, medial vastus, and vastus lateralis muscles and weight distribution during squat exercise. Methods : This study was conducted with 30 healthy adult men and women in their 20s, and all subjects were randomly assigned to the experimental group and the control group. Squat exercise was performed for 6 weeks. The experimental group received squat exercise while wearing a posture holding band, and the control group applied without wearing a posture holding band. Muscle activity of the quadriceps femoris (rectus femoris, vastus medialis, and vastus lateralis) and weight distribution (knee flexion 0 °, 30 °, 60 °, and 90 °) was measured. Results : According to the results of this study, all three muscles showed a main effect on time and group, and a significant interaction was shown only in the vastus lateralis. In addition, the value of the weight distribution difference according to the knee flexion angle did not show a main effect according to time and group at 30 ° of knee flexion, but showed an interaction. Conclusion : It was confirmed that the application of the posture holding band during squat exercise increased the muscle activity of the quadriceps muscle, and showed greater changes in the vastus lateralis muscle. In addition, it was confirmed that the difference in weight distribution was reduced in the knee flexion, and in particular, a greater change was shown in reducing the difference in weight distribution in the knee flexion of 30 °. Therefore, it is considered that the effect of the exercise can be further enhanced if the unnecessary movement of the trunk is controlled by using equipment such as a posture holding band during squat exercise.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.9 no.2
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• pp.31-38
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• 2011

Purpose : The purpose of this study was to compare the effects of different supporting surfaces on trunk muscle activities during core stabilization exercises. Methods : A total of 20 healthy college students participated in this study for 6 weeks. In this study, we divided participants into a stable surface exercise group and an unstable surface exercise group. Each group performed core stabilization exercises of Curl-ups, Bridges, and Quadrupedal position. Core stabilization exercises were performed 3 times a week for 30 minutes during 6 weeks. The stable surface exercise group used a yoga mat while the unstable surface exercise group used AERO step. This study was designed using pre-test and post-test measurements. We used Surface Electromyograpy (sEMG) to measure for the rectus abdominis, external abdominal oblique, and multifidus muscle of trunk muscle activities. Data was processed using a paired sample t-test on SPSS 18.0. Results : For the stable surface exercise group there was a meaningful improvement in left rectus abdominis, left external abdominal oblique, and right multifidus (p<0.05). For the unstable surface exercise group, a meaningful improvement was seen in the left external abdominal oblique and right multifidus. Conclusion : From the experiment, we concluded that differences in surface can make various degrees of improvement in muscles activities, which suggests patients can choose a better option under their own conditions when planning to have a core stability exercise.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.19 no.2
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• pp.55-60
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• 2013

Background: The purpose of this study was to determine if there is a difference in activation of the rectus femoris, vastus medialis oblique, vastus lateralis, semitendinosus, and biceps femoris when performing normal free squat with standinding position and free squat with $30^{\circ}$ flexed hip joint. Methods: Electromyograph surface electrodes were placed on the rectus femoris, vastus medialis oblique, vastus lateralis, semitendinosus, and biceps femoris of 19 healthy college students. The participants performed standing bilateral squats and standing bilateral squats with $30^{\circ}$ flexed hip joint with EMG measures taken upon initiation of muscle activity as confirmed by an electronic goniometer. Participants completed one trial with the EMG time measurements on each type. Results: There was a significant difference between normal squats(standing squats) and normal squats with $30^{\circ}$ flexed hip joint. The normal squat exercise was statistically higer than normal squat exercise with $30^{\circ}$ flexed trunk except for semitendinosus and biceps femoris that shown slightly high. Conclusions: As a result of this study, there were increases of muscle activity in both ways. In particular, it may be more beneficial for knee joint stabilization to perform normal squat exercise with standing position relatively.

• Physical Therapy Korea
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• v.14 no.2
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• pp.21-28
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• 2007

The purpose of this study was to compare the onset times of muscle activities and the order of muscle firing in erector spinae, multifidus, rectus abdominis and biceps brachii during perturbation between subjects with and without work-related chronic low back pain (LBP). Twenty-nine subjects, 14 with and 15 without LBP, participated in this study. The muscle responses were measured by surface EMG (electromyography) during perturbation in eye opened and eye closed conditions. The EMG onset times of the erector spinae, multifidus, rectus abdominis and biceps brachii were similar between groups in eye closed condition. But the onset times of the erector spinae, multifidus, rectus abdominis were significantly delayed in subjects with LBP in eye opened condition. The results provide an evidence for impaired feed-forward control of the trunk muscles in subjects with LBP. Further studies are needed to identify whether the impaired feed-forward control of the trunk muscles is the contributing factor to LBP.

• Korean Journal of Applied Biomechanics
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• v.17 no.1
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• pp.111-119
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• 2007

The purpose of this study was to investigate muscle activity and gait pattern in lower limb depending on the outsole of heel rockers. Fifteen healthy men volunteered for this experiment. Each subject performed totally three trails with two pairs of different heel rocker shoes and a pair of normal running shoes at speed of 1.33m/s for 1 minute during walking on a treadmill. Kinematic data gathered in 100Hz was recorded and analyzed by using the 3D motion capture system to measure the trunk tilt and joint angle of the right lower limb. And the lower extremity muscle activities were simultaneously recorded in 1000Hz and assessed by using EMG. The statistical analysis was the one-way ANOVA with the repeated measures to compare among the three kinds of shoes. The level of statistical significance for all tests was 0.05. Joint angle of lower limb was showed statistically significant different in MST(hip joint), LHS(ankle joint), and RTO(knee and ankle joint). Muscle activity of rectus femoris and biceps femoris was statistically increased in both heel rocker shoes during gait cycle on treadmill. The maximum peak time of tibialis anterior in the negative heel rocker showed the delay of approximately 23.8%time than normal shoes. Gait pattern variability of the negative heel rocker was increased in the first half of the stance phase and the variability of the positive heel rocker was increased in the terminal stance phase. In Conclusion, stability was decreased in between joints of lower limb on positive heel rocker than negative heel rocker. This study found that there were different joint angle, muscle activity, gait pattern and coordinate system of the lower limb in each kind of shoes. These unstability affected the lower extremity and the whole body. A further study has to be continued with study of rehabilitation and exercise for a long-term.

• Physical Therapy Korea
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• v.24 no.1
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• pp.61-70
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• 2017

Background: Scapular winging is a prominence of the entire scapular medial border, mainly caused by insufficient activity of the serratus anterior (SA) and imbalance of scapulothoracic muscles. Push-up plus (PUP) exercise has been commonly used to increase SA muscle activity. The facilitation of abdominal muscle may affect scapular muscle activity by myofascial connections. Thus, the sequential activation of the turnk muscles is suggested to facilitate the transition of proper force from upper limb and restore force couple of scapular muscles. The abdominal drawing-in maneuver (ADIM) has been effective in improving activation of the deep trunk muscles during movement. Objects: The aim of this study was to determine the effect of ADIM on the activity of the upper trapezius (UT), lower trapezius (LT), and SA during PUP exercises in subjects with scapular winging. Methods: Fourteen men with scapular winging (determined as a of distance between the scapular medial border and thoracic wall over 3 cm) volunteered for our study. The subjects performed the PUP exercise with and without ADIM. Surface electromyography was used to collect the electromyography data of the UT, LT, and SA. A scapulometer was used to measure the amount of scapular winging. Results: SA activity was significantly greater and scapular winging significantly lower during the PUP exercise with ADIM than during those without ADIM. Conclusion: PUP exercise with ADIM can be used as an beneficial method to improve SA activation and to reduce the amount of scapular winging in subjects with scapular winging.

• The Journal of the Korea Contents Association
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• v.11 no.4
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• pp.235-243
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• 2011

The purpose of the study was to examine the thickness of the trunk muscles ie. external obliques (EO), transversus abdominis (TrA), and multifidus and the trunk endurance strength in order to determine any relationship between the presence or absence of low back pain (LBP) and the size of trunk muscles. Data were obtained from 50 subjects, aged between 19-29 years. Participants had no experience of spinal problems that had resulted in a restriction of normal activity or time-off work and no current spinal symptoms. Measurements of muscle thickness of the trunk muscles were collected at rest, contraction and 15 seconds of post contraction during endurance strength tests. Background information was obtained followed all physical measures. Subjects were divided into two groups based on their experience of LBP. In draw-in maneuver, increasing the thickness of TrA was observed in all participants while EO was decreased at contraction in group 1 and increase in group 2. Only subjects in the group 2 had TrA increased during the flexion endurance test. In the side-bridge endurance test, the thickness of the right TrA was also observed differently between groups. Therefore, the results of the study may suggest that a function of specific muscle should be addressed for training persons with LBP.