• Journal of the Korean Society of Physical Medicine
• /
• v.11 no.2
• /
• pp.53-62
• /
• 2016

PURPOSE: The purpose of this study was to investigate the effects of a supplementary Ki-hap technique and verbal encouragement on the activation of abdominal muscles during performance of crunch exercise in healthy subjects. METHODS: 93 subjects were randomly allocated to three group, crunch exercise group (CG), crunch exercise with Ki-hap group (CKG), and crunch exercise with Ki-hap and verbal encouragement group (CKVG), with 31 subjects in each group, respectively. The interventions were conducted over three trials in each group, and measurements were performed on each subject by one examiner in three trials. The activation of rectus abdominis (RA), external oblique (EO), and internal oblique (IO) muscles were evaluated using electromyography (EMG) during performance of crunch exercise with non-Ki-hap, Ki-hap and Ki-hap combined with verbal encouragement. RESULTS: Our results showed a significantly greater increase in the EMG patterns of all muscles during performance of crunch exercise in the CKG (p<0.05) compared to the CG and CKVG. The results also showed that there were significantly greater increase in the activation of EO and IO muscles in those of the CKVG (p<0.05) compared with the CG. CONCLUSION: These findings demonstrated that addition of the Ki-hap technique and verbal encouragement during performance of crunch exercise, at the same time, would suggest positive evidence for improving activation of abdominal muscles.

• Journal of the Korea Safety Management & Science
• /
• v.11 no.3
• /
• pp.79-85
• /
• 2009

In this study, the effects of psychosocial stress (box color and precision demand) on muscle activity were evaluated in laboratory setting. Eight subjects performed sagittally symmetric lifting tasks. Box color (yellow, black), precision demand (yes, no), and box weight (5%MVC, 10%MVC, 15 %MVC) were varied and surface EMG signals from seven muscles(medial deltoid right, biceps brachii right, lateral triceps right, latissimus dorsi right, erector spinae right, external oblique right, internal oblique right) were recorded. EMG signals were band-pass filtered($10{\sim}400\;Hz$), rectified, RMS smoothed and normalized (NEMG). Analysis of variance tests were conducted on the total NEMG (TNEMG: the sum of the seven muscles' NEMGs) and on the individual muscle's NEMGs. Box color had no effect on the TNEMG and on the seven muscles activities(p>0.05). When precision demand was required at the end point of lifts, the mean NEMG showed higher values than no precision demand conditions: TNEMG (14% increase) and medial deltoid(40% increase), biceps brachii(10% increase), lateral triceps(26% increase), latissimus dorsi(25% increase) muscles. Those increases showed more conspicuous as the box weight increased in the muscles of medial deltoid, lateral triceps, and latissimus dorsi.

• Physical Therapy Korea
• /
• v.20 no.4
• /
• pp.16-21
• /
• 2013

The purpose of this study was to determine the effect of contralateral hip adduction (CHA) on the muscle activity of lumbar stabilizers and the angle of pelvic lateral tilting during hip abduction in side lying. Twenty healthy male subjects with no medical history of lower extremity or lumbar spine disorders were recruited for the study. Subjects randomly performed preferred hip abduction (PHA) and hip abduction with contralateral hip adduction in side lying. The muscle activities of the dominant side rectus abdominis, external oblique, internal oblique, quadratus lumborum, gluteus medius, and non-dominant side hip adductor longus were measured during PHA and CHA by using a surface electromyography (EMG) system. Pelvic lateral tilting motion was measured by using a three-dimensional motion analysis system. Data on EMG and pelvic motion were collected at the same time during PHA and CHA. A paired t-test was used to compare EMG activity and the angle of pelvic lateral tilting in the two exercises. The study found that the EMG activities of all muscles were more increased significantly in CHA than PHA condition. The angle of pelvic lateral tilting was more decreased significantly in CHA than PHA condition. These findings suggest that CHA could be recommended as a hip abduction exercise for activating lumbar stabilizers and decreasing compensatory pelvic lateral tilting motion.

• PNF and Movement
• /
• v.21 no.2
• /
• pp.243-253
• /
• 2023

Purpose: This study aimed to investigate the effects of an abdominal drawing-in maneuver (ADIM) with a light load while sitting on transverse abdominis contraction in subjects with and without low back pain. Methods: In this study, 20 participants with chronic low back pain and 20 controls participated. Ultrasonography was used to assess the thickness of the external oblique (EO), internal oblique (IO), and transversus abdominis (TrA) muscles. Muscle thickness was measured at rest and during ADIM in three different sitting postures: (1) just sitting, (2) sitting loaded position (holding a 1 or 2 kg dumbbell in each hand), and (3) sitting loaded shoulder flexion position (holding a 1 or 2 kg dumbbell in each hand). Results: The contraction ratio (CR) and preferential activation ratio (PAR) of the TrA during ADIM had no significant interactional effect between the group and the sitting postures. However, the CR and PRA of the TrA during the ADIM showed significant differences among the three different sitting postures. The CR of the TrA during the ADIM in the sitting loaded shoulder flexion position was significantly increased compared to that in the sitting position (p<0.05). Moreover, the PRA of the TrA muscle during ADIM in sitting loaded and sitting loaded shoulder flexion positions was significantly higher than that in the sitting position (p<0.05). Conclusion: The findings suggest that ADIM in the sitting-loaded shoulder flexion position should be implemented to facilitate TrA activity.

• Journal of The Korean Society of Integrative Medicine
• /
• v.10 no.4
• /
• pp.175-185
• /
• 2022

Purpose : This study was conducted to determine the effect of Kegel exercise using a pressure biofeedback unit (PBU) for 2 weeks on maximum voluntary ventilation (MVV) and abdominal muscle thickness based on previous studies. Methods : The subjects of this study were 20 healthy female students in their 20s. Subjects were randomly assigned to two groups. Eleven subjects were assigned to the experimental group (EG) and 9 subjects were assigned to the control group (CG). Subjects measured MVV with a spirometer. In hooklying position, transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) of the dominant side were measured using ultrasound. For the measurement value, the average value of three times was adopted. After 2 weeks of intervention, the measurements were measured in the same way. In the EG, pelvic setting training using PBU was performed before Kegel exercise. The PBU was first placed at the waist in the Kegel exercise position and the starting pressure was set at 40 mmHg and adjusted to 60 mmHg through pelvic floor muscle contraction. After performing pelvic control using PBU, Kegel exercise was performed with 8 seconds of contraction, 8 seconds of relaxation, and 3 sets of 10 reps per set. A significance level of 𝛼=.05 was used to verify statistical significance. Results : In the variable of MVV, a significant increase was confirmed in the EG (p<.05). In the abdominal muscle thickness variable, significant increases were confirmed in IO and TrA in the EG (p<.05). In addition, a significant increase in IO was confirmed in the CG (p<.05). Significant increases in IO and TrA were confirmed between groups (p<.05). Conclusion : Based on the previous study, this study confirmed that Kegel exercise using a PBU had a positive effect on MVV and abdominal muscle thickness based on a 2-week intervention.

• The Journal of the Korea Contents Association
• /
• v.9 no.12
• /
• pp.348-356
• /
• 2009

The purpose of this study was to examine the effect of bridging using Swiss ball, whole body vibration (WBV), and mat on trunk and lower extremity muscle activity and postural stability. The results were as follows: 1) EMG activity of internal oblique increased significantly in WBV condition compared with mat condition (p<.05). 2) EMG activity of rectus femoris and medial gastrocnemius increased significantly in Swiss ball condition and WBV condition compared with mat condition (p<.05). 3) The muscle activity of medial hamstrings increased significantly in Swiss ball condition compared with mat condition (p<.05). 4) The limit of stability in three groups increased significantly in all directions after 4-week intervention (p<.05). 5). There were no significant differences in the limit of stability among three groups after 4-week intervention (p>.05). Therefore the trunk and lower extremity muscle activity increased in Swiss ball and WBV conditions, and postural stability was improved in three groups after intervention period.

• Physical Therapy Korea
• /
• v.19 no.3
• /
• pp.11-19
• /
• 2012

This study aimed to investigate whether isometric lower limb exercise can activate contralateral trunk muscles and whether the magnitude of muscle activation is related to lower limb movement in sitting. This study included 25 healthy young subjects (20 males and 5 females). The magnitude of trunk muscle activation was measured using surface electromyography (EMG) during hip flexion, extension, adduction, and abduction, and a significant difference was observed in the activation levels of trunk muscles among the tests (p<.01). The EMG activity of the multifidus (MF) and erector spinae (ES) muscles on the contralateral side were significantly greater during hip extension. However, the activation levels of the contralateral internal oblique (IO) and rectus abdominis (RA) muscles were greatest during hip flexion. The MF : ES EMG ratio was significantly greater during hip isometric during hip isometric flexion and abduction compared to hip extension and adduction. There was no significantly difference in the IO : RA ratio during the isometric contractions toward different directions. These findings indicate that isometric lower limb exercise can elicit trunk muscle contraction on the contralateral side and may therefore be helped for developing contralateral trunk muscle strength in individuals undergoing rehabilitation.

• Physical Therapy Korea
• /
• v.22 no.1
• /
• pp.37-48
• /
• 2015

This study aimed to investigate the effect of the abdominal drawing-in maneuver (ADIM) and abdominal expansion maneuver (AEM) on trunk stabilization, as well as trunk muscle activities and differences in quadruple visual analogue scale, Korean Oswestry Disability Index, and Fear Avoidance Beliefs Questionnaire scores, in patients with chronic low back pain and lumbar spine instability. To increase intra-abdominal pressure during the trunk stabilization exercise, the technique of pushing the abdomen out using diaphragmatic abdominal breathing suggested by Pavel Koral was used, which we termed the AEM. Fifty patients who tested positive on more than three of the five lumbar spine instability tests were separated from 138 patients with chronic low back pain of these patients, 16 were placed in the control group (trunk stabilization exercise), 17 were placed in the ADIM group (trunk stabilization exercise with ADIM), and 17 were placed in the AEM group (trunk stabilization exercise with AEM). Each group participated in the study for 30 minutes three times weekly for 4 weeks. Surface electromyography was used to measure the trunk muscle activities during the kneeling forward and supine bridging positions, and one-way repeated analysis of variance was used to determine the statistical significance of the trunk muscle activities in the rectus abdominis, internal oblique (IO), erector spinae, and multifidus (MF) muscles. The ADIM and AEM groups showed relatively larger improvements in psychosocial and functional disability level than control group. There were significant changes among the three groups, those from the measured values of the AEM group was significantly higher than the other two groups in changes in IO and MF trunk muscle activities (p<.05). This finding demonstrates that trunk stabilization exercises with AEM is more effective than ADIM for increasing trunk deep muscle activity of chronic low back pain patients with lumbar spine instability.

• Physical Therapy Korea
• /
• v.22 no.1
• /
• pp.93-102
• /
• 2015

Prolonged sitting can contribute to low back pain. The lumbar taping can be applied to correct the sitting posture. This study aimed to investigate the effect of lumbar taping on lumbar kinematics and the muscle activities of multifidus (MF) and internal oblique in the individuals with nonspecific chronic low back pain (NSCLBP) as they type for 30 minutes. Nineteen subjects with NSCLBP (9 people in non taping group and 10 people in taping group) were recruited. Lumbar taping was applied to the taping group before typing. Both groups started typing in a neutral sitting position with their feet on the floor. The change of posture and S2 posterior tilting (S2P) were measured to investigate kinematic data. Three sensors were attached on T12, L3, and S2 to identify the change of posture. Surface electromyography was used to measure the muscle activities. Palpation meter was used to standardize the angle of pelvic tilt in sagittal plane before typing. All instruments were used to measure each data before and after typing. Independent t-test was used to compare the changing values of lumbar kinematics and muscle activities before and after typing between both groups. The changing values of S2P and change of posture of L3 and S2 were significantly smaller in the taping group compared to the non taping group (p<.05). The changing value of muscle activities of MF between before and after typing was significantly smaller in the taping group compared to the non taping group (p<.05). In conclusion, the lumbar taping during the 30-minute typing task can be applied to maintain correct sitting posture in the lumbar and pelvis and to maintain activation of MF.

• Physical Therapy Rehabilitation Science
• /
• v.4 no.1
• /
• pp.11-16
• /
• 2015

Objective: Prone bridge exercise is one of the core strengthening exercise for improving abdominal, lower and upper extremity muscles. In addition, coactivation of the trunk muscles and extremities is important for treatment of low back pain. This study aimed to investigate the correlation between the thickness, cross-sectional area of the target muscle, and endurance during prone bridge exercise. Our hypothesis was that an increase in muscle thickness is positively related to the hold time for the static prone bridge exercise. Design: Cross-sectional study. Methods: Fourteen healthy university students (8 men and 6 women) voluntarily participated in the study at Sahmyook University. Hold time for the prone bridge with one and both legs was measured. The resting and contracted thickness of the lateral abdominal, rectus femoris, and triceps muscles was measured using rehabilitative ultrasound imaging. The correlation between muscle thickness and endurance for maintenance time was evaluated. Results: The prone bridge with both legs and the contraction thickness of the triceps muscle showed a positive correlation (r=0.692, p<0.05); the prone bridge with one leg and the contraction thickness of the internal oblique and transversus abdominis muscles showed a positive correlation (r=0.545, 0.574, p<0.05, 0.05, respectively). Conclusions: Endurance for the prone bridge exercise with a stable support surface is correlated with the contraction thickness of arm muscles; the prone bridge exercise with an unstable support surface is correlated with the contraction thickness of the deep abdominal muscles.