• Physical Therapy Korea
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• v.16 no.4
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• pp.16-22
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• 2009

The purpose of this study was to investigate the trunk and lower extremity muscle activity induced by three different intensity conditions (intensity 1, 3, 5) of whole body vibration (WBV) during bridging exercise. Surface electromyography (EMG) was used to measure trunk and lower extremity muscles activity. Eleven healthy young subjects (6 males, 5 females) were recruited from university students. The collected EMG data were normalized using reference contraction (no vibration during bridging) and expressed as a percentage of reference voluntary contraction. To analyze the differences in EMG data, the repeated one-way analysis of variance was used. A Bonferroni's correction was used for multiple comparisons. The study showed that EMG activity of the rectus abdominis, external oblique, internal oblique, erector spinae and rectus femoris muscles was not significantly different among three intensity conditions of WBV during bridging exercise (p>.05). However, there were significantly increased EMG activity of the medial hamstring muscle (p=.001) and medial gastrocnemius muscle (p=.027) in the intensity 3 condition compared with the intensity 1 condition. This result can be interpreted that vibration was absorbed through the distal muscles, plantar flexor and knee flexor.

• Physical Therapy Korea
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• v.17 no.4
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• pp.1-7
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• 2010

The aim of this study was to investigate the effects of lumbar stabilization on both trunk and lower limb muscle activity and center of pressure (COP) in single leg standing. Surface electromyography (EMG) was used to collect muscle activity data, the mean velocity of COP was measured using a force plate, and a pressure biofeedback unit was used for lumbar stabilization training. The findings of this study are summarized as follows: 1) The EMG activity of the erector spinae decreased significantly and the activity of the rectus abdominis, internal oblique, external oblique, gluteus maximus, and gluteus medius increased significantly with lumbar stabilization single leg standing. 2) No differences in activity in the tibialis anterior, medial gastrocnemius, rectus femoris, and medial hamstrings were found with single leg standing. 3) The mean velocity of COP in the antero-posterior and medio-lateral directions in the lumbar stabilization single leg standing decreased significantly compared with the preferred single leg standing. The findings of this study therefore indicate that lumbar stabilization can facilitate the co-activation of deep stabilization and global muscles that improve postural control capability during single leg standing.

• PNF and Movement
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• v.16 no.1
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• pp.151-159
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• 2018

Purpose: The aim of this study was to examine the activation of the contralateral upper and lower extremities and trunk muscle during ipsilateral upper extremity diagonal isokinetic exercise. Methods: Twenty-one healthy male subjects with no history of shoulder injury undertook ipsilateral diagonal isokinetic exercise at 60, 120, and $180^{\circ}/sec$, utilizing a standard Biodex protocol. Muscle activation amplitudes were measured in the upper trapezius, pectoralis major, biceps brachii, rectus abdominis, external oblique, rectus femoris, adductor longus, and biceps femoris muscles using electromyography. A one-way analysis of variance and paired t-tests were conducted, and the data were analyzed using SPSS, version 21.0. Results: The results revealed no statistically significant interaction between motion and angular velocity and no statistically significant contralateral muscle activation according to angular velocity (p>0.05). However, they revealed statistically significant contralateral muscle activation according to motion (p<0.05). Conclusion: These results suggest that the movements involved in contralateral upper extremity diagonal isokinetic exercise can enhance muscle strength in patients affected by stroke, fracture, burns, or arthritis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.522-525
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• 2005

The purpose of this study was to analyze the pattern of muscle usage during swing motion with a soft golf club in comparison with that with a normal golf club. The subjects were normal healthy young adults. The subjects performed swing motion using normal and soft golf clubs in turn. Then, we compared and analyzed the muscular activities for the two cases. The muscular activities of the subject was measured using MP100(BIOPAC Systems, Inc.). For the analysis of muscular activities, we measured EMG(Electromyography) of the subjects during swing motion. The muscles analyzed were deltoid, latissimus dorsi, external oblique, and rectus abdominis of the upper limbs and rectus femoris, biceps femoris, gastrocnemius, and soleus of the lower limbs. The result of the experiment showed that the pattern of muscle usage with soft golf club was similar to that with a normal golf club but the muscular activities with the soft golf was smaller than that with the normal golf club.

• PNF and Movement
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• v.18 no.3
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• pp.315-321
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• 2020

Purpose: Recent studies have indicated that applying different inclination angles and suspension devices could be a useful way of performing exercises that include the co-activation of the trunk muscles. Present study was to examine the influences of changes in the inclination angle during trunk muscle activity while engaging in a bridge exercise with a suspension device. Methods: 18 healthy, physically active male volunteers completed three trunk inclination angles (15°, 30°, and 45°) for bridge exercise variations. The surface electromyography responses of the rectus abdominis, internal oblique (IO), erector spinae (ES), and rectus femoris (RF), as well as the subjective difficulty (Borg RPE score), were investigated during these bridge exercises. Results: The bridge with a 45° inclination angle suspension significantly increased the muscular activities of the RA and RF and increased the Borg RPE scores (p<0.05). The bridge with a 15° suspension significantly elevated the ES activities when compared to the other conditions. Conclusion: The present study demonstrated that a higher inclination angle could not activate the overall trunk muscles during the bridge exercise. The RA and RF produced greater activation during the bridge exercise with the higher inclination angle. On the other hand, the activities of the erector spine were greater during the bridge exercise with the lower inclination angle. The present study suggests that applying a low trunk inclination angle for the supine bridge exercise is suitable for activating the erector spine muscles.

• The Journal of Korean Physical Therapy
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• v.34 no.4
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• pp.175-180
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• 2022

Purpose: Leg length discrepancy causes the posture deformation, gait asymmetry, and lower back pain. The purpose of this study is to investigate the correlation among functional leg length discrepancy (FLLD), muscle activity, muscle contraction onset time and vertical ground reaction force (vGRF) during simple lifting task. Methods: Thirty-nine subjects participated in this study. FLLD was measured from the umbilicus to medial malleolus of left and right leg using a tape. The subjects performed to lift a 10 kg box from the floor to chest. The muscle activity and muscle contraction onset time of rectus abdominis, erector spinae and rectus femoris was measured using EMG system and vGRF was measured by two force plate. Pearson correlation was used to fine out the correlation among FDDL, muscle activity, muscle contraction onset time and vGRF during simple lifting task. Results: Correlation between FLLD and difference of muscle activity of short-long side was very high (r>0.9) during simple lifting task. Correlation between FLLD and difference of muscle contraction onset time of short-long side was very high (r>0.9) during simple lifting task. And correlation between FLLD and difference of vGRF of short-long side was high (r>0.7) during simple lifting task. Conclusion: This study suggests that there is high correlation between FLLD and muscle activity, muscle contraction onset time, and ground reaction force during simple lifting task. Therefore, FLLD could negatively affect the postural balance.

• Proceedings of the ESK Conference
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• 1996.10a
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• pp.21-25
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• 1996

The Electomyographic (EMG) signals of flexor-extensor muscle pairs were investigated to identify the neural excitation pattern of low-back pain (LBP) patients during a repetitive bending motion. New parameters and EMG normalization technique were developed to quantitatively represent the difference of temporal EMG patterns between ten healthy subjects and ten LBP patients. Flexor-extensor muscle pairs such as rectus abdominis(RA)-erector spinae (ES at LS), external oblique(EO)-internal oblique(IO), rectus femois (quadriceps: QUD)-biceps femoris(hamstrings:HAM), and tibialis anterior(TA)-gastrocnemius(GAS) pairs of muscles were selected in this study. Results indicated that the temporal EMG pattern such as the peak timing difference of QUD-HAM muscle pair and the duration of coexcitation of ES-RA muscle pair showed a statistically isgnificant difference between healthy subjects and LBP patients. These results indicated that the new technique and parameters could be used as a diagnostic tool especially for LBP patients with soft tissue injuries that are rarely dentified by traditional imaging techniques such as X-ray, CT scan or MRI. Improtantly, the new EMG technique did not require the maximal volutary contraction(MVC) measure for normalization that helped patients minimize the pain experience during and after the session. Further study needs to be made to validate and refine this method for clinical application.

• Archives of Plastic Surgery
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• v.50 no.2
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• pp.153-155
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• 2023

The vascular anatomy of the deep inferior epigastric artery perforator (DIEP) flap has been well studied in the planning for autologous breast reconstruction. Preoperative imaging with computed tomography angiography (CTA) provides accurate assessment of this vascular anatomy, which varies widely across patients. Several papers to date have described their encounter with an anomalous "epiperitoneal" or "peritoneo-cutaneous" perforator during flap harvest, a perforator that pierces the posterior rectus sheath from a peritoneal origin, to traverse rectus abdominis and supply the DIEP flap integument. In the course of over 3,000 CTA assessments of the vascular anatomy of the abdominal wall, we have encountered dominant peritoneo-cutaneous perforators in 1% of cases, and smaller perforators seen in many more cases, approaching 5% of cases. With increasing sensitivity of imaging, we also describe a unique case of multiple large bilateral peritoneo-cutaneous perforators, and present these findings in the context of DIEP flap harvest. It is critical to recognize these peritoneo-cutaneous perforators preoperatively to avoid mistaking them for a DIEP during the raising of a DIEP flap. The routine use of preoperative CTA enables the safe identification of individual vascular anatomy, including significant peritoneo-cutaneous perforators.

• Physical Therapy Korea
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• v.16 no.1
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• pp.1-9
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• 2009

An abdominal drawing-in maneuver (ADIM) with a pressure biofeedback unit can be used to prevent excessive lumbar lordosis during bridging exercise. Therefore, in this research, the effects of an ADIM on lumbar lordosis and lower extremity muscle activity during bridging exercise were investigated in thirty healthy adults. Surface electromyography (EMG) and VICON system were used to collect kinematic data and muscle activity, respectively. A paired t-test was used to determine a statistical significance. The results showed as follows: (1) When performing bridging exercise with an ADIM, the height of the anterior superior iliac spine and greater trochanter decreased significantly (p<.05). (2) When performing bridging exercise with an ADIM, the trunk extension angle and pelvic angle increased significantly (p<.05). (3) When performing bridging exercise with an ADIM, the EMG signal amplitude increased significantly in the rectus abdominis, internal oblique abdominis, external oblique abdominis, medial hamstring, and lateral hamstring (p<.05). (4) When performing bridging exercise with an ADIM, the EMG signal amplitude decreased significantly in the erector spinae (p<.05). From the result of this research, an ADIM trained with pressure biofeedback unit during bridging exercise is effective to prevent excessive contraction of erector spinae, to limit excessive motion of pelvis from sagittal plane and to increase muscle activity of abdominal muscles and hamstring muscle.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.3
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• pp.13-20
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• 2019

PURPOSE: Sitting with crossed legs may have an effect on maintaining a healthy body posture and proper functioning of the respiratory system. Thus, this study's objective was to identify whether or not sitting with crossed legs affects the vertebral angle, chest wall mobility, the pulmonary function, and the activity of the respiratory muscles. METHODS: Thirty healthy subjects were recruited for this study (16 males and 14 females). The vertebral angle, chest wall mobility, pulmonary function, and the activity of the respiratory muscle were measured while the subjects sat in the correct posture and these factors were again measured with the subjects seated with their legs crossed. Three-dimensional motion analysis was used to determine the trunk and lumbar vertebral angles. Surface electromyography was employed to measure the sternocleidomastoid, the rectus abdominis, and the external and internal oblique abdominis muscles. A tapeline was utilized to evaluate the subjects' chest wall mobility. Spirometry was assessed to determine the forced vital capacity and forced expiratory volume in one second. Paired t-tests were then performed (p<.05). RESULTS: There were significant differences in the trunk and lumbar flexion angles, the chest wall mobility, the activity of the right external oblique muscle, and the left internal oblique abdominis muscle. However, the difference in pulmonary function did not reach statistical significance. CONCLUSION: A crossed leg posture caused slight thoracic extension and lumbar flexion, which may lead to a decrease of the chest wall mobility and also to an imbalance of the abdominal muscles. Therefore, sitting with a crossed leg posture should be avoided. Yet a crossed leg posture did not have any clinical effect on the pulmonary function of healthy people. It may be necessary to study the effects of sitting with crossed legs over an extended period of time for patients suffering with impaired respiratory function.