• 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 Physical Medicine
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• v.7 no.3
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• pp.339-348
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• 2012

Purpose : The purpose of this study is to compare muscle activations of neck, trunk and leg in cerebral palsy of spastic diplegia with genu recurvatum and knee flexion contracture, when using anterior and posterior walkers. Methods : We selected 21 cerebral palsy and received the written consent to participate in this study. The inclusion criteria for participation required patients to have spastic diplegic CP; to be between 3~6 years of age, to have a GMFCS III grade, to have no botulinum toxin injection and orthopedics surgery within before six months starting the study. Measurements of muscle activities (sternocleidomastoid, splenius capitis, rectus abdominis, erector spinea, gluteus maximus, rectus femoris, medial hamstring and calf muscles) were evaluated anterior and posterior walker ambulations. Statistical evaluation of these data were accomplished by utilizing the paired t-test and independent t-test by SPSS 20.0 program. Significance level was set at p<.05. Results : The following results were obtained. There was significant difference on muscle activation of neck, trunk and legs(soleus except) in anterior and posterior walkers. There was no significant difference in muscle activation of neck but significant difference in muscle activation of trunk, legs between genu recurvatum and knee flexion contracture(rectus abdominis, medial hamstring when using anterior walker, rectus abdominis, erector spinea, gluteus maximus, medial hamstring when using posterior walker). Conclusion : The conclusion of this study is the different knee joint forms would have different effect on muscle activation of trunk and legs while cerebral palsy of spastic diplegic ambulated with anterior walker and posterior walker.

• Physical Therapy Rehabilitation Science
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• v.10 no.1
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• pp.16-21
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• 2021

Objective: To control the rate at which body weight drops, forefoot initiates floor contact with the limb relatively extended at each joint. However, when the knee joints could not extend enough with going down the stairs, the forefoot cannot be contact initially. The purpose of this study was to investigate the differences between forefoot and whole foot in initial contract on soleus and tibialis anterior for health young adults when descending stairs. Design: A cross-sectional observational study design. Methods: Fifteen healthy young adults participated in this study. To compare between forefoot and whole foot in initial contact when going down the stairs, this study measured muscle activation on soleus and tibialis anterior. This study used the paired t-test to analyze the collected data and compare the supporting conditions. Results: After analyzing, the muscle activation of soleus was not statistically significant difference as 25.16% at forefoot initial contact and 24.37% at whole foot initial contact when descending stairs (p>0.05). However, the muscle activation of tibialis anterior muscle was significantly difference was 49.19% at forefoot contact and 71.55% at whole foot contact. Conclusions: The results of this study was that the muscle activation of the tibialis anterior was a higher at whole foot contact than that at fore foot contact when descending stairs. This study suggests that the landing strategy of the initial contact is a beneficial effect at the forefoot contact to maintain the postural balance and the muscle performance effectively when descending stairs in individuals with healthy young adults.

• PNF and Movement
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• v.7 no.3
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• pp.17-27
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• 2009

The purpose of this study was to investigate the effect of close kinetic chain(CKC) and open kinetic chain(OKC) posion on proprioceptive neuromuscular facilitation applied to the unilateral upper extremity on the muscle activation of lower extremity. All subjects were randomly assigned to two groups: open kinetic chain group(n=5),closed kinetic chain group(n=5). All participants were PNF patterns applied on the unilateral upper extremity in all subjects were the kinetic chain(CKC) and open kinetic chain(OKC) posion on flexion/abduction/external rotation. The hold and approximation techniques for the irradiation were applied to end range. All measurements for each subject took the following tests: pre-test, post - test in 4weeks, post-testin 8weeks. EMG data was collected from the vastus medialis, tibialis anterior, biceps femoris, and gastrocnemius muscle of both lower extreamity using surface EMG system, Each EMG value in individual muscle was normalized for maximal voluntary contraction. The data were analyzed using Two-way analysis of variance(ANOVA) with repeated measures to determine the statistical significances. The results of this study are summarized as follows. First, during for close kinetic chain(CKC) and open kinetic chain(OKC) posion on PNF pattern application, all of the %MVIC values of close kinetic chain and open kinetic chain posion increased sign ificantly compared(p<0.05). Second, The close kinetic chain(CKC) and open kinetic chain(OKC) posion on PNF pattern application was significantly increased with in the intervention period(p<.05). Third, there was a no significant open kinetic chain posion on PNF pattern application of sing muscle group with in the intervention period.(p<0.05) there was a significant close kinetic chain posion on PNF pattern application of sing muscle group with with in the intervention period(p<0.05). Forth, interaction of the exercise position and muscle was also significant. Post-hoc tests revealed that the activation levels of vastus medialis muscle and tibialis anterior muscle was higher in the closed kinetic chain position(p<.05). that the activation levels of vastus medialis and gastrocnemius muscle was higher in the open kinetic chain position(p<.05). In conclusion, it was found that the application of PNF patterns to the unilateral upper extremity effect on the muscle activation of lower extremity and both open kinetic chain exercise and closed kinetic chain exercise was significantly increased muscle activity. Further studies are needed to analyzed long term effects and subjects resulting from these changed.

• PNF and Movement
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• v.12 no.1
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• pp.39-43
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• 2014

Purpose: This study was to examine lateral abdominal muscle activation during maximum expiration exercise between healthy and chronic low back pain(CLBP) patients. Methods: The subjects were 16 CLBP patients and 16 healthy people between the ages of 22 and 53. The thickness of the abdominal muscles was measured using ultrasonography(LOGIQ Book XP, GE, USA). We instructed the subjects how to perform the exercises and measured changes in thickness of the transversus abdominis(TrA) and internal oblique(IO) muscles during the maximum expiration. The main outcome variables were the ratios of the TrA and IO thickness during the exercise versus in the relaxed position(TrA and IO activation ratios). Results: There were significant differences between CLBP patients and healthy subjects for TrA in the relaxed position. However there was no difference in the ratio of change in the muscle activity(TrA, IO). Conclusion: These findings, CLBP patients exhibited atrophy of the TrA muscle, but voluntary TrA muscle activation was similar to that of the normal subjects. Therefore, this exercise could be used during core strengthening in CLBP patients.

• Journal of The Korean Society of Integrative Medicine
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• v.6 no.4
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• pp.91-100
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• 2018

Purpose : The study investigated the effects of Pilates exercise on strengthening trunk muscles of females who perform such exercise for the purpose of comparing activation of trunk muscles that contact while performing Pilates motions between females with or without at least 8 weeks of Pilates experience. Methods : The study investigated 10 females with at least 8 weeks of Pilates experience in the past 6 months (experienced group) and 10 healthy females without Pilates experience (non-experienced group). The study used basic Pilates postures involving hip abduction, lift, and leg swing motions as the measurement postures in comparing the activation of muscles used for stabilization, such as the rectus abdominis, external oblique abdominal, and transverse abdominis & internal oblique abdominal muscles. Surface electromyography was used for measuring muscle activation, and the measurements targeted activation of the rectus abdominis, external oblique abdominal, transversus abdominis, and internal oblique abdominal muscles. Results : The study results showed that, as compared to the non-experienced group, the experienced group had significantly higher muscle activation in the transverse abdominis and internal oblique abdominal muscles during hip abduction (p<.05) and significantly higher muscle activation in the rectus abdominis, external oblique abdominal, and transverse abdominis & internal oblique abdominal muscles during lift and leg swing motions (p<.05). Conclusion : Pilates exercise performed over a long period can be recommended as an effective exercise method that can increase the activation of trunk muscle, and especially, repeated performance of highly difficult motions can increase muscle activation even more, which can help promote spinal stabilization, prevent pain, and improve performance of activities of daily living.

• Journal of Industrial Technology
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• v.28 no.A
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• pp.155-161
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• 2008

Muscle force prediction in forward dynamic analysis of human motion depends many muscle parameters associated with muscle actuation. This research studies the effects of various parameters of Hill type muscle model using the simple hand raising motion. Motion analysis is carried out using motion capture system, and each muscle force is recorded for comparison with muscle model generated muscle force. Using Hill type muscle model, muscle force for generating the same hand rasing motion was setup adjusting 5 activation parameters. The test showed the importance of activation parameters on the accurate generation of muscle force.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.1
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• pp.1-9
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• 2018

PURPOSE: This study investigated the neurophysiological and behavioral adaptation during one or both hands movement in chronic stroke patients. METHODS: The study included sixteen hemiplegic stroke patients. Neurophysiological data (brain activation and muscle activation) were examined by electroencephalography (EEG) and electromyography (EMG), and behavioral adaptation was examined by wrist extension angle during wrist extension with one hand or both hands. Outcome variables of one hand or both hands were; mu rhythm of the EEG, EMG amplitude of wrist extensor and flexor muscles, and wrist angle of Myomotion 3D motion analysis. RESULTS: Our results revealed that wrist extension angle was significant increased during both hands movement compared to one hand movement (p<.05). Furthermore, in affected sensorimotor area, there was significant increase in the brain activation during both hands movement compared to one hand movement (p<.05). However, there was no significant different between one hand and both hands movement in muscle activation (p>.05). CONCLUSION: According to the findings of this experiment, bilateral arm movement improved brain activity on affected sensorimotor area and wrist extension angle. Therefore, we suggest that bilateral arm movement would positive effect on stroke rehabilitation in terms of increase in brain activation on affected motor area and wrist extension during bilateral arm movement.

• Physical Therapy Korea
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• v.23 no.1
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• pp.80-86
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• 2016

Background: Prone hip extension (PHE) can be performed to measure the lumbopelvic motor patterns and motions. Imbalances in lumbopelvic muscle activity and muscle weakness can result in instability including pain in lumbopelvic region. The posterior oblique sling (POS) muscles contribute to dynamic lumbopelvic stability. In addition, POS are anatomically aligned with the trapezius muscle group according to shoulder positions. Objects: This study compared the electromyography (EMG) activity of POS and pelvic compensations during PHE with and without pre-activation of lower trapezius muscle (lowT). Methods: Sixteen healthy males were recruited. PHE was performed in randomized order: PHE with and without lowT pre-activation. Surface EMG signals were recorded for biceps femoris (BF), gluteus maximus (GM) (ipsilateral), lumbar multifidus (MF) (bilateral), and the lowT (contralateral). An electromagnetic tracking motion analysis was used to measure the angle of pelvic rotation and anterior tilting. Results: The ipsilateral GM and bilateral MF EMG amplitudes were greater during PHE with lowT pre-activation compared to PHE without lowT pre-activation (p<.05). The BF amplitude during PHE without lowT pre-activation was significantly greater than that during PHE with lowT pre-activation (p<.05). The angles of pelvic rotation and anterior tilting during PHE with lowT pre-activation were significantly smaller compared to PHE without lowT pre-activation (p<.05). Conclusion: PHE with lowT pre-activation, which is aligned with the POS, showed more increased MF and GM muscular activity with smaller lumbopelvic compensations in rotation and anterior tilting compared to PHE without lowT pre-activation.

• The Journal of Korean Physical Therapy
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• v.25 no.5
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• pp.316-321
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• 2013

Purpose: The aimed of this study was to investigate muscle activation related to postural stability according to different frequency of whole body vibration during quiet standing, to identify the most effective training conditions that cause the highest neuromuscular responses, and to evaluate the difference of EMG activation according to the anatomical position of the muscle - proximal or distal from the vibration platform. Methods: Eighteen healthy subjects voluntarily participated in this single-group, repeated-measures study in which EMG data from upper trapezius, rectus abdominalis, external oblique abdominalis, elector spinae, gluteus maximus, rectus femoris, semitendinosus, and gastrocnemius were collected over different frequencies (0-5-10-15-20-25Hz) for each subject during quiet standing. Results: We observed a statistically significant difference in the mean values of %RVC of muscular activation according to different frequencies of whole body vibration during quiet standing in all muscles (p<0.05). Conclusion: Our results indicate that lower frequencies of vibration result in low muscular activation, and higher frequencies elicit high muscular activation. However, the most effective training condition that caused the highest activation was 20 Hz. In addition, the proximally located lower extremity muscles (GCM, RF, ST, GM) showed higher activation than the distally located trunk and neck muscles (ES, EO, RA, UT) together with increasing frequency.