• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.29 no.1
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• pp.1-9
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• 2023

BACKGROUND: The purpose of this study was to find out which exercise is more effective for the activation of the trunk, when the suspension plank and modified bridge exercise are performed. Weakening of the trunk muscles can lead to secondary injuries such as back injuries. In order to prevent injury, trunk muscles must be strengthened, and representative trunk strengthening exercises include planks and bridges. Each has been developed with a modified method, but since there is no paper comparing which exercise is more effective for trunk muscle strength, it was written to compare the two exercises. METHODS: The subjects were a random sample of 30 healthy men who agreed to participate in the study. The subjects were divided into two groups of 15 people each, and the suspension plank and the modified bridge exercise were performed for six weeks. The thickness of the transverse abdominis (TrA), internal abdominal oblique (IO), external abdominal oblique (EO), rectus abdominis (RA), multifidus (MF) was measured before and after the exercise. The two groups were analyzed using an independent t-test and paired t-test to compare the muscle thickness and the difference before and after exercise. RESULTS: The trunk muscle thickness was increased in both groups with suspension plank and modified bridge exercise, and there was a statistically significant difference. When comparing the two groups, the suspension plank group also showed a significant difference in RA (p<.05). CONCLUSION: As a result of this study, suspension plank exercise can have a positive effect on activating the trunk muscles and strengthening the strength of RA. Therefore, it is considered that suspension plank exercise is a more effective intervention to strengthen trunk muscle than modified bridge exercise.

• Science of Emotion and Sensibility
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• v.24 no.4
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• pp.69-78
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• 2021

The development of smart healthcare wearables for health is accelerating. Among them, many wearable products using EMS electrical stimulation, which is one of the active research fields, have been released. However, the EMS wearable, which has been studied or released, is released in a comprehensive full-body suit that does not focus on muscle segmentation or a belt that covers the entire abdomen. Therefore, this study intends to use two breathing methods by applying an EMS pattern that subdivides specific muscles and attach a stretch sensor that can measure breathing to the abdominal pressure belt. The measurement method was conducted by inhaling and exhaling, and the subjects were 10 men in their 20s with healthy bodies. As a result of this study, the sensor's sensitivity was 5 and 3 mm, and the basic sensor in both thoracic and abdominal breathings and the EMS abdominal pressure belt showed improved respiration activation after applying electrical stimulation before and after application. It is concluded that, because of the two patterns produced based on the physical function, the difference in respiration activation effect and sensitivity between sensors could be confirmed with three sensors rather than not applying electrical stimulation suitable for the respiration method. Based on the results of this study, a follow-up study aims to develop breathing smart clothing that can be monitored in real time in clothing-type wearable products that incorporate EMS patterns and stretch sensors.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.4
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• pp.295-303
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• 2016

Rehabilitation of upper limb motor function of hemiplegic patient must maintain interest and demand a device for a quantitative evaluation of rehabilitation training. In this paper, we developed the device that is composed of arm cradle, handle, and balance ball for rehabilitation exercise. We have performed experiment for validity as to whether to use the rehabilitation device when tilting the upper extremity training device developed to measure changes in the EMG signal to the main upper limb muscles for 7 healthy volunteers. We have analyzed muscle activation signals on agonist and antagonist as a reference in the muscle contraction and relaxation in the upper limb extension and flexion when the balance-handle device is tilted to front-rear and left-right. The experimental results showed that a tendency of muscle activation of biceps, triceps, and deltoid used in upper limb motor function of hemiplegic patients from extension and flexion evaluation items of Fugl-Meyer Assessment(FMA). These results may be helpful for rehabilitation training for upper limb motor function of hemiplegic patients by utilizing a developed unit.

• Physical Therapy Korea
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• v.18 no.3
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• pp.1-7
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• 2011

The effects of an abdominal drawing-in maneuver (ADIM) using a pressure bio-feedback unit (PBFU) were compared to the effects of a pelvic belt (PB) on the muscle activities of the hip and back extensor muscles during hip extension in the prone position. Fifteen healthy male participants all performed prone hip extensions under three conditions: 1) preferred hip extension (PHE), 2) performing an ADIM, and 3) using a PB. The muscle activities of the erector spinae, the gluteus maximus, and the medial hamstring on the right side were recorded by surface electromyography. The muscle activity of the erector spinae was significantly lower while performing an ADIM during prone hip extension than during PHE or with a PB (p<.05). Gluteus maximus muscle activity was significantly higher while performing an ADIM (p<.05). No significant difference was found for the medial hamstring muscle among the three conditions (p>.05). We concluded that the internal stabilization of the pelvis and lumbar spine afforded by the ADIM using a PBFU could be more effective than the external stabilization provided by a PB in terms of increasing selectively gluteus maximus activation during prone hip extension.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.3
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• pp.405-412
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• 2010

Purpose : The purpose of this study was to assess the effects of the trunk muscle activity on bridging exercise according to the knee joint angle. Methods : Twenty-five healthy adults volunteered to participate in this study. Subjects were required to complete following four bridging exercises; knee joint flexion $120^{\circ}$, $90^{\circ}$, $60^{\circ}$, $45^{\circ}$. Surface electromyography from selected trunk muscles was normalized to maximum voluntary isometric contraction. Muscle activity was measured by QEMG-4 system(LXM 3204, Laxtha Korea). A repeated measures of one-way ANOVA with post-hoc Bonferroni's correction was used to determine the influence of bridging exercise on muscle activity for each muscle and descriptive statistics was used to determine local/global muscle ratio. Results : The internal oblique of bridging exercises $120^{\circ}$, $90^{\circ}$ showed significantly(p<.05). The erctor spinae of all bridging exercises showed significant excepted between $60^{\circ}$ and $45^{\circ}$(p<.05). Median of internal oblique/rectus abdominis ratio of $120^{\circ}$ was 4.41, $90^{\circ}$ was 3.94, $60^{\circ}$ was 3.58, $45^{\circ}$ was 3.39. Median of internal oblique/external oblique ratio of $120^{\circ}$ was 2.66, $90^{\circ}$ was 2.43, $60^{\circ}$ was 2.87, $45^{\circ}$ was 2.64. Conclusion : Angular motion decreasing with knee joint flexion made erector spinae activation increase. on the other hand, as decreasing abdomen muscle activation, the more performing motor learning is required for abdomen muscle strength and co-contraction for the trunk stabilization.

• The Korean Journal of Physiology
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• v.21 no.2
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• pp.191-200
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• 1987

The activation mechanism of the sustained contractions induced by norepinephrine and K-depolarization was studied in renal vascular muscle. Helical strips of arterial muscle were prepared from rabbit renal arteries. All experiments were performed in Tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept at $35^{\circ}C$. Renal arterial muscles developed a contracture rapidly when exposed to a 40 mM K-Tyrode solution. In the absence of external $Ca^{2+}$, however, no K-contracture appeared. The contracture induced by K-depolarization was abolished by the treatment with $Ca^{2+}-antagonist\;(verapamil)$ or lanthanum $(La^{3+})$. From these results, it is obvious that K-contracture of renal arterial strip required $Ca^{2+}$ in the medium and this contracture was developed by the increased $Ca^{2+}-influx$ due to K-depolarization. Noradrenaline (5 mg/l) induced also a similar sustained contraction rapidly in all strips. Even on the K-contracture and in $Ca^{2+}-free$ Tyrode solution and also in the Tyrode solution pretreated with verapamil or $La^{3+}$, noradrenaline produced a contraction. However, the contraction in $Ca^{2+}-free$ Tyrode solution was not sustained and decreased gradually. The amplitude of noradrenaline-induced contracture was dependent on external $Ca^{2+}$; The contracture increased dose-dependently, but over 3 mM $Ca^{2+}$, decreased. The results of this experiment suggest that K-contracture was developed by an increased $Ca^{2+}-influx$ due to membrane depolarization, while noradrenaline-induced contracture was developed by both transmembrane $Ca^{2+}-influx$ and the mobilizaiton of cellular $Ca^{2+}$

• Physical Therapy Korea
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• v.24 no.4
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• pp.60-67
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• 2017

Background: Scapular downward rotation syndrome (SDRS) is a common scapular alignment impairment that causes insufficient upward rotation and muscle imbalance, shortened levator scapulae (LS) and rhomboid, and lengthened serratus anterior (SA) and trapezius. A modified shrug exercise (MSE), performing a shrug exercise with the shoulders at $150^{\circ}$ abduction, is known as an effective exercise to increase scapular stabilizer muscle activation. Previous studies revealed that scapular exercise are more effective when combined with trunk stabilization exercises in decreasing scapular winging and increasing scapular stabilizer muscle activation. Objects: The purpose of our study was to clarify the effect of MSE with or without trunk stabilization exercises in subjects with SDRS. Methods: Eighteen volunteer subjects (male=10, female=8) with SDRS were recruited for this experiment. All subjects performed MSE under 3 different conditions: (1) MSE, (2) MSE with an abdominal draw-in maneuver (ADIM), and (3) MSE with an abdominal expansion maneuver (AEM). The muscle thickness of the lower trapezius (LT) and the SA were measured using an ultrasonography in each condition. Electromyography (EMG) data were collected from the LT, LS, SA, and upper trapezius (UT) muscle activities. Data were statistically analysed using one-way repeated analysis of variance at a significance level of .05. Results: The muscle thickness of the LT and the SA were the significant different in the MSE, MSE with ADIM (MSE+ADIM) and MSE with AEM (MSE+AEM) conditions (p<.05) In both LT and SA, the order of thick muscle thickness was MSE+AEM, MSE+ADIM, and MSE alone. No significant differences were found in the EMG activities of the SA, UT, LS, and LT in all condition. Conclusion: In conclusion, MSE is more beneficial to people with SDRS when combined with trunk stabilization exercises by increased thickness of scapular stabilizer muscles.

• Journal of the Korean Society of Physical Medicine
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• v.7 no.4
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• pp.541-550
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• 2012

PURPOSE: The purpose of this study was compare quadriceps femoris muscle activity while performing wall slide squats of four methods. METHODS: Forty subjects, with no history of patellofemoral pain, quadriceps injury, or other knee injury volunteered for this study. Muscle activation of the vastus medialis obliquus, rectus femoris, vastus lateralis muscles were recorded while subjects performed 10 consecutive wall slide squats. Subjects performed the wall slide squats during four different methods: (1) basic wall slide squat, (2) keep back upright against fitness ball, (3) standing of unstable surface, (4) squeezing ball between both knees. Statistical analysis were accomplished by utilizing the one-way ANOVA(Bonferroni's post-hoc test) by SPSS 20.0 program. Significance level was set at p<.05. RESULTS: Muscle activations induced wall slide squats of four methods compared and results showed that there was significant difference only in vastus medialis obliquus and rectus femoris but there was no significant difference in vastus lateralis. The vastus medialis obliquus was significantly different only keep back upright against fitness ball at post-hoc test. The rectus femoris was significantly different keep back upright against fitness ball and standing of unstable surface at post-hoc test. CONCLUSION: Based on these results, we conclude that quadriceps femoris muscle activations are differenced by performing wall slide squats of four different methods in healthy subjects. These data suggest that for quadriceps muscle strengthening, exercise professionals can perform the wall slide squats by altering several task variables. Further research is needed to determine the exact mechanism by which quadriceps function is altered.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.2
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• pp.119-125
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• 1999

Mammalian gastric smooth muscles generate spontaneous rhythmic contractions which are associated with slow oscillatory potentials (slow waves) and spike potentials. Spike potentials are blocked by organic $Ca^{2+}-antagonists,$ indicating that these result from the activation of L-type $Ca^{2+}-channel.$ However, the cellular mechanisms underlying the generation of slow wave remain unclear. Slow waves are insensitive to $Ca^{2+}-antagonists$ but are blocked by metabolic inhibitors or low temperature. Recently it has been suggested that Interstitial Cells of Cajal (ICC) serve as pacemaker cells and a slow wave reflects the coordinated behavior of both ICC and smooth muscle cells. Small segments of circular smooth muscle isolated from antrum of the guinea-pig stomach generated two types of electrical events; irregular small amplitude (1 to 7 mV) of transient depolarization and larger amplitude (20 to 30 mV) of slow depolarization (regenerative potential). Transient depolarization occurred irregularly and membrane depolarization increased their frequency. Regenerative potentials were generated rhythmically and appeared to result from summed transient depolarizations. Spike potentials, sensitive to nifedipine, were generated on the peaks of regenerative potentials. Depolarization of the membrane evoked regenerative potentials with long latencies (1 to 2 s). These potentials had long partial refractory periods (15 to 20 s). They were inhibited by low concentrations of caffeine, perhaps reflecting either depletion of $Ca^{2+}$ from SR or inhibition of InsP3 receptors, by buffering $Ca^{2+}$ to low levels with BAPTA or by depleting $Ca^{2+}$ from SR with CPA. They persisted in the presence of $Ca^{2+}-sensitive$ $Cl^--channel$ blockers, niflumic acid and DIDS or $Co^{2+},$ a non selective $Ca^{2+}-channel$ blocker. These results suggest that spontaneous activity of gastric smooth muscle results from $Ca^{2+}$ release from SR, followed by activation of $Ca^{2+}-dependent$ ion channels other than $Cl^-$ channels, with the release of $Ca^{2+}$ from SR being triggered by membrane depolarization.

• Journal of The Korean Society of Integrative Medicine
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• v.4 no.2
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• pp.29-36
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• 2016

Purpose : The purpose of this study was to find out the effects on muscle activations of serratus anterior and upper trapezius muscles when push-up plus exercise togu applied differently depending on the body part. Method : Thirty six volunteers took part in this study and we divided into three groups(upper arm togu group 12, leg togu group 12, upper arm-leg togu group 12). Each experimental group performed push-up plus exercise. All volunteers received a total of 18 exercise session over a 6 week period (three times per week). Exercise program was composed of serratus anterior and upper trapezius push-up plus exercise. Then we measured muscle activation of scapular stabilizer by electromyography. Repeated ANOVA was used to examine the effects of the intervention on each outcome measure. Result : After the six week intervention, there was a significant difference between the pre and 6 week in serratus anterior and upper trapezius muscle activity(p<0.05). After the six week intervention, there was a significant difference among the three group in serratus anterior muscle activity but no significant difference in upper trapezius muscle activity(p>.05). Conclusion : Serratus anterior and upper trapezius showed high muscle activity during push-up plus exercise. Therefore have a positive impact of scapular stabilizer. The larger the area of the unstable support surface, the larger muscle activity was larger of variation quantity.