• International Journal of Contents
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• v.5 no.4
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• pp.35-39
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• 2009

The purpose of this study was to evaluate the changes in skeletal muscle architecture and qualitative properties by muscle contraction force when neuromuscular electrical stimulation (NMES) of 50% MVIC was applied. Sixteen subjects (8 male, 8 female) without neuromuscular disease volunteered to participate in the study. All subjects were divided into two subgroups: control (no electrical stimulation) group and 50% maximal voluntary isometric contraction (MVIC) group. NMES training program was performed in the calf muscle three times a week for 10 weeks. Before and after the experiments, the MVIC of ankle plantar flexor was measured by the use of dynamometer, and the ultrasonography in the gastrocnemius medialis muscle was measured. The following results were obtained; MVIC was significantly increased in the electrical stimulation groups. Pennation angle, muscle density, and white area index also considerably changed in the electrical stimulation groups. In conclusion, the NMES training of 50% MVIC, comparative low level, improved the skeletal muscle architecture and the qualitative properties as well as the muscle contraction force.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.428-433
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• 2004

The aim of this study was to investigate the histochemical parameters of muscle fibers, and to estimate the correlation between these histological parameters and carcass traits in pigs. A total of 230 crossbred Duroc$\times$(Yorkshire$\times$Landrace) pigs (149 gilts and 81 castrated male pigs) was evaluated. Carcass traits (carcass weight, backfat thickness, and loin eye area), muscle fiber size (crosssectional area, diameter, and perimeter), muscle fiber number (density of fibers/$mm^2$ and total number of fibers), and fiber type composition (percentages of myofibers and relative areas of each fiber type) were evaluated. Mean cross-sectional area (CSA) and type IIB fiber CSA were positively correlated to carcass weight, backfat thickness and loin eye area. Mean fiber CSA was mostly related to type IIB CSA (r=0.98) as a result of the high percentage of type IIB fibers in the longissimus muscle. Correlations between fiber diameters and perimeters were also high, and showed similar results with CSA. Mean fiber density was negatively correlated to carcass weight (r=-0.24), backfat thickness (r=-0.18) and loin eye area (r=-0.27). To the contrary, total fiber number was positively correlated with carcass weight (r=0.27) and loin eye area (r=0.53). Carcass weight and loin eyZe area were not significantly related to muscle fiber composition. For backfat thickness, there was an opposition between type IIA percentage, which was positively related and type IIB percentage, which was negatively related. Fiber type composition of type I and IIA fibers were negatively correlated to that of type IIB fibers (r=-0.67 to -0.74). In the present study, carcass weight and loin eye area were positively correlated to CSA and negatively correlated to fiber density. But, these relationships were generally low. The fiber density was strongly affected by muscle fiber size and the total fiber number was affected either by CSA of muscle fiber and loin eye area. Fiber type composition was much more related to their numerical abundance than their CSA.

• The Journal of Korean Physical Therapy
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• v.18 no.1
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• pp.83-94
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• 2006

Purpose: This study conducts quantitative evaluation or structural and functional characteristics or normal skeletal muscle with ultrasound image and surface electromyography, and is to provide basic materials for utilizing ultrasound image analysis in physical therapy diagnosis and assessment of skeletal muscle. Methods: Measurement of three stages was conducted with 88 normal adults between their twenties and seventies, correlations and differences using collected data according to age and gender were compared and correlations among measured items were analyzed and then the following conclusions were obtained. Results: Analysis of ultrasound image of normal skeletal muscle showed that density, median frequency had the closest relations with age. In addition, it was found that there were high correlations between density explaining structural characteristics of skeletal muscle and median frequency explaining functional characteristics. Conclusion: Analysis of ultrasound image makes complex evaluation of structure and function of skeletal muscle possible when it is connected with functional evaluation method using physical measurement surface electromyography as well as quantitative evaluation of structural changes of skeletal muscle and is effective in complementing physical therapy diagnosis centering around functionality evaluation.

• Journal of Sericultural and Entomological Science
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• v.51 no.2
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• pp.123-129
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• 2013

The purpose of this study is to investigate the effects of supplementation of mulberry powder, mulberry extract and silkworm powder during the 8 weeks of resistance exercise on muscle increase of rats. Fifty males, Sprague-Dawley rat, were randomly divided into 5 groups: CON(control group, n = 10), REG(resistance exercise group, n = 10), MP REG(mulberry powder intake and resistance exercise group, n = 10), ME REG(mulberry extract intake and resistance exercise group, n = 10) and SP REG(silkworm powder intake and resistance exercise group, n = 10). After climbing the ladder without weights during the 1 week of adaptation period, the rats in the resistance exercise group were trained to climb a 0.98-m vertical(80 degree incline) ladder with weights in their tail during 7 weeks(10 times each day, 2 days per week). After exercise, the skeletal muscle was extracted from the flexor hallucis longus. The absolute weight of skeletal muscle was measured by the electronic balance and the relative weight of skeletal muscle about the weight was calculated. The strength and density of legs muscle were analyzed by the computed tomography scan. After 8 weeks of resistance exercise, the absolute weight of skeletal muscle wasn't significant, but it increased in MP REG 8%, ME REG 8% and SP REG 10% compared to REG. The relative weight of skeletal muscle increased significantly in SP REG compared to REG (p < 0.05). Additionally, there was a significant increase of density and strength of the forelegs in SP REG compared to CON (p < 0.05). However, there was no significant increase of density and strength of the hind legs. In conclusion, regular resistance exercise made rats muscle increase and there was more muscle increase effected by providing silkworm.

• Physical Therapy Korea
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• v.13 no.1
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• pp.47-53
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• 2006

Since ultrasound has different reflections depending on components of organization, analysis of ultrasound images of skeletal muscle can offer both quantitative and qualitative reports as concerns skeletal muscle structure. This study is focused on the ultrasound method for evaluating the structural characteristics of skeletal muscle and also conducted to examine its practicality. After obtaining images of the elbow flexors from an ultrasound image device with 88 normal subjects whose ages were between twenty and seventy years old (44 men and 44 women), muscular density and white area index (WAI) which indicated structural characteristics of skeletal muscle were analyzed with gray scale analysis. The study examined correlations between subject's age and items which obtained from measuring ultrasound images and the differences in relations to sex and age. Muscular density and WAI had a high correlation with age and were significantly increased in men and women with greater age. The quantitative evaluation method of skeletal muscle structure which analyzed the ultrasound images has high practicality because it is a non-invasive method which complements physical therapy diagnosis and research methods and promotes functionality evaluation.

• Journal of muscle and joint health
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• v.7 no.2
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• pp.294-308
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• 2000

This study was conducted to test the effect of brisk walking & muscle strengthening exercise program on bone mineral density(BMD) of the lumbar & femur in rheumatoid arthritis women. Research design was a quasi-experimental study of non-equivalent control group pretest-posttest design(16 weeks). 14 for the experimental group and 14 for the control group were selected from the outpatients on rheumatoid arthritis clinic of Dong-A University Hospital. The experimental group underwent 16 weeks of brisk walking and muscle strengthening exercise. Bone mineral density was measured before and after 16 weeks of exercise by DXA at lumbar spine, femoral neck, Ward's triangle and trochanter. The results were summarized as follows : 1. BMD of the lumbar spine in experimental group who carried out the brisk walking and muscle strengthening exercise was not significantly increased after 16weeks and there was no significant difference between experimental and control group(U=70.00 p>.05). 2. BMD of the femoral neck in the experimental group who carried out the brisk walking and muscle strengthening exercises was significantly increased after 16 weeks(Z=-2.901 p<.01). But, there was no significant difference between experimental and control group(U=83.00 p>.05). 3. BMD of the femoral Ward's triangle in the experimental group who carried out the brisk walking and muscle strengthening exercises was significantly increased after 16 weeks (Z=-2.355 p<.05). But, there was no significant difference between experimental and control group(U=86.00 p>.05). 4. BMD of the femoral trochanter in experimental group who carried out the brisk walking and muscle strengthening exercise was not significantly increased after 16weeks and there was no significant difference between experimental and control group(U=75.00 p>.05). These results suggest that brisk walking and muscle strengthening exercise program has an effect on promoting bone mineral density of femoral neck and Ward's triangle in rheumatoid arthritis women.

• Korean Journal of Radiology
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• v.22 no.4
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• pp.624-633
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• 2021

Objective: To evaluate the reliability of CT measurements of muscle quantity and quality using variable CT parameters. Materials and Methods: A phantom, simulating the L2-4 vertebral levels, was used for this study. CT images were repeatedly acquired with modulation of tube voltage, tube current, slice thickness, and the image reconstruction algorithm. Reference standard muscle compartments were obtained from the reference maps of the phantom. Cross-sectional area based on the Hounsfield unit (HU) thresholds of muscle and its components, and the mean density of the reference standard muscle compartment, were used to measure the muscle quantity and quality using different CT protocols. Signal-to-noise ratios (SNRs) were calculated in the images acquired with different settings. Results: The skeletal muscle area (threshold, -29 to 150 HU) was constant, regardless of the protocol, occupying at least 91.7% of the reference standard muscle compartment. Conversely, normal attenuation muscle area (30-150 HU) was not constant in the different protocols, varying between 59.7% and 81.7% of the reference standard muscle compartment. The mean density was lower than the target density stated by the manufacturer (45 HU) in all cases (range, 39.0-44.9 HU). The SNR decreased with low tube voltage, low tube current, and in sections with thin slices, whereas it increased when the iterative reconstruction algorithm was used. Conclusion: Measurement of muscle quantity using HU threshold was reliable, regardless of the CT protocol used. Conversely, the measurement of muscle quality using the mean density and narrow HU thresholds were inconsistent and inaccurate across different CT protocols. Therefore, further studies are warranted in future to determine the optimal CT protocols for reliable measurements of muscle quality.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.11 no.1
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• pp.21-29
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• 2013

Purpose : The purpose of this study was to determine the changes in ultrasound imaging of the lower limbs in patients with degenerative osteoarthritis who received a total knee replacement (TKR). Methods : The participants for the study were ten patients who were to receive a total knee replacement. Measurements were taken a total of three times: before receiving a total knee replacement, and one week and two weeks after receiving a total knee replacement. The vastus medialis, rectus femoris muscle, tibialis anterior and gastrocnemius muscle were measured using ultrasound imaging. Results : Muscle thickness of the vastus medialis, rectus femoris muscle, tibialis anterior and gastrocnemius muscle had no significant interaction over time whether surgery was performed or not. White area index (WAI) and density of vastus medialis, rectus femoris muscle, tibialis anterior and gastrocnemius muscle had no significant interaction over time whether surgery was performed or not. Conclusion : In conclusion, lower quality muscles were due to a decrease in muscle fiber and an increase in fat fiber. Therefore, initial physical therapy after total knee replacement should consider this point and be designed appropriately as a therapeutic approach for total knee replacement patients.

• The Journal of Korean Physical Therapy
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• v.6 no.1
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• pp.61-74
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• 1994

This study was carried out to determine effects of electrical stimulation on the soleus, target muscle of the sciatic newt, of white rat normal muscles. The biometric, histochemical, ultrastructural observations were made. The following results were obtained. A daily electrical stimulation of the skeletal muscle of the normally-functioning rat caused an increase of girth and weight of the muscle fibers for 2 weeks. No noticeable change was observed afterwards. More specifically, the density of volume of the red muscle fiber increased. whereas the density of the white muscle fiber decreased. The electrical stimulation group(experimental group) showed hypertrophy of the muscle fibers and narrowing of the space between perimysium and endomysium. Normally, glycogen granules are accumulated regardless of classification of muscle fibers. In addition, the NADH-TR reaction results were in agreement with the biometric findings, in that the red muscle fibers significantly increased. The ultrastructural observations revealed that mitochondria was formed in the red muscle fiber parallel to the muscle fibers of normal muscle, while mitochondria was observed in the sarcomere region of the white muscle fiber. However, activation of mitochondria took place in the sarcolemma region of the muscle fiber, and generation of mitochondria was observed in the sarcomere region of the white muscle fiber.

• The Journal of Korean Physical Therapy
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• v.19 no.2
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• pp.11-19
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• 2007

Purpose: The purpose of this study were to analyze ultrasonography on both sides of gastrocnemius medialis of stroke patient. Methods: In fourteen subjects with stroke, the gastrocnemius medialis(GM) muscle were scanned with ultrasonography at the muscle belly at rest at ankle angles of 0 degree (neutral position) and it were measured with ultrasonography on both sides of the leg. Muscle architecture (thickness, pennation angle, fascicle length, density, white area index) was examined using real-time B-mode ultrasonography with 7.5MHz linear-array prob. Results: Thickness of non-paratic side was significantly thicker than paratic side. Pennation angle of non-paratic side was significantly larger than paratic side. Fascicle length of non-para tic side was significantly smaller than paratic side. Density of non-paratic side was significantly smaller than paratic side. White area index of non-paranc side was significantly smaller than paratic side. Conclusion: This study showed that stroke have influenced on mechanical properties and quality properties of skeletal muscle architecture.