• Asian-Australasian Journal of Animal Sciences
• /
• v.30 no.2
• /
• pp.254-261
• /
• 2017

Objective: The effects of aging and freezing/thawing sequence on color, physicochemical, and enzymatic characteristics of two beef muscles (Mm. gluteus medius, GM and biceps femoris, BF) were evaluated. Methods: Beef muscles at 3 d postmortem were assigned to four different combinations of aging and freezing/thawing sequence as follows; aging at $2^{\circ}C$ for 3 wk (A3, never-frozen control), freezing at $-28^{\circ}C$ for 2 wk then thawing (F2, frozen/thawed-only), aging at $2^{\circ}C$ for 3 wk, freezing at $-28^{\circ}C$ for 2 wk then thawing (A3F2), and freezing at $-28^{\circ}C$ for 2 wk, thawing then further aging at $2^{\circ}C$ for 3 wk (F2A3). Results: No significant interactions between different aging/freezing/thawing treatments and muscle type on all measurements were found. Postmortem aging, regardless of aging/freezing/thawing sequence, had no impact on color stability of frozen/thawed beef muscles (p<0.05). F2A3 resulted in higher purge loss than F2 and A3F2 treatments (p<0.05). A3F2 and F2A3 treatments resulted in lower shear force of beef muscles compared to F2 (p<0.05). Although there was no significant difference in glutathione peroxidase (GSH-Px) activity, F2A3 had the highest ${\beta}-N-acetyl$ glucominidase (BNAG) activity in purge, but the lowest BNAG activity in muscle (p<0.05). GM muscle exhibited higher total color changes and purge loss, and lower GSH-Px activity than BF muscle. Conclusion: The results from this present study indicate that different combinations of aging/freezing/thawing sequence would result in considerable impacts on meat quality attributes, particularly thaw/purge loss and tenderness. Developing a novel freezing strategy combined with postmortem aging will be beneficial for the food/meat industry to maximize its positive impacts on tenderness, while minimizing thaw/purge loss of frozen/thawed meat.

• Korean Journal of Applied Biomechanics
• /
• v.15 no.1
• /
• pp.197-206
• /
• 2005

The purpose of this study was to quantify the maximum EMG levels and determine if there are differences in these EMG levels with respect to different knee flexion angles. Eight university students with no known musculoskeletal disorders were recruited as the participants. The maximum voluntary isometric knee extensions and flexions were taken from each participant sat on the isokinetic exercise machine (Cybex 340) at five different knee flexion angles ($10^{\circ}$, $30^{\circ}$, $50^{\circ}$, $70^{\circ}$, $90^{\circ}$) After surface electrodes were attached to rectus femoris, vastus medialis, vastus laterlis, biceps femoris, and semitendinosus, maximum EMG levels at five different knee flexion angles were measured. The results showed that there was no significant difference in maximum EMG levels among five different knee flexion angles. Although there was no significant difference in EMG levels and were some variations among different knee flexion angles, the EMG signals of quadriceps in extension and biceps femoris in flexion were the greatest at $30^{\circ}$. It seems that different joint angles or relative locations of body segments might affect the magnitude of EMG levels. Because the maximum EMG levels could change with a different knee flexion angle, an attempt should be made to more accurately measure these values. If then, %MVIC measure provides more reliable data and is most appropriate for EMG normalization.

• Korean Journal of Applied Biomechanics
• /
• v.13 no.3
• /
• pp.265-276
• /
• 2003

The objective of this research is to provide basic data for improving athletic performances, suggesting methods that can be utilized at games and coaching movements in the snatch, by analyzing the level of contribution of muscles to the movements of the snatch lift through three-dimensional imaging and EMG analysis between skilled and unskilled lifters. To this end, three high school students (the skilled group), three middle school student (the unskilled group) were selected; two digital video cameras and electromyography were used. The muscles measured by an EMG include gastrocnemius muscle, biceps femoris muscle, erector spinae, latissimus dorsi muscle, trapezius muscle, and brachioradialis. Based on the Ariel Performance Analysis System (APAS) program, the results of the analysis are summarized as follows. 1. In performing snatch pulls, the skilled lifters were found to simultaneously move the weight centers of the body and the barbell close to vertical, close to the shoulders in the pulling portion; in snatching and grabbing the barbell from a sited position, it was observed that the shorter the time for adjusting to change in the height of the barbell by using rotational inertia, the better it is to perform the movements. 2. The skilled lifters were observed to perform stable and efficient movements in grabbing the bar in a sited position, by moving the barbell and weight center of the body close to vertical and moving the shoulder joint under the bar fast. 3. The results of the EMG analysis of the entire movements from the snatching portion to the portion of grabbing the bar in a sited position show that when the skilled lifters lifted the barbell vertically during the pulling portion, their shoulder joints were extended to put more weight on biceps femoris muscle and brachioradialis; and in snatching and grabbing the bar from a sited position, it was found desirable to increase the myoelectrical activity of erector spinae in order to achieve a balance in the movements of the hip joint between font and rear, as the weight centers of the body and the barbell move higher. On the other hand, the unskilled lifters were found that in response to change in posture, they increase their muscular strength inefficiently in performing the movements throughout the entire lifting process.

• Journal of Korean Neurosurgical Society
• /
• v.61 no.4
• /
• pp.509-515
• /
• 2018

Objective : In Asians, kneeling and squatting are the postures that are most often induce common peroneal neuropathy. However, we could not identify a compatible compression site of the common peroneal nerve (CPN) during hyper-flexion of knees. To evaluate the course of the CPN at the popliteal area related with compressive neuropathy using magnetic resonance imaging (MRI) scans of healthy Koreans. Methods : 1.5-Tesla knee MRI scans were obtained from enrolled patients and were retrospectively reviewed. The normal populations were divided into two groups according to the anatomical course of the CPN. Type I included subjects with the CPN situated superficial to the lateral gastocnemius muscle (LGCM). Type II included subjects with the CPN between the short head of biceps femoris muscle (SHBFM) and the LGCM. We calculated the thickness of the SHBFM and posterior elongation of this muscle, and the LGCM at the level of femoral condyles. In type II, the length of popliteal tunnel where the CPN passes was measured. Results : The 93 normal subjects were included in this study. The CPN passed through the "popliteal tunnel" formed between the SHBFM and the LGCM in 36 subjects (38.7% type II). The thicknesses of SHBFM and posterior portions of this muscle were statistically significantly increased in type II subjects. The LGCM thickness was comparable in both groups. In 78.8% of the "popliteal tunnel", a length of 21 mm to <40 mm was measured. Conclusion : In Korean population, the course of the CPN through the "popliteal tunnel" was about 40%, which is higher than the Western results. This anatomical characteristic may be helpful for understanding the mechanism of the CPNe by posture.

• Clinics in Shoulder and Elbow
• /
• v.19 no.4
• /
• pp.223-228
• /
• 2016

Background: The aim of study was to confirm the clinical effectiveness and results of wide and single anterior approach for fractures occurring along length of humerus. Methods: A total of 23 patients with humeral fracture were enrolled into our study who were able to participate in at least one year of follow-up. Seven patients had segmental comminuted humeral fractures and 16 patients had distal humeral fractures. We made various tractions of the muscles to expose the proximal and the middle third humerus between the biceps and brachialis and the distal humerus by partial splitting of lateral side of biceps through a single incision. Postoperatively, we measured the Mayo elbow performance index (MEPI). Results: we achieved bone union in all 23 patients. Solid union of the bone was achieved at an average 13.9 weeks. Postoperatively, two complications were observed screw loosening and nonunion. Revision surgery was performed in both patients. The patient with bone nonunion was treated using bone grafts. No postoperative infections or peripheral neuropathies were observed. At the final follow-up (average 20 months), we found that the average MEPI functional score of the patients was 91.7 points regardless of the fracture site. Conclusions: Our whole humerus with a single incision was effective for the treatment of segmental comminuted and distal fractures. we believe it is a useful alternative to preexisting methods of fracture fixation.

• The Journal of Korean Orthopaedic Ultrasound Society
• /
• v.8 no.1
• /
• pp.21-25
• /
• 2015

Diagnosis of the long head tendon of biceps is not easy. and an ultrasonography is helpful at the office. We report a case who visited with the right shoulder pain and was diagnosed as a mass around the bicipital groove using the ultrasonography, finally undertook an arthroscopic resection. On the histologic examination, synovial lining cell were not found, the wall was thickened. He diagnosed as ganglion.

• Journal of Korean Physical Therapy Science
• /
• v.22 no.1
• /
• pp.43-48
• /
• 2015

Background : The purpose of this study was find out more effective method for improving muscle strengthening in lower extremities according squatting exercise method among knee joint angle 45, 60, 90 degree and between gym ball behind back and wall. Methods : Participants were 21 university students(males 10, females 11) who didn't have any problem with orthopedic surgery. We divided participants to two groups with gym ball group and wall group. Gym ball group were performance squatting exercise with gym ball behind back. Each group had performance squatting exercise according knee joint angle 45, 60, 90 degree. We collected data from E.M.G of Biceps femoris, Gastrocnemius, Vastus medialis and lateralis, Tibialis anterior in lower extremity according knee joint angle 45, 60, 90 degree of each groups. We analyzed data using by ANOVA and ANCOVA of SPSS PC ver. 12.0 in order to determine more effective method according various squatting exercise. Results : Each groups show significantly difference value of biceps femoris, vastus lateralis and medialis, tibialis anterior, gastrocnemius lateralis and medialis among knee joint angle 45, 60, 90 degree. But there was no significantly difference value between gym ball group and wall group according knee joint angle. Conclusions : We suggested that squatting exercise with gym ball was more effective method improving lower extremity muscle strengthening, and changing knee joint angle was more effective compared than continued knee joint angle.

• The Korean Journal of Physiology
• /
• v.24 no.1
• /
• pp.103-113
• /
• 1990

The role of cervical proprioceptors in the control of body posture was studied in bilaterally labyrinth-ectomized, decerebrate cats. The animals were suspended on hip pins with the neck extended horizontally. With this placement the EMG activities of extensor and flexor muscles of the upper extremities were observed by means of sinusoidal head rotator. The rotator can induce two kinds of neck movement: The one is 'pitch' which describes a rotatory neck motion to transverse axis of the body and mainly occurs at skull-C1 (atlantooccipital) joint and the other is 'roll', side-to-side relation of the neck to longitudinal axis, whose center is C1-C2 (atlanto-axial) joint. The following results were obtained. 1) Responses of EMG activity were closely dependent on the rotatory range of the neck. And the EMG activity was not changed during sustained neck torsion, eliciting a typical tonic neck reflex. 2) On pitching movement, the head-up rotation produced the excitation of bilateral triceps muscles, whereas the head-down rotation produced the inhibition. And the response of bilateral biceps muscles was the opposite to that of triceps. 3) On rolling movement, the side-up rotation of the head produced the excitation of ipsilateral triceps muscles and the inhibition of contralateral ones. And the response of biceps muscles was the opposite to that of triceps. 4) The minimum requirement of motion to evoke EMG activities in the upper extremities was $3.2^{\circ}{\sim}12.5^{\circ}$. These results have shown that the cervical proprioceptors produce tonic discharge on the upper brachial muscles, regulate the EMG activities of those muscles, and are very sensitive to neck rotation. And it can be stated that the cervical proprioceptors may play an important role in the control of body posture and movement.

• Journal of International Academy of Physical Therapy Research
• /
• v.4 no.2
• /
• pp.595-599
• /
• 2013

The purpose of this study is to identify the bridge exercise posture for the efficient exercise by comparing the muscle activity of the lower limbs according to the changes in muscle length because of knee angle in bridge exercise. The subjects of this study were 9 randomly selected males in their 20s living in D city from those who satisfied inclusion criteria. The measured muscles were Vastus medialis oblique, Vastus lateralis, Semitendinosus, Biceps femoris, Gluteus maximus, Gluteus medius, Tensor faciae latae, and Adductor longus. Data were analyzed through paired comparison test. In the result, ST, BF, and TFL muscle activities were high when knee joint flexion angle was $90^{\circ}$ Although in most cases higher muscle activity was shown at $90^{\circ}$ than $60^{\circ}$ there was no statistical significance. Interestingly, it was lower at $90^{\circ}$ than $60^{\circ}$ in VL. In ST, BF, and TFL, it was significantly higher at $90^{\circ}$ than $60^{\circ}$ (p<.05). Conclusively, knee angles in bridge exercise may affect the muscle activity, and in particular when the activity of two joint muscles such as semimenbranosus muscle, biceps femoris muscle, and tensor fasciae latae muscle increase as the angle gets higher. Therefore, it is considered that this study will provide helpful tips to develop muscular strength enforcement program for the patients with damages in the lower limbs through bridge exercise in clinical situations.

• Journal of Korean Academy of Nursing
• /
• v.18 no.1
• /
• pp.34-43
• /
• 1988

The present study has been undertaken to assess the electrical activity of right tibialis anterior, right gastrocnemius, right rectus femoris, right biceps femoris and right paralumbarvertebral muscles quantitatively by EMC while standing erect on the height of 0cm, 3cm, 5cm and 7cm heels. The inclinations of the heels were 0, 6, 11, 17 degrees, respectively. Foully young women ranging from 18 to 24 of age were examined. Electrical activity of various muscles while standing erect on the height of various heels were compared with that of 0cm heel. The results obtained were as follows : 1. Electrical activity of the tibialis anterior increased significantly as the height of heels became higher ; which was thought to be due to the effort to counteract the instability standing with high heels. 2. There was a significant increase in electrical activity of the gastrocnemius as the height of heels increased. It might be due to compensatory activity against shifting of the center of gravity forward. 3. There was a significant increase .in electrical activity of the rectus femoris and biceps femoris at the height of 3cm, 5cm and 7cm heels ; which seemed to be due to the effort to stabilize the knee joint. 4. Electrical activity of the paralumbarvertebral muscles increased significantly at the height of 5cm and 7cm heels ; which was considered to be due to the effort to prevent forward imbalance. From These results, it may be concluded that electrical activities of various postural muscles increase significantly while standing erect on the height of 3cm, 5cm and 7cm heels to counteract an instability of their posture and compensate the forward shifting tendency of the center of gravity.