• Asian-Australasian Journal of Animal Sciences
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• v.12 no.5
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• pp.788-793
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• 1999

To determine the interrelationship between thyroid status and the reparitioning action of clenbuterol (CLE) in broilers, two-week-old female chickens were fed diets containing an antithyroid substance, propylthiouracil (PTU, 0 or 0.3%), CLE (0 to 1 mg/kg), or both for 18 days in a $2{\times}2$ factorial design experiment. Muscle weights (breast muscle, gastrocnemius and peroneus longus) increased only in the normal chickens fed CLE. As absolute mass, protein of leg muscle quantitatively increased in the CLE-fed normal birds. In contrast, inhibition of the CLE-induced protein accretion, especially of peroneus longus, occurred in the PTU group. A quantitative increase in DNA was observed in leg muscles of the normal chickens, but no DNA response to CLE was shown in the PTU-treated chickens. The decreased RNA in leg muscles of the PTU group was more reduced by CLE feeding. Although not statistically significant, the reduced degradation rate of whole muscle protein in normal chickens fed CLE was not confirmed in the PTU-fed group. The present study, therefore, concluded that metabolic action of thyroid hormones was a prerequisite for the hypertrophic effect of ${\beta}$-agonist in broilers.

• Physical Therapy Korea
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• v.31 no.2
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• pp.114-122
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• 2024

Background: The peroneus longus (PL) and peroneus brevis (PB) function as the primary muscles of eversion, a movement closely associated with tibial external rotation for ankle mortise stability. Ankle motion and tibial rotation vary based on different ankle and knee positions. Objects: This study aimed to investigate the PL, PB, and biceps femoris (BF) muscle activation and eversion strength during side-lying isometric eversion exercise based on different ankle positions (neutral [N] and plantarflexion [PF]) and knee positions (90° flexion [KF] and extension [KE]). Methods: Thirty healthy adults with an Ankle Joint Functional Assessment Tool score of ≥ 22 were recruited (mean age = 24.8 ± 3.1 years). Maximal isometric eversion strength and submaximal muscle activation of the PL, PB and BF were measured during isometric eversion exercise in side-lying. A 2 × 2 repeated measures analysis of variance was performed to investigate differences in muscle activation and strength. Results: The PL and PB muscle activation showed significant main effects with the knee and ankle positions (p < 0.05); activation was greater in the KE and PF positions than in the KF and N positions. The BF muscle activation showed a significant interaction effect with knee and ankle positions, which was greater in knee extension and ankle plantarflexed (KEPF) position than in knee flexion and ankle plantarflexed (KFPF) position (p < 0.05). Eversion strength showed a significant main effect only in ankle position (p < 0.05) and was greater in the N position than in the PF position. Conclusion: The results of this study indicate that the KEPF position can be recommended to facilitate contraction of the PL and PB during side-lying eversion exercise. Furthermore, the effects of the knee-ankle positions should be considered for measuring ankle eversion strength and implementing the isometric submaximal side-lying eversion exercise.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.4
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• pp.391-397
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• 1998

The present study was conducted to examine the effects of dietary protein (20, 22, 24%) with a constant protein-to-energy ratio on clenbuterol-induced performance in broilers. The protein-to-energy ratio was based on adequate level (22% protein, 3,100 kcal of energy). Female broiler chickens were used for a $3{\times}2$ factorial arrangement and fed diets with or without 1 ppm clenbuterol from 14- to 32-days of age. Feed efficiency improved with increasing dietary protein level, regardless of clenbuterol treatment. The dietary clenbuterol increased weights of breast and leg muscles (gastrocnemius and peroneus longus), and clenbuterol markedly reduced protein content of leg muscles in chickens fed the 20% protein diet, but did not in chickens fed the 22 and 24% protein diets. Feeding the 24% protein diet with clenbuterol improved the protien accretion (peroneus longus) by 8.4%. Clenbuterol decreased DNA content and increased the protein/DNA ratio in breast muscle regardless of dietary protein intake. Clenbuterol had no effect on RNA content in both breast and leg muscles. The present results demonstrated that various protein levels which retain the same protein-to-energy ratio in the diet markedly alter the protein accretion induced by ${\beta}$-agonist in broilers.

• The Journal of Korean Physical Therapy
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• v.27 no.3
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• pp.159-163
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• 2015

Purpose: This study aimed to determine the interaction among the neck, trunk, and lower extremities on the non-paretic side in head rotation along with non-paretic-side weight shifting of stroke patients. To compare stroke patients' ability to control posture through muscle activity variation related to pertubation during head rotation along with the non-paretic limb. Methods: We tested 15 hemiplegic patients and 15 normal individuals. Each group's muscle activity was measured by electromyography in neutral head position and head rotation position. We compared each group's resu lt based on measured values in patients' non-paretic neck muscles, trunk muscles, and lower limbs muscles activation. Results: The study showed that muscle activity increased in the sternocleidomastoid muscle (102.26%, 53.00%), splenius capitis muscle (97.93%, 54.93%), erector spinae muscle (241.00%, 127.60%), external oblique abdominal muscle (256.66%, 152.00%), and internal oblique abdominal muscle (252.80%, 152.6%), peroneus longus muscle (117.53%, 137.13%) and gastrocnemius muscle (119.06%, 137.20%), while the results for the sternocleidomastoid muscle, splenius capitis muscle, erector spinae muscle, external oblique abdominal muscle, internal oblique abdominal muscle, peroneus longus muscle, and gastrocnemius muscle showed a statistically significant difference (p<0.05). Conclusion: It is hard for stroke patients to engage in normal movement control under suggested conditions because of the insufficient movement against gravity on the stroke patient's non-paretic side and impaired cooperative patterns. To solve these problems, patients need their bodies to improve through effective movement, resulting in advanced control of their effective and functional activity.

• PNF and Movement
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• v.19 no.2
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• pp.153-162
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• 2021

Purpose: The purpose of this study was to investigate the difference in the dynamic balance and leg muscle activity of adults in their 20s with or without shoes. Methods: In this study, seven male and 11 female university students in their 20s were randomized to determine the order of being with or without shoes, and the dominant foot was supported on the central platform of dynamic balance according to the order procedure. Using the opposite foot, the distance of leg stretching in the anterior, posterior medial, and posterior lateral directions and the muscle activity of the supporting leg were measured. Muscle activity measurement sites were attached to the dominant vastus medialis oblique muscle, vastus lateral oblique muscle, tibialis anterior muscle, peroneus longus muscle, and lateral gastrocnemius muscle. Results: As a result of this study, the distance of leg stretching was significantly increased in the anterior, posterior medial, and posterior lateral directions when barefoot rather than when wearing shoes (p < 0.05). The muscle activity of the vastus medial and lateral oblique muscles was significantly increased in all three directions when barefoot rather than when wearing shoes (p < 0.05). The muscle activity of the tibialis anterior was significantly increased in the anterior direction when barefoot (p < 0.05), the peroneus longus muscle was significantly increased when it was barefoot in the posterior medial direction (p < 0.05), and the lateral gastrocnemius muscle activity significantly increased when barefoot in the posterior direction (p < 0.05). Conclusion: The movement of the legs is freed when barefoot as compared to when wearing shoes, and being barefoot can effectively activate muscle activity and improve balance ability.

• Physical Therapy Korea
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• v.20 no.2
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• pp.1-10
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• 2013

The purpose of this study was to determine the effect of the changes that occur in the leg muscle activity of unstable surface with different levels of air pressures. Three groups of college students have been placed randomly on unstable surfaces with different air pressures at group 1.0 psi ($n_1$=36), group 1.4 psi ($n_2$=40), and group 1.8 psi ($n_3$=40). Using surface electromyography, the recruitment of the tibialis anterior, peroneus longus, and the gastrocnemius was measured. Maximal voluntary isometric contraction was measured at the different air pressures based on the manual muscle test, then normalizing the value to %maximal voluntary isometric contraction (%MVIC). The tibialis anterior muscle activity was significant change from the unstable surface with difference levels of air pressures between group 1.0 psi and 1.8 psi and between group 1.4 psi and 1.8 psi. peroneus longus muscle activity was significant changes in muscle activity occurred between 1.0 psi and 1.4 psi group and between 1.0 psi and 1.8 psi group. Gastrocnemius muscle activity was significant change in muscle activity occurred between 1.0 psi and 1.4 psi group and between 1.0 psi and 1.8 psi group. In conclusion it identify that 1.0 psi group is most effective on muscle activity than the other groups. These suggest that the rehabilitation or strengthening of patients with ankle injuries, balance exercise with low air pressure like 1.0 psi can be more effective.

• Journal of The Korean Society of Integrative Medicine
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• v.5 no.3
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• pp.57-61
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• 2017

Purpose : The purpose of study was to find out the environmental risk factor that can be easily occurred imbalance muscle activities according to direction for using the ramp during one legged standing. Method : The subjects were 20 normal adults with a mean age of $23.15{\pm}2.14years$ and a Body Mmass Index (BMI) of $22.74{\pm}1.07$. Participants were measured muscle activities on vastus medialis, vastus lateralis, tibialis anterior, peroneus longus during one legged stance at four conditions ramp (down ramp, up ramp, medial ramp, lateral ramp). The statistical analyses were performed using IBM SPSS(Ver. 23) and p-value less than .05 were considered statistically significant for all cases. Result : In this study, the activity of the lower extremity muscle and the ratio of the vastus medial and lateral muscles according to the direction of use of the ramp were investigated. The changes in the muscle activity of the lower limbs along the direction of the ramp were significantly different between the vastus medial muscle and the peroneus longus muscle. Conclusion : For a short time on a ramp or a pedestrian crossing, a clerk in a ramp can move or stand by placing the lower limbs in various directions, but if performed in consideration of the individual's disease characteristics or unstable foot position, It is thought that there will be an effect to prevent on the ankle and knee unstability.

• The Journal of Korean Physical Therapy
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• v.31 no.2
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• pp.129-133
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• 2019

Purpose: This study aimed to investigate effect of ankle instability on peripheral muscle activation among female ballet dancers to provide information on the development of prevention programs for ankle injury rehabilitation. Methods: 32 female ballet dancers were randomly divided into two groups: experience ankle sprain group (n=16, age, $20.7{\pm}0.8years$, BMI $18.6{\pm}1.2kg/m2$) and non-experience ankle sprain group (n=16, $age=21.0{\pm}0.8years$, BMI $19.6{\pm}2.0kg/m2$). Activation of the peroneus longus, tibialis anterior muscle, and gastrocnemius during vertical landing, half pointe, and gait between the two groups were measured. Body composition analyzer was used to examine skeletal muscle mass and body fat mass. Results: A total of 32 patients were included. In the experience ankle sprain group (n=16: left sprain 14, right sprain 2), average ankle sprain injury occurred 7.5 months before the study. The average age of the dancers in the experience ankle sprain group and non-experience ankle sprain group was $20.7{\pm}0.8$ and $21.0{\pm}0.8years$, major period was $64.5{\pm}23.8$ and $71.6{\pm}25.8months$, BMI was $18.6{\pm}1.2$ and $19.5{\pm}2.0kg/m2$, respectively. No significant differences were found on body composition between the two groups (p>0.05). The experience ankle sprain group showed significantly lower tibialis anterior and peroneus longus muscle activation (p<0.5), while gastrocnemius muscle activation appeared to be significantly higher (p<0.05) during landing, half pointe, and normal gait. Conclusion: Ankle sprain can cause a decline in peripheral muscle activation and coordination, which increased the risk for repetitive ankle sprain in the future. Moreover, ankle peripheral muscle selective strength training, coordination program development, and application need to be considered to prevent ankle sprain.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.4
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• pp.299-309
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• 2021

Purpose : The purpose of this study was to compare the ankle pronation squat with the general squat and investigate the effect on the geun varum and the muscles around the knee. Methods : Subjects were chosen as the target for squat exercise with the distance between the knees more than 5 cm. The selected 30 students were randomly divided into 15 pronation squat group and 15 general squat group, and performed five sets movements 20 times. Global postural system (GPS) and digital goniometer were used to check the distance between the knees and the Q angle, and muscle activity was measured with EMG during squat exercise. Results: The result is as follows. First, as a result of analyzing the change in the distance between the knees, the distance between the knees decreased and the Q angle increased in the pronation squat group after exercise. Second, as a result of analyzing the change in muscle activity of the peroneus longus, the muscle activity increased in the pronation squat group after exercise, and it was more effective than the general squat group. Third, as a result of analyzing the change in the VMO (vastus medialis oblique) and VL (vastus lateralis) muscle activity ratio, the activity ratio of the pronation squat group increased after exercise, and the imbalance in the VMO/VL muscle activity was decreased. Conclusion: The pronation squat exercise applied to the ankle will greatly affect what is made into a balanced leg as decreased of the distance between knees, increased of Q angle, increased of the muscle activity of the peroneus longus and the ratio of VMO/VL.

• Journal of the Korean Society of Physical Medicine
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• v.3 no.3
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• pp.151-160
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• 2008

Purpose : The purpose of this study is to know the muscle activation after sub-talar joint mobilition and active exercise, and the low leg muscle activity through the well-balanced interaction of ankle joint around muscle. Methods : For this study 61 experimental subjects are divided into 24 people of supination foot group, pronation foot group 17 people of, 20 people of control group through navicular drop test. Surface EMG was used in order to measure the muscle activities. following is the result of the data analysis about each experiment that has been carried on a week, 2 weeks, 3 weeks, 4 weeks before, and even comparing with pre-experimental state. Results : In electromyogram study, the higher muscle activation there was before the experiment, the more muscle activation increase there was after the experiment in Tibialis Anterior, Peroneus Longus, Peroneus Brevis.(p<.05). Conclusion : This study shows the balanced activation of foot and ankle-around muscle. It shows that foot shape affects the balanced activation recovery of lower leg muscles.