Background: Choosing to perform squats on an unstable surface potentially offers advantages surpassing those of their stable counterpart. Objectives: The purpose of this study was to compare muscle activation during squats on stable and unstable surfaces and investigate the relationship among thigh muscles. Design: Observational study. Methods: Nineteen adults participated in this study. The stable surface consisted of a flat floor. The unstable surface involved the use of an air cushion. An air cushion was positioned beneath each foot of the study participants. Surface electromyography was employed to measure muscle activation. %MVC was calculated by measuring muscle activation during squat execution and manual muscle testing. Results: The comparison of muscle activation during squats between stable and unstable surfaces revealed a significant difference in the rectus femoris and biceps femoris (P<.05). On stable surfaces, positive correlations were observed in the rectus femoris, vastus lateralis, and vastus medialis (P<.05). On unstable surfaces, positive correlations were found between the rectus femoris and vastus medialis (P<.05). Conclusion: This study observed an increase in muscle activation of the rectus femoris and biceps femoris during squats on an unstable support surface compared to a stable support surface.

The objective of this study was to determine the effect of dietary oils on the levels of the γ-linolenic acid in chicken meat lipids. Three hundred ten five, 1-d old, male, Ross strain, broiler chicks were fed for 35 d to compare diets containing evening primrose oil(EPO) and hemp seed oil(HO) to a control diet. Fatty acid composition of lipid from chicken skin, thigh and breast muscle were determined at the end of the trial. The level of γ-linolenic acid of lipids from chicken meat fed diets containing EPO or HO was significantly higher than that of the control group(p〈0.05). The level of γ-linolenic acid of lipids from chicken skin was highest in the group, which had been fed the EPO 0.85%, followed in order by EPO 0.7%, 0.5%, EPO mixed oil, HO and HO mixed oil. There was a significant difference in the level of γ-linolenic acid of chicken skin between the control and treatment groups(p〈0.05). The level of γ-linolenic acid of lipids from chicken thigh muscle was also similar to skin, and significantly higher than that of the control group(p〈0.05). The level of γ-linolenic acid of lipids from chicken breast muscle was highest in the group, which had been fed the EPO 0.5%, followed in order by EPO 0.7%, 0.85%, HO 0.5% and HO mixed oil. There was a significant difference in the level of γ-linolenic acid of chicken breast muscle between the control and treatment groups(p〈0.05).

The purpose of this study was to compare the differences of hip and thigh muscle activities between subjects with increased and decreased femoral anteversion during stair ascent. Twelve healthy female volunteers participated in this study. The subjects were divided into two groups (group 1 with increased anteversion of the hip, group 2 with decreased anteversion of the hip). This study analyzed differences in each mean peak gluteus maximus (GM), gluteus medius (GD) and tensor fascia lata (TLF) EMG amplitude: composite mean peak hip muscles (GM, GD, TFL) EMG amplitude ratios and in each mean peak vastus medialis oblique (VMO), vastus lateralis (VL), biceps femoris (HM) and semitendinosus (HL) EMG amplitude: composite thigh muscles (VMO, VL, HM, HL) EMG amplitude ratios among subjects with decreased or increased relative femoral anteversion. EMG ratios were compared in the stance and swing phase of stair ascent. Group 1 showed an increased standardized mean GM and GD EMG amplitude and decreased standardized mean TFL to composite mean hip muscles EMG amplitude ratios in stair ascent during both stance and swing phase. Also, group 1 showed an increased standardized mean HL EMG amplitude and decreased standardized mean VL and HM to composite mean thigh muscles EMG amplitude ratios in stair ascent during both stance and swing phases. There was no statistically significant difference in vastus medialis oblique between subjects with increased or decreased relative femoral anteversion. In order to provide rehabilitation professionals with a clearer picture of the specific requirements of the stair climbing task, further research must be expanded to include a wider range of age groups that represent the general public, such as including middle-aged healthy persons.

우리나라는 태권도의 종주국임에도 불구하고 신체활동량과 그에 따른 에너지 소모량에 대한 기초연구가 미흡하며 이에 대한 연구가 시급한 상태이다. 본 연구에서는 센서(SenseWear® PRO2 Armband)를 이용하여 태권도의 신체활동 량을 획득하였고, Inbody 520을 통하여 체성분 데이터를 획득 하였으며, CT로 하체부위(허벅지)를 스캔하여 허벅지 근육면적 데이터를 추출하였다. 획득된 데이터를 이용하여 허벅지 둘레와 근육면적의 상관관계, 허벅지 근육면적과 분 당 에너지 소모량의 상관관계를 분석하였다. 분석결과 실험자 8명의 평균 허벅지 근육면적은 132.79 cm2 였으며, 무 릎뼈(Pattela) 위 20 cm의 평균 허벅지 전체 면적은 178.79 cm2이었다. 실험자들의 허벅지 둘레와 근육면적은 상관 관계가 있는 것으로 나타났다. 실험자들의 평균 분당 에너지 소모량은 6.94 칼로리였으며, 허벅지 근육면적과 평균 분 당 에너지 소모량도 상관관계가 있는 것으로 나타났다.

The objective of this study was undertaken to investigate changes in fatty acid profile of breast and thigh muscle of old laying hens as transferred from cage to backyard raising system and to provide basic information on using old laying hens to producers for environmental managements. Overall, percentages of unsaturated fatty acid obtained from breast and thigh muscle with cage and backyard raising system are the most abundant, followed by saturated fatty acid. For breast muscle, there were no differences (P>0.05) between cage rearing system and backyard raising system in saturated fatty acid (SFA) and mono unsaturated fatty acid (MUFA). Poly unsaturated fatty acid (PUFA) and PUFA:SFA ratios were significantly higher in backyard raising systems in comparison with cage rearing systems (P<0.05). No differences (P>0.05) were detected between both rearing systems for MUFA, PUFA, and PUFA:SFA ratios with thigh muscles. SFA in thigh muscle was significantly (P<0.05) higher in cage rearing systems compared with backyard raising systems. In conclusion, using breast and thigh muscle meats from old laying hens as functional foods or investigating impact assessment on the improvement of farm management system may serve as a good management practice to encourage producers.