• The Journal of Korean Physical Therapy
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• v.34 no.5
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• pp.267-271
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• 2022

Purpose: This study examined the effects of a kettlebell and aqua bag on the gluteus maximus, gluteus medius, and vastus medialis lower extremity muscle strength during a one-leg deadlift, a top-down exercise. Methods: Twenty healthy adults were enrolled in the one-leg deadlift exercise under two conditions. The muscle activity of the gluteus maximus, gluteus medius, and vastus medialis was measured by surface electromyography (S-EMG). A paired t-test was used for statistical analysis, and the statistical significance criteria were set to p<0.05. Results: A comparison of the muscle activity according to the degree of contraction of the gluteus maximus revealed low muscle activity in AD exercise compared to KD exercise (p<0.05), and there was no significant difference in the gluteus medius and vastus medialis (p<0.05). Conclusion: These results suggest that when the one-leg deadlift exercise is performed according to the weight characteristics, the gluteus maximus is suitable for intervention using a kettlebell, and the gluteus medius and vastus medialis are more suitable for intervention by providing instability using an aqua bag.

• Physical Therapy Korea
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• v.30 no.1
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• pp.8-14
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• 2023

Background: Excessive hamstring (HS) activation due to the weakness of the gluteus maximus (GM) causes pain in the hip joint. A single-leg deadlift is a hip extensor exercise, especially GM, that includes functional movements in daily life and complex multi-joint training. In single-leg deadlift, the muscle activity depends on the forward trunk lean angle, and it's necessary to study which muscles are used dominantly depending on the angle. Objects: The purpose of this study was to compare the effect on the muscle activity of the GM and HS during single-leg deadlift according to different forward trunk lean angles and the ratio of the GM vs HS (GM/HS). Methods: Twenty-one healthy female participants were recruited. The muscles activities of the GM, HS and the GM/HS ratio were measured through electromyography during single-leg deadlift according to three condition of forward trunk lean angles (30°, 60°, and 90°). Results: The GM and HS activities significantly differed among three conditions (p < 0.05). GM/HS ratio was significantly higher at 30° and 60° of forward trunk lean compared to 90°. Moreover, the GM activity was significantly higher at 60° of forward trunk lean than at 30° (p < 0.05). Conclusion: The single-leg deadlift at 60° of forward trunk lean is a proper GM muscle strengthening exercise.