• PNF and Movement
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• 제15권3호
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• pp.259-266
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• 2017

Purpose: This study aimed to compare muscle activities in the right leg during squatting on an angle-adjustable inclined wooden plate at three different angles. Methods: The subjects were 19 healthy adult men and women. An angle-adjustable inclined wooden plate was used for the experiment, and the subjects performed squatting at three adjusted angles of $0^{\circ}$ ankle angle, $10^{\circ}$ ankle flexion, and $10^{\circ}$ plantar flexion. Squatting was randomly performed without a sequence. The knee angle was set at $45^{\circ}$, and a goniometer was used to measure the angles accurately. Electromyography was employed to measure and compare muscle activity in the right leg in each condition. The measured data were converted to root mean square values to calculate the muscle activities. Results: This study showed no statistically significant difference at a $0^{\circ}$ ankle angle, but a statistically significant difference was found in the vastus medialis at $10^{\circ}$ of ankle flexion. Moreover, statistically significant differences were observed in the vastus medialis and lateralis at $10^{\circ}$ of plantar flexion. Conclusion: This study showed a statistically significant difference in the vastus medialis at $10^{\circ}$ of ankle flexion and statistically significant differences in the vastus medialis and lateralis at $10^{\circ}$ of plantar flexion. Therefore, it may be effective to perform squatting at $10^{\circ}$ of ankle flexion when intending to selectively strengthen the vastus medialis and at $10^{\circ}$ of plantar flexion when intending to strengthen both the vastus medialis and lateralis.