J Korean Phys Ther.  2023 Apr;35(2):53-57. 10.18857/jkpt.2023.35.2.53.

Comparison of the Changes in the Activation of the Quadriceps Muscle based on the Plantar Flexion Degree of the Ankle Joint in Healthy Young Females during the Stand-to-Sit movement

• Son SM

• KMID: 2552709
• DOI: http://doi.org/10.18857/jkpt.2023.35.2.53

Abstract

Purpose
The purpose of this study was to compare the changes in the muscle activation of the quadriceps muscle (rectus femoris, vastus lateralis, vastus medialis) during the stand-to-sit (StandTS) movement according to the plantar flexion angle of the ankle joint.
Methods
A total of 22 healthy young females participated in this study. During the StandTS under the three conditions (plantarflexion angle 0°, 20°, and 45° of the ankle), electromyography (EMG) data (% maximum voluntary iso¬metric contraction) of the rectus femoris, vastus lateralis, and vastus medialis were recorded using a wireless surface EMG system.
Results
There was a significant difference in the muscle activation of rectus femoris, vastus lateralis, and vastus medialis according to the plantar flexion angle (0°, 20°, and 45°) of the ankle. The muscle activation of the quadriceps was the highest at a 45° angle of plantarflexion and the lowest at 0°. One-way repeated ANOVA was used to analyze the muscle activation data of the lower extremity muscles according to the angle of the ankle joint.
Conclusion
Based on the results of our study, it was confirmed that the muscle activity of the quadriceps can be increased even in the StandTS movement, which involves the eccentric contraction of the quadriceps muscle. This suggests that maintaining a plantar flexion posture for a long time, say by wearing high-heeled shoes, can quickly cause muscle fatigue in the lower-limb muscles, which can cause a decrease in balance ability leading to falls.

Keyword

Stand-to-sit; Plantar flexion; Quadriceps; Muscle Activation