The difference effect of estrogen on muscle tone of medial and lateral thigh muscle during ovulation

The purpose of this study was to investigate the difference effect of estrogen on muscle tone of medial and lateral thigh muscle during ovulation (OV). Twenty-eight untrained eumenorrheic healthy women tested muscle stiffness and frequency of vastus medialis, vastus lateralis, semitendinosus, and biceps femoris during menstrual cycle (MC). MC were divided into menses (MS), OV, and luteal phase (LP). The muscle frequency of vastus medialis and semitendinosus were significant higher in OV (13.83 +/- 1.58 Hz, 15.62 +/- 2.39 Hz) than LP (13.18 +/- 0.85 Hz, 14.67 +/- 1.62 Hz). Also the muscle stiffness of vastus medialis and semitendino-sus were significant higher in OV (211.74 +/- 46.03 N/m, 241.95 +/- 48.35 N/m) than LP (184.26 +/- 26.09 N/m, 215.42 +/- 35.29 N/m). The present study showed the highest muscle stiffness and frequency at OV and this might be due to the rapid increase of sole hormone in estrogen. Especially, medial part of quadriceps and hamstrings might be influenced during the MC with high concentration of estrogen at OV.