Abstract：
INTRODUCTION:The significant sex disparity in sports-related knee injuries may be due to underlying differences in motor control. Although the development of sex-specific movement patterns is likely multifactorial, this study specifically focuses on the potential modulatory role of sex hormones. PURPOSE:This study aimed to investigate the muscle stretch reflex (MSR) across the menstrual cycle. We hypothesized that the MSR would fluctuate throughout the menstrual cycle and that the lowest response would correspond with peak concentrations of estrogen. METHODS:Nineteen healthy women age 18-35 yr participated in this study: 8 eumenorrheic women and 11 women taking oral contraceptives. Serum estradiol and progesterone concentrations, anterior knee laxity (AKL), and the MSR response of the quadriceps muscles were measured three times during the menstrual cycle. RESULTS:The MSR response of the rectus femoris (RF) varied significantly across the menstrual cycle in both groups. Specifically, the RF MSR response was 2.4 times lower during the periovulatory phase when compared with the luteal phase (P = 0.007). The same trend was seen in the vastus medialis, but this did not reach statistical significance (P = 0.070). The MSR response of the vastus lateralis did not change significantly across the menstrual cycle (P = 0.494). A mixed model comparison did not show an association between endogenous concentrations of estradiol and progesterone, exposure to hormonal contraceptives or AKL, and the MSR response for any muscle. CONCLUSIONS:Our results demonstrate that the RF MSR response varies throughout the menstrual cycle with the lowest response around the time of ovulation. Additional research is needed to clarify the exact relationship between sex hormones, AKL, and MSR response and to determine the specific origin of the change along the monosynaptic reflex arc.
journal_name
Med Sci Sports Exercjournal_title
Medicine and science in sports and exerciseauthors
Casey E,Hameed F,Dhaher YYdoi
10.1249/MSS.0000000000000134subject
Has Abstractpub_date
2014-03-01 00:00:00pages
600-9issue
3eissn
0195-9131issn
1530-0315journal_volume
46pub_type
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journal_title：Medicine and science in sports and exercise
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doi：10.1249/01.MSS.0000069553.47739.36
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journal_title：Medicine and science in sports and exercise
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journal_title：Medicine and science in sports and exercise
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更新日期：1985-02-01 00:00:00
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journal_title：Medicine and science in sports and exercise
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更新日期：1993-10-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 临床试验,杂志文章,随机对照试验
doi：
更新日期：1992-11-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 临床试验,杂志文章,随机对照试验
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更新日期：2011-04-01 00:00:00
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doi：10.1097/00005768-200107000-00010
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journal_title：Medicine and science in sports and exercise
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doi：
更新日期：1984-12-01 00:00:00
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pub_type： 临床试验,杂志文章
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journal_title：Medicine and science in sports and exercise
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更新日期：1995-09-01 00:00:00
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更新日期：1995-03-01 00:00:00
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更新日期：1984-08-01 00:00:00
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journal_title：Medicine and science in sports and exercise
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journal_title：Medicine and science in sports and exercise
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更新日期：1992-09-01 00:00:00
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journal_title：Medicine and science in sports and exercise
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更新日期：2004-02-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 杂志文章
doi：
更新日期：1994-07-01 00:00:00
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journal_title：Medicine and science in sports and exercise
pub_type： 临床试验,杂志文章
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更新日期：2000-06-01 00:00:00
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更新日期：2006-01-01 00:00:00
