Search tips
Search criteria 


Logo of jathtrainLink to Publisher's site
J Athl Train. 1999 Apr-Jun; 34(2): 144–149.
PMCID: PMC1322903

Hormonal Changes Throughout the Menstrual Cycle and Increased Anterior Cruciate Ligament Laxity in Females

Ned A. Heitz, MS, CSCS,* Patricia A. Eisenman, PhD, Charles L. Beck, MD, and James A. Walker, PhD



To determine whether women experience significantly greater anterior cruciate ligament (ACL) laxity in conjunction with estrogen and progesterone surges during a normal 28- to 30-day menstrual cycle.

Design and Setting:

Serial estrogen and progesterone levels were measured via radioimmunoassay procedures to identify the follicular and luteal phases of a subject's menstrual cycle and to determine periods of peak hormonal surges. Concomitant ACL laxity measures were taken using a knee arthrometer. Hormone levels and ACL laxity were assessed on days 1, 10, 11, 12, 13, 20, 21, 22, and 23 of the menstrual cycle. Day 1 corresponds to the menstrual phase, when estrogen and progesterone levels are at their lowest. Days 10 through 13 correspond to peak estrogen surge (follicular phase), and days 20 through 23 correspond to peak progesterone surge (luteal phase).


Seven active females between the ages of 21 and 32 years with at least one apparently healthy knee (no known knee anomalies) volunteered for participation in this study. Each subject stated that she experienced a normal (28- to 30-day) menstrual cycle and was not currently taking any type of hormone therapy (eg, birth control medication).


Blood was drawn on days 1, 10, 11, 12, 13, 20, 21, 22, and 23 of each subject's menstrual cycle, and ACL laxity measurements were assessed immediately after the blood draws. Estrogen and progesterone levels were determined via radioimmunoassay procedures, and ACL laxity was determined using a knee arthrometer.


A within-subjects, repeated-measures analysis of variance was applied to determine the presence or absence of significant differences in ACL laxity values over the course of a subject's menstrual cycle. We found a significant difference in ACL laxity when comparing baseline levels of estrogen with peak levels of estrogen. A significant increase in ACL laxity was also noted when comparing baseline levels of progesterone with peak levels of progesterone.


ACL laxity increased significantly throughout the menstrual cycle when comparing baseline with peak levels of estrogen and progesterone.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.0M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Click on the image to see a larger version.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Beck JL, Wildermuth BP. The female athlete's knee. Clin Sports Med. 1985 Apr;4(2):345–366. [PubMed]
  • DeHaven KE, Lintner DM. Athletic injuries: comparison by age, sport, and gender. Am J Sports Med. 1986 May-Jun;14(3):218–224. [PubMed]
  • Johnson RJ. The anterior cruciate: a dilemma in sports medicine. Int J Sports Med. 1982 May;3(2):71–79. [PubMed]
  • Hutchinson MR, Ireland ML. Knee injuries in female athletes. Sports Med. 1995 Apr;19(4):288–302. [PubMed]
  • Liu SH, Al-Shaikh RA, Panossian V, Finerman GA, Lane JM. Estrogen affects the cellular metabolism of the anterior cruciate ligament. A potential explanation for female athletic injury. Am J Sports Med. 1997 Sep-Oct;25(5):704–709. [PubMed]
  • Liu SH, al-Shaikh R, Panossian V, Yang RS, Nelson SD, Soleiman N, Finerman GA, Lane JM. Primary immunolocalization of estrogen and progesterone target cells in the human anterior cruciate ligament. J Orthop Res. 1996 Jul;14(4):526–533. [PubMed]
  • Loumaye E, Depreester S, Donnez J, Thomas K. Immunoreactive relaxin surge in the peritoneal fluid of women during the midluteal phase. Fertil Steril. 1984 Dec;42(6):856–860. [PubMed]
  • Kolowich PA, Paulos LE, Rosenberg TD, Farnsworth S. Lateral release of the patella: indications and contraindications. Am J Sports Med. 1990 Jul-Aug;18(4):359–365. [PubMed]
  • MacLennan AH. The role of the hormone relaxin in human reproduction and pelvic girdle relaxation. Scand J Rheumatol Suppl. 1991;88:7–15. [PubMed]
  • Wojtys EM, Huston LJ, Lindenfeld TN, Hewett TE, Greenfield ML. Association between the menstrual cycle and anterior cruciate ligament injuries in female athletes. Am J Sports Med. 1998 Sep-Oct;26(5):614–619. [PubMed]
  • Daniel DM, Malcom LL, Losse G, Stone ML, Sachs R, Burks R. Instrumented measurement of anterior laxity of the knee. J Bone Joint Surg Am. 1985 Jun;67(5):720–726. [PubMed]
  • DeHaven KE, Lintner DM. Athletic injuries: comparison by age, sport, and gender. Am J Sports Med. 1986 May-Jun;14(3):218–224. [PubMed]
  • Markolf KL, Graff-Radford A, Amstutz HC. In vivo knee stability. A quantitative assessment using an instrumented clinical testing apparatus. J Bone Joint Surg Am. 1978 Jul;60(5):664–674. [PubMed]
  • Myrer JW, Schulthies SS, Fellingham GW. Relative and absolute reliability of the KT-2000 arthrometer for uninjured knees. Testing at 67, 89, 134, and 178 N and manual maximum forces. Am J Sports Med. 1996 Jan-Feb;24(1):104–108. [PubMed]

Articles from Journal of Athletic Training are provided here courtesy of National Athletic Trainers Association