The Effects of Oral Contraceptive Use on Muscle Stiffness Across the Menstrual Cycle

作者：Bell David R^*; Blackburn J Troy; Ondrak Kristin S; Hackney Anthony C; Hudson Jeffrey D; Norcross Marc F; Padua Darin A

来源：Clinical Journal of Sport Medicine, 2011, 21(6): 467-473.

DOI：10.1097/JSM.0b013e318230f50a

• hormone
• estrogen
• menstrual cycle
• anterior cruciate ligament

Objective: To determine the effect of oral contraceptives (OC) on hamstring neuromechanics and lower extremity stiffness across the menstrual cycle (MC).
Design: Causal comparative.
Setting: Research laboratory.
Participants: Thirty, healthy, normally menstruating female volunteers who were using OC (OC group, n = 15) or not (non-OC group, n = 15).
Assessment of Risk Factors: Stiffness and hamstring neuromechanics were assessed at 2 points of the MC corresponding to low (menses) and high (ovulation) hormone concentrations. Menses testing took place 3 to 5 days after the onset of menses (or pills 3-5 for the OC group). Ovulation test session occurred 2 to 4 days after ovulation identified using a commercial ovulation kit (or pills 15-17 in the OC group).
Main Outcome Measures: Lower extremity stiffness and hamstring neuromechanics [stiffness, electromechanical delay, rate of force production (RFP), time to 50% peak force (T50%)] and blood plasma concentrations of estradiol-beta-17, free testosterone, and progesterone.
Results: Estradiol-beta-17, free testosterone, and progesterone increased at ovulation in the non-OC group and remained constant in the OC group. No changes were observed across the MC or between the groups in other variables (P > 0.05).
Conclusions: Although previous literature suggests a prophylactic effect of OC use with respect to musculoskeletal injury risk, our results indicate that OC use does not affect muscle properties in manners thought to reduce ACL injury risk.

• 出版日期2011-11