Effects of the menstrual cycle on Achilles tendon properties in women

Effects of Menstrual Cycle Phases on Plantar Flexor Neuromechanical Properties and Achilles Tendon Mechanical Properties of Eumenorrheic Women and Hormonal Contraception Users

Observational Federal University of Rio Grande do Sul · NCT06214442

This study looks at how different phases of the menstrual cycle affect the strength and flexibility of the Achilles tendon in women.

Quick facts

Study typeObservational
Enrollment40 (estimated)
Ages18 Years to 30 Years
SexFemale
SponsorFederal University of Rio Grande do Sul Academic / other
Locations1 site (Porto Alegre)
Trial IDNCT06214442 on ClinicalTrials.gov

What this trial studies

This observational study investigates how the menstrual cycle influences the mechanical properties of the Achilles tendon in women. It focuses on the variations in estrogen and progesterone levels throughout the cycle and their potential effects on tendon structure and function. Participants will be evaluated based on their menstrual cycle phases, with specific inclusion criteria for eumenorrheic women and those using hormonal contraception. The study aims to enhance understanding of how hormonal fluctuations may impact physical performance and tendon health.

Who should consider this trial

Good fit: Ideal candidates include eumenorrheic women aged 18-35 with a regular menstrual cycle and normal ankle function.

Not a fit: Patients who have irregular menstrual cycles, use hormonal contraception, or have a history of lower limb injuries may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide insights into optimizing physical performance and injury prevention strategies for women based on their menstrual cycle.

How similar studies have performed: While there have been studies exploring hormonal effects on tendon properties, this specific focus on the menstrual cycle's impact on the Achilles tendon is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Inclusion criteria for the group of eumenorrheic women

  * Being eumenorrheic with a regular menstrual cycle lasting between 21 and 35 days during the last 6 months prior to study participation.
  * Body Mass Index between 20 and 25 kg/m2.
  * Normal ankle function and range of motion.
  * Do not use hormonal contraception of any kind or supplements hormones for at least the 6 months prior to the study.
  * No complaints of pain or history of lower limb injury.
  * In view of the COVID-19 pandemic, have completed vaccination will be used as an inclusion criteria.
  * For the physically active group, practice regular physical exercise at least 3 times a week for the past 6 months.
  * For the sedentary group, not practicing regular physical exercise in the last 6 months.

Inclusion criteria for the group users of hormonal oral contraception:

* Body Mass Index between 20 and 25 kg/m2.
* Normal ankle function and range of motion.
* Make use of any method of oral hormonal contraception (compressed).
* Make use of combined oral hormonal contraception with estrogen and progesterone (ethinylestradiol + Drospirenone) for at least 6 months before participating in the study.
* Do not use other hormone supplements for at least 6 months prior to the study.
* No complaints of pain or presence of pathologies in the lower limb
* In view of the COVID-19 pandemic, have completed vaccination will be used as an inclusion criteria.
* For the physically active group, practice regular physical exercise at least 3 times a week for the past 6 months.
* For the sedentary group, not practicing regular physical exercise in the last 6 months

Exclusion Criteria:

Exclusion Criteria for eumenorrheic and contraception hormonal groups:

Health problems - contraindication to maximal effort exercise. Additionally, the following subjects will be excluded:

* Women who have anovulatory cycles or phase lutea deficiency.
* Women in early menopause.
* Pregnant or lactating women.
* Women with oligomenorrhea (menstrual cycles longer than 35 days, or delay of menstruation for the same period).
* Women with hypothalamic amenorrhea.
* Female smokers.
* Women with metabolic syndrome.
* For women using hormonal contraceptives, women who use adhesive, injectable, intrauterine devices, implants, vaginal rings, as well as progesterone-only CH methods.
* Does not meet the inclusion criteria.

Where this trial is running

Porto Alegre

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Menstrual CycleAchilles Tendonmechanical propertiesmaterial propertiesmorphological properitesestrogenprogesterone
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.