The Effect of Phase of Menstrual Cycle on Joint Mobility in the Cervical Spine and Extremities in Nulliparous Women: A Cross-Sectional Study

Sex differences in musculoskeletal injury and disease risks across the lifespan: Are there unique subsets of females at higher risk than males for these conditions at distinct stages of the life cycle?

Sex differences have been reported for diseases of the musculoskeletal system (MSK) as well as the risk for injuries to tissues of the MSK system. For females, some of these occur prior to the onset of puberty, following the onset of puberty, and following the onset of menopause. Therefore, they can occur across the lifespan. While some conditions are related to immune dysfunction, others are associated with specific tissues of the MSK more directly. Based on this life spectrum of sex differences in both risk for injury and onset of diseases, a role for sex hormones in the initiation and progression of this risk is somewhat variable. Sex hormone receptor expression and functioning can also vary with life events such as the menstrual cycle in females, with different tissues being affected. Furthermore, some sex hormone receptors can affect gene expression independent of sex hormones and some transitional events such as puberty are accompanied by epigenetic alterations that can further lead to sex differences in MSK gene regulation. Some of the sex differences in injury risk and the post-menopausal disease risk may be "imprinted" in the genomes of females and males during development and sex hormones and their consequences only modulators of such risks later in life as the sex hormone milieu changes. The purpose of this review is to discuss some of the relevant conditions associated with sex differences in risks for loss of MSK tissue integrity across the lifespan, and further discuss several of the implications of their variable relationship with sex hormones, their receptors and life events.

The influence on menstrual cycle phases on trunk flexion mobility assessed with finger floor distance test: a preliminary study

Background: The menstrual cycle plays an important role in a woman's body and the relationship between different phases of the menstrual cycle and flexibility has not been well known. Aim of the study: This study aimed to examine whether the different phases of the menstrual cycle could affect trunk flexion mobility in young, healthy, physically active women who had not used hormonal contraception and had not received hormone treatment. Material and methods: In total, ten healthy female nulliparas aged 25 - 30 participated in the study. The inclusion criterion for the study was regular menstruation (25 - 35 cycle days). The exclusion criteria were: hormonal treatment, use of hormonal contraception, BMI > 25, and history of pregnancy. To assess trunk flexion mobility the finger floor distance test was used. The test was performed on each participant three times: during menstruation (follicular phase), during ovulation (ovulatory phase), and after day 15 of the cycle (luteal phase). Friedman ANOVA was used to determine the effect of the menstrual cycle phases on the finger floor distance test results. It was followed by Wilcoxon signed rank test. Results: There was a significant effect of the phases of the menstrual cycle on the results of the finger floor distance test (p = 0.03). Significantly higher values for the finger floor distance test result in the follicular phase as compared to the ovulatory phase were found (p = 0.02). Conclusions: The comparison of finger floor distance test results obtained in young healthy nulliparas in three phases of the menstrual cycle indicates decreased trunk flexion mobility in the follicular phase.