The effects of the menstrual cycle on the static balance in healthy young women

Effect of the menstrual cycle on knee joint position sense and dynamic balance

The objective of this study was to examine how the menstrual cycle affects knee joint position sense (JPS) and dynamic balance. Forty-five physically active women (age 20.87 ± 0.54 years) participated in this study. Pain was measured with a Visual Analogue Scale (VAS). Knee JPS was measured using the passive-active repositioning method using a digital inclinometer. The modified Star Excursion Balance Test was used to assess dynamic balance (SEBT). The VAS scores were higher in the menses phase compared to the mid-luteal phase (p < 0.001) and mid-follicular phase (p = 0.002). No significant differences were found between phases of the menstrual cycle for JPS in 30° (p > 0.05) and 60° of knee flexion (p > 0.05). There were significant differences in the anterior (p = 0.028), posteromedial (p < 0.001), and posterolateral (p < 0.001) directions of the modified SEBT. The values of the anterior direction in a mid-follicular phase were higher than the menses phase (p = 0.017). Mid-luteal phase values in the posteromedial direction were greater than mid-follicular phase (p = 0.008) and menses phase (p < 0.001). The values of the posterolateral direction in the mid-luteal phase (p < 0.001) and mid-follicular phase (p = 0.009) were higher than in the menses phase. In conclusion, the knee JPS did not change during the menstrual cycle in physically active women. However, the dynamic balance performance was at the lowest level in the menses phase. The risk of injury should be considered during menstruation, especially in activities that require dynamic balance skills in physically active women.

Biological sex-related differences in whole-body coordination during standing turns in healthy young adults

Biological sexes (male and female) have been reported to influence postural control and balance due to differences in musculoskeletal structures, hormonal factors, and neuromuscular control. These factors can contribute to the turning performance, potentially leading to an increased incidence of falls, particularly during turning. Therefore, this study aimed to explore the whole-body coordination and stepping characteristics and during standing turns in healthy adults to determine the effects of biological sex and turn speed. Fifty participants (25 males and 25 females) completed 180° standing turns on level ground. Inertial Measurement Units (XSENS) were used to measure whole-body movement turning kinematics and stepping characteristics. Moreover, clinical outcome of dynamic balance was measured by the Timed Up and Go (TUG). Participants were randomly tasked to turn at three speeds; fast, moderate, or slow to the left and right sides. Mann-Whitney U tests were used to compare the independent variables between male and females, and Friedman tests with Dunn's tests for pairwise comparisons were used to compare between the three turning speeds within the two groups. The results demonstrated that significant differences were seen between males and females during fast turning for the leading foot onset (p = 0.048) and in the slow speed for the total step (p = 0.033), showing that these were greater in female with an increase in turn speed. In addition, significant differences were seen only in the males when comparing different speeds in the trailing foot onset latency (p = 0.035), step size (p = 0.009), and total number of steps (p = 0.002), while in the females a significant difference was found in peak head yaw velocity between fast and slow turn speeds, and moderate and slow turn speeds. Finally, there was no significant difference in TUG between groups. Therefore, these findings show differences between biological sexes in the response to whole-body coordination and step characteristics, indicating that females tend to have more changes in stepping characteristics compared to males due to differences in turning speed. This can affect their balance and stability. However, the differences in biological sex did not impact the dynamic balance and fall risk due to the lack of a significant difference shown by TUG between males and females.

Does Phase of the Menstrual Cycle Affect Balance and Postural Control?

The aim of the study is to examine the effects of menstrual cycle phases (MCP) on balance and postural control. The study was carried out with 63 volunteer women. Digital ovulation kits and, a Menstrual Cycle Regularity Questionnaire (MCRQ) to detect menstrual cycle regularity and duration, Premenstrual Syndrome Questionnaire (PMSQ) to question the presence of premenstrual syndrome, Menstruation Attitude Questionnaire (MAQ) to assess menstrual attitudes, International Physical Activity Questionnaire Short Form (IPAQ-SF) to question physical activity level was used. Balance and postural oscillation were evaluated with Balance Master balance and performance test device and Tekscan MatScan™ Pressure Mat System, respectively. All evaluations were repeated twice, in the preovulatory period and the postovulatory period. When the evaluations of the preovulatory period and the postovulatory period were compared, there was %3 increase in the percent weight-bearing of the non-dominant extremity (p = 0.01) and %2.5 decrease in the percent weight-bearing of the dominant limb in the postovulatory period (p = 0.01). %8 increase in functional reach distances was detected in the postovulatory period (p < 0.01). It was determined that there was %7.4 decrease in the oscillation rate of the center of gravity in the static stance with eyes open and %9 decrease in the static stance with eyes closed in the postovulatory period (p = 0.35, p = 0.18, respectively). It has been determined that the balance and postural control of young women are negatively affected in the preovulatory period and the function improved from the preovulatory period to the postovulatory period.

Effect of ovulation on postural sway in association with sex hormone variation across the menstrual cycle in college students: an observational study

Background

Poor balance associated with increased postural sway is a risk factor for the high incidence of injuries found during specific menstrual cycle phases. This fact led to the hypothesis that female reproductive hormones affect soft tissue and neuromuscular function, reducing postural balance and resulting in a high injury prevalence among female college students. So, the current study aimed to identify the influence of ovulation in association with sex hormone variation across the menstrual cycle on postural sway in college students.

Material and methods

Forty female college students were enrolled in this study. They were recruited among physical therapy students at Deraya University, New Minya, Egypt. They were aged from 17 to 22 years. They were allocated to a single group. Progesterone and estradiol blood levels were measured to detect the timing of the follicular and luteal phases, and a urine luteinizing hormone (LH) strip test was used to determine when ovulation occurred. The dynamic postural sway index was assessed by using the Biodex Balance system. All measurements were taken on the early follicular (1st–3rd) day, the ovulatory (11th–13th) day, and the mid-luteal phase (21st–23rd) day from the onset of menstruation.

Results

Statistical analysis showed that the anteroposterior, mediolateral, and overall sway index increased significantly during the ovulatory phase compared to the earlier follicular and mid-luteal menstrual cycle phases in female college students (P < 0.05). There was no significant variance between the early follicular and mid-luteal phases (P > 0.05).

Conclusions

It can be concluded that increased female sex hormones during ovulation affect postural sway, which may disturb balance and increase the risk of injuries in college students.

Insights in the Effect of Fluctuating Female Hormones on Injury Risk—Challenge and Chance

It is time to take on the challenge of investigating the complex effect of fluctuating female hormones on injury risk as this offers a chance to improve female athletes’ health and performance. During the recent decade, the body of knowledge on female hormones and injury risk has largely been increased. New insights have been offered regarding the association of certain phases of the menstrual cycle and injury prevalence as well as regarding relationships between hormone levels and musculoskeletal changes such as, for example, ligamentous stiffness and knee laxity. However, current research often follows the theme of a causal relationship between estrogen levels and musculoskeletal function or injury and thus—one might argue—further enhances a rather simplistic approach, instead of uncovering complex relationships which could help in establishing more nuanced ways of preventing female injuries. To uncover real effects and to truly understand the physiological responses, we suggest to reflect on potential bias regarding research questions and current approaches. It may enhance future studies to apply a more nuanced approach to causation, to include multidimensional perspectives and to implement an interdisciplinary methodology.

Iron deficiency anemia induces postural control disorders in young women

BACKGROUND

Due to menstruation and restrictive dietary practices, women are at a particular risk of iron deficiency anemia (IDA). This hematologic manifestation could impair postural control as it induces fatigue, muscle weakness, cognitive and neurological functions alteration.

AIM

This study aimed to investigate IDA effects on postural control in young women in comparison to healthy counterparts.

MATERIAL AND METHODS

Twenty-four young women with IDA and twenty-four controls participated in this study. Center of pressure (CoP) excursions, in the bipedal and semi-tandem postures on the firm and foam surfaces in the eyes opened (EO) and closed (EC), were recorded, and Romberg index was calculated to evaluate postural control. Besides physical performance, attentional capacity, fatigue, and heart and respiratory rates were assessed.

RESULTS

Young women with IDA had significantly higher CoP velocity (CoPv) values in the bipedal posture in both vision and surface conditions (EO [firm: P < 0.001 and foam: P < 0.01]; EC: P < 0.001), as well as in the semi-tandem posture (EO [firm: P < 0.01 and foam: P < 0.001]; EC: P < 0.001) compared to controls indicating that they had worse postural control than their peers. In addition, values of the respiratory rate (P < 0.001), attentional capacity (P < 0.001), physical performance (P < 0.001), fatigue (P < 0.001), and Romberg index on the foam surface in both postures (P < 0.05) were significantly higher in young women with IDA compared to controls.

CONCLUSIONS

Physical performance, fatigue, tachypnea and attentional capacity resulting from IDA may explain postural control disorder in young women.

The Disturbing Effect of Neuromuscular Fatigue on Postural Control Is Accentuated in the Premenstrual Phase in Female Athletes

This study explored the fatigue effect on postural control (PC) across menstrual cycle phases (MCPs) in female athletes. Isometric maximal voluntary contraction (IMVC), the center of pressure sway area (CoParea), CoP length in the medio-lateral (CoP_LX) and antero-posterior (CoP_LY) directions, and Y-balance test (YBT) were assessed before and after a fatiguing exercise during the follicular phase (FP), mid-luteal phase (LP), and premenstrual phase (PMP). Baseline normalized reach distances (NRDs) for the YBT were lower (p = 0.00) in the PMP compared to others MCPs, but the IMVC, CoParea, CoP_LX, and CoP_LY remained unchanged. After exercise, the IMVC and the NRD decrease was higher at PMP compared to FP (p = 0.00) and LP (p = 0.00). The CoParea, CoP_LX, and CoP_LY increase was higher in the PMP compared to FP (p = 0.00) and LP (p = 0.00). It was concluded that there is an accentuated PC impairment after exercise observed at PMP.

Analysis of the effects of hypothalamic-pituitary-adrenal axis activity in menstrual cycle on ankle proprioception, dynamic balance scores and visual-auditory reaction times in healthy young women

OBJECTIVES

Menstrual cycle (MC) can affect not only the female reproductive system, but also functions such as neuromuscular performance. For this reason, the aim of this study is to investigate the effect of hypothalamic-pituitary-adrenal axis (HPA) activity in MC on proprioception, balance and reaction times.

METHODS

For cortisol analysis, saliva samples were taken from the same women (n=43) in the four phases of MC. While State Trait Anxiety Inventory-I (STAI-I) was applied in each phase to support cortisol analysis, pain was measured with visual analogue scale (VAS). Proprioception, dynamic balance, visual and auditory reaction times (VRT-ART) measurements were made in the four phases of MC.

RESULTS

Cortisol, STAI-I and VAS scores, angular deviations in proprioception measurements, dynamic balance scores, VRT and ART measurements were found to show statistically significant difference between MC phases (p<0.05). As a result of the post hoc test conducted to find out which MC phase the statistical difference resulted from, it was found that statistically significant difference was caused by the mensturation (M) phase (p<0.05).

CONCLUSIONS

It was found that neuromuscular performance and postural control was negatively affected by HPA axis activity in M phase of MC and by pain, which is a significant menstrual symptom.

Bidirectional Interactions between the Menstrual Cycle, Exercise Training, and Macronutrient Intake in Women: A Review

Women have a number of specificities that differentiate them from men. In particular, the role of sex steroid hormones and the menstrual cycle (MC) significantly impact women's physiology. The literature has shown nonlinear relationships between MC, exercise, and nutritional intake. Notably, these relationships are bidirectional and less straightforward than one would suppose. For example, the theoretical implications of the MC's phases on exercise performance do not always translate into relevant practical effects. There is often a disconnect between internal measures (e.g., levels of hormone concentrations) and external performance. Furthermore, it is not entirely clear how nutritional intake varies across the MC's phases and whether these variations impact on exercise performance. Therefore, a thorough review of the existing knowledge could help in framing these complex relationships and potentially contribute to the optimization of exercise prescription and nutritional intake according to the naturally occurring phases of the MC. Throughout this review, an emerging trend is the lack of generalizability and the need to individualize interventions, since the consequences of the MC's phases and their relationships with exercise and nutritional intake seem to vary greatly from person to person. In this sense, average data are probably not relevant and could potentially be misleading.