The Correlation Between Menopause and Quiet Standing Variable Changes

Purpose: During menopause, individuals experience hormonal changes that can affect body systems contributing to balance. It has been established that balance declines with increasing age, but cohort studies have shown that there is a significant increase in falls during the perimenopausal phase of an individual’s life. A previous study has also been able to relate kyphosis and osteoporosis, postmenopausal changes often associated with estrogen deficiency, to altered standing balance specifically an increase in velocity of the center of pressure (COP) displacement compared to premenopausal females, though this study had a relatively small sample size. The purpose of our study is to measure sway to determine if there are meaningful balance changes that occur during the menopausal transition. This could indicate intervention strategies and decrease risk for falls in postmenopausal females.

Methods: Data was obtained from ongoing quiet standing project at the University of North Texas Health Science Center (UNTHSC). Patients visiting the osteopathic manipulative medicine (OMM) and geriatric clinic were asked to quietly stand on a Bertec force plate (Bertec, Columbus, Ohio) for 30 seconds with their eyes open and eyes closed. A total of 475 females were stratified into two groups those less than 48 years old were considered premenopausal (total = 188) and those 48 and older were considered perimenopausal or postmenopausal (total = 287).

Results: When comparing the menopausal group to the pre-menopausal group with eyes open, 13 out of 20 sway variables showed a statistically significant difference, similarly with eyes closed, 17 out of 20 variables showed statistical significance. The most significant changes in variables in participants with their eyes open were found for the range of the COP in the anterior posterior direction (AP) and velocity. For the premenopausal group, the average range of COP AP direction was 13.09 mm, while the average range of COP AP in the postmenopausal group was 16.45 mm. The velocity showed a similar change in that the premenopausal group showed an average velocity of 7.84 mm/s2, while the menopausal group had an average velocity of 10.76 mm/s2.

Conclusion: The increase in the average range of COP AP and average velocity between the two groups leads us to hypothesize that the menopausal group may have a decline in postural control due to hormonal changes. With the significant difference in the majority of the SWAY variables, it appears the menopausal group has increased movement during quiet standing at an increased velocity. Suggesting that this group is having increased difficulty in modulating the position of their body, which could lead to increased likelihood of fall. We also hypothesize that the menopausal group likely relies on vision more for stability because of age related changes in proprioception and strength. Further studies would be required to determine if these changes are related to age or menopause. In the future, identifying balance changes associated with menopause should be studied. This will lead to better monitoring and early preventative measures to prevent falls.