Osteopathic Research Web

Investigation into changes in laxity and flexibility across the menstrual cycle as measured by lumbar range of motion

Item

Title

Investigation into changes in laxity and flexibility across the menstrual cycle as measured by lumbar range of motion

Author(s)

Cowen Victoria

Abstract

OBJECTIVE - To investigate whether there are any changes in laxity and flexibility across the menstrual cycle by measuring lumbar range of motion.
DESIGN AND METHODOLOGY - Measurement of the lumbar spine using the Back Range of Motion (BROM II) device in all three planes of motion (flexion, extension, lateral flexion and rotation) and measurements of height, weight, waist, ankle, chest size, blood pressure and temperature. The measurements were taken on four separate occasions throughout the menstrual cycle - Day one of menstruation, day of ovulation (around day 14), day of mid-luteal phase (around day 21) and day one of menstruation in the proceeding cycle. The experiment took place in the same environment throughout the investigation. All subjects acted as their own control to investigate potential measurement effects. This was done by comparing day one of menstruation against day one of menstruation in the proceeding cycle to see if they remained the same.
SUBJECTS - A random sample of 12 healthy asymptomatic female students from the British College of Osteopathic Medicine, all of who matched the strict inclusion criteria. The age range was between 21-42 (mean = 27.4 years old).
RESULTS - Repeated measures one-way ANOVA tests found no significant difference in weight (P=0.2645), ankle size (P=0.5221), waist circumference (P=0.2579), diastolic blood pressure (P=0.1487), systolic blood pressure (P=0.1106) or temperature (P=0.1641). There was a significant increase in chest size on day one of both menstruations (P=0.0005) and a significant increase in lumbar range of motion in all vectors on day of ovulation and day of mid-luteal phase (P<0.0001). A post hoc tukeys multicomparison test (<0.05) found an increase in range of motion from day one of menstruation to day of ovulation in all vectors (P<0.01). A further significant increase in range of motion was found from day of ovulation to day of mid-luteal phase in flexion (P<0.05) and left rotation(P<0.01). No further significant change in range of motion was found in extension, right rotation and lateral flexion from day of ovulation to day of mid-luteal phase (P>0.05). A significant drop in range of motion in all vectors was found from day of mid-luteal phase to day one of both menstruations (P<0.001). There was no significant change in range of motion between day one of both menstruations (P>0.05).
CONCLUSION - The findings support the hypothesis that there is an overall change in lumbar range of motion throughout the menstrual cycle, which could be due to fluctuating sex-hormones. An increase in range of motion was found at the ovulatory and luteal phases of the menstrual cycle. During these phases in the menstrual cycle circulating levels of Oestrogen, Progesterone and Relaxin are higher so could be affiliated with this change in range of motion via their mediated effect on their tissue target sites in ligaments, fibroblasts and synovial linings acting on joint laxity. Contributing variables such as temperature, psychological status, hydration levels, water retention and anatomical variations could also be playing a roll in this increase or decrease of mobility throughout the menstrual cycle. On the basis of these findings, the Osteopath may choose to alter treatment techniques for different times in the menstrual cycle, for example, it may be easier in a mobile female to get sufficient locking for a manipulation during menstruation when there is less flexibility or vice versa. Care should be taken with hypermobile women during the ovulatory and mid-luteal phases where there is increased mobility to reduce the risk of increasing mobility further or cause injury or subluxation. For the purposes of diagnosis and reassessment, these changes in the menstrual cycle could give the practitioner false representations of the female patients mobility, although this is fairly subjective from one Osteopath to another.
FURTHER RESEARCH
This study has investigated changes in laxity and flexibility across the menstrual cycle as measured by lumbar range of motion but there is tremendous scope to take these investigations further. With a larger sample size, the following are some suggestions for future work based on a similar study to this:
Investigate whether fluctuating hormones in the menstrual cycle have an affect on RoM in a peripheral joint, i.e. a single joint
Comparing men against women throughout the course of one or two menstrual cycles
Comparing post-menopausal women against pre-menopausal women.
Comparing women using the oral contraceptive pill (OCP) against women not using the OCP, or any hormone derived contraceptives.
Comparing women following a naturopathic diet or any form of dietry interventions against women not following a naturopathic diet to see if joint mobility is affected.
Conduct a similar study over two or three menstrual cycles.
Measuring prepubescent girls against young menstruating women.

presented at

British College of Osteopathic Medicine

Date Accepted

0

Date Submitted

1.1.1970 00:00:00

Type

osteo_thesis

Language

English

Submitted by:

62

Pub-Identifier

13664

Inst-Identifier

1076

Recommended

0

Item sets

Thesis

Cowen Victoria, “Investigation into changes in laxity and flexibility across the menstrual cycle as measured by lumbar range of motion”, Osteopathic Research Web, accessed April 27, 2024, https://www.osteopathic-research.com/s/orw/item/1093