HORMONES AND INJURIES
ARE WOMEN MORE SUSCEPTIBLE TO INJURIES THAN MALES?!
In short, yes, women are often more susceptible to a wide variety of injuries than males.
For example, women are up to 10 times more likely to rupture their anterior cruciate ligament (ACL) than men. But why?!
GENETICS AND HORMONES
There are many well-documented genetic differences that make women more susceptible to injuries than males. If we look at the ACL again, there are anatomical differences that are commonly seen in women which increases loading through the ACL. The other obvious difference between men and women is hormones. The relationship between hormones and injuries is something which is currently being debated, however, at The Injury Clinic we have seen many injuries where we feel hormones have contributed.
WHAT DO WE KNOW ABOUT HORMONES AND INJURIES?
Women are, in particular, susceptible to tendon injuries and bony stress reactions (or stress fractures). When we specifically look at the research available on the effect hormones have on these two types of injuries, there is a relatively significant amount of evidence indicating female sex hormones can contribute to injury.
In a study that looked at cross sectional tendon area, no difference was observed when untrained women are matched with experienced female runners; whereas, experienced male runners were characterized by a bigger tendon cross sectional area when compared to untrained men. These researchers felt the difference may be related to the stimulating effect of exercise being counteracted by estradiol (female sex hormone) in women, whereas in men testosterone and exercise have a combined anabolic effect (which increases tendon size and strength).
Another well documented fact is women are far more susceptible to developing osteoporosis (where bones become brittle and more likely to fracture). This is something more commonly seen later in life and is associated with the decline in estrogen (female sex hormone) during and after menopause. There has also been some associations between the use of oral contraceptives and changes to bone mineral density (which affects bone strength) in young women.
ORAL CONTRACEPTIVES AND INJURIES
It does appear that there is a link between the use of oral contraceptives and an increased rate of injury. This link is, however, currently being debated and there is conflicting evidence available. As previously mentioned, at The Injury Clinic we have seen cases and injuries where we feel the use of contraceptives (both oral and other forms of hormone contraceptive) have contributed to the development of these injuries. While this is never the sole reason, it is a factor we feel is well worth acknowledging. With up to 80% Australian women using oral contraceptives at some point in their life, the relationship between hormones, contraceptive use and injuries is something we feel is important to consider.
So, what do we know about contraceptive use and injury rates…
- Tendon collagen synthesis rates both at rest and after exercise were lower in women exposed to oral contraceptives in compared to those who aren’t.
- Muscle collagen synthesis rates were increased for 24hrs post exercise in those not using oral contraceptives, however, no increase or change was observed in those using oral contraceptives.
- Women who have taken oral contraceptives at any stage in their life have been shown to have a significantly lower bone mass than those who have never taken oral contraceptives. This is despite no significant differences in age, height, weight, body mass index (BMI), hours of exercise per week and calcium intake between the two groups studied.
If we look specifically at bone mineral density and oral contraceptive use, there are several factors that appear to further affect the likelihood of injury…
- Gynecological age when oral contraceptive use started is important; which means the duration after the initial menstrual period where oral contraceptives started. The earlier the use of contraceptives, the more significant the bony changes.
- Age at which oral contraceptive use started. So not only is gynecological age important but a person’s true age is also an important factor.
- Total duration taking oral contraceptives. It appears the longer the duration of oral contraceptive use the greater the bony changes were.
These aspects play a significant role as we often see the initiation of oral contraceptive use during teenage years, which is when crucial bone development and modelling occurs. An example of this is in the hip, where at the ages of 16-19 years old peak bone modelling occurs. In the lower back, peak bone density often isn’t achieved until women are 40. The hormones used in oral contraceptives have been shown to suppress bone formation and remodeling in young women. So, in the years that women are supposed to be developing strong bones, the use of oral contraceptives may prevent the body’s ability to lay the foundations to build strong bones.
WHAT DOES THIS MEAN FOR PEOPLE TAKING ORAL CONTRACEPTIVES?
While this information can be alarming, when looking at injuries we must consider all factors. Contraceptive use may be only one of a multitude of reasons that a woman has developed an injury. If you feel the use of contraceptives may be contributing to a recurrent injury you have, please ensure you discuss the use and relationship between contraceptives and injuries with the appropriate health professionals. While this article is outlining the potential link between oral contraceptive use and injury risks, we are not suggesting you stop taking your contraceptives as a way to prevent injuries, nor are we suggesting contraceptive use causes injuries.
At The Injury Clinic, we take a holistic approach to the management of all injuries and will always try to consider all aspects that may be contributing to an injury profile. We feel all injuries are multifactorial but have particularly noticed a link between hormones and injuries. If you have any questions about hormones and injuries, please do not hesitate to contact us on (03) 5229 3911 or firstname.lastname@example.org.