Hormonal factors that impact female athletes’ risk of injury.

In my last post, I discussed the anatomical factors that female athletes possess that increase ACL injury risk. As mentioned in part 1 of this article series, there are numerous factors that need to be considered in the heightened ACL injury risk we see in female athletes. I this article I will be expanding on the hormonal factors influencing female athlete’s injury risk.

Following puberty, females display a plateau or decline in motor performance and strength. The discrepancies in strength between males and females post-puberty are explained mostly by the effect of hormones on the muscles impacting muscular growth which is attributed to the large increase in strength seen in males rather than females/

There are significant differences in the hormonal status of females who sustain ACL injuries compared to those who do not. Large changes in female sex hormones throughout the phases of the menstrual cycle may be related to a heightened ACL injury risk in female athletes. Two hormonal factors impacting young female athletes are their levels of the hormones estrogen as well as testosterone and progesterone. Each of these hormones has different effects on the body and too much or too little can increase the risk of injury.

Estrogen levels

The hormone estrogen is responsible for promoting the development and maintenance of female characteristics within the human body, particularly in females. Estrogen binds to receptors on the ACL and decreases collagen production, which impacts the laxity of the knee. Decreased laxity can decrease the ability of ligaments to absorb force during cutting, pivoting, and landing, consequently increasing the risk of a knee injury.

It has also been suggested that during the menstrual cycle when estrogen levels are highest (during the luteal phase) that the ACL may be more likely to occur compared to the follicular phase when estrogen is lower.

However, it is also important to note that ACL injuries occur during all phases of the menstrual cycle, although typically higher in the luteal phase due to decreased joint laxity.

Testosterone and progesterone levels

Studies have shown that athletes who have sustained an ACL injury exhibit lower levels of testosterone and progesterone compared to those who have not. The hormone testosterone is a naturally occurring steroid within the body important for strengthening and stabilizing the ligaments. Female athletes with lower levels of the hormones testosterone and progesterone are at a greater risk of ACL rupture.

Compared to males, females have levels of hormones such as estrogen, testosterone, and progesterone that may compromise ACL’s laxity, strength, and stability and increase knee injury risk in sports such as netball, involving high forces during decelerating and landing where strength and stability are vital. 

Hormone levels of young females play important roles in determining how prone females are to injury. And have received more attention in the media due to the increase in ACL injuries in female AFL. However, although a contributor this is not the dominant factor predisposing females to ACL injury and are unmodifiable and as such, there is not much we can do about them but be aware. In the next post, I will be talking about the DOMINANT mechanism of injury in female athletes. The neuromuscular factors.

Mandy (MSc)



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