Over the last decade, torn and ruptured anterior cruciate ligament (ACL) in female athletes have increased at an alarming rate.
Consistently, it has been found that a higher prevalence of ACL injuries occurs in female athletes over their male counterparts. Women are 2.4 to 9.7 times more likely to suffer from ACL injury when compared to men of similar competition and training levels.
Females involved in sports involving landing from a jump, abrupt changing of directions and cutting, such as basketball, soccer, gymnastics, skiing and gymnastics are especially at risk. Reports state that women basketball players are 5 to 7 times more likely to have an ACL injuries than men and that female soccer players are injured more than twice as often as men (American Council on Exercise, 2009). On average, women rupture their ACL ligaments 5 years earlier than men do. In addition, majority of females with torn ACLs are between the ages of 15 and 25.
Although the exact cause is still unclear, and the possibility of a complex interplay between different factors is likely, possible explanations of the gender difference in the rate of ACL injuries have been suggest and reviewed. The suggested reasons are anatomic differences, joint laxity, range of motion, hormonal secretion and training techniques are suggested factors that predispose women to ACL injuries.
There are two different factors that can influence an injury. The first is intrinsic factors. Intrinsic factors are internal factors with the body that can increase the risk of injury.
5 Intrinsic factors that Lead to ACL Injuries in Females
#1 – The Pelvis – The female pelvis is wider than the male pelvis. A wider pelvis causes a more forward tilted femur near the hips as the shin bone is angled toward the knee, resulting in knock-knees, which in turn, place a great amount of stress on the ACL.
#2 – Narrow Notch – Females have narrower intercondylar notch, through which the ACL passes through. It has been suggested that cutting and jumping movements with narrow femoral notches may weaken the ACL.
#3 – Smaller ACL – Women have smaller anterior cruciate ligament size, making it more vulnerable to fraying.
#4 – Hormones – Generally, women have greater knee laxity, which may be influenced by the hormones secreted in large amounts by the females. Receptors for estrogen and progesterone have been identified on the ACL; thus, hormonal fluctuations occurring during the menstrual cycle may influence the structure of the ACL. It was found that women are more susceptible to ACL tears during the ovulatory phase (days 5 through 12 of the menstrual cycle), when the estrogen and progesterone levels are high, increasing the laxity and susceptibility of the ligament to overstretching.
#5 Weaker Leg Strength – Women have lesser muscle strength and slower muscle reaction times when compared to men. A strong and fast-reacting hamstrings is vital to keep the ACL intact during abrupt changes of direction. In addition, women also tend to recruit or use their front thigh musles or quadriceps, increasing the risk of AC L injuries. The hamstrings protect the ACL by decreasing the stress applied on the knee as the lower leg moves forward. The quadriceps pulls the shin bone forward, consequently placing additional stress on the ACL.
This is part 1 of this article. In part 2, I will go through extrinsic factors that lead to more ACL injuries in females.