That distinctive pop of a tearing ACL is a sound no athlete wants to hear—and female athletes hear it far more often than their male counterparts. Women's anterior cruciate ligaments, the ligaments inside the knee that stabilize movement during cutting, turning, twisting, and jumping, are up to eight times more likely to rupture or tear in female athletes compared to men, according to Dr. Deanna Brinks, a physical medicine and rehabilitation and sports medicine physician at the Mayo Clinic Health System in Mankato.
The disparity stems from several converging biological and biomechanical factors still being studied by researchers. Women's wider pelvises create a greater angle from the hip to the knee, changing how force travels through the joint. The ACL itself is thinner in women than in men. There's also a muscle imbalance: women's quadriceps, the muscles in the front of the thigh, are typically stronger than their hamstrings, the muscles in the back. When women land from a jump, their powerful quads can overpower their hamstrings, reducing knee stability—the opposite pattern seen in men. Adding another layer of complexity, recent research is exploring whether hormones affect the ACL during the menstrual cycle. Relaxin, a hormone that softens ligaments in preparation for childbirth, is at higher levels in women's bodies leading up to their period, potentially making the ACL more prone to injury.
"Awareness of the factors behind increases in injuries can lead to improved training for women that addresses proper technique, muscle strength, balance, and biomechanics," Dr. Brinks explains. One accessible tool for prevention is the FIFA 11+ Warm-up Program, developed by an international group of experts and available online for free. Though originally designed for soccer players, the 20-minute warmup can translate to any sport, from basketball to pickleball. Divided into three segments with progression levels that add difficulty and variation, the exercises pay particular attention to knee strength and positioning.
Commitment matters. "Whether you follow this program or something similar, players should commit to strength, balance, and knee-position work for at least 10 minutes, three or more times a week," Dr. Brinks says. "There's a push to incorporate this kind of training into youth, high school, and college programs."
When an injury does occur, treatment depends on severity. About 70% of ACL injuries are noncontact—caused by pivoting or landing from a jump—and diagnosis typically involves an MRI. Sprains may heal with a knee brace and intensive physical therapy over weeks to months. A complete rupture requires surgery to reconstruct the ligament using a graft from the patient's own patellar, quadriceps, or hamstring tendon, followed by at least nine months of recovery and rehabilitation.
The good news: return-to-play rates are excellent, around 80%. But there's a cautionary note. About one in four athletes will experience a second ACL injury, particularly those in their teens and early twenties. Dr. Brinks emphasizes that "part of recovery is regaining confidence in the injured knee," something physical therapy can help reinforce as athletes work their way back to sport.