ACL Injuries in Female Athletes: Why Are They More Common?

Anterior Cruciate Ligament (ACL) injuries are a well-known concern in sports, particularly in activities that involve sudden stops, cutting movements, or pivoting—such as football, netball, basketball, and skiing. Interestingly, female athletes are significantly more likely to sustain ACL injuries than their male counterparts, with studies suggesting a risk up to 6–8 times higher in similar sports.

Understanding the anatomical, hormonal, and biomechanical factors contributing to this increased risk is essential for athletes, coaches, and clinicians alike. Preventative strategies, early diagnosis, and evidence-based rehabilitation can make a substantial difference in long-term outcomes.

Anatomical Differences: Structure and Alignment

One of the key reasons for increased ACL injury risk in women lies in anatomical variation. Females tend to have a wider pelvis, which alters the alignment of the thigh bone (femur) and shin bone (tibia). This increases the Q-angle—the angle at which the femur meets the tibia—placing greater lateral stress on the knee.

Additional anatomical contributors:

• Smaller ACL size and cross-sectional area

• Greater joint laxity

• Shallower intercondylar notch (space for the ACL in the femur)

These structural factors mean that female knees may be more vulnerable to strain under twisting or landing forces.

Hormonal Influences on Ligament Laxity

Hormonal fluctuations throughout the menstrual cycle can affect ligament elasticity. Oestrogen, in particular, has been shown to reduce collagen stiffness, which may weaken the ACL during high-risk phases of the cycle.

Observations include:

• Increased ligament laxity around ovulation

• Greater susceptibility to injury in the mid-cycle window

• Potential impact of oral contraceptives on joint mechanics

While hormones alone do not cause ACL injuries, they may lower the threshold for injury during intense activity or poor movement patterns.

Biomechanical and Neuromuscular Differences

Female athletes often display different movement patterns during dynamic tasks. This includes a tendency toward knee valgus (inward collapse of the knee), reduced hamstring activation, and delayed muscle response times compared to males.

Common biomechanical risk patterns:

• Stiff landings with minimal knee bend

• Over-reliance on quadriceps rather than hamstrings

• Poor core and hip stabilisation

These neuromuscular imbalances place excessive strain on the ACL during high-speed direction changes, jumping, or deceleration tasks.

Training, Equipment, and External Factors

In some cases, disparities in coaching methods, equipment fitting (such as footwear), and strength and conditioning exposure contribute to injury risk. Females may have fewer opportunities for neuromuscular training or may participate in sports on less optimal surfaces or with gear not tailored to their anatomy.

Key points to consider:

• Inadequate strength conditioning programmes

• Mismatched footwear or poorly maintained playing surfaces

• Lack of sport-specific injury prevention warm-ups

These factors can often be mitigated through targeted education and structured training programmes.

Preventing ACL Injuries in Female Athletes

The good news is that many ACL injuries are preventable. Neuromuscular training programmes that improve balance, landing technique, core control, and hamstring strength have been shown to significantly reduce risk in female athletes.

Effective preventative strategies include:

• The FIFA 11+ warm-up programme

• Plyometric and agility drills with feedback on form

• Hip and core strengthening

• Balance and proprioceptive training

In addition, MAI-Motion™ biomechanical analysis can help identify movement asymmetries and guide individualised correction programmes.

Frequently Asked Questions (FAQs)

Why are ACL injuries more common in women?
Due to a combination of anatomical, hormonal, and neuromuscular factors. These include wider hips, greater joint laxity, and different muscle activation patterns.

Can ACL injuries be prevented?
Yes—structured neuromuscular training programmes can reduce the risk by improving biomechanics and strength. Screening tools like MAI-Motion™ can also help identify high-risk athletes.

Does the menstrual cycle affect ACL injury risk?
Hormonal fluctuations may influence ligament elasticity, particularly during ovulation. Monitoring cycles and adjusting training loads may reduce risk, although evidence is still emerging.

What are the symptoms of an ACL injury?
A sudden popping sound, pain, swelling, and a feeling of instability in the knee. Most athletes are unable to continue playing immediately after injury.

Is surgery always required for an ACL tear?
Not always. Partial tears or low-demand individuals may respond to physiotherapy. However, athletes aiming to return to high-impact sports often require surgical reconstruction.

How long is recovery from ACL surgery?
Typically 9–12 months, depending on graft type, rehab progression, and return-to-sport criteria. A structured rehabilitation plan is essential to regain stability and prevent re-injury.