Understanding and Preventing ACL Injuries
A GUIDE FOR PARENTS OF YOUTH (FEMALE) ATHLETES
INTRODUCTION
As a parent of a youth female athlete, understanding the risks and prevention strategies for ACL (anterior cruciate ligament) injuries can make a significant difference in your child’s athletic journey. This handbook provides essential information to help you support your young athlete.
What is the ACL?
The ACL (anterior cruciate ligament) is one of the key ligaments that help stabilize the knee joint. It connects the thighbone (femur) to the shinbone (tibia) and controls the back-and-forth motion of the knee, especially during activities that involve sudden stops, changes in direction, or jumping.
FUNCTIONS OF THE ACL
- Stabilizes the knee joint
- Prevents the tibia from sliding out in front of the femur
- Provides rotational stability to the knee
Why Do Girls Tear Their ACL More Than Males?
Female athletes are 4-6 times more likely to suffer ACL injuries compared to their male counterparts due to a combination of anatomical, hormonal, and biomechanical factors:
- Anatomical Differences: Wider pelvis leading to a greater Q-angle, affecting knee alignment.
- Hormonal Influences: Fluctuations in estrogen levels can affect ligament laxity.
- Biomechanics: Different landing and cutting mechanics, often with less knee flexion and more inward knee collapse.
- Muscle Imbalance: Stronger quadriceps relative to hamstrings, affecting knee stability.
Why Is the Q Angle Important in Female Athletes?
💡 Female athletes naturally have a wider pelvis than male athletes — especially post-puberty — which increases the Q angle. This wider angle can cause the knees to move inward (called valgus collapse) during movement. When that happens under high speed or load (e.g., landing from a jump or cutting on the field), the ACL is placed under much more stress.
🔺 Increased Q angle = higher risk of ACL injury if not addressed with proper training.
Can We "Fix" the Q Angle?
The Q angle is structural — meaning we can’t change the angle itself — but we can change how the body moves with it. That’s where strength and neuromuscular training come in.
✅ What we can improve:
- Glute strength (especially glute medius and glute max) to control hip movement
- Core stability to improve alignment
- Single-leg control and balance to prevent knee collapse
- Jumping and landing mechanics to reinforce safe movement under pressure
- Hamstring strength to support the knee from behind
Sports Where ACL Injuries Are Most Prevalent
ACL injuries commonly occur in sports that involve:
- Soccer: Sudden changes in direction, pivoting, and contact
- Basketball: Jumping, landing, and quick directional shifts
- Volleyball: Repeated jumping and rapid movements
- Gymnastics: High-impact landings and tumbling maneuvers
- Skiing: Twisting falls and sudden stops
How To Prevent ACL Tears
Preventing ACL injuries involves a combination of strength training, neuromuscular control, and proper technique. Here are key prevention strategies:
- Neuromuscular Training Programs: Focus on balance, proprioception, and agility exercises.
- Strength Training: Emphasize hamstrings, glutes, and core strength to support knee stability.
- Proper Technique: Teach correct landing mechanics with knees aligned over toes and avoiding inward collapse.
- Dynamic Warm-Ups: Incorporate dynamic stretching and activation drills before practices and games.
- Flexibility Training: Improve hip, hamstring, and calf flexibility to reduce strain on the knees.
Exercises To Prevent ACL Tears
The best prevention is performance! How we integrate all this information into our programs!
Proper neuromuscular and strength training can reduce the risk of ACL injuries in female athletes by up to 67–88%.
(Source: Mandelbaum et al., 2005; Gilchrist et al., 2008; Myklebust et al., 2003)
These studies had programs that included posterior strength training, jumping and landing mechanics, balance and proprioception and core work/ agility training.
At Wildewood Sport Performance, we operate with a female sport performance lens, ACL injury prevention is built into everything we do at Wildewood. We understand the unique risks female athletes face — especially related to hip and knee alignment.
That’s why we assess each athlete’s valgus rating (which reflects similar risk factors as Q angle) during their initial movement screen. This helps us identify if their knees collapse inward during squatting, jumping, or landing — a key contributor to ACL injuries.
It’s not just about performance — it’s about building strong, confident, injury-resistant athletes from the ground up.
