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ACL Injuries In Female Athletes - The 7 Reasons They Are More At Risk Than Males

Written by: Nick Jack
Category: 2014
on 15 February 2018
Hits: 13041

Injury in sport has and always a risk that any athlete both professional and amateur take the minute they cross the line to participate. The risk of putting your body on the line in difficult situations and awkward positions and pushing your body to the limits will sometimes come at a cost. And in collision sports like football, rugby, and even basketball the stakes are even higher. But of all the injuries that are sustained in sports, the ACL rupture or tear would be right up there as the worst. This particular injury is a season-ending injury and even a career-ending injury for some! And with females, the chances of this injury occurring are a staggering 5-8 times higher than males in sports like soccer, basketball and more recently in Australia in Women's AFL. As opposed to collision injuries that are being in the wrong place at the wrong time, up to 70% of ACL injuries are non-contact injuries, meaning they were caused from a poor cutting move or pivot or landing poorly from a jump. This is not bad luck but something that could have been avoided if a correct training program was employed early enough that addressed the bio-mechanical warnings of this upcoming injury. Unfortunately, this rarely happens as fitness training is preferred over quality of movement. This article we are going to share with you the seven reasons females are more at risk with an ACL injury, and more importantly what you can do about it. Most of this information has been gathered by dedicated research and analysing the results of successful methods and programs used in our rehabilitation programs for over 14 years with athletes from all sports. We want to share with you the secrets we were able to uncover so you can avoid this horrible injury.

What Causes An ACL Injury?


Before jumping straight into the reasons behind the risk factors with the girls we need to be clear on exactly how this injury is created. The video above is a brief summary of everything we are about to discuss in this article.

ACL tears happen when you plant your foot on the ground and attempt to rotate your body in relation to the planted foot, placing your weight on it. This creates a twisting force through the knee joint, which the ACL must absorb. When the ACL cannot cope with the force it ruptures. This movement is the common movement seen in basketball when a player tries to change direction off the dribble or in football when evading an opponent from a tackle or landing from a jump.

The ACL has a very important role in trying to maintain the integrity of the knee joint but it can only do so much and has very little chance of overcoming repetitive poor movement at high speeds or force. When you understand what causes the problem it is much easier to select the right exercises to prevent it. This is true for males just as much as females and you will often see many male athletes suffer this same injury. The ACL cannot withstand poor movement no matter who you are. Just the female athlete has a much higher risk which we will explain shortly.

In approximately 50% of cases, other structures of the knee such as ligaments, cartilage, or meniscus are damaged. This can lead to chronic instability and the onset of severe osteoarthritis later in life. The rehabilitation program is normally 9-12 months to allow the ligament time to heal and get the necessary blood flow as it has very poor circulation due to its location. Another scary statistic is that more than 50% of athletes are never the same after the injury! So if you can prevent this injury from happening you would want to start straight away right.

Take a look at the statistics below to see the age and gender more at risk and you see a dramatic spike at the teenage years for females playing sports!

But why are females more at risk?

There are many reasons for this but to narrow this down to the "big" factors we have found there is seven key things to look at. If you address each of these factors you reduce your chances of sustaining this injury considerably. This article we are going to give you detailed information as to the "why" regarding this injury. For detailed information about how to correct or prevent ACL injuries, I encourage you to get a copy of our online program below. This program is called "Strength Training Secrets For ACL Knee Injury". This is suitable for both kids and adults and includes specific exercises for rehabilitation and injury prevention.

A must-have program for anyone playing ball sports right now. Click here to see more about what is included.


If you have already suffered this injury and are currently in the rehab process make sure you check out our article called What To Do If You Tear Your ACL

Risk Factor #1: Poor Neuromuscular Control

What exactly is neuromuscular control? This is where our body via the nervous system creates movements we need for work, sports, and daily activities.

Our bodies are a very complex and sophisticated system of systems all bound by one another. Very, very rarely do muscles work in complete isolation or anywhere close to it. When we move some muscles contract, others stretch and elongate to while some muscles provide stability, and all of this is done within a split second without you having to think about it. This is what is known as a pattern of movement and these patterns are like groups of movements linked together in a big chunk of information. The chunk of information is known as a motor program (like software on a computer). These motor programs link many movements together all at once to complete a specific task. 

This is where it gets very interesting, for the body will not question whether these patterns or chunks of information are good or bad, it will use the pattern it knows the most!

If you have learned a poor movement pattern from poor training, lack of development, previous injury or lack of skill the body will compensate, and create these faulty patterns that eventually become encoded into your nervous system as a permanent motor program. Compensation ruins your ability to effectively stabilize as the timing will be thrown out. Now it just a matter of time until you eventually blow out your joints.

Read our article Stability Training What Is It & Why It Is So Important for more detail on motor programs and why timing is crucial for stabilizers to work.

Take a look at the picture below as this is a classic example of poor neuromuscular control and a faulty motor program with running, cutting and definitely landing from a jump. This is a red flag with any athlete, and this is very common with teenage females.

Lack of performance, stiffness, and maybe strains at other joints will precede the ACL injury and are warnings of upcoming disaster.

A good trainer or coach who understands that MOVEMENT is everything will be able to spot this early on and change it before it is too late. Unfortunately, there are not many people who acknowledge the principle of MOVE WELL FIRST before FITNESS training. And even when they do see it, the methods used to try and correct it are poor choices and in some cases exacerbate the problem. For they are trying to correct a neuromuscular problem at a muscular level which is impossible. To change a motor program like the one pictured above you must change the program itself. You cannot use planks, leg curls, Nordic curls or leg press to do this. I will expand more on this later, but firstly how do you identify the weakness?

The easiest test to do is using a single leg squat or toe touch drill test. Watch the video below of how to do this and the second video is an example of a loss of motor control with a client who has suffered an ACL injury.


When assessing this movement we start at the ground and work our way up, looking for clues as to where joints are not functioning correctly. What you will see is that every second joint needs mobility and the other joints need the exact opposite being stability. In nearly every case of injury, the joints needing stability are compromised and forced into excessive movement due to a loss of mobility at the joints demanding control. This information is crucial to know in determining what course of action you may need to take, or what to investigate further to be able to change the faulty program.

Read our article specifically on this topic for more detail on assessing each joint - How To Use The Single Leg Squat As An Assessment To Identify Weakness

Risk Factor #2: Anatomy

The female anatomy and bone structure is not a design that is designed efficiently for cutting movements and explosive jumping and landing. This doesn't mean they cannot do it, just that the risk is greater than males due to their bio-mechanical structure.

Females tend to have wider hips, for childbirth, greater foot pronation and most important of all a larger Q angle, (Quadriceps angle). Normal Q angle is between 5 and 20 degrees. This large Q angle creates what is known as a valgus condition, otherwise known as 'knock knees" and as we have already seen this is where the knee is placed in the point of no return. So before even attempting to move the structure is in a poor position. Added on top of this is that most females have an excessive anterior tilt of the pelvis which encourages more hip internal rotation that creates a greater Q angle but also inhibits the powerful hip extensors and abductor muscles being the glutes and hamstrings. And you will see in the next risk factor how important these muscles are in preventing knee injuries.

Always remember that in order to protect the knee you want to ensure the hips are stacked on top of the knee and in alignment with the ankle.

Compare the pictures below of a male versus a female to see examples of this.

You cannot change the skeletal structure but you can definitely improve the lordosis posture and decrease the valgus collapse at the knee. The only way to do this is by using strength training. To keep this article short I won't go into too much detail of how to do this but you will find stacks of information about this in the article below.

Best Exercises To Improve Posture

Risk Factor #3: Quadriceps To Hamstring Ratio

Most people, males, and females exhibit quad dominance in leg movements. In over 13 years of training all types of injuries, sports, and ages I would safely say that 90% of the clients I see have a tendency towards dominating lower limb movements with their quads. When it comes to females this is closer to 100% for the reasons we explained in risk factor 2. But why is this so bad, for isn't strong quads a good thing?

When you understand that 60-80% of ACL injuries occur when the knee is forced into the position of flexion and the rotation. Hamstrings work in combination with the ACL to resist the forward movement of the tibia that the quads produce. The bigger the difference between the quads and hamstrings increases the anterior shear force at the knee flexion angles that occur during single-leg landing and pivoting movements that we already know are high risk. Add on top of that the glutes work as a force couple with the hamstrings, otherwise known as the posterior chain, and play a vital role in controlling the hip and preventing excessive internal rotation that causes valgus collapse. 

Studies on this which you can read in the book "Understanding & Preventing Non Contact ACL Injuries" show that females have disproportionate firing (four times greater) of their lateral hamstrings than medial hamstrings during landing, which demonstrated a decreased ratio of medial to lateral quadriceps recruitment. This means the VMO muscle, a crucial muscle needed to provide stability of the knee is in a weakened position to fire.

Many females who are quad dominant will tend to land more vertical in order to use the more dominant quads. When you land from a jump, cut and pivot in an upright position with less knee and hip flexion, this greatly increases valgus collapse and internal rotation of the hip coupled with external rotation of the tibia. And due to this you now have less knee stability as it is getting torqued in two different directions, and the quadriceps are in a perfect position to dominate the hamstrings whose job it is in combination with the ACL to resist this.

Does this mean you start doing heaps of hamstring isolation exercises? Well, it may help, but again you need to strengthen this in patterns of movement that it is to be used. Best exercises are deadlifts and single leg deadlifts for doing this. More on strength exercises in risk factor 5 where I show you a few videos.

You can read more about how to strengthen the posterior chain in the article - How To Strengthen The Glutes

Below is a FREE Checklist you can download to help you. Click Here to get your copy.

Risk Factor #4: Joint Laxity & Hypermobility

Females have much greater flexibility and greater joint laxity and while this can be a good thing as it allows for full range of movement it can come at a cost if there is not enough stability and a lack of motor control as discussed earlier. The main reason females have this extra joint laxity is to allow for childbirth, if their body was as stiff as a male, they would be unable to give birth. During pregnancy, there is even a secretion of relaxant hormones to further enhance this. 

Knee laxity is greater in females than males, and increased knee joint laxity has been found to be a great predictor of ACL injury.

Stretching, Yoga and various movements that encourage excessive mobility must be treated with caution for the female athlete, for even though this may look impressive and may not cause any pain at the time, this extra mobility is potentially creating a severe loss of functional stability at other joints. Too much flexibility is just as bad as not enough, in fact, I would go further to say it is actually worse. Not enough flexibility results in muscle tears and sprains, whereas excessive mobility results in dislocations and bone injuries. I know which one I would prefer.

Stretches like the ones pictured below will result in poor stability and poor motor control. The two pictures shown below are two examples of how you can severely weaken your hamstrings by excessively stretching. Now, remember from the previous risk factor how dangerous this is. And to add on top of that these are also great ways to ruin your lower back, with either facet joint or SIJ problems, and secondly herniated discs.

Always remember - STRETCHING WEAKENS MUSCLES. This is sometimes needed and a good thing, but if the muscle is already lengthened too much it needs stiffness, not more loosening.

When you know how to move well you never need to spend too much time stretching, for you will do this within the movements themselves. You know exactly how to achieve a great range of movement with squats, lunges, bending and even pushing and pulling with the upper body, by perfectly timing mobility with stability. This is how the joints remain free from stiffness and able to do amazing movements without fear of injury. Every now and then you may need to address tight areas specific to you, but if your workouts are well balanced and designed specifically to your weaknesses then this will not be a problem.

A great article to read with more information on this topic is - Hypermobile Joints & Why Stretching Too Much Is A Disaster For Your Joints

Risk Factor #5: Poorly Designed Strength Programs

This factor is one that really annoys me as the ignorance of some coaches, clubs and worse trainers to understanding movement is incredible. Many exercises I see being used to correct all the things we have just discussed do not even come close to doing any good at all, and in many cases are actually contributing to the problem. I have recently seen programs advising to do shuttle runs, lunges, squats and planking with the belief that this will decrease the chances of ACL injury in women's football. Perhaps the lunges and squats might have a chance if there is an emphasis on perfect technique and motor control, but I seriously doubt that as this was just used as a warm-up before training.

Remember risk factor 1 where if you have poor neuromuscular control and do not change it early enough with enough repetitions it becomes permanent. This is where in a team situation where quality is compromised to just "get it done" actually encourages more poor form!

We must change the way we choose exercises and disregard the belief that you just need to focus on isolated muscles in order to make a difference. You cannot change a movement pattern with isolated exercises EVER! Machine training is an example of how you can easily ruin your stabilizers during a movement. You can watch the videos below for detailed explanations why some of the common exercises used are a waste of time.


Great articles to read about this are below

What should you do?

Well, there are many things to consider here and again to keep this article relatively short I will just leave you with a few ideas.

But if you want a complete program with over 60 specific exercises, a 6 phase program all mapped out with instructions and a 60-minute video our Knee Pain program below is the best. Click here to see more about this program.

Otherwise, you need to begin designing a program that covers all of the fundamental movement patterns.

These key patterns are:

  1. Squat
  2. Lunge
  3. Bend
  4. Twist
  5. Push
  6. Pull
  7. Gait (single leg stance and running is included here)

Watch the video below for an explanation of each with examples of how to do this. 

The real big secret with your strength training program will be with single leg exercises & lateral movements and on a lesser scale will be deadlifts, lunges, and squats. All of these patterns are where you really learn stability and coordination that evolves into strength and eventually power, needed to enhance performance and also be able to brake quickly and efficiently using muscles and not joints.

A good rule to always abide by when selecting exercises for sports is to follow the sports performance pyramid below.

You cannot develop the sports specific skills or improve fitness if the base is not built correctly. By spending time with the bottom two layers you can safely and effectively move towards the performance side of training.

Great articles to read with more detail on this are below

Risk Factor #6: Ignorance To Treating The Cause Of ACL Injury

This is really a follow up to the previous factor.

We are so trained into treating symptoms that we forget to look beyond the area in pain and look for what is causing the pain. And when it comes to ACL injuries as you have already begun to see it has very little to do with the knee itself. In most cases, before a non-contact ACL injury, there were several warnings beforehand. Sometimes it may have been stiff ankles from an ankle sprain injury or stiffness in the lower back that comes after training, or maybe shin splints from running drills.

The problem with pain is that it changes so many things. Pain is the fastest way to change how you move! If I was to kick you in the leg you would instantly adopt a limping walking pattern. I would be able to change how you walk instantly. When we change how we move to avoid more pain and create compensatory movements, it causes a chain reaction of a whole set of new problems, and often bigger ones that result in guess what? More pain! We always get many warning signs that are not painful yet to do something but we are so trained to ignore these warnings and go about our day.

Two of the biggest causes are the FEET and the HIPS. With females, the feet in particular, can be a real problem. Why? High heel shoes!

In our recent article about feet stability we covered this in great detail, but here is a quick explanation as to the danger of high heel shoes to your body, that has a potential to create an ACL tear.

Our feet are designed to do 2 critical things.

  1. ABSORB shock and then.
  2. Provide the ability to PUSH off the ground when we walk, run or jump.

The foot needs to act like a spring being a soft flexible foot to cushion the stress of each step we make, and then instantly become stiff enough to provide enough power to move us forwards or upwards. This is also known as being able to lock the foot at one point and then being able to unlock the foot at the very next part of the movement. Problems arise if we lose either one of these two things, and ultimately lose our spring. This is where injuries will occur at other joints.

If the body were rigid a two-inch heel would displace it 22.5 degrees forward, while the four-inch heel would displace it 45 degrees forward. Because the head and eyes must always remain level for reasons of posture and balance the body has to make adjustments at other joints to maintain this. The forward leaning creates compensation at all joints above the foot! Postural problems from these shoes are seen below.

Now it is fair to say you would not see many males in shoes like this. Having said that even leather shoes and most runners have the high heel to make up for the fact that the feet are weak or the ankle unstable. The problem is in a basketball shoe or a football boot these shoes DO NOT have this heel adjustment. Now the feet have to find an extreme range of motion that they never see, and at high speeds in multiple directions! In our strength training assessments for knee injuries over 90% of the clients we see have very poor foot stability and a loss of ankle range of motion. This places the knee joint at an extremely dangerous position as it will be forced into positions it should never be in as the joint below being the ankle was unable to do its job.

Again I cannot tell you how many people who have come to see us for help with knee problems and when we assess them and tell them this information they are completely surprised as all the therapists and trainers they have seen before never even looked at their feet!

Below are some good videos about the danger of foot stability.


#Risk Factor #7: Ignorance Of Running Technique & Braking Drills

We all know that to be great at sports you have to spend a great deal of time learning the skills of their game. We know it is important to get specialized coaching on how to shoot a basketball, kick a ball, hit a forehand in tennis, for if we adopt poor form early on it is hard to change later. But what is often ignored is the importance of running technique, or learning the skills of stopping and change of direction. And just like learning how to shoot a ball poorly or hit a tennis forehand with poor technique, learning to run poorly will come at a cost to your body and will be very difficult to change later.

This risk factor is not just limited to females, and possibly this may be even worse in many males.

We assume that running is just running and that being better at it just requires more. When really technique is everything. Just ask an elite level sprinter or middle distance runner how important technique and how much time they devote to getting better at it even though they are already better than all of us. Yet in sports, there is rarely any time or even a thought given to this fact, and this is where the potential for injury, let alone poor performance is increased. This is where we may have been adopting all the right strength training exercises, mobilizing ankles, and doing some great stuff all for you to go and run with poor form. The running technique will undo all your hard work and you will be back to where you started.

Below are some videos you can watch on running technique to give you some ideas as to the common mistakes we see and how you can change them with simple drills.


In addition to running, and something very specific to ball sports is learning the skills of BRAKING! This could fall into the category of strength training, but we like to categorize this as skill development at first.

We use a clever acronym that was devised by Twist Conditioning called BRAKES.

The BRAKES acronym is as follows:

  • Balance (Performance Balance)
  • Reaction
  • Agility
  • K(q)uickness
  • Explosive Speed AND Eccentric Strength

The key part with regards to ACL injury prevention is eccentric strength. If your body and the muscles are not effectively trained to withstand eccentric loading (deceleration), potential energy is lost and worse injury is more likely to occur. As mentioned earlier this is where we see so many of the non-contact ACL injuries occur usually from a single leg landing after a jump or lateral change of direction pivot. Without the efficient control of deceleration, there is no stability or leverage to maintain the integrity of the joint and secondly be able to produce the necessary force needed for Explosive Speed and Power.

You can read more about this in our article - Strength Training For Sports Is All About Learning To Brake

Great videos to see examples of this for ACL prevention is below.



We certainly covered a lot of stuff in this article and I apologize for the length of this but I wanted to make sure that you have all the details of what you must consider if you are female playing sports. Knowing the risk factors makes you one massive step closer to avoiding the dreaded ACL rupture or tear that can derail your sporting career. And it is not just the physical damage that an injury like this can cause, it can have a big impact on you mentally and emotionally so by having the right knowledge and some tools provided in this article you can play your chosen sport without the fear or limitation.

For more ideas and information on specific topics I may not have covered in detail be sure to check out our INDEX PAGE on the website that has over 300 of our best articles. These are all sorted into categories for quick reference so you can find what you are after more easily. You can also subscribe to our FREE fortnightly newsletter by clicking here.

And lastly if you live in Melbourne and would like to know more about our Personal Training or Sports Specific Programs click the image below and I will be in touch within 24 hours to schedule an free consultation.

About The Author

Nick Jack is owner of No Regrets Personal Training and has over 15 years’ experience as a qualified Personal Trainer, Level 2 Rehabilitation trainer, CHEK practitioner, and Level 2 Sports conditioning Coach. Based in Melbourne Australia he specializes in providing solutions to injury and health problems for people of all ages using the latest methods of assessing movement and corrective exercise.


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  • Diagnosis & Treatment Of Movement Impairment Syndromes - By Shirley Sahrman
  • Low Back Disorders - by Stuart McGill
  • Knee Injuries In Athletes - by Sports Injury Bulletin
  • The ACL Solution - by Robert G Marx
  • Understanding & Preventing Non-Contact ACL Injuries - American Orthopaedic Society For Sports Medicine
  • Anatomy Trains - by Thomas Meyers
  • Motor Learning and Performance - By Richard A Schmidt and Timothy D Lee
  • Assessment & Treatment Of Muscle Imbalance - By Vladimir Janda
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  • Scientific Core Conditioning Correspondence Course - By Paul Chek
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