ACL Injury Prevention is just Good Training

Upon hearing about the recent string of Anterior Cruciate Ligament (ACL) injuries in the current AFLW competition, I thought it was a good time to write about my thoughts on why these are occurring at such a consistent rate for these female athletes, but also the best ways in which we can train to prevent them.

Before we get too deep into this much more common than it should be topic, I'd like to point out that I am in no way attacking the AFLW clubs or staff, because I know for a fact that they are doing the best they can with the contact hours, facilities, and available gym time that they get to work with in order to build resilient athletes.

An ACL injury, be it a tear, partial rupture or full rupture is a common injury among many sports people who engage in a sport that involves turning sharply to change direction (cutting), or a sport that involves contact. For the sake of this piece, contact injuries won't be the focus as they can be sometimes unavoidable, and just bad luck.

There is a well accepted notion that female athletes are at a greater risk of suffering an ACL injury, but why is this? There are many different reasons why this is the case, but that doesn't mean that a female athlete is guaranteed to have this injury occur. But, the structure and training time devoted to the AFLW athletes is certainly not helping.

HOW DOES AN ACL INJURY OCCUR?

**I would like to point out that the biggest predictor of future injury is past injury, and a lot of the girls going in to AFLW have extensive injury histories, including past ACL or other knee injuries.**

The ACL acts as a stabiliser to the knee during rotation, helping to prevent the tibia (shin bone) from sliding forward of the femur (thigh bone). If the force of a change of direction movement, a heavy landing or the rotational torque through the knee is too great upon landing, the ACL is at risk of becoming injured. It has been noted that a high number of ACL injuries can occur when an athlete lands flat footed coming from a lateral movement or when attempting to change direction and the knee is in a more straightened position. This action can cause a majority of the forces to be directed straight up through the tibia and into the knee joint, and if the knee is in a more straightened position the tibia can then slide forward of the femur placing a vast majority of the load into the now vulnerable ACL. If the force is too great, the ACL can become injured. The knee will cave medially (inward) if the ACL and other supporting structures fail.

For the female athlete, the risk of this injury occurring is far greater than that of their male counterparts. In fact, they can be two to eight times more likely to strain their ACL in sports than involve cutting and jumping (basketball, netball, football).

The major players for these increased risk factors for women are less active muscular protection of the knee joint, the greater "Q angle" (quadriceps angle) which drives more medial torque through the knee joint, relative ligament laxity caused by differences in hormonal activity from oestrogen and relaxin, bone structure and dimensions, and muscular strength.

THE Q ANGLE

The Q Angle refers to the angle of which the femurs are presented at rest. In men, this angle is on average around 14 degrees, and in women it sits around 17 degrees, due to wider hips. This means there is a sharper "inward" angle of the femurs for females, resulting in a naturally higher medial torque through the knee joint. This anatomical difference may lead to an increased risk of an ACL injury. Since we know the knee will cave medially (most commonly) if someone injures their ACL, then this knowledge acts as a higher risk factor for the female athlete.

WHY SUCH A HIGH RATE OF ACL INJURIES IN AFLW?

Australian Rules Football (ARF) is a 360 degree game, including a myriad of ACL injury producing movements like cutting, sharp turns, jumping and tackling. Add to this the above increased risk factors for women, and this game is a very high ACL risk for most athletes, but especially females.

But these athletes are receiving training to prevent these sort of injuries, right? Why, then, are we continuing to see such a high rate of these injuries in these women? The answer is not a straight forward one.

For starters, AFLW isn't a fully professional sport yet. A lot of these women are students and full-time workers. They get a limited number of hours in order to train for their sport, sometimes coming straight from work or picking the kids up and dropping them off again so they can get to training. Add to that, their pre-seasons are very short relative to what they need AND they sometimes only receive 20 minutes of dedicated gym time with the team, 2-3 times per week. Compare this to a sport like Netball, where a lot of the athletes are full-time and you'll notice that whilst ACL injuries still exist, we aren't seeing them at the rate at which the AFLW are currently producing them.

The staff at AFLW teams do the best they can with the time that they have, we cannot lay the blame on them. However, I think a lot of the blame can be placed on the clubs, or the AFL itself. If these ladies were receiving enough money to train full time, limit stress factors, and have longer to prepare their bodies, I have no doubt we would see a big drop in ACL injuries throughout an AFLW season.

A lot of the AFL girls, some of which I have trained myself, have also never stepped foot into a gym before joining their teams. They are somehow expected to just partake in high levels of skill work, game structure drills, and conditioning with far less than desirable strength bases. On top of this, some of the girls have not played more than 1 season of regular football before being drafted. Those missed years of body awareness and conditioning are a huge factor to these athletes.

All of these factors, plus the gender difference regarding risk factors add up to a pretty high ACL injury rate.

HOW DO WE TRAIN TO TRY AND PREVENT ACL INJURIES FROM OCCURRING?

As the title of this article suggests, ACL prevention training is just, well, good training. But we do need to take into consideration a few key things when designing a training program for these female athletes that will not only help prevent ACL injuries, but also increase performance:

1. Are they strong enough?

What constitutes "strong enough" is a debate or another day, but making sure these girls can lift efficiently and at decent loads is key to ensuring they can produce AND absorb high loads. Remember, muscle strength around the knee and in general is very important to address for females. Squat, deadlift, bench press, chin ups are all good places to start building strength. Getting strong underpins all other athletic abilities. If you are strong, you have more room to develop power and speed.

2. What key sporting actions need to be addressed?

In AFLW, the need to cut, land and turn sharply are prevalent and there is more to ACL prevention than simply getting stronger.

3. Are they receiving adequate conditioning, outside of running at moderate speeds and in straight lines?

Most teams would adopt straight line conditioning such as Maximum Aerobic Speed (MAS) running and similar because they are time efficient, but while these are shown to increase V02max, they simply don't address change of direction or higher end running speeds at which ACL injuries (and other injuries) are more likely to occur.

So, how can we get these girls more resilient?

STRENGTH

We can place a BIG focus on increasing strength and the ability to decelerate. If we think about a change of direction movement and the muscles in the legs, we begin to realise that in order to change direction in the first place an athlete actually needs to decelerate first, using what's called an eccentric muscle action (a muscle stretching under load, think the lowering phase of a bench press and the pecs), then they enter an isometric muscle action, where the muscles actually hold static, and only then can the athlete push off in the other direction. If the athlete is weak, these muscle actions are far less efficient and can lessen the support around the joints and their ligaments because they cannot handle the demand placed upon them.

Single leg and glute strength

Single leg strength must be a priority when training to reduce ACL injuries. For females especially, the aforementioned Q Angle can cause a natural inward shift of the knee and therefore it is highly important that they learn to control where the knee tracks in relation to the hip and the ankle joints. Becoming strong and efficient at single leg exercises such as split squats, single leg squat variations, single leg deadlifts etc. will go a long way for female athletes to learn where the most stable positions are and then strengthen them. Performing these single leg movements effectively will strengthen the muscles of the lateral hip such as the glute medius and minimus muscles, which will assist the athlete in keeping correct alignment of the femurs during higher threshold movements. Targeted strengthening of these muscles in isolation may help, too.

Ankle and foot strength

The ankles and feet play a highly important role in how the strength will be distributed through the rest of the leg. If an ankle joint is highly unstable, the strength of the glutes will be inhibited. An ankle joint that falls into pronation (ankle caving inwards relative to the foot) will all but switch the glutes off and create an extra reliance on the quads to try and stabilise the knee joint. Adequate training of the feet and ankles must be included in a training program aiming to try and reduce the risk of ACL injuries.

WHAT KEY SPORTING ACTIONS NEED TO BE ADDRESSED?

There are a myriad of sporting actions that ARF demands, and they need to be prepared for (keeping in mind general training loads) in order to withstand competition. As mentioned above, running in straight lines at moderate intensities are great if you're sole goal is to improve V02max, but this type of running doesn't condition one's body for higher threshold activities such as sprinting, changing direction at high speeds, and landing from a jump.

Sprinting

Sprinting at maximum (or near maximum) effort is paramount during the pre-season (and in season to maintain conditioning) in order to keep the muscles and connective tissues resilient to this type of activity. Some argue that players will receive this conditioning during skills work or game simulation training. I argue that if you asked an athlete to run at max effort for 20 meters, they would run faster than at any time during their drills. What happens in a game when they are called upon to sprint at maximum effort to catch or outrun an opponent and they aren't ready for it due to being used to working at sub maximal intensities during training? An increased risk of injury.

Addressing sprinting action in the gym is also important in order to be sure that the athlete is performing sprinting actions with better technique to help produce more power and conditioning to support structures.

Change of Direction

As we now know, stopping suddenly to change direction is one of the highest risk positions we can get into in order to injure our ACL. Including drills in our gym programs that teach an athlete how to decelerate in the correct position, and push off the correct part of the foot in order to transfer weight effectively and safely is absolutely critical.

Landing Efficiency

Every female athlete should be dedicating time to learning how to land efficiently. You will never see an ACL rupture during a jump, but you can see plenty upon the landing if the athlete has insufficient awareness of positioning, strength and stability to land correctly.

If all of these qualities are being addressed in an athletes program you are giving them or yourself the best chance of avoiding a non contact ACL injury.

These are my thoughts on why the ACL injury rates in AFLW are so high at this point, and my ideas on how we can help and how athletes can approach their own training in order to help bring the rates of occurrence down.