ACL injury prevention is becoming a more popular focus in many sports.
No-one wants to be on the sidelines and ACL injuries typically have the longest recovery time of all knee injuries.
In the US, approximately 200,000 people per year suffer an ACL injury with about half of these requiring surgery.
The recovery process is long and for sports people, it usually means being side-lined for about one year. When it comes to ACL injuries it is definitely a case where prevention is much better than cure.
ACL injury prevention starts by understanding how the ligament works and how it tends to get damaged.
The ACL (anterior cruciate ligament) is one of four knee ligaments that are responsible for controlling stability. It sits between the thigh and shin bones in the middle of the knee joint and controls the forwards and twisting movements of the skin bone (tibia).
Functionally, the ACL works for all movements of the leg, but it is especially important with starting, sudden stopping and twisting movements.
High risk sports for ACL knee injuries include:
The ACL is flexible and can stretch to a degree, but too much strain through it will cause it to tear. This usually happens in one of two ways:
1. Direct Trauma: Anything that puts too much force through the ligament such as a sports tackle, hard fall or car accident
2. Twisting: Sudden turning and twisting the leg when the foot is stuck to the ground e.g. with studs or cleats
Effective rehab to reduce the risk of ACL injuries should incorporate a number of things:
Warming up before exercise is one of the oldest pieces of advice out there but it really does play an important role in knee injury prevention. Warm ups usually last about 15 minutes and should be designed to get your body prepared for activity.
Activities such as
jogging, shuttle runs and running in different directions should be
incorporated into warms ups focusing on ACL injury prevention.
Stretches are an essential part of ACL injury prevention as they help to improve the flexibility and therefore performance of the knee, both of which reduce the risk of knee injuries.
Stretches for the quads, hamstrings, calves, hip flexors, inner thigh and glutes muscles should all be done regularly.
The most effective way to stretch is to hold the stretch for 30 seconds and repeat it 2-3 times.
Find out all about how to effectively do stretches and check out our simple tests to see how tight your muscles are in the knee stretches section.
Improving the strength of the quadriceps, hamstrings, glutes, calf and trunk muscles helps the muscles work together to provide more stability to the knee thus supporting the ACL and reducing the risk of injury.
It is very easy to think that just playing sport is enough, but actually, exercises that focus not just on the strength of the knee, but also the stability of the knee are really important for ACL injury prevention.
In the knee strengthening exercises section you will find loads of information on the best ways to strengthen all the different knee muscles including loads of top tips to help you get the best from your exercises.
Neuromuscular training is becoming a very popular part of ACL injury prevention programmes, designed to improve dynamic stabilisation of the knee. Neuromuscular programmes also teach individuals how to land from jumps, pivot and change direction without putting too much force through the ACL.
One element of this is plyometric exercises - specialised, high intensity exercises to improve power, strength and speed through various jumping and hopping activities. They work by causing the muscle to first lengthen and then quickly shorten. Plyometric exercises should only be done under close supervision as they involve high-risk movements and if done incorrectly, can result in injury.
Having good proprioception is a vital part of preventing ACL knee injuries. Proprioception is the reflex control at the knee through small muscle and ligament adjustments that provides the stability of the knee joint.
The anterior cruciate ligament is responsible for providing the primary proprioceptive input at the knee so exercises targeting the ligament can make a massive difference.
Balance exercises such as
exercises on one leg, on a wobble board and with your eyes closed
helps improve balance and proprioception and thus are an important part
of ACL injury prevention.
ACL injuries often occur when the foot is stuck to the ground and the knee twists. Where possible, avoid shoes with cleats/studs, particularly if playing contact sports.
There is some controversy over whether wearing a knee brace helps with ACL injury prevention.
Pros: Wearing a knee brace can help reduce the risk of over stretching the ligament but
Cons: knee braces can create a false sense of security
In the general population, there is usually no need to wear a knee brace when playing sports, but in high-level athletes participating in high-risk activities, an ACL knee brace may help reduce the risk of injury.
Knee braces can be particularly useful
after a ACL reconstruction surgery to reduce the risk of further injury during
the rehab and recovery phase, whilst working on the strength, stability and
Effective ACL knee injury prevention combines some or all of the suggestions above. Coaches of high risk activities such as basketball, soccer and football should ensure they are encorporating exercises specifically targeting ACL injury prevention into their programmes to help reduce the risk of injury.
You can find out loads more about ACL knee injuries in the following articles.
Page Last Updated: February 26th, 2020
Next Review Due: February 26th, 2022