Ligaments are tough bands of tissue that connect the ends of bones. The posterior cruciate ligament is located in the centre of the knee joint. It connects the front of the femur (thighbone) and crosses to the back of the tibia (shinbone).
The posterior cruciate ligament is made of two thick bands of tissue bundled together. One part of the ligament tightens when the knee is bent; the other part tightens as the knee straightens. This is the reason the posterior cruciate ligament injury occurs at the same time as the anterior cruciate, when the knee is forced to straighten too far, or hyper extend.
posterior cruciate ligament injury causes
The most common way for posterior cruciate ligament injury to occur is from a direct blow to the front of the knee while the knee is bent. The posterior cruciate ligament controls how far backward the tibia moves in relation to the femur. If the tibia moves too far, posterior cruciate ligament injury can occur. The most severe form of posterior cruciate ligament injury is rupture, where the ligament tears completely.
If the posterior cruciate ligament is only strained, then symptoms include pain and slight swelling within the knee joint. The knee will feel stiff and be difficult to walk on for a couple of weeks. However posterior cruciate ligament strain will not cause major instability in the knee.
A posterior cruciate ligament injury that leads to rupture can have varied symptoms. Unlike an anterior cruciate ligament tear, swelling is minimal with posterior cruciate ligament injuries. Symptoms will feel like a cruciate strain however the knee will also feel unstable. Athletes usually describe the knee as ” giving way” when weight bearing.
The pain and moderate swelling from the posterior cruciate ligament injury will usually go away after two to four weeks, but the knee may still feel unstable requiring treatment. If posterior ligament injury is left untreated, long-term instability can lead to arthritis of the knee.
!!!The following advice pertains to ligament strain only! If the posterior cruciate ligament has been injured and rupture is suspected, medical help should be sought.!!!
Posterior cruciate ligament injury can occur at the contact phase of gait (when the foot hits the ground) due to increased biomechanical stress at this point. It is therefore vital to strengthen the ankle and control biomechanical forces.
Golden rule- Don’t ignore the problem, it won’t go away!
The way we function biomechanically is predominantly controlled by genetics, its hereditary (runs in the family). The way you function is set and cannot be cured. What you can do however is control lower limb biomechanics by altering foot position during the contact phase of gait. This can be achieved by wearing a good shoe (see our shoe guide) with orthotics (foot beds), knee strengthening and knee support.
Check your footwear
Are your running shoes worn and in need of replacing? If so change them. The chances of anterior posterior ligament injury is greatly increased with higher impact forces so a good shock absorbing shoe is a must. For more advice on running trainers our running shoe advice page is worth reading. Read more->
Below are a selection of trainers that are ideal for athletes.
Trainers for a neutral foot type
Trainers for over pronators
rectify Poor biomechanics with orthotics
The way your foot strikes the ground and the forces that are placed on it can have a direct effect on biomechanics causing posterior cruciate ligament injury and can also delaying healing times. Check our biomechanics page for detailed information. Read more->
The single best exercise to improve the strength of the muscles around the knee is eccentric loading. This is usually done none weight bearing., however the use of a wobbleboard is an excellent way to strengthen muscles around the knee, foot and ankle in a controlled gentle manner. Whilst our clinicians have found it a brilliant way to strengthen muscles around the knee, traditionally a wobbleboard was used to help balance (proprioception). Proprioception is the nerve connection from the brain to the foot. This is often damaged/ disrupted after injury and can increase the chances of injury from recurring. It can also significantly delay recovery.
Use of a wobbleboard therefore has a dual benefit in the treatment of posterior cruciate ligament injury.
One of the most vital considerations after suffering cruciate ligament injury. This device provides extra stability to the knee when playing sports. The material also causes localised vasodilation (opening of the blood vessels) increasing circulation to the area. Ligaments have a notoriously poor blood supply. Increasing circulation to the ligaments can reduce the chances of further cruciate ligament injury.
Posterior cruciate ligament injury prevention checklist summary
- Rectify Biomechanics if necessary
- Check Running shoes
- Knee strengthening
- Knee support
Returning to Activity
The goal of rehabilitation is to return you to your sport or activity as soon as is safely possible. If you return too soon you may worsen your posterior cruciate ligament injury which could lead to permanent damage. Everyone recovers from cruciate ligament injury at a different rate.
Returning to your activity is determined by how soon your cruciate ligament recovers, not by how many days or weeks it has been since your anterior cruciate ligament injury occurred.
You may safely return to your sport or activity when, starting from the top of the list and progressing to the end, each of the following is true:
You have full range of motion in the injured leg compared to the uninjured leg.
You have full strength of the injured leg compared to the uninjured leg.
You can jog straight ahead without cruciate ligament injury pain.
You can sprint straight ahead without posterior cruciate injury pain.
You can do 45-degree cuts, first at half-speed, then at full-speed.
You can do 20-yard figures-of-eight, first at half-speed, then at full-speed.
You can do 90-degree cuts, first at half-speed, then at full-speed.
You can do 10-yard figures-of-eight, first at half-speed, then at full-speed.
You can jump on both legs without pain and you can jump on the injured leg without pain.
Posterior cruciate ligament surgical intervention
If a complete rupture has occurred, the only realistic option is surgery to repair torn the ligament.
Below is a video showing surgery