Your knee is a hinge joint which contains four ligaments. Sprains to the knee damages one or more of these ligaments. The ligaments are strong fibrous tissues which connect the bones in the knee joint, keeping them aligned and able to move freely. These ligaments are easily damaged if they are overstretched, or stretched in a direction outwith their normal range of movement. These injuries are known as sprains and are a relatively common, particularly in certain sports.
A knee sprain occurs when you overstretch or tear the ligaments in the knee. This usually happens if you exert too much pressure on a ligament, such as when changing direction or stopping suddenly when you are running. It can also be caused by an external blow to the joint.
The knee is not designed to move from side to side, so any lateral stress is likely to result in pain and perhaps a sprain.
The symptoms you experience will depend on how you injured your knee, and the severity of the damage. Knee sprains have been split into three categories depending on the extent of the damage:
- Grade 1 – this is the least severe type of injury you can sustain. It usually involves overstretching the ligament and may include some small tears in the ligament. The pain will not be severe, and you should be able to bear your own weight, although it may not feel as strong as the other knee
- Grade 2 – this involves partial tearing of the ligament. It will be sore to move and tender to touch. You may not be able to put your full weight on the injury and it may seem a little unstable. Some bruising and swelling may develop
- Grade 3 – this is when you have torn most of or have completely ruptured a ligament. It will be very painful, and you will not be able to bear your own weight. There will be significant instability in the joint. Bruising and swelling may develop which will also restrict the movement of your joint.
It is impossible to completely free yourself from the risk of a knee sprain. However, you can minimise your chances by employing some simple techniques – mostly a bit of care and common sense!
Wearing proper trainers when exercising is the first step towards protecting your joints. They will stabilise your foot and ankle making lateral movements of the knee less likely. It is important to learn the correct techniques in a sport, or you will cause more damage to muscles and joints than just your knee. Incorrect technique may also lead to Repetitive Strain Injury (RSI).
It is important to warm up all your muscles and joints before you start exercising to make sure that they are fully flexible and ready for increased stress. You may also find that knee strengthening exercises may reduce your chances of a sprain.
Knee sprains can also occur if you twist your knee in an awkward way if you fall. Avoiding icy or slippery conditions will not only reduce your chances of incurring a knee sprain, but other injuries as well.
The treatment for your knee sprain will depend entirely on how you have damaged your knee and the severity of your symptoms. Immediately after spraining your knee you should follow the PRICE procedure, and within the next 72 hours you should also protect your injury against further HARM.
You may also find that pain killers and anti-inflammatories, including herbal remedies such as those containing the arnica can help ease your discomfort.
For some injuries, particularly Grade 3 sprains, or if you are unable to bear weight on your leg, you may need to seek medical attention. It is important to give your injury adequate recovery time so that it returns to full strength and mobility.