Assessing and treating a sprained ankle

September 2, 2021

Ankle injuries are very common but difficult to diagnose. Slips, trips and falls are common in the outdoors. If someone takes a tumble and hurts their ankle, how do we know if it is broken, sprained or strained? Unless you see a bone sticking out then it is very hard to diagnose what is happening inside the body. Even in a hospital with an X-ray, it isn’t always easy to tell if an ankle is broken or not.

  • Sprains and strains are responsible for almost 10% of all hospital A&E visits.
  • Lower leg injuries are the biggest cause of mountain rescue call-outs in the UK.
  • Ankle sprains are the most common sports injury.

What are the different types of ankle injuries?

Soft tissue – Soft tissue refers to all muscles, ligaments, tendons, skin and internal organs. Injuries include blisters, cuts, sprains and strains.

Sprain – A joint sprain is tearing or overstretching of the ligaments. A ligament connects two bones together at a joint. One of the commonest sprains in the ankle. It is common for sprains to show bruising.

Strain – A joint strain is tearing or overstretching of the muscles and tendons. Tendons connect muscles to bones. It is common for strains to be associated with muscle spasms in the affected muscle.

Hard tissue – Hard tissue generally refers to bone and teeth. We would often think of a fracture or chipped bone as a hard tissue injury or a break.

Always consider the mechanism of injury

The most common mechanism of injury for an ankle is for the ankle to be “rolled” over in an outwards direction. This usually occurs as either a non-contact injury or when someone lands badly from a step or fall. Many casualties state that they have heard something “snap” during a fall. However, feeling a tearing sensation or hearing a snap does not always correlate with the severity of the injury.

It is hard to diagnose a sprain, a strain or a break without medical knowledge. Most certainly there will be an immediate feeling of heat in the injured foot, a lot of volume from your casualty and then some time to settle.

Once they’ve settled down from the initial shock of the injury, asking the casualty what happened will help you understand the potential level of the injury.

Boot on or boot off?

It would be very good to have a look at what is happening inside the casualty’s boot or shoe. In an urban situation, you may not do this as if the injury is serious, we would be calling the paramedics and they may arrive within 30 minutes.

In the outdoors we won’t get professional help so quickly, therefore, it would be good for us to take a look. Therefore, in a remote setting where we are more than 30mins from medical help – boots off! People have lost feet due to their circulation being severely compromised. If this severity of the injury is missed, the foot will be turning blue or grey within the boot so it’s better to see what is happening over time with your casualty’s feet.

What to check in the feet:

Most casualties have two legs and so it should be possible to compare the injured limb to the uninjured one. This will give an idea of how bad the injury is.

Pedal pulse check – Remember that there is a pulse in the top arch of the foot so you can also monitor the difference in pulse between the two feet. This is called the pedal pulse and is found at the highest point of the bone that runs along the top of the foot. You may have to move your fingers along the bone or slightly to either side to feel the pulse.

Check Colour, Sensation and Movement (CSM) around the ankle and foot and again you can compare and contrast between the two feet.

Colour – There may be discolouration and bruising around the ankle but also a loss of colour in the foot itself. The foot or toes turning white (pale) or blue would indicate a circulation problem. A capillary refill check regularly will help you monitor any change in the injury.

Sensation – Casualty can’t feel their toes or your fingers running along with the tips of their toes. Do they have any numbness, tingling or pain at the end of the limb? This could indicate a damaged nerve as a result of the injury.

Movement – Casualties can’t move their toes at all or have minimal movement of the foot.

Any compromise of Colour, Sensation or Movement is serious, and the injury needs to be immobilised effectively and safely. To achieve this, it would be wise to have attended some training!

To ICE or not to ICE a sprained ankle?

How to treat a sprained ankle – where there is NO LOSS of Colour, Sensation or Movement (CSM)

For soft tissue injuries, we are advised to ‘RICE’ the injury which will help reduce swelling and pain around the injury site.

R = Rest

I = Ice, actually cool the injury site

C = Comfort/compression bandage around the injury site

E = Elevate

Rest is important as you need to stop the activity and prevent any further injury to the site. You, the first aider, will also need to look at the injury.

Ice does two main things. It numbs the pain sensors and therefore reduces pain but also prevents some swelling. You can use any cold wet material, hats or bandages to apply the cooling required if you have no ice packs. Be careful not to apply ice for too long – 10 mins on, 10 mins off is a good rule of thumb for an ankle treatment in the initial stages. The NHS then recommends 15-20 minutes of cooling therapy every 2-3 hours over 3 days following the injury. This is easier for the casualty to self-manage once they have returned home.

Compression involves giving the limb some support and may limit some swelling. A compression bandage is usually an elasticated type and should not be so tight as to compromise circulation – again – compare with the uninjured foot. The bandage can be left on during the day but should be REMOVED AT NIGHT.

Elevation may also help reduce swelling and pain by limiting the amount of blood going to the limb. It should be remembered that we need some blood going to the injured site as the blood contains the ‘repair kit’ required to fix the injury.

When not to ICE a sprained ankle:

  • Don’t put ice over an open wound or fracture
  • If icing causes numbness or lack of sensation at the end of the injured limb, remove the ice
  • If icing causes more pain, remove it.

The Progressive Function Test for assessing ankle movement and strength:

Assuming CSM above is not compromised, you can carry out a Progressive Function Test on the injured joint. But do this before asking the casualty to do any weight-bearing or similar action requiring a lot of strength.

The test starts by asking the casualty to actively move their joint through 6 directions of movement (Up, Down, Left, Right, Twist in, Twist out). As with CSM above, use the uninjured joint for comparison. Support both feet with your hands holding behind each calf. 

Then you can carefully move the casualties joint for them through the same 6 directions and comparing the range of movement again, this is passive movement. 

Assuming no pain is felt in the first two parts of the function test, you can then assess the strength of the joint through the same 6 motions, by providing a resistance to the movement of the joint. Put a little force on the foot using your hand and see how they resist it. Do this in the same 6 movements.

It is useful in all stages of this test to look at their face for reactions, not at their foot.

If there is no pain at any of these three stages, it would be reasonable to ask the casualty, after a little time, to stand up carefully and try and weight bear. Give them some support to do this by helping them stand.

Recovery and return to activities?

If they’re feeling fully recovered, you can then get them to try and replicate the movements required for a return to the activity. This might include back-pedalling on a bike for cyclists or walking unaided for walkers.

As you have a conscious casualty, it is important to get their permission to do any first aid techniques or treatments. Don’t force them back onto their feet or to sit and accept some ankle immobilisation. The opposite might also apply! They may want to continue but you may feel their injury requires rest, immobilisation and/or evacuation.

More than just a sprained ankle?

Immobilising an injured foot – where there is SOME LOSS of colour, sensation or movement:

When considering the need to immobilise the foot, consider the time it may take to get medical help, whether the casualty will have to be moved and how much pain they are in. Now is also the time to ensure you’ve phoned 999/112 and help is on its way as this casualty is not to be moved.

The casualty may prefer to maintain their limb in a set position and not have any treatment. Encourage them to sit with it in the most comfortable position until medical help arrives.

Some strapping may help support the injured limb as long as it is not too tight. This can be done with broad tape to keep the ankle in the correct anatomical position or use bandages, again not too tight, to simply support the limb.

Immobilisation with bandages, strapping or splints will help prevent further pain or damage as it limits the movement of the ankle. This will aid evacuation in remote settings when the time comes.

With any treatment in a remote setting, ensure you have access to the toes so you can monitor and compare colour, sensation and movement in the injured and the non-injured foot.

Other important points to note:

One thing to remember is that the casualty, and particularly they’re injured joint, are probably very cold by now. So warm them up slowly and return them to their activity in a controlled manner if required.

It is always important to remember that there are many bones inside the foot and some may chip off and not be evident in a first aid assessment. Feet are complicated structures! – if in doubt, get them checked out at A&E.

Because the feet are complicated structures and because we rely on them for our daily activities, it always seems to take ages to recover fully. It’s important to ensure that care is taken during the recovery period to avoid further damage or prolong the recovery period. Ongoing treatment, medication and physiotherapy will help with a speedier recovery but it will never be instant!

Get confident in your first aid – get some training!

Attending some training on all of this is going to be very beneficial. Injuries such as ‘going over on your ankle’ happen regularly and this is one of the most likely incidents you’ll have to deal with in the outdoors as a first aider.

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