If you have never sprained your ankle, chances are you know somebody who has. Lateral ankle sprains are one of the most common musculoskeletal injuries sustained in sport and during daily activities. Often the initial injury can not be prevented, however if it is managed correctly the chances of re-injuring the ankle can be reduced and recurrent ankle sprains can be avoided.
The most typical ankle sprain involves damage to the ligaments on the lateral, outer side of the ankle. This happens when the foot lands in plantar flexion and inversion - with the toes pointed down and the foot rolled inwards so that it lands on the outside edge of the foot. This leads to over stretching and/or tearing of these lateral ankle ligaments. Some people describe a twinge or 'pop' at time of injury felt on the outside of the foot.
The lateral ankle ligaments comprise the posterior talo-fibular ligament, the calcaneo-fibular ligament and the anterior talo-fibular ligament. These ligaments connect the bones of the leg and ankle and are highlighted in the diagram below. Usually it is the anterior talo-fibular ligament that is damaged the most, any 1, 2 or all three of the ligaments may be damaged. At the same time the muscles on the outside of the leg (the fibularis muscles) may be over stretched, and the bones in the ankle joint may be jarred or bruised. Your physio will assess your ankle and injury mechanism to reach a provisional diagnosis regarding the source of your symptoms. Medical imaging is not usually indicated in the acute phase unless there is suspicion or indications of significant soft tissue injury, fracture or bony fragment (clinician's use the 'Ottawa Ankle Rule' to decide).
When the ligaments are injured the associated tissue damage leads to bleeding. This causes the typical pattern of bruising, inflammation and swelling that may extend throughout the foot. The more damage, the more swelling, bruising and pain. There is usually a degree of pain in weight bearing and the ankle is stiff and sore to move initially. These symptoms typically improve a lot in the first 7-14 days (with some help from your friendly physio, ice/elevation/compression +/- some analgesia or anti-inflammatories from GP consult). Within 2-4 weeks most people are back walking and running comfortably and feel they are ready to return to their usual work/sport/exercise. But will their ankle be as strong, mobile and well controlled as before injury?
In short the ankle is not as strong, well controlled or mobile as before injury. The ankle ligaments not only serve to bind the bones together that form the ankle joint, they are also sensory structures. Think of them as rubber bands - as your joint moves around, they stretch/become slack. They send this information to the brain via sensory pathways in the spine to tell you about what position your ankle is in, how fast it is moving and how much pressure it is under. This helps us to control our ankle through reflexive and anticipatory muscle contractions of the muscles in our calf, foot and around our shin. Similarly the ankle joint has receptors on the cartilage that tell the brain about joint compression. These are often damaged at the time of the sprain. The rolling of the foot inwards also leads to over stretching of the fibularis muscles on the outside of the leg, causing strain/damage and an impaired ability to contract properly.
In combination, this loss of sensory feedback from the joint and ligament receptors, and strain of the fibularis muscles, leads to a loss of sensory information that is needed to control the ankle in a quick and coordinated fashion, and the muscles are weak and slow to react to disturbances. This manifests as poor balance on the affected leg, and an increased risk of re-injury. Many people sprain there ankles time and time again, and this is why! As the damaged tissues heal they may also scar, and the ankle can lose mobility in certain directions which can contribute to further dysfunction and injury on returning to exercise.
The good news is that a lot can be done to reduce this risk of re-injury by improving balance, strengthening the ankle and by ensuring adequate ankle mobility. Whilst the sensory receptors that are damaged at the time of injury can never heal, balance can be trained to compensate for this loss of information. Similarly the ankle muscles (especially the fibularis) can be strengthened and their reaction speed improved to help protect the joint. Training focuses on improving strength and control in at risk positions and situations - where you are on the point of your toes, on variable/soft ground, or on one leg and under high load such as when jumping or landing. These exercises are gradually introduced after your injury, initially only as simple exercises that do not provoke pain or over stress the damaged area. Your physio may also give you exercises and perform manual therapy to restore full range of motion in the ankle.
After 2-4 weeks (depending on sprain severity) the tissues are healing and inflammation settles, higher level exercises can be introduced. It is these exercises that are the most important for restoring the strength and control around the ankle that we have discussed. Some examples of specific, challenging and effective exercises are shown in the videos below:
Bosu Ball hops: In this exercise the aim is to land on your affected ankle and maintain your balance. In the video shown, the patient bounds forward onto their right ankle, landing with the knee slightly flexed. They then try to 'stick' the landing, keeping their balance by controlling their position with their hip, knee and ankle muscles. This exercise can be progressed to hopping with one leg, and by performing in multiple directions e.g. forwards, backwards, sideways and diagonals. Drills such as throwing/catching can also be incorporated for specific sports such as netball.
Star balance exercises: The aim with these exercises is to load the ankle in multiple planes to challenge anticipatory balance and muscle control. In the video, the patient stands on their affected leg, knee slightly bent. Their other leg is held off the ground and moved in diagonal patterns in multiple directions, as marked by the tape pattern. The aim is to hold your balance as your limb moves through these different directions and disrupts your equilibrium.
Ankle eversion strength in a plantar-flexed position: This exercise aims to add strength and control to the ankle in its vulnerable position - on the point of the toes with the foot rolling outwards. The patient stands with their affected foot on the point of their toes. An elastic band pulls their ankle outwards (into inversion). From this position, the patient practices returning their foot to a middle position after it is pulled outwards into inversion. This movement targets the fibularis muscles on the side of the leg that are responsible for controlling the ankle and preventing sprains.
This exercise can be progressed so the patients stands on the tip toes on both feet, or only on the one leg.
Before you hit the gym or get back on the sporting field after an ankle sprain, make sure you are properly rehabilitating your ankles to reduce your chance of further injury. If you are victim of recurrent ankle sprains, try adding in some of these exercises to assist your recovery and talk to your physio for advice. Make strong stable ankles your staple!
The Gap Physio