Mechanism of Injury
A sprained ankle is a common injury that is often undertreated and recurring. The most common mechanism of injury occurs when the foot is in its least stable position, the pointed position (plantarflexion), and rolls inwards (inversion). For example an ankle roll over the side of a curb, sudden changes in direction or landing awkwardly from a jump. These cases may result in damage to the structures on the outside of the ankle, called a lateral ankle sprain.
The lateral ankle complex is made up of three ligaments (anterior talofibular, calcaneofibular, and posterior talofibular ligaments), a nerve (branch of the peroneal nerve) two tendons (peroneals longus and brevis), and a fibrous tissue overlying some of these structures called a retinaculum. These can all be damaged following a sprained ankle. More often than not, the anterior talofibular ligament is involved.
NB: if you notice pain or irritation higher up the ankle, particularly as you step forward over the affected ankle, this may indicate a more severe injury to the syndesmosis (fibrous tissue between the lower portion of the two shin bones) and may need more specific treatment. Consult a physiotherapist.
Grades of Severity
There are three grades of ankle sprain which indicate the severity of injury.
Grade 1: involves overstretching and/or microscopic tearing of the ligaments. These heal relatively quickly within 2-4 weeks. The symptoms of a grade 1 injury may result in some mild pain with little to no swelling. The person involved will often be able to carry on with the activity they were doing and may just have a feeling of stiffness through the ankle.
Grade 2: results in partial tearing of the tissues. This can cause bruising and swelling around the area to develop instantly or over the next 48-72 hours. There is moderate to severe pain causing the person to stop the activity that they were doing and will likely affect their ability to walk. The ankle will have both feelings of stiffness but also instability.
Grade 3: is a complete tear of the ligament(s). There will be immediate severe pain (although this may quickly subside). Swelling will develop immediately with bruising developing over the next 48-72 hours. The ankle will be unstable and weak and walking may confer a feeling of giving way and pain. Severe ankle sprains can take up to 3 months to heal and will often require x-ray investigations to rule out bone fracture.
Initial treatment (2-4 weeks) of ankle sprains include:
- swelling management using the RICE(D) principles;
- aggravation management;
- walking retraining to avoid compensation injury;
- and perhaps the use of external stability i.e. taping or brace support.
The second phase of treatment (up to 3 months) focuses on:
- restoring full, pain-free range of movement at the ankle;
- retraining functional patterns of the affected lower limb including ankle strategy and balance reactions;
- and improving lower limb biomechanics in relation to trunk control and stability.
Sports-specific exercises are included when appropriate i.e. change of direction, acceleration and deceleration loads and/or impact loading drills to build resilience for a return to sport or higher activity level.
Treatment time of ankle sprain varies depending on the grade of strain, the underlying biomechanics which may have precipitated the initial injury, development of movement strategies to avoid pain or to compensate for instability or weakness, and the level of activity the client is returning to.
It is important to fully rehabilitate an ankle sprain because a lack of range or stability can influence the way you move and feeds in to the development of longer term, chronic issues such as achilles pain, arch pain, arthritis, knee pain or a tibial stress syndrome (think shin splints). Depending on severity this can take between 3-6 months or up to a year.