What happens in an ankle sprain
In the typical mechanism the foot rolls inwards and the load is taken by the ligaments on the outer side of the joint – most often the anterior talofibular ligament. Depending on the force of the injury they are stretched, partly torn or torn through completely. Swelling and bruising appear within a few hours and in themselves say little about how severe the damage is.
Beyond the ligaments, proprioception suffers too. Receptors in the joint capsule stop telling the muscles in time how the foot is positioned, so the protective reaction to the next roll comes too late. That explains why the ankle gives way even when nothing hurts any more.
When to see a doctor first
The Ottawa rules are a simple set of criteria for deciding whether an X-ray is needed. There are in fact two sets – one for the ankle and one for the foot. They share the first condition: imaging is done when, straight after the injury and during the assessment, you cannot transfer your body weight onto the leg and take four steps.
The remaining criteria differ. An X-ray of the ankle is indicated when there is tenderness over the back edge or the tip of the lateral or medial malleolus – along about six centimetres upwards. An X-ray of the foot – when the base of the fifth metatarsal or the navicular bone is tender. We check these points at the first visit and, if needed, refer you to a doctor before starting treatment.
How we run the rehabilitation
The first stage is to restore walking: controlled loading, reducing the swelling and regaining dorsiflexion of the foot, without which you cannot squat properly or run down stairs. We use manual therapy for the ankle and the foot, and soft tissue work on the calf.
The second stage decides whether the injury will happen again. We strengthen the peroneal muscles and the calf and introduce balance exercises – first on a stable surface with your eyes open, then on a soft mat, with ball throws and changes of gaze direction. At the same time we rebuild the strength of the whole leg, because after a few weeks of sparing it the difference in calf strength can be considerable and shifts load higher up, as far as the knee.
Returning to sport on criteria
Instead of asking how many weeks, it is better to ask what you need to be able to do. We go back to running when walking is pain-free and symmetrical and the swelling does not return after a day of activity. We go back to playing when a single-leg hop for distance and repeated side hops come out comparably on both legs. We write that plan individually and update it at follow-up visits.
A separate question is a brace or taping. When you return to team sport, external ankle support in the first weeks makes sense and reduces the risk of a repeat injury – as long as it accompanies balance and strength training rather than replacing it. We take it off once the tests come out symmetrical on both legs.
It is also worth remembering that recurrent sprains can, over the years, lead to chronic instability and changes in the joint cartilage. That is the argument for working properly through even a mild injury that stops hurting after a week.