You may not notice your ankle much except to wonder at the knobbly bits that stick out at the bottom of your leg. However, you will know, if you have had a sprained ankle, that it can be painful and restrict your movement. So what actually happens?
The most common (85%) ankle sprain happens when the foot is turned inwards under the leg. The ankle is pushed outwards and the body weight is accidentally put on the ankle in this odd position. It is easily done when walking if you trip or slip off a kerb or step. It occurs in sport when landing off balance or in the midst of sporting contact. People often talk about “turning over” the ankle.
Those who are unfit or who have failed to warm up before exercise are more likely to suffer this injury. A repeat of the same injury is quite common.
The piece of elastic type material which holds the ankle bone (talus) to the back leg bone (fibula) is called the anterior talofibula ligament. There are a number of ligaments in the ankle area but this is the one which suffers the extra pressure first and is the one usually damaged.
By pulling or twisting on this ligament too hard, you will tear some of its fibres and feel pain. The wound attracts fluid which will cause swelling to the ankle and the combined effect of the pain and swelling will be to restrict movement. You may find difficulty putting any weight at all on that foot.
Although Orthopedic doctors find this is the most common foot or ankle injury, there are more complicated sprains involving other ligaments too. This is more likely to be the result of a more serious incident and may result in the ligament being torn altogether.