Do I need an X-ray? The Ottawa ankle rulesStrong evidence
After a twisted ankle, clinicians use the Ottawa ankle rules to decide who needs an X-ray. An ankle X-ray is needed if the back edge or tip of either ankle bone is tender to press, or you couldn't take four steps straight after the injury or when you are examined. A foot X-ray is needed if the navicular (the bony bump on the inner midfoot) or the base of the fifth metatarsal (the bump halfway along the outer edge of the foot) is tender, or the same four-step test fails.
The rules are very good at ruling fractures out. In the study that refined them, they picked up every fracture and could cut ankle X-rays by about a third; a review of 27 studies (15,581 people) found they missed almost no ankle or midfoot fractures, in children too, and could cut X-rays by 30 to 40%.
They are a guide for clinicians, not a self-test. If you can't walk four steps, if pressing on one of those bony points hurts, if the foot looks out of shape, or if you're unsure, get it checked the same day. Ligament damage is best judged 4 to 5 days after the injury, once the swelling has gone down.
Sources 1, 2, 3, 4
Who gets itEmerging evidence
The ankle takes about 1 in 5 new running injuries (19%), and about a third of injuries in ultramarathon runners. Achilles tendon pain (about 10% of new running injuries) and ankle sprains (about 6%) lead the diagnoses. Running loads the leg with about 2 to 3 times your body weight with each step, against about 1 to 1.5 times when walking, in a lab study of 12 men.
In pooled studies, sprains were 8.5% of injuries in distance runners but about a quarter in orienteers and cross-country runners, and a review of trail running calls them its commonest sudden injury. Across sports, women and children sprain their ankles more than men and adults.
Gradual ankle pain usually comes from a tendon: the Achilles at the back, the peroneal tendons on the outside or the tibialis posterior on the inside. In 1,929 recreational runners, 5.2% developed Achilles tendon pain between signing up for an event and a month after it (7.4% of marathon entrants), and a past episode raised the odds about 6 times; in another cohort, more running went with more Achilles pain. The NHS says ankle pain is often caused by exercising too much or wearing shoes that are too tight.
Sources 5, 6, 7, 8, 9, 10, 11, 12
The stress fractures not to missEmerging evidence
Stress fractures at the ankle are uncommon, but some matter a lot. The inner ankle bone (medial malleolus), the talus (the bone at the top of the ankle joint) and the navicular (on top of the inner midfoot) are high-risk sites: they heal less well and are often treated off weight in a cast or boot. In 8 people with a stress fracture of the inner ankle bone, the pain was in one spot on the inner ankle, the first X-ray showed the fracture in only 3, and those treated without surgery avoided running and jumping for at least 3 months; all healed within 5 months.
The fibula, the thin outer leg bone, is a lower-risk site, and a stress fracture a few centimetres above the outer ankle can make the outside of the ankle swell. Return to sport took about 8 weeks on average (56 days) after a fibula bone stress injury and about 4 months (127 days) after one in the navicular. Most foot and ankle stress fractures heal in about 6 to 8 weeks.
Sources 13, 14, 15, 16, 17, 18
When a scan helps, and what it can't tell youEmerging evidence
After a twist, the X-ray rules above decide. For one sore spot on a bone, an X-ray comes first, but it is often normal in the first weeks; magnetic resonance imaging (MRI) or a bone scan is more sensitive, and a computed tomography (CT) scan or MRI is used if a navicular fracture is suspected. For Achilles pain, a Dutch guideline uses ultrasound only when the diagnosis is unclear, and advises against scans to predict how it will go or to check progress. Tendon pain and impingement are mostly diagnosed from the story and an examination.
Sources 16, 15, 19
How it usually goesEmerging evidence
In new runners whose injuries a physiotherapist diagnosed, the middle time to recovery was 53 days for an ankle sprain, 82 for Achilles tendon pain and 86 for peroneal tendon pain, from small numbers. The NHS says most sprains feel better after 2 weeks, advises avoiding strenuous exercise such as running for up to 8 weeks, and says severe sprains can take months. An NHS hospital leaflet says healing takes about 6 to 12 weeks, and pain and swelling can last 3 to 6 months.
Repeat sprains are the main problem: a third of athletes in the comparison group of a large trial sprained the same ankle again within a year, and not managing jump-landing tasks 2 weeks after a first sprain predicted an ankle that keeps giving way. For the Achilles, the Dutch guideline expects a return to full sport only after a few months of active treatment; 85% of athletes return, and going back within days raises the chance of it coming back. No one can promise a date.
Sources 20, 4, 21, 22, 23, 19