The commonest basketball injury, and mostly shortStrong evidence
Basketball's jumps, landings in a crowd, cuts and sideways slides load the ankle at the end of its range, often when a foot lands on another player's. In US college basketball, the ankle sprain was the commonest injury (17.9% of men's and 16.6% of women's injuries); in the NBA, outer ankle sprains were 13.2% of injuries and "more than twice as common as any other injury", and about 1 in 4 players (25.8%) sprained an ankle each season. In the Women's NBA (WNBA), outer ankle sprains were the commonest injury (20%), though knee injuries cost more games. In US high schools, boys' and girls' basketball had the highest ankle injury rates of all sports, and across 181 studies of all sports, indoor and court sports had the highest rate of ankle sprains. Across 22 studies, the ankle was the commonest site, 25.8% of basketball injuries; in Canadian youth players counting every complaint, the ankle led in girls (45%) and the knee in boys (51%).
Most are short: 56% of NBA ankle sprains didn't cost a game, and the rest cost a median of 2; in US college athletes, 44.4% of outer ankle sprains were back within a day; and most college basketball ankle injuries were treated without surgery, were new injuries and cost less than 7 days.
Sources 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
How it happensEmerging evidence
In recreational players, there were 3.85 ankle injuries per 1,000 times a player took part, landing caused 45% of them, and almost half (45.9%) missed a week or more. In college basketball, contact with another player was the commonest way it happened (men 57.6%, women 50.4%) and rebounding the commonest activity (34.4%), and 71.2% of NBA sprains involved contact. The NBA authors call the sprain count "not surprising in light of the frequency of jumping and landing in a crowd of players".
Sources 12, 10, 3, 2
Repeat sprains and ankles that keep giving wayStrong evidence
A past sprain is the biggest risk for another: recreational players "with a history of ankle injury were almost five times more likely to sustain an ankle injury", the NBA rate was 1.41 times higher after a previous sprain, and 21.1% of women's and 19.1% of men's college basketball sprains were repeats. Poor one-leg balance before the season went with nearly seven times as many ankle sprains in high school players. The International Ankle Consortium says repeat sprains are common and lead many people to develop chronic ankle instability.
Estimates of instability in players vary widely: 30% of 57 US college players in an older study, and 76% in a self-report survey of 391 Taiwanese college and semi-professional players, which is likely a high estimate. Across sports, repeat sprains were the most reported feature of an unstable ankle.
Sources 12, 3, 9, 13, 14, 15, 16
High ankle sprains, and the front of the ankle after many sprainsEmerging evidence
About 7% of college basketball ankle injuries were high ankle (syndesmosis) sprains. Across US college sports they were about a fifth as common as outer ankle sprains, and "High ankle sprains resulted in significant participation restriction time from sport participation".
In 100 adults having surgery for an ankle that kept giving way, 63% had an irritated joint lining (synovitis), mostly at the front, 17% cartilage damage and 12% bony impingement at the front; in 148 people with long-lasting instability, cartilage damage was found in 66% of ankles with outer ligament injuries. These are surgical series of the hardest cases, not typical sprains, but they explain why front-of-ankle pain that won't settle after repeated sprains needs assessing.
Sources 10, 17, 18, 19
The Achilles, and the outer edge of the footEmerging evidence
Achilles tendon pain affected 4.3% of 515 Canadian youth players over a season, against 19.0% for patellar tendon pain. An Achilles rupture is rare, about 2.1 per 100,000 people a year in US emergency data, but basketball was the commonest cause; the highest rate was in men aged 20 to 39, and the biggest rise was in people aged 40 to 59 playing recreational sport. At one US referral centre, basketball caused 48% of sports ruptures, at a mean age of 46. In NBA players on video, the commonest mechanism was taking off from a stopped position with the ankle bent up.
A fracture at the base of the fifth metatarsal (a Jones fracture), on the outer edge of the foot, also happens in basketball; in NBA players, 85% returned to their previous level. Our outer foot pain guide covers it.
Sources 20, 21, 22, 23, 24
When a scan or test mattersStrong evidence
Most rolled ankles need no X-ray. Clinicians use the Ottawa ankle and foot rules (see the warning signs): across 27 studies of 15,581 people, "The instrument has a sensitivity of almost 100% and a modest specificity, and its use should reduce the number of unnecessary radiographs by 30-40%". A Dutch guideline judges ligament damage by examination 4 to 5 days after the injury, and the International Ankle Consortium asks clinicians to check every recent sprain for mechanical and sensorimotor problems, such as a loose joint, weakness or poor balance.
A scan matters for pain above the ankle after a twist outwards (a high ankle sprain can be unstable), deep pain that hasn't settled 6 weeks or more after a sprain (a cartilage injury), a suspected stress fracture, or a tendon that slips.
Sources 25, 26, 27
How it usually goesEmerging evidence
The NHS says "After 2 weeks, most sprains and strains will feel better", and to "Avoid strenuous exercise such as running for up to 8 weeks, as there's a risk of further damage". NHS inform says to speak to a healthcare professional if your ankle isn't getting better by 8 to 12 weeks or is getting worse. NBA sprains that cost games cost a median of 2, and about two-thirds of college basketball ankle injuries cost under a week. After high ankle sprains, 99% of elite athletes returned, at about 4 weeks without surgery and 7 weeks with it in high-level athletes, and across 312 athletes the mean was 46 days. Repeat sprains are the main long-term problem, and the consortium links them with more ankle osteoarthritis later.
After an Achilles rupture repair, NBA players returned at a mean of 10.5 months, and return rates ranged from 61% in an older NBA series to 80% in a newer one; across leagues, players who returned performed like uninjured players 2 years after surgery. These are averages from small groups of professionals, and no one can promise a date.
Sources 28, 29, 3, 10, 30, 31, 14, 23, 32, 33, 34
When it isn't basketball: the causes the warning signs cover
Some ankle pain has causes basketball didn't create, and the warning signs follow the pages behind them. The NHS broken ankle page says to go to A&E for an ankle at an odd angle, a bone sticking out or toes that look blue or white, and the Ottawa ankle rules, tested in emergency departments and in a review of 27 studies, pick out who needs an X-ray. After a twist outwards, the outer leg bone can break high up near the knee (a Maisonneuve fracture): a case series of 5 missed ones says the whole bone should be examined in every ankle injury, and two reviews describe how such injuries are treated. A tendon slipping over the outer ankle bone needs a specialist review, an international consensus says, and a review calls peroneal tendon problems a cause of outer ankle pain that can be hard to tell from a ligament injury. Pain, clicking, locking or swelling that carries on despite good rehab can mean cartilage, tendon or other problems alongside an unstable ankle, as our chronic ankle instability guide sets out from a US clinical practice guideline and the same peroneal review. A snap at the back of the heel can be an Achilles tendon rupture, as an NHS hospital's leaflet describes. A sudden hot, red, swollen joint can be gout or a joint infection, which the NHS septic arthritis page says needs urgent treatment, and hot, swollen, painful skin can be cellulitis, which the NHS cellulitis page says needs a 999 call with signs of a serious infection. A foot that is suddenly cold and pale without an injury is a vascular emergency, unlike the gradual leg pain the NHS peripheral arterial disease page describes, and a throbbing, swollen calf after an injury or a boot can be a blood clot, as the NHS DVT page explains. With diabetes, the National Institute for Health and Care Excellence (NICE) asks for a new foot problem to reach a specialist foot service within 1 working day. Someone who faints while exercising needs a 999 call, as the NHS fainting page says.
One spot on a bone that hurts with every step, and later at night, can be a stress fracture, as Health New Zealand describes. The inner ankle bone, the outer edge of the midfoot and the front of the shin are high-risk sites that heal less well, two reviews of high-risk stress fractures say, and in 8 people with a stress fracture of the inner ankle bone the first X-ray showed it in only 3. More than one stress fracture, periods that stop, or eating too little for your training needs a GP: the International Olympic Committee calls this relative energy deficiency in sport (REDs), and an Endocrine Society guideline covers periods that stop. Bone pain that is constant or worse at night needs checking, the NHS bone cancer page says, though that is rare.
Sources 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78
