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Part of Ice hockey and skiing injuries: ski boots, skates and what each sport does to a body

Ski and hockey knee injury: which ligament, and what happens next

A ski knee injury serious enough to reach a hospital is usually a ligament, and in the one series where every knee was scanned the anterior cruciate ligament was involved in all of them, most of them with something else torn alongside it. A hockey knee injury is a different animal, and sorting the two out is what this page is for: on snow the usual story is a twist or a backward fall with nobody else involved and the boot still fixed to the ski, while on ice it is most often a blow to the outside of the knee that opens the inner side and sprains the medial collateral ligament. Nothing here can tell you which one you have, because that takes an examination and often a scan rather than anything you can work out on a mountain. What it can do is set out the mechanisms, say honestly what the equipment research supports and what it does not, and point you at the right program. Two situations do not wait: a knee that swelled within a few hours of a twist, fall or blow, or that felt a pop, is an emergency department visit, and so is a knee that felt as though it slid right out of place and went back by itself, however normal it looks now.

Warning signs, and when to get help

Which knee ligament do skiers tear?

The answer most pages give is the one from the 1980s, and it has changed. A two-season study at an Austrian sports clinic in a large ski area scanned every knee injury it saw, all of them hurt badly enough to need hospital care, and among 282 recreational skiers, 51.8 percent of them women, the anterior cruciate ligament (ACL) was involved in every knee injury recorded: 182 of them, 64.5 percent, with other structures torn as well, and 100, 35.5 percent, with the cruciate alone (Posch and colleagues, 2021). Among those with more than one structure injured, the medial collateral ligament (MCL) was the commonest companion at 92 patients, 50.5 percent, then the medial meniscus at 73, 40.1 percent, and the lateral collateral ligament at 41, 22.5 percent.

The paper's own conclusion is the interesting part: before carving skis arrived, the MCL was reported as the knee's most commonly injured part, and now most ski knee injuries at this severity are cruciate injuries with other structures torn alongside them (Posch and colleagues, 2021).

Read that with the population attached, because it does half the work. This is a clinic series of knee injuries severe enough to need hospital care, all confirmed on a scan, which is a level III design. It describes the serious end of the mountain and not every sore knee coming off a chairlift, and nothing readable gives the breakdown for the whole hill. So the useful statement is not that the MCL claim is wrong, it is that the MCL claim describes a different era and a milder severity band.

One older prospective series adds a detail worth having if you ski with family. Across two Vermont areas from 1981 to 1994, the commonest injury in the final eight years was a knee bruise in children, a thumb ligament sprain in adolescents and a grade III cruciate sprain in adults (Deibert and colleagues, 1998). The same study recorded adult tibial fractures falling 89 percent while cruciate injuries rose 280 percent, which is the equipment story in two numbers.

What does a ski knee injury feel like when it happens?

Three mechanisms account for most of it, and they feel different from each other. The frequencies come from one survey, run over six ski seasons, of 541 recreational skiers with a fresh knee injury, each asked to pick which of six descriptions came closest to what happened to them: 32.9 percent for the knee being driven inward while the lower leg turns outward, 22.5 percent for the backward fall onto the inside edge of the downhill ski, often called the phantom foot, and 19.0 percent for the knee being forced straight past straight, with 7.8 percent for the boot driving the shin forward, 2.2 percent for collisions and 15.6 percent for everything else (Shea and colleagues, 2014, as reported in Davey and colleagues, 2019). Take the method with the numbers. Those shares depend on injured skiers recalling a fall that lasted a fraction of a second and then choosing from a list, and the review that carries them says in plain terms that recall of the injury event is not reliable.

What people describe afterward is fairly consistent. Something went in the knee, often with a pop or a bang that other people heard, the leg would not take weight properly for a few minutes, and the knee filled up over the afternoon. Fast swelling after a twist, a fall or a blow is the sign that puts this in the first group of warning lines at the foot of this page, because a joint that fills within a few hours has usually bled inside.

One picture matters more than the rest. If the whole knee felt as though it shifted right out of place and then went back, or if it now feels loose in more than one direction, that is not a single ligament and it is not a clinic appointment next week. It can tear several ligaments at once and injure the artery or the nerve behind the knee, and the knee can look almost normal while that is true. LCL injury covers that corner of the knee and the nerve that lifts the foot, which wraps around bone on the outer side and is stretched by the same force.

Knee pain after skiing with no swelling, what is that?

A common search and an honest answer: usually not a torn ligament, and not something this page can name for you. A knee that aches after a few days of skiing, with no swelling, no giving way and no moment you can point to, behaves much more like overload than injury. Every part of that gate matters, and one half of it is worth saying on its own: if there was a definite twist, a fall or a blow to the knee, have it examined even if it never swelled much, because a ligament can be sprained without the joint filling up and the only way to sort that out is someone testing it. Ski boots hold the ankle still and leave the knee to do the absorbing, and most people ski more hours in a week than they walk hills in a month.

The things that change that reading are the ones in the warning list: a knee that gives way, locks, swells later for no reason, or hurts at night and keeps getting worse. If the knee feels unstable rather than sore, knee giving way sorts the causes, and if it has quietly filled up days afterward, swollen knee does the same.

A knee that catches and frees itself, or that hurts along the joint line when you twist, can also be a meniscus rather than a ligament. Meniscus tear is the program for that, and telling a meniscus tear from an ACL or MCL tear is how a clinician separates them.

Why hockey tears the MCL and skiing tears the cruciate

Different force, different ligament. In eight seasons at one college hockey program there were 13 MCL injuries in 10 players, an incidence of 0.44 per 1000 athlete exposures, and contact with another player was the mechanism in 10 of the 13, 77 percent, with defensemen and forwards equally represented, no injuries at all in goaltenders and grade 2 the commonest severity (Grant and colleagues, 2013). The paper describes the force the way players describe it: checked into the boards or falling, with the skate caught or tangled, which loads the inner side of the knee while the foot cannot turn. The grade predicted how long players were out. Thirteen injuries is thirteen injuries, so treat the rate as one program's experience, but it matches the bigger dataset: across five seasons of college men's ice hockey, an MCL tear was the third most common specific diagnosis at 3.7 percent of all injuries (Boltz and colleagues, 2021).

Skiing produces the other pattern because nothing hits you. The boot and binding fix the foot, the ski is a long lever, and the fall twists or hyperextends the knee from the ground up. In the hospital series above, the MCL is still involved, but it comes along with the cruciate instead of standing in for it (Posch and colleagues, 2021).

That distinction decides which program you read. For the hockey version, MCL sprain holds the graded rehabilitation. For the cruciate version, the ten pages built around ACL reconstruction rehab cover the operation, the phases and the timeline, and an ACL tear without surgery covers the route that does not involve an operation at all. PCL injury covers the ligament at the back, which more often comes from a fall onto a bent knee.

Do ski bindings protect your knee?

No, and the clearest statement of it comes from the review that gathered the engineering evidence. Ski boot binding systems were designed and refined to protect the tibia, and they have cut tibial shaft fractures, boot-top bruising and ankle injuries; the same review states that these changes were not designed to protect the knee from sprains, and that forces capable of rupturing the cruciate can occur without a normally functioning binding releasing (Davey and colleagues, 2019).

Two things follow, and they point in opposite directions from the marketing. Getting your bindings checked and adjusted is still worth doing. The review reports that more than three quarters of the gear involved in lower leg injuries did not meet the applicable standards, and that a trial which randomized skiers to having their bindings inspected and reset to ordinary shop practice found fewer equipment-related lower limb injuries. Both of those trace back to engineering symposium volumes, from 2006 and from 1989, which we could not obtain and read, so they are given here as the review gives them. Neither was counting knee ligaments either: the injuries in both were to the lower leg. And no binding should be bought as knee protection, whatever a brochure or a magazine says. Percentages quoted for individual brands are left off this page on purpose: the research behind them was not something we could obtain and read, so there is nothing here to stand behind.

What about the ski, the boot and the hire shop?

This is where the measurable equipment findings are, and they are unglamorous enough that almost nobody repeats them. A case-control study of 1817 recreational skiers across six winter seasons, 392 of whom, 21.6 percent, had a cruciate injury, with a mean age of 39.1 plus or minus 12.9 years, found that a greater binding standing height ratio and more wear at the toe of the boot sole were associated with higher risk in both sexes and independently of skill level (Ruedl and colleagues, 2023). Riskier behavior raised the risk only in men. Longer skis raised it only in less skilled women. Older age, using rented or borrowed skis, and more wear at the heel were independent risk factors among the more skilled skiers of both sexes.

The rented ski finding has its own paper. Among 1780 skiers, cruciate injury risk was associated with rented skis at an odds ratio of 3.2 with a 95 percent confidence interval of 2.5 to 4.0, and rented skis differed systematically from owned skis in length, sidecut radius, widths and standing heights (Ruedl and colleagues, 2022).

Both are associations from case-control work, not trials, so they describe who gets hurt and not what to change. Still, a worn boot sole and a hire ski that nobody measured against you are two things you can look at on the first morning of a holiday, and they are a better use of ten minutes than most of what is sold alongside them.

On training: nothing yet establishes that a strength, balance or neuromuscular program prevents knee injury in recreational skiing, and the evidence that does exist sits in narrower populations. A systematic review of physical therapy recommendations for injury prevention in alpine skiing included 10 studies and found no evidence-based prevention programs less than ten years old for physical preparation, in a population of competitive racers, and recommended borrowing from other non-contact sports with similar mechanisms (Kresal and colleagues, 2022). One study it does not include is worth knowing about: Swedish ski high school students who were given two seasons of core stability and neuromuscular exercises had 12 cruciate injuries among 305 skiers, 3.9 percent, against 35 among the 431 students of the five preceding seasons who served as controls, 8.1 percent (Westin and colleagues, 2020). That is competitive adolescent racers, in a study that randomized nobody: the comparison is with students from five earlier seasons rather than with a parallel control group, so anything else that changed at those schools between the two periods is mixed into the result. It does not tell a recreational skier what a gym program will do for their knee.

The other skiing-specific knee result is 31 years old, used awareness training and not exercise, and was done in ski-area staff: serious knee sprains fell 62 percent among trained patrollers and instructors at 20 areas, with no fall at 22 untrained areas (Ettlinger and colleagues, 1995). So getting fit before a ski trip is worth doing for every other reason and may well help, but nobody has measured it in holiday skiers, and a borrowed figure from football or handball is not skiing evidence unless the sport it was measured in is named beside it.

What to do in the first hours, away from home

The first decisions are about urgency and not diagnosis, and the warning lines at the foot of this page set the speed rather than this paragraph. Four of them go to an emergency department and not to an appointment or a clinic: a knee that swelled fast or felt a pop, a knee that felt as though it slipped right out of place, a foot that went numb, weak, cold or pale, and a knee pointing at an odd angle. Ski patrol or a resort doctor is the fastest way to start that journey on a mountain, but they are the route to a hospital on the day and not the end of it. A knee that felt as though the whole joint came out of place needs the circulation and the nerves in that leg examined, rechecked over the hours that follow, because an injured artery does not always announce itself at once, and scanned if there is any doubt. Across pooled hospital series of knee dislocations, 18 percent had injured an artery and 25 percent a nerve, and 12 percent of the artery injuries that were repaired still ended in an amputation (Medina and colleagues, 2014). Those series lean toward higher energy injuries than a fall on a piste, which is the reason the leg is checked rather than assumed either way. A knee that locked, that keeps giving way, or a leg you cannot put weight on is a same-day assessment, which a resort clinic or urgent care can do. Do not drive yourself for any of them.

For everything else, the sensible version is dull. Stop skiing or skating for the day, whatever the knee feels like an hour later, because the commonest way a single ligament injury becomes a complicated one is another fall on the same afternoon. Stay off snow and ice after that day too, until the knee has been examined.

Keep moving within comfort instead of parking the leg, and keep walking if you can do it without limping badly. If you cannot, that is not something to walk off: keep the weight off it, borrow crutches or use a ski pole in each hand to get about, and get the knee looked at the same day rather than the next one. Then get the knee examined, and do not wait to see how it is next week.

No source on this page settles whether you should be scanned or seen before flying home. It depends on the examination, on what is available where you are and on who can follow you up when you land, so ask the clinician who looks at the knee. One thing worth saying out loud: the long flight or drive home after a knee injury is also a blood clot risk, which is why the calf and thigh line is in the warning list below. The NHS counts any trip over 4 hours by plane, car or train, and it puts the risk higher again if you are pregnant or had a baby in the last 6 weeks, if you are over 60, if you have had a clot before, or if you have had surgery. Say which of those apply to you to the clinician who sees the knee, before you travel rather than after, because that is the conversation that decides whether you need anything for the trip home.

Which program is yours

Match the ligament to the page once somebody has named the ligament. Until then, read whichever page fits what you have been told but do not start the exercises on it, because this page has already said you cannot tell an ACL from an MCL from the outside, and that is as true of picking a program as it is of naming the injury. The card of related programs lower down is a map and not a plan. If you are not sure which sport story fits, start with the hub.

For the cruciate: ACL reconstruction rehab and its question pages, including the recovery timeline and an ACL tear without surgery. The inner side of the knee is MCL sprain, and the outer side with the corner behind it is LCL injury. PCL injury covers the ligament at the back, and meniscus tear covers the cartilage.

If you have had an operation on this knee, your surgeon's protocol comes before anything written here, and the warning lines below include the ones written for a reconstructed knee that has been twisted or has started giving way. If you are planning to ski again on a reconstructed cruciate, the brace question is answered in the common questions further down, where the evidence happens to be skiing specific, and the decision still sits with the surgeon who managed that knee. When the question is whether you are ready to ski or skate again, the return to sport test battery sets out the tests clinicians use, and the sport-by-sport comparison is on the ice hockey and skiing injuries hub.

When to see a physio

For a knee that was injured, within days and not weeks. Sooner if any warning line below applies. The reason is not that early physiotherapy fixes a torn ligament; it is that the first assessment decides what kind of problem this is, what the knee needs in the meantime, and whether anything on it has to be checked the same day.

Take the story with you in detail. Which direction the knee went, whether anybody hit you, whether you heard or felt a pop, how fast it swelled, whether it has given way since, and what you were wearing on your feet at the time. Boot, binding and ski details matter here more than on most knee pages.

One thing is worth asking for by name if you are 55 or over. A decision rule written for emergency departments choosing who needs an X-ray after a knee injury, the Ottawa Knee Rule, counts being 55 or older as a reason on its own, alongside tenderness at the bony bump on the outer side of the leg just below the knee, tenderness on the kneecap and nowhere else, not being able to bend the knee to 90 degrees, and not being able to put weight on the leg for four steps (Stiell and colleagues, 1995). Any one of the five is enough on its own. In the controlled trial of putting it into practice, it picked up all 58 knee fractures it was tested against, a sensitivity of 1.0 with a 95 percent confidence interval of 0.94 to 1.0 (Stiell and colleagues, 1997). So an older skier whose knee is being treated as a soft tissue injury can reasonably ask whether an X-ray is needed.

Then ask for criteria instead of dates. What has to be stable, strong and painless before you go back on snow or ice, and how that will be tested. The warning signs below come first, at whatever speed each line sets.

Related exercise programs

Warning signs

Get emergency help now

  • Emergency: the knee has moved out of place, looks misshapen or is pointing at an odd angle, or you have tingling or no feeling in the knee, leg or toes, or your foot turns cold, pale or blue. Go to an emergency department straight away. Do not drive yourself: ask someone to drive you or call an ambulance.
  • Emergency: the whole knee, not just the kneecap, felt as though it slid or shifted right out of place at the moment of injury, even if it went back straight away, or the knee now feels loose or wobbly in more than one direction. Go to an emergency department straight away. Do not drive yourself: ask someone to drive you or call an ambulance. A knee that comes out of place and goes back can tear several ligaments at the same time and can damage the artery or the nerve behind the knee. That damage is not always obvious at first, and the knee can look almost normal, so it is checked in hospital on the day rather than worked out at home.
  • Emergency: the knee became very swollen very quickly, within a few hours of a twist, fall or blow, or you felt a pop or snap. Go to an emergency department straight away. Do not drive yourself: ask someone to drive you or call an ambulance. A knee that fills up that fast has usually bled inside the joint, which can come from a torn ligament, a kneecap that slipped out or a break, so it needs checking before you play again.
  • Emergency: your foot became weak or numb at the moment of the knee injury or in the hours after it, for example your foot drags, catches on the ground or slaps down when you walk (foot drop), you cannot pull your foot or toes upward, or the top of your foot has lost feeling. Go to an emergency department straight away. Do not drive yourself: ask someone to drive you or call an ambulance. The nerve that lifts the foot wraps round the bone on the outer side of the knee, and the same force that injures the knee can stretch it. A foot that has been weak or numb from that moment goes with the more severe injuries, where more than one ligament has been torn or the whole knee has been out of place, and in those the artery behind the knee has to be checked on the day. So this one is not watched at home to see whether it gets worse.
  • Emergency: you have just fallen and cannot get up, or you think you may have hurt your head, neck, back or hip. Stay where you are, keep warm and call emergency services, or get someone to call for you. Nobody should try to lift you off the floor, and nobody should pull you up by the arms: being hauled upright can move a broken bone that has not slipped yet and can make an injured neck or back worse. Someone helping should call for help, keep you warm and stay with you. If you got up and walked without trouble and only notice pain later, use the same-day lines in this list instead.
  • Emergency: you fell and cannot remember the fall or how it happened. Go to an emergency department straight away, and do not drive yourself. You may have blacked out or hit your head without knowing it.
  • Emergency: after a knock to the head, being very drowsy or finding it hard to keep your eyes open, confusion, a fit (seizure), new weakness or numbness anywhere in your body, new trouble understanding, speaking, walking or keeping your balance, new problems seeing or hearing, clear fluid coming from your ears or nose, bleeding from your ears or bruising behind them, a black eye when your eye was not hit, a dent in your head or a wound with something stuck in it, or a change in behavior. Call emergency services straight away. These can be signs of an injury to the brain.
  • Emergency: a knock to the head in a high-energy accident, even if you feel completely well. That means a fall from a height of more than 1 meter (about 3 feet) or more than 5 stairs, a crash at high speed, a car that rolled over, being thrown from a vehicle, being hit by a vehicle while walking or cycling, a bike crash, an accident on a quad bike or similar motorized vehicle, a fall from a horse, a diving accident, or any other heavy, fast impact to the head. Call emergency services straight away, without waiting to see how you feel. A high-energy head injury is a reason for emergency assessment on its own, with no symptoms needed.
  • Emergency: after a knock to the head, you were knocked out, even for a moment, you cannot remember what happened just before or after, you have had a headache ever since, or you are being sick (vomiting). The same applies, even if you feel fine, if you take medicine that thins your blood, other than aspirin on its own, have a bleeding or clotting condition, have had brain surgery in the past, or had been drinking alcohol or taking drugs when it happened. Go to an emergency department straight away, and do not drive yourself.
  • Emergency: severe neck pain after a knock to the head, whatever the fall or the knock was like. Keep still and call emergency services, and do not let anyone move you until someone trained has checked your neck. If the neck pain only starts later and nobody has checked your neck since, go to an emergency department straight away, and do not drive yourself.
  • Emergency: after a knock to the head, swelling, a deep cut or severe pain at the exact spot that was hit. Call emergency services or go to an emergency department straight away, and do not drive yourself. These can be signs of a broken skull.

Get help now, day or night

  • In a knee brace, immobilizer, splint or cast, or in a knee support or compression wrap you put on yourself, the pain gets worse, your foot or toes feel numb, tingle or burn or look more swollen, or it feels too tight. Take off anything you put on yourself. Leave a brace, splint or cast your team fitted on and do not cut it or unwrap it, but if it has straps, loosen the straps. Lie down and rest the leg with the foot at about hip level and no higher, keep moving your toes and contact your fracture clinic or surgical team, or get medical advice straight away. Do not prop the leg higher than that and do not put ice on it, because if pressure is building up inside the leg both of those cut down the blood reaching your foot. If you cannot move your toes, the pain is severe even after painkillers, or the numbness, tingling, burning or swelling has not settled within 30 minutes, go to an emergency department straight away, and do not drive yourself.

Get help today

  • Same day: you have had a knock to the head and you take aspirin on its own, without any of the emergency signs above. Get medical advice the same day. Aspirin on its own is the only blood thinning medicine left out of the emergency line above, and the NHS still asks anybody taking a medicine that thins the blood to get urgent advice after a head injury.
  • Same day: the injured knee belongs to a child or teenager who is still growing. Get them seen by a doctor the same day rather than waiting to see how the knee is tomorrow, and say how the fall or the blow happened. A growing knee fails in its own way. The growth plate is the last part of the bone to harden, which is what makes it easy to injure, and the American Academy of Orthopaedic Surgeons lists skiing among the recreational activities these breaks happen in and says a possible growth plate injury should be seen by a doctor as soon as it can be, because a child's bone heals fast and needs to be in the right position before it does. It also says growth plate breaks around the knee carry a higher rate of problems later and so are followed up closely, and that some of them cannot be seen on a first X-ray. So keep any follow-up appointment even if the knee feels better, and keep them off snow, ice and sport, and off any exercise program, until they have been checked.
  • Same day: the knee is locked, which means it is stuck bent and you cannot fully straighten it, even after gently trying to move it, or you cannot bend or straighten the leg at all. Get assessed the same day by a doctor, at urgent care or at an emergency department. A meniscus tear can happen alongside a knee ligament injury, and a torn piece of meniscus can get caught in the joint and block it, so it needs checking early. A knee that catches for a moment and then frees itself is not the same as a locked knee, but tell your physio or doctor about it.
  • Same day: the knee straightens when someone else moves it for you, but you cannot lift the straight leg off the bed yourself or hold the knee straight against gravity, or you can feel a gap or a dip just above or just below the kneecap. Get assessed the same day by a doctor, at urgent care or at an emergency department. The tendon that straightens the knee can tear, which is not a meniscus or a ligament problem and is not treated with exercises. It is usually repaired, and a tendon repaired late does less well than one repaired early.
  • Same day: you felt the kneecap slip out of place and it went back by itself. Get assessed the same day.
  • Same day: you cannot walk or put weight on the leg, whether or not there was a fall or injury, or you have very bad knee pain after a fall or injury, or very bad knee pain that came on suddenly with no injury at all. Get medical advice the same day.
  • Same day: the knee keeps giving way under you, or it gave way after a recent injury, or it gives way and is also very painful or swollen. Get medical advice the same day. If it only happens now and then, with no recent injury and no swelling, it is not an emergency, but book an assessment with a physio or doctor in the next few days. Until it has been checked, leave out the exercises you do standing on one leg, hold the rail on stairs and take care on uneven ground, because a knee that gives way without warning is how people fall.
  • Same day: since your knee ligament was reconstructed, your knee gives way, or you feel a pop, a shift or a twist inside it, and it swells up within a few hours or is very painful. Keep your weight off it and contact your surgical team, or get assessed the same day at urgent care or an emergency department. A fall or a twist can damage the new ligament (graft) or a meniscus repair. If the knee looks out of shape, or your foot turns numb, cold or pale, go to an emergency department straight away, and do not drive yourself. One route sits above that one: if the knee swelled very quickly after a pop or a snap, the emergency department line in the warning signs above applies whichever operation you had, and a call to your surgical team is not a substitute for it. If the knee only feels a little unsteady now and then, with no swelling or pain, it is not an emergency, but tell your physio or surgeon in the next few days.
  • Same day: since your operation, your wound is oozing, leaking or has pus coming out of it, or its edges start to come apart, or your knee is tender, swollen, painful or red and it is not getting better or is getting worse, or you have a high temperature or feel hot and cold or shivery. Redness can be harder to see on brown or black skin. Contact your surgical team the same day, or get urgent medical advice if you cannot reach them. These can be signs of an infection in the wound or the knee joint. If you feel very unwell, go to an emergency department. If you have a very high or very low temperature, shivering you cannot control, you are breathing very fast or finding it hard to breathe, you are confused or your speech is slurred, your skin, lips or tongue look blue, gray, pale or blotchy (on brown or black skin this can be easier to see on the palms of the hands or soles of the feet), or you have a rash that does not fade when you press it, call emergency services, as this can be sepsis.
  • Same day: the knee is hot, red and swollen, or you have knee pain with a high temperature or feel hot, cold or shivery. Get medical advice the same day, and go to an emergency department if you feel very unwell. This can be a sign of infection in the joint, which needs treatment quickly.
  • Same day: the knee swells up with no clear reason, especially if you take medicine to thin your blood. Get medical advice the same day.
  • Same day: a calf or thigh that is newly swollen or getting more swollen, warm, tender, red or darker than usual, has swollen veins that are sore to touch, or has a throbbing or cramping pain that does not fit your injury or condition, or that feels different from normal muscle soreness after exercise. This can be a sign of a blood clot (deep vein thrombosis), especially after surgery, an injury, time in a cast or boot, a long trip or a spell of being much less mobile than usual. Get medical advice the same day. If you are also short of breath or have chest pain, call emergency services.
  • Same day: a leg or foot that is getting weaker, for example your foot drags, catches on the ground or slaps down when you walk (foot drop). Get medical advice the same day. If the weakness is getting worse by the hour, go to an emergency department. If the weakness started at the moment of your knee injury or in the hours after it, the emergency department line above applies instead.
  • Same day: pain at night or at rest that keeps getting worse. If you are being treated for cancer now, contact your cancer team the same day.

Book an appointment

  • Within a day or two: pain at night or at rest that keeps getting worse. If you have had cancer, now or in the past, see your doctor sooner, within a day or two, and mention it, even if the pain is not getting worse. Do the same if you have knee pain and are losing weight without trying, even if it does not hurt at night.
  • Within a few days: pain at night or at rest that keeps getting worse. See your doctor within a few days.

Common questions

Is skiing bad for your knees?

Skiing asks a lot of the knee and the data says so, but the question as usually meant, whether skiing wears your knees out, is not what the research measured. What it measured is sudden injury: across the series pulled together in one clinical review, the knee accounted for 27 to 41 percent of all skiing injuries, more than any other region (Davey and colleagues, 2019). Over a decade of resort reports from 29 western Canadian ski areas, skiers were the group most prone to knee injuries, while snowboarders were most prone to wrist injuries (Dickson and Terwiel, 2021). Two things make a real difference to that risk and neither is skill: being a beginner skier came out at an odds ratio of 2.72 in a meta-analysis of 55 pooled studies, and renting equipment at 2.58 for skiers and snowboarders counted together, both with 90 percent confidence intervals (Hume and colleagues, 2015). So the fair answer is that skiing carries a real risk of a knee ligament injury, that it is concentrated in people new to it and people on hire gear, and that long-term wear is a separate question none of these studies set out to answer.

Is it an ACL or an MCL?

You cannot tell from the outside, and the two most useful clues are the sport and the mechanism, not where it hurts. A non-contact twist, a backward fall onto the inside edge, or the knee being forced straight past straight while skiing points toward the cruciate (Davey and colleagues, 2019); a blow to the outside of the knee in hockey that opens the inner side points toward the MCL, and contact with another player was the mechanism in 10 of the 13 MCL injuries, 77 percent, in one eight-season college series (Grant and colleagues, 2013). Beyond that, the two commonly happen together: among 282 recreational skiers whose knee injuries needed hospital care and were all scanned, the MCL was the commonest structure injured alongside the cruciate, in 50.5 percent of those with more than one injury (Posch and colleagues, 2021). Fast swelling within a few hours, a pop at the moment it happened, or a knee that feels loose in more than one direction all make this urgent, not diagnosable at home. Telling a meniscus tear from an ACL or MCL tear goes through how a clinician separates them.

Do I need a scan before I fly home?

Nothing this page cites settles that, and it would be inventing an answer to pretend otherwise. What is settled is the urgent end: a knee that swelled within a few hours, felt a pop, gave way, locked, or that slipped out of place and went back needs to be seen the same day, wherever you are, and that applies at a resort clinic as much as at home. For everything short of that, the decision depends on what the examination finds, what imaging is available where you are, and whether you can be followed up when you land, so it is a conversation with the clinician who looks at the knee and not a rule. One practical point in favor of being seen before you travel: the clinician who examines the knee can tell you what to do with it on the journey, whether you need crutches or a brace for it, and what to ask for when you land.

Does a knee brace stop a ski knee injury?

For a knee that has never been injured, no, or at least nothing readable says yes. The equipment research behind this page tested helmets, wrist guards for snowboarders, binding condition and binding adjustment, and the 2019 review of alpine skiing injuries does not discuss knee braces anywhere in its text (Hume and colleagues, 2015; Davey and colleagues, 2019). For a knee that has already had its cruciate reconstructed, or that is skiing on a cruciate that was torn and never reconstructed, the answer is different and worth having. At one destination resort, 820 skiing staff who were at least 2 years past an ACL reconstruction were screened before the season. The 257 who chose to ski in a functional brace had 4.0 subsequent knee injuries per 100 knees per ski season against 8.9 in the 563 who did not, and unbraced skiers were 2.74 times more likely to be hurt again, with a confidence interval of 1.2 to 4.9 (Sterett and colleagues, 2006). A screening of 9410 professional skiers over much the same years found 180 skiing on a cruciate that had been torn and not reconstructed, where a further knee injury happened to 13 percent of the unbraced and 2 percent of the braced (Kocher and colleagues, 2003). Both looked at a functional brace, the hinged kind fitted for an unstable or reconstructed knee, and not at an elastic sleeve. Read them with their limits attached: nobody was randomized, the skiers chose for themselves, and these were resort staff skiing far more days in a season than anyone on a week's holiday. In the 2006 series the braced knees were the looser ones when they were examined before the season, which makes that result harder to explain away rather than easier. A 2021 review of bracing after reconstruction is blunt about the rest of sport: outside skiing, functional braces have not consistently improved outcomes, graft retear rates or return to sport (Knapik and colleagues, 2021). So a brace after a cruciate injury is a conversation with the surgeon who managed that knee, and skiing is the one sport where the conversation has numbers behind it. Two things a brace is not. It is not a reason to get back on snow earlier, and it does not stand in for the strength, stability and control the knee has to show first, so your surgeon's clearance and the test criteria come before the device. And if somebody is selling you a brace on the strength of a percentage, ask which study produced the number and in which population, because braces, pads and bindings are what gets sold against these searches and the selling runs well ahead of the evidence.

References

  1. Davey A, Endres NK, Johnson RJ, Shealy JE. Alpine Skiing Injuries. Sports Health. 2019;11(1):18-26. https://doi.org/10.1177/1941738118813051
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Written and checked by the PocketPhysio editorial team. Last updated 2026-11-06.

This page is general education, not a diagnosis or a personal treatment plan. See a physiotherapist or doctor for advice about your own situation.