If you are thinking about starting Brazilian Jiu-Jitsu, this is probably the first question on your mind. It is in our FAQ too: "I'm scared of getting injured." The honest answer has two parts. BJJ is not risk-free. At the same time the risk is well studied, and it looks different from what most people expect from the outside: it is rarely about the head and mostly about joints, and most of it happens in one particular training situation. Here are the numbers, with sources, and what we do about them.

How often do people get injured in BJJ?

The best current estimate comes from a survey of 881 practitioners in several countries, published in 2025 in BMJ Open Sport & Exercise Medicine (Stegerhoek et al., 2025). The result: 5.5 injuries per 1,000 training hours. 81% of respondents reported at least one injury in the previous year.

A second large survey of 1,140 practitioners from 62 countries counted only injuries that meant at least two weeks off training (Hinz et al., 2021). The result: 308 such injuries per 1,000 practitioners per year, or roughly one such injury for every three practitioners each year.

The most important finding is somewhere else, though: 89% of injuries happened in training, not in competition, and in training almost four in five happened during free sparring (Stegerhoek et al., 2025). Technique drills and warm-ups account for only a small share (Hinz et al., 2021). So the risk sits where two people work freely against each other, which is exactly where it can be influenced most.

StudyWhat was countedResult
Stegerhoek et al., 2025 (881 practitioners)injuries in training5.5 per 1,000 training hours
Stegerhoek et al., 2025injuries in competition55.9 per 1,000 matches
Hinz et al., 2021 (1,140 practitioners)injuries with at least two weeks off308 per 1,000 practitioners per year
Scoggin et al., 2014 (tournaments in Hawaii)injuries recorded by a physician in competition9.2 per 1,000 match exposures
Kreiswirth et al., 2014 (No-Gi Worlds 2009)all reported injuries, including nosebleeds and abrasions38.6 per 1,000 match exposures

Don't let the differences confuse you. Hours, matches and years are different units, and every study defines "injury" differently. The Hawaii tournament study counted only what a doctor had to treat; the Worlds study counted nosebleeds too. That is why the competition figures are so far apart. Only figures with the same unit can be compared directly.

Which injuries are most common?

Knee and shoulder first

In both large surveys the knee is the most frequently injured area (25% and 27% of all injuries), followed by the shoulder (13 to 15%). After that come hands, fingers and the ribcage. A review of seven studies with 2,847 practitioners in total found the knee and the ribs level at the top, at 22% each (Santos et al., 2024).

By type of injury, sprains and strains dominate. Fractures and ligament tears happen, but much less often.

How do they happen? In the survey of 1,140 practitioners the causes were spread fairly evenly:

Among the joint locks, the armbar topped the list in that survey. In the newer survey arm locks and leg locks were level, at 37% each; the armbar alone accounted for 21%.

One detail: a study of brown and black belts compared competition divisions where the heel hook (a leg lock that twists the knee) is allowed with divisions where it is banned (Piekarski et al., 2026). With heel hooks there were 26.5 knee injuries per 1,000 matches, without them only 2.2. The relative risk was 12, but with a very wide margin of uncertainty (95% confidence interval 1.5 to 96.1), because there were few cases overall. The direction is clear; the exact size is not.

That is why our rule is: we train heel hooks only from brown belt.

How long is the time off?

Most BJJ injuries are sprains and strains. Serious knee injuries such as a cruciate ligament tear are rare, but they carry weight: among respondents with a cruciate tear in the Hinz et al. survey, 41% never competed again. That is not a reason not to start. It is a reason to take the knee seriously in sparring, and it is exactly why you learn to tap early with us, leg locks included.

Does experience protect you from injury?

Not automatically. In the survey of 1,140 practitioners, injuries rose with age, with the number of competitions and with belt rank. Advanced practitioners usually train harder, with stronger partners and for more hours. Experience helps you recognise danger, but it does not replace discipline in sparring.

Do people get concussions in BJJ?

This is where BJJ differs most clearly from striking sports. A systematic review in the British Medical Bulletin (Lota et al., 2022) brought together measurements of the head's rotational acceleration from 22 studies. Around 4,500 rad/s² is treated as a rough threshold for a concussion.

The important caveat: the measurements were taken in wrestling and judo. There are no such sensor measurements for BJJ itself yet. Since BJJ has no strikes and most of a match happens on the ground, the transfer is plausible, but it remains a transfer.

BJJ still isn't free of head contact. In takedowns and scrambles the head can hit the mat or a partner. In a US survey of 778 practitioners (Spano et al., 2019), about a quarter reported at least one concussion over their time training. Women reported it almost twice as often as men (43% versus 23%). The study relies on self-reporting and cannot explain why.

One finding from the same study stayed with us: 30% of those affected kept training the same day. That is exactly what you should not do after a blow to the head.

Our rule: anyone who has symptoms after a knock to the head, such as a headache, dizziness or feeling dazed, stops training for the day and gets checked by a doctor. You come back to the mat only once the symptoms are gone and a doctor has cleared you.

Are chokes dangerous?

Chokes look like the most dangerous thing from the outside. The data tells a different story.

That figure is a lower bound: people who had serious consequences and stopped training rarely take part in surveys like this.

Rare but serious complications do exist. The medical literature describes individual cases in which a choke led to an injury of a neck artery (Stellpflug et al., 2022). No frequency can be calculated from this, because nobody knows how many millions of chokes are applied every year without consequences.

What follows is simple: a cleanly applied choke works fast. In a video analysis of professional MMA fights, the time to unconsciousness averaged about nine seconds (Stellpflug, Menton et al., 2020). That is why you tap early, and your partner lets go immediately. It isn't politeness; it is the most important safety rule in BJJ.

More on this, with every study and our rules for chokes: Chokes in BJJ: How Dangerous Are They Really?

Does warming up prevent injuries?

We have to be honest here: it is not proven. The only randomised trial of an injury prevention programme in a grappling sport was run in judo, with 269 recreational athletes (von Gerhardt et al., 2023). The special warm-up programme did not reduce injuries significantly.

In the survey of 1,140 BJJ practitioners, sleep, nutrition, mobility work and strength training also showed no measurable link with fewer injuries. For comparison: in football, a structured warm-up programme cuts injuries by around 30% according to a systematic review (Sadigursky et al., 2017). Nobody has managed that for grappling yet.

We warm up anyway, because it makes sense for the class. But we won't sell it to you as injury protection. According to the data, what matters most is how people behave in sparring.

Hygiene: ringworm, herpes and cauliflower ear

In a sport with this much skin contact, hygiene is part of safety. There are hardly any studies on BJJ itself; the following figures come from wrestling and judo, where skin contact is similar.

What is ringworm and how do you prevent it?

Ringworm (tinea gladiatorum) is a fungal skin infection, usually caused by Trichophyton tonsurans. It shows up as a round, reddish, often scaly patch. In an analysis of 13 studies with almost 5,000 wrestlers, on average about a third were affected (Kermani et al., 2019), with huge differences between teams.

What is recommended is unspectacular:

The same applies to herpes. In an outbreak at a wrestling camp, a third of participants were infected (Belongia et al., 1991). The authors recommended excluding athletes with visible skin lesions from training immediately.

Does everyone get cauliflower ear?

No. Cauliflower ear develops when blood collects under the skin of the outer ear after friction or pressure and is not treated. It is common among elite judoka with years of competition training: in an analysis of profile photos, 70% of men and 32% of women showed visible changes (Nitsch et al., 2023). There are no comparable figures for recreational BJJ practitioners.

If your ear swells after training, don't wait: see a doctor promptly. If you want to prevent it, you can wear ear guards.

Our hygiene rules

What we do at Imperial Ground about injuries

We built Imperial Ground as a place where everyone feels safe and welcome. The data shows where the risk sits: in free sparring, at the knee and shoulder, and in moments when someone taps too late or lets go too late. That is what we build our training around.

On top of that, three fixed rules: heel hooks only from brown belt; anyone with symptoms after a knock to the head stops for the day and gets checked by a doctor; and you train with a skin issue only once it has been checked.

To be honest: what these numbers don't show

Frequently asked questions

Is BJJ more dangerous than other martial arts?

On head load, wrestling and judo measure far lower than boxing and taekwondo. There are no such measurements for BJJ itself yet. Injuries to the knee, shoulder and fingers, on the other hand, do happen regularly.

Where do people get injured most often in BJJ?

The knee, followed by the shoulder, hand and ribs. Most are sprains and strains, and most happen during free sparring.

Do people get concussions in BJJ?

Rarely from strikes, because there are none. They can happen from falls or collisions, though: in a US survey, about a quarter reported at least one concussion over their time training.

Are chokes dangerous?

Applied correctly and with an early tap, they rarely cause injuries. But a choke works fast, so you tap early and your partner lets go immediately. Serious complications have been described only very rarely.

How can I lower my risk of injury?

Roll with control, tap early, don't try to win sparring at all costs, and take a break when something hurts. A warm-up programme alone has not yet been shown to protect you in grappling.

Do I need to worry about skin fungus?

With clean mats, a shower after training and the rule that you don't train with suspicious skin patches, the risk stays small.

Sources

  1. Stegerhoek PM, Brajovic B, Kuijer PPFM, Mehrab M. Injury prevalence among Brazilian Jiu-Jitsu practitioners globally: a cross-sectional study in 881 participants. BMJ Open Sport & Exercise Medicine 2025;11(1):e002322. https://doi.org/10.1136/bmjsem-2024-002322
  2. Hinz M, et al. Injury Patterns, Risk Factors, and Return to Sport in Brazilian Jiu Jitsu: A Cross-sectional Survey of 1140 Athletes. Orthopaedic Journal of Sports Medicine 2021;9(12). https://doi.org/10.1177/23259671211062568
  3. Scoggin JF 3rd, et al. Assessment of Injuries During Brazilian Jiu-Jitsu Competition. Orthopaedic Journal of Sports Medicine 2014. https://doi.org/10.1177/2325967114522184
  4. Kreiswirth EM, Myer GD, Rauh MJ. Incidence of Injury Among Male Brazilian Jiujitsu Fighters at the World Jiu-Jitsu No-Gi Championship 2009. Journal of Athletic Training 2014;49(1):89–94. https://doi.org/10.4085/1062-6050-49.1.11
  5. Santos SP, et al. Epidemiology of Injuries and Their Implications in Jiu-Jitsu Practitioners: An Integrative Systematic Review. Revista Brasileira de Ortopedia 2024;59(3):364–371. https://doi.org/10.1055/s-0044-1785662
  6. Piekarski M, et al. Knee Injury in Competitive Brazilian Jiu Jitsu Athletes: Implications for Training. Sports Health 2026. https://doi.org/10.1177/19417381251400303
  7. Lota KS, et al. Rotational head acceleration and traumatic brain injury in combat sports: a systematic review. British Medical Bulletin 2022;141(1):33–46. https://doi.org/10.1093/bmb/ldac002
  8. Spano M, et al. Epidemiology of Sports Related Concussion in Brazilian Jiu-Jitsu: A Cross-Sectional Study. Sports 2019;7(2):53. https://doi.org/10.3390/sports7020053
  9. Stellpflug SJ, et al. The safety of sportive chokes: a cross-sectional survey-based study. The Physician and Sportsmedicine 2020;48(4). https://doi.org/10.1080/00913847.2020.1754734
  10. Stellpflug SJ, Menton WH, et al. Time to unconsciousness from sportive chokes in fully resisting highly trained combatants. International Journal of Performance Analysis in Sport 2020;20(4):720–728. https://doi.org/10.1080/24748668.2020.1780873
  11. Stellpflug SJ, et al. Cervical Artery Dissections and Ischemic Strokes Associated with Vascular Neck Compression Techniques (Sportive Chokes). Journal of Emergency Medicine 2022. https://doi.org/10.1016/j.jemermed.2022.04.015
  12. von Gerhardt AL, et al. Effectiveness of a judo-specific injury prevention programme: a randomised controlled trial in recreational judo athletes. British Journal of Sports Medicine 2023. https://doi.org/10.1136/bjsports-2022-105869
  13. Sadigursky D, et al. The FIFA 11+ injury prevention program for soccer players: a systematic review. BMC Sports Science, Medicine and Rehabilitation 2017. https://doi.org/10.1186/s13102-017-0083-z
  14. Kermani F, et al. Tinea Gladiatorum and Dermatophyte Contamination Among Wrestlers and in Wrestling Halls: A Systematic Review and Meta-analysis. Current Microbiology 2019. https://doi.org/10.1007/s00284-019-01816-3
  15. Belongia EA, et al. An outbreak of herpes gladiatorum at a high-school wrestling camp. New England Journal of Medicine 1991;325:906–910. https://doi.org/10.1056/NEJM199109263251302
  16. Nitsch A, et al. Prevalence of cauliflower ear in high level judoka. Scientific Reports 2023;13. https://doi.org/10.1038/s41598-023-42635-8

About the author. João Macedo is a 1st-degree black belt in Brazilian Jiu-Jitsu, has been on the mats for more than 14 years, and is co-founder and head coach of Imperial Ground Martial Arts in Düsseldorf-Derendorf.

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