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The Karate Instructor’s Injury Survey - Does Karate Practice Hurt Us?

By: Dr. Alex Sternberg
Jun 28, 2018


Dr Alex SternbergMartial arts development goes back a long way. According to legend, Bodhidharma traveled from India to China to teach his brand of Buddhism. The monks at the Shaolin monastery where he stopped to teach did not possess the physical stamina required for hours of meditation, so Bodhidharma taught them physical endurance exercises in order to increase their stamina. As the story is told, these monks became very fierce fighters as a result of these exercises and thus the origins of martial arts were born.

Over the next many centuries, the development of jiu-jitsu and subsequently karate was done in secret, handed down from teacher to pupil and often from father to son. Knowledge of this secret and powerful art was a family business, to be perfected to the highest level. Lack of preparation often resulted in severe injury and even death. Everyone trained hard to survive. Later on, warriors such as the samurai, continued training in hand to hand combat and continued the tradition of perfection of all of the techniques that they learned. To best serve their lord, the highest level of skill mastery was expected.

This is the culture of traditional karate as handed down thru the ages from sensei to students. This is the way my generation was trained. The more grueling the workout, the more obstacles we overcame, the prouder we all were. We proudly bragged of workouts where we performed over a thousand punches and five hundred kicks. Nothing was too difficult and no hardship was insurmountable on the road to ‘perfection.’ When I began to train in 1963, we did lots of ‘makiwara’ training at the end of each workout. Our knuckles bled but we kept on pounding. We also did lots of repetitions of all techniques. The workouts lasted 3 hours nightly, six days a week.

Now after 40 and more years of training, many of us have had knee and hip surgery. I had two on my knees and two on my hip. So many sensei’s have had such injuries, that we can’t keep tabs on everyone anymore. The question is why is this happening, who is it happening to and what, if anything, can be done about it?

Overuse injuries occur when joints are subjected to repeated explosive, manipulation or use causing microtrauma. This microtrauma degenerates into microdamage when there is not enough time in between workouts for the joints to recover and rest. This does not happen only in martial arts training. Ballet dancers also report high incidence of injuries that accompany their training. Musicians are also affected. Think about a violinist, or a cello player. How many hours do they spend practicing daily, bent over their instruments moving their arm forward and back as they play.  For that matter, we have all heard of carpal tunnel syndrome that plagues typists after many years of constant typing. So, we in karate ought not be surprised, if the many hours of hard explosive practice, results in wear and tear of our knee and hip joints. In fact, this has been diagnosed as “overuse syndrome.”

Injuries associated with other occupations are tracked easier. According to labor laws, when an employee is injured a form is filled out and the injury is logged with the US Bureau of Labor Statistics (BLS), part of the US Department of Labor. Karate does not have any designation as an occupation at the BLS and thus there is no way to log it in. Furthermore, overuse injuries appear slowly, over long periods of time. You begin to feel some discomfort that slowly turns into pain. It doesn’t always hurt in the beginning, but with time, it hurts all the time. This process usually takes years to unfold. Most instructors may not even make the connection between their knee or hip pain and constant karate training. Therefore, diagnosing such injuries as training-related is difficult.

Up until now, each investigation of karate-related injuries dealt with tournament and sparring injuries primarily. Articles have been published showing the amount and type of injuries suffered by competitors at specific tournaments. Such injuries usually were of the broken nose, contusion, and concussion variety. These investigations, however, are of little interest for the vast majority of the national karate training population because most karate students don’t compete.

One departure from this trend was a study reported in Switzerland in 2009 that examined the hips of 50 karate fighters for signs of wear and tear. They used an MRI to scan the hip joints of fighters of various ages and levels of experience. The MRI showed very significant tears in hip cartilage in 78% of the fighters. Only 15% of these fighters had normal hips.

As time passes, more and more instructors are training for over 30 and 40 years. As a result, the damage that seems to accompany hard training is seen with increased frequency. Magazines have written about this problem and we have all heard about instructors that needed hip and knee surgeries. I am sure we all know colleagues who had such surgeries. As a result of this growing problem and faced with little information about it, I undertook my investigation.


My research was not supported by any of the major karate organizations. In fact, the president of one such group wondered if: “we even need to know or publicize such information.” My research was conducted in conjunction with and under the supervision of the State University of New York College of Medicine-School of Public Health, where I was studying for a doctorate in Environmental and Occupational Health Science. In fact, this research was my successful doctoral dissertation.

I chose to focus on this topic rather than Asthma or environmental pollution because after 50 years practicing and teaching karate, I feel that we need to focus scientifically on what it is that we do for hours every day.

I developed a survey with 64 questions that asked for information about the age of each instructor who answered the survey, the age when they began to train, and their primary style of practice. Additionally, I asked about training methods, how much kihon, kata, and kumite they practiced nightly. I also asked how often they trained.

I placed my survey on-line and began a national campaign to publicize the survey and recruit instructors to fill it out. I chose to publicize within FaceBook pages devoted to karate and websites of national magazines. All together 983 instructors answered the survey. I conducted a statistical analysis of the answers to determine scientifically if there was any connection between the way instructors trained, their age and style and the development of injuries.

My survey wanted to answer two specific questions:

1-     Does one have a higher risk for injuries the longer one trains?

2-     Does style predict the type of injuries one may develop?


Almost 70% of the instructors who answered the survey reported having developed non-sparring related injuries over the years of training. When I compared the instructors who trained over 40 years with those instructors who have trained for less than 20 years, the longer training group had over twice the risk of developing injuries. Also, the instructors who trained kihon nightly had a risk for twice as many injuries as those instructors who seldom or never practiced kihon.



983 total respondents


Caucasian= 553(83.3%), Black=28 (4.2%), Hispanic =49(7.4%),

Asian =34(5.1%)


≤35= 95 (14.1%), 36-50= 285 (42.2%), 51-60= 190 (28.1%),

61≥ = 106 (15.7%)


Male=583 (87.1%)    Female= 86  (12.9%)

Years training

10-19=182 (25.5%), 20-29= 198 (27.8%), 30-39= 187 (26.2%),

40≥= 146 (20.5%)

Style  Practiced

Shotokan= 271 (28.1%),  Shito-ryu= 54 (5.6%),

Goju-ryu=52 (5.4%), Wado-ryu=71 (7.3%)  Other = 518 (53.6%)

Ever treated for injury

Yes= 427 (66.5%),     No = 156 (24.3%)

Health, Fitness course

Yes = 276 (38.8%)     No = 435  (61.2)

Earn additional salary

Yes = 622 (80.9%)     No = 147  (19.1%)

Over all 21% of all instructors, regardless of style, admitted to having hip pain and choosing to live with the pain. Six percent of Shotokan instructors had hip surgeries with an additional 13% admitting that their hips hurt but they “chose to live with the pain.” That is to say that they ‘suck up’ the injuries and tough it out. That is a very high percentage especially when comparing it with the US national trend in hip surgeries, which is less then 0.001%. That is, less than 1 percent among the nation who gets such surgeries.

Twenty two percent of all instructors (in my survey) had knee surgeries. An additional 20% are living with knee pain. Surprisingly, when I analyzed the data on knee surgeries, I found that those who practiced goju-ryu had an over 4 times higher odds of needing knee surgery that those who practiced the other styles. Why is that?

Unfortunately, my survey revealed many questionable things in our industry and in the way we train. 81% of all instructors have a job in addition to teaching karate! Wow! Eighty one percent of us need to juggle another job in order to make ends meat. When we compare this with other professions, we realize that something is not right. Do hair stylists have another job in addition to cutting and styling hair? How about electricians or carpenters? For that matter, English or math teachers? Why do 81 % of karate instructors struggle economically?

We need to understand the implications of this research. Traditionally, many of us train and teach the methods we were taught. We respect our teachers’ methodology and certainly respect our teachers’ mastery of the arts. There is nothing wrong with that! But there comes a time when we may need to re-examine our ‘time honored’ training methods and see where we can make our practice safer and injury free.

My study was devoted to examining our rates of injuries and the type of training it seems to be connected to. We must now understand what can be done to prevent injuries from shortening our careers. We need to convene a meeting with recognized industry experts where training techniques can be discussed.

My survey also showed that 61% of instructors had never participated in a health and fitness instructor’s course, where injury prevention was taught. While 56% revealed that they had participated in an “instructor’s course,” 60% received such instruction from their instructors in their dojos! Only 8% claimed to have received an instructor’s certificate from an educational organization other than from their sensei.

While I understand the issues with demanding that each and every instructor receive training in injury prevention and be trained in modern methods of instruction, I feel that the time for such training is past due.

Eighty seven percent of all instructors in my survey disagreed with the notion that every black belt is qualified to teach simply because they received a black belt diploma. Sixty eight percent agreed that all instructors should have to pass an instructor’s course before they can begin to teach. But 62% felt that such a course should be taught by the instructors in the dojo. Seventy two percent were strongly against such courses offered by a state regulatory organization.

If anything, this survey revealed that most instructors feel that instructor training focusing on injury prevention is vital in our industry. But many are satisfied with each instructor being qualified to teach such courses.

Undoubtedly, we need to reexamine how we train so we can reduce injuries. A discussion is now vital for the organizations that claim to ‘govern’ and ‘regulate’ karate training in the nation to come together and form a consensus of what such training should entail and who should be teaching it.

Dr. Alex Sternberg

Dissertation synopsis for Doctor of Public Health-Environmental and Occupational Health

SUNY College of Medicine-School of Public Health

About the Contributor

Founder and chief instructor of Shotokan Karate USA, is a 8th dan conferred upon him by leading senior senseis throughout the USA. He received his 7th Dan from the USA National Karate-do Federation (USA-NKF) member of the US Olympic Committee, as well as from the prestigious International Shotokan Research Society. He has also earned a 6th Dan from the Japan Karate Association (JKA) personally issued by Master Tetsuhiko Asai and from the World Karate Federation (WKF) member of the International Olympic Committee. He has been practicing Karate for 54 years.

Read more about Dr. Alex Sternberg »


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