“Some of the injuries” sustained in Martial arts, and particularly in JKD, FMA and Brazilian Jiujitsu are ambiguous and at times they can be attributed to unexpected micro-weaknesses in joints, ligaments, and tendons which in turn they can have other causes.
There are also injuries that are sustained in professional fights that are also understandable and are obviously expected to occur from time to time. But that being said, most injuries during the training are not of that nature and have more to do with the following causes:
1) You may be of the personality type that thinks maximum progress can be attained overnight and therefore, you try to do too many things in one night at your max.
2) You may be of the personality type that likes to rely on too much speed, or that speed is your primary attribute that you keep focusing on. The fact is, speed should be your last concern, and that timing and footwork are far more important to develop first. By going fast all the time, you either pull something, or end up hurting your partner. Raw speed for beginners is poisonous and toxic.
3) You may be of a personality type that uses too much strength percussively/ explosively and worse yet, you do it in an erratical way, because you don’t have enough experience yet. So again, you either damage yourself or end up hurting your parter. Stop thinking that you can muscle through everything.
4) You are a beginner and have not grasped the “emotional content”, or what I like to call the “necessary emotional development” (NED), to be able to simultaneously apply your killer instinct AND at the same time think about the safety of your partners in training. This is difficult for some people, and it can take a good year or two to fully grasp and develop the NED. Coaches should watch of for patterns of this type of behaviors in students. In any case, the lack of NED during the training has been a major cause of injuries in all JKD, Kali, and Jiujitsu trainings. I am sure this has been a pattern, observed in most of the systems of martial arts.
5) Lack of proper strength and conditioning regiment in one’s weekly training can potentially leave the joints, muscles, tendons, and ligaments vulnerable and prone to injuries. Martial arts is not just about doing self-defense techniques.
6) Inappropriate body positioning before executing a move, especially in jiujitsu and JKD has been another cause of injuries. If you do not have the right body positioning before executing a move, it can create adverse and unnecessary injuries. For example, having your foot trapped on the mat while the rest of your body is turning to the right or left could eventually lead to knee, ankle, and hip issues. There are many examples on this, regardless of whether we are training in JKD, Kali (FMA), or Brazilian Jiujitsu.
7) Tap when you know something bad is about to happen. Don’t wait till you hear something snap. Again, beginners need to understand this. If you wait a second or two too late when you are sleeping, then obviously it’s already too late. Students, especially the beginners must go slow, so they can learn critical stages where the joints can snap or beyond which they can hurt a partner’s areas of the neck where blood and oxygen intake determines a person’s state of consciousness.
8) Not giving your body any recovery time is another cause of injuries. Every workout causes micro-tears, which is normal and healthy if it is followed by some rest time. But if you take no rest, you would keep compounding those micro-tears and instead of getting stronger with your body, you could slowly run yourself down where you become more and more prone to injuries.
9) Improper amounts of protein (some 20 amino acids) and vitamin/mineral intake. The body needs amino acids to repair itself. Without these proteins, the micro-tears do not repair themselves fast enough for your body to be able to sustain the next stress cycle(s), at least in long term, without injuries.
So train hard, but make sure you are wise, and scientific about it.

Photo by Bellator MMA