In order to better learn to heal and treat patients, modern doctors spend years in difficult, specialized study before they are even allowed to begin practicing. Not for nothing is their profession among the most respected in the world. Surely these are the people you most want to turn to if you find yourself afflicted with some serious injury.... right?
Not in fiction. There, often the people with the greatest expertise in fixing injuries are those trained in inflicting them. Particularly if he or she follows the Path of Peace, a martial arts instructor is liable to be far better versed in treating physical trauma than ordinary doctors, and an Old Master will probably turn out to be a medical miracle worker.
This has some basis in fact; traditional kung fu training was often accompanied with instruction in Chinese medicine, and jujitsu masters were often trained bonesetters. Any good martial arts instructor should have some idea of how to respond to injuries likely to crop up during training. However, in fiction, this tends to be exaggerated to the point of martial arts masters offering the best medical care available, along with ridiculous fare like punching people to cure deformities and illnesses and the like.
- Ma Kensei and Akisame Koetsuji of Kenichi: The Mightiest Disciple are masters of Chinese medicine and acupuncture/bonesetting respectively. Together, they have the skills to revive Kenichi from any trauma that occurs to him during training up to and including death. Koetsuji also fixed the boxer Takeda's lamed arm after doctors told him it was irreparable. To say nothing of "deceiving death" to keep Apachai Hopachai among the living after his battle with Agaard.
- This is taken even further by the villainess, Kushinada Mikumo, whose Jujitsu style apparently also teaches the secret of eternal youth as she is implied to be around the same age as Furinji Hayato, having fought alongside him in the past, and yet doesn't even look middle-aged. It's also implied that part of this involves some form of dietary restrictions as her disciple, Chikage, is frequently overwhelmed by the novelty of sweet foods that are rather mundane to everyone else.
- Sanji of One Piece isn't a medic, but his kicking skill is such that he can remodel your face and body with magical plastic surgery. Yes, that's right, Sanji can kick the ugly out of you.
- Kenshiro of Fist of the North Star can use Hokuto Shinken to heal as well as to make heads asplode, such as what he did for Lin in the very first episode, who was rendered mute due to the trauma of having her parents murdered right in front of her.
- Partially justified due to the fact that he's essentially performing a type of acupressure.
- This is explicitly the style that Toki, Kenshiro's older adopted sibling, uses. He walks the wastelands curing the sick with his compassionate version of Hokuto Shinken. Doesn't keep him from firing lasers from his arms to kill people using Hokuto Shinken.
- In the martial arts manga Kenji, Kenji's grandfather treats some injuries he picked up in a fight with Chinese medicine, noting that he's "still much better than your average doctor."
- In Naruto, Hinata Hyuga uses her X-Ray Vision granting Magical Eye and Pressure Point based Supernatural Martial Arts to help fix the titular character's Dramatic Dislocation in Chapter 617.
- Bleach: There's one example in this story of someone whose expertise in killing people became a useful tool for them to develop medical abilities. And, no, it's not Mayuri. Captain Unohana was the greatest Master Swordsman in Soul Society history. And its most diabolical criminal. She developed healing abilities because her special power is the ability to dissolve her opponents to death. By healing herself as she fights, she can keep fighting indefinitely while her victims melt to death around her. When she finally became The Atoner, she put aside the blood lust and instead became Soul Society's best healer.
- Lady Shiva, a martial artist and assassin in The DCU is also a skilled medic, and has been shown doing everything from reviving a man who had been shot and drowned to relieving neck pain. This is explained as a result of the intensive knowledge of human anatomy that is required for her particular fighting style.
- Tim Drake, Robin III/Red Robin III, has had a higher degree of medical training than his fellow Robins as after training under Batman and Nightwing he traveled to study under the Rahul Lama, and Old Master who taught him healing arts that were a part of his ancient martial arts tradition and subsequently studied under Lady Shiva and spent quite a bit of time learning disguise and medical knowledge from Alfred over the years.
- Mr. Miyagi (healing palm) and Mr. Han (Chinese medicine) from the original version and remake of The Karate Kid.
- Terminator 2: Judgment Day. The T-800 treats Sarah Connor's injuries. Later he is shown field-dressing Dyson's bullet wound.
John Connor: You know what you're doing?
Terminator: I have detailed files on human anatomy.
Sarah Connor: I'll bet. Makes you a more efficient killer, right?
- Discworld: In Terry Pratchett's Pyramids, when the protagonist starts having supernatural symptoms his friends take him to the doctor and, when he fails to identify the problem, to their school — the assassins' guild. In this case it's not so much that the Assassins are so great (although they do have, shall we say, a certain applied knowledge on the subject) as the doctors in Ankh-Morpork being utterly incompetent: To give you some idea, the doctor they tried initially claimed that apart from minor details like the fact he was still breathing, Teppic was presenting enough symptoms to make a diagnosis of death and the best thing they could do was find an undertaker. The only decent doctors in the city are said to be trained in Klatch or veterinarians (on the theory that if a human patient dies, the doctor can get away with it by saying it's the gods' will, whereas if a prized racehorse dies, certain people will be upset and no mistake).
- Played straight in Leverage in The Bank Shot Job — Eliot is the only member of the group whose job regularly involves violence (actually, his job basically is violence) so it stands to reason that he's the one who's going to know what to do with a gunshot wound.
- On Person of Interest Shaw is a deadly government assassin and is shown to be highly proficient in medical matters. It ends up being subverted when a flashback reveals that she used to be a medical resident but was forced to quit because her bedside manner was deemed unacceptable in a doctor. So she already had extensive medical knowledge when she was recruited by the CIA.
- The Path of the Healthy Tiger from Feng Shui is split into two main paths, one focused on healing and the other on counterattacks. A Tiger master is definitely an example of this particular trope.
- The Monks of Etrian Odyssey III are that game's main healers, and their unique "Form Qi" skill makes their healing abilities that much more effective. On the other hand, the Fist Mastery branch of their skill tree exists for a reason.
- Dr Q. Huaong in Jagged Alliance 2 is also one of the few mercenaries with the martial arts skill.
- Fallout 2, Fallout Tabletop RPG and Fallout Tactics has "Living Anatomy" perk. It requires some medical skill and gives bonus both to healing and to damage against living creatures.
- Citan of Xenogears has a bit of this, serving as both the local doctor and Fei's martial arts teacher. He's also one of the best fighters in the game, in and out of gears.
- Fist of the North Star: Lost Paradise has Toki and Kenshiro use their Hokuto Shinken expertise for healing others, like in canon. The latter even gets a minigame where he has to work at a clinic, alternating between using his skills to heal the sick and wounded and kill thugs trying to steal Eden's limited medicine supply.
- In medieval Europe, the one person in the local lord's employ most likely to know how to treat severe injuries effectively was the local torturer. This makes sense when you understand that his job was to keep very badly injured people alive.