A groin attack is a deliberate attempt to cause pain to the groin area of one's opponent. Often used in self-defense, the technique can be quickly debilitating, due to the large number of sensitive nerve endings in the penis and testicles of males, as well as the highly innervated vulva of females. A sufficiently powerful blow may fracture the pubic bone of the victim, resulting in physical disability. This technique has been popularized as a comedic device in various forms of media.
An attack to the groin is considered to be a "low blow" not only in the literal sense, but is the origin of the metaphor as well. In a playful attack, or attack in the framework of a sport, a low blow is seen as unfair or improper and is often considered dishonourable.
Boxing forbade strikes to the groin as far back as the Marquess of Queensberry Rules, and they are almost universally forbidden in martial arts competitions including kickboxing, and mixed martial arts. UFC rules dictate a groin strike is a foul in both male and female matches, with the competitor who has received such a strike given up to five minutes to recover. However, the rules also implicitly acknowledge that attacks on vulva are less painful and dangerous than attacks on the testicles by requiring male competitors to wear groin protectors and prohibiting female competitors from wearing groin protection.
Testicle attacks were, however, allowed until the 1980s in international Thai boxing (Muay Thai) and are still permitted in Thailand itself (though the boxers wear cups to lessen the impact.)
Direct strikes to the groin are generally considered illegal in professional wrestling as well, and unofficial rings may consider it shameful, however, in certain "hardcore" matches the rules are relaxed and such attacks are allowed by mutual consent.
In street fighting, a low blow may be considered more appropriate as a self-defense technique. The attack can allow a much weaker combatant to temporarily disable an assailant, making it easy for them to escape. When one's opponent is at close range, a knee attack to the groin is easy to execute and difficult to defend against. It is often, though not always, effective.
Intentional or deliberate low blow has been a subject for an internet meme known as a "nut shot", commonly in the form of a practical joke video uploaded to video sharing services such as YouTube. Aside from low blows, the meme sometimes also involves an accidental (often comedic) injury to the groin, usually as a result of falling or struck by an object.
The testicles lack anatomical protection and are highly sensitive to impact. The pain caused by impact to the testicles travels through the spermatic plexus. In extreme cases, a hard strike to the testicles can cause one or both to rupture, potentially sterilizing the victim.
While less often depicted in media, a strike to the groin can cause pain for female victims too. The skin of the vulva and the clitoris are highly sensitive, making laceration injuries especially painful. In extreme cases, nerve damage can occur to the clitoris.