Finger in the context of Dactyly

Knuckle-walking is a form of quadrupedal walking in which the forelimbs hold the fingers in a partially flexed posture that allows body weight to press down on the ground through the knuckles. Gorillas and chimpanzees use this style of locomotion, as do anteaters and platypuses.

Knuckle-walking helps with actions other than locomotion on the ground. Gorillas use fingers for the manipulation of food, whereas chimpanzees use fingers for the manipulation of food and climbing. In anteaters and pangolins, the fingers have large claws for opening the mounds of social insects. Platypus fingers have webbing that extends past the fingers which aids in swimming, thus knuckle-walking is used to prevent stumbling. Gorillas move around by knuckle-walking, although they sometimes walk bipedally for short distances while carrying food or in defensive situations. Mountain gorillas use knuckle-walking plus other parts of their hand—fist-walking does not use the knuckles, using the backs of their hand, and using their palms.

A hand is a prehensile, multi-fingered appendage located at the end of the forearm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs. A few other vertebrates such as the koala (which has two opposable thumbs on each "hand" and fingerprints extremely similar to human fingerprints) are often described as having "hands" instead of paws on their front limbs. The raccoon is usually described as having "hands" though opposable thumbs are lacking.

Some evolutionary anatomists use the term hand to refer to the appendage of digits on the forelimb more generally—for example, in the context of whether the three digits of the bird hand involved the same homologous loss of two digits as in the dinosaur hand.

A digit is one of several most distal parts of a limb, such as fingers or toes, present in many vertebrates.

Arm span or reach (sometimes referred to as wingspan, or spelled armspan) is the physical measurement of the length from one end of an individual's arms (measured at the fingertips) to the other when raised parallel to the ground at shoulder height at a 90° angle. The arm span measurement is usually very close to the person's height. Age, sex, and ethnicity have to be taken into account to best predict height from arm span. Arm span is sometimes used when a height measurement is needed but the individual cannot stand on a traditional stadiometer or against a wall due to abnormalities of the back or legs, such as scoliosis, osteoporosis, amputations, or those who are confined to a bed or wheelchair. Other, possibly more accurate measuring techniques include knee length or recumbent length when possible.

Because any decrease in height will cause an increase in the ratio of arm span to height, a large span to height ratio may sometimes be an indicator of a health problem that caused a vertical height loss such as postural changes due to ageing or any spinal conditions such as degenerative disc disease.

Sexual penetration is the insertion of a body part or other object into a body orifice, such as the mouth, vagina or anus, as part of human sexual activity or sexual behavior in non-human animals.

The term is most commonly used in statute law in the context of proscribing certain sexual activities. Terms such as "sexual intercourse" or "carnal knowledge" are more commonly found in older statutes, while many modern criminal statutes use the term "sexual penetration" because it is a broad term encompassing (unless otherwise qualified) any form of penetrative sexual activity, including digital (i.e., the fingers) or with an object, and may involve only the most minimal penetration. Some jurisdictions refer to some forms of penetration as "acts of indecency", or other terminology.

Fingering is sexual stimulation of the vulva (including the clitoris) or vagina by using the fingers. Vaginal fingering is legally and medically called digital penetration or digital penetration of the vagina. The term "digital" takes its significance from the English word 'digit', which refers to a finger, thumb, or toe. Fingering may also include the use of fingers to stimulate the anus.When someone performs fingering on another person's vulva or vagina, it is a form of manual sex, and is analogous to a handjob (manual stimulation of the penis). It may be used for sexual arousal or foreplay, constitute an entire sexual encounter, or be used as non-penetrative sexual activity. Fingering performed on one's own vulva or vagina is a form of masturbation.

In music, strumming is a way of playing a stringed instrument such as a guitar, ukulele, or mandolin. A strum or stroke is a sweeping action where a finger or plectrum brushes over several strings to generate sound. On most stringed instruments, strums are typically executed by a musician's designated strum hand (typically the musician's dominant hand, which is often responsible for generating the majority of sound on a stringed instrument), while the remaining hand (referred to as the fret hand on most instruments with a fingerboard) often supports the strum hand by altering the tones and pitches of any given strum.

Strums are often contrasted with plucking, as a means of vibrating an instrument's strings. In plucking, a specific string or designated set of strings are individually targeted to vibrate, whereas in strumming, a less precise targeting is usually used. Compared to other plucking techniques, any group of strings brushed in a single sweep by a plectrum could be considered a strum due to the plectrum's less precise string group targeting (however, a plectrum might simultaneously pluck a small group of strings without being considered a strum). In contrast, a musician could utilize a technique with more precise string group targeting (such as a fingerstyle or fingerpick technique) to pluck all the strings on a stringed instrument at once and this would still be considered a pluck, not a strum.

Plucked string instruments are a subcategory of string instruments that are played by plucking the strings. Plucking is a way of pulling and releasing the string in such a way as to give it an impulse that causes the string to vibrate. Plucking can be done with either a finger or a plectrum.

Most plucked string instruments belong to the lute family (such as guitar, bass guitar, mandolin, banjo, balalaika, sitar, pipa, etc.), which generally consist of a resonating body, and a neck; the strings run along the neck and can be stopped at different pitches.

The knuckles are the joints of the fingers. The word is cognate to similar words in other Germanic languages, such as the Dutch "knokkel" (knuckle) or German "Knöchel" (ankle), i.e., Knöchlein, the diminutive of the German word for bone (Knochen). Anatomically, it is said that the knuckles consist of the metacarpophalangeal (MCP) and interphalangeal (IP) joints of the finger. The knuckles at the base of the fingers may be referred to as the 1st or major knuckles while the knuckles at the midfinger are known as the 2nd and 3rd, or minor, knuckles. However, the ordinal terms are used inconsistently and may refer to any of the knuckles.

The index finger (also referred to as forefinger, first finger, second finger, pointer finger, trigger finger, digitus secundus, digitus II, and many other terms) is the second digit of a human hand. It is located between the thumb and the middle finger. It is usually the most dextrous and sensitive digit of the hand, though not the longest. It is shorter than the middle finger, and may be shorter or longer than the ring finger (see digit ratio).

A glove is a garment covering the hand, with separate sheaths or openings for each finger including the thumb. Gloves protect and comfort hands against cold or heat, damage by friction, abrasion or chemicals, and disease; or in turn to provide a guard for what a bare hand should not touch.

Gloves are made of materials including cloth, knitted or felted wool, leather, rubber, latex, neoprene, silk, and (in mail) metal. Gloves of kevlar protect the wearer from cuts. Gloves and gauntlets are integral components of pressure suits and spacesuits.

A fingerprint is an impression left by the friction ridges of a human finger. The recovery of partial fingerprints from a crime scene is an important method of forensic science. Moisture and grease on a finger result in fingerprints on surfaces such as glass or metal. Deliberate impressions of entire fingerprints can be obtained by ink or other substances transferred from the peaks of friction ridges on the skin to a smooth surface such as paper. Fingerprint records normally contain impressions from the pad on the last joint of fingers and thumbs, though fingerprint cards also typically record portions of lower joint areas of the fingers.

Human fingerprints are detailed, unique, difficult to alter, and durable over the life of an individual, making them suitable as long-term markers of human identity. They may be employed by police or other authorities to identify individuals who wish to conceal their identity, or to identify people who are incapacitated or dead and thus unable to identify themselves, as in the aftermath of a natural disaster.

In human anatomy, the metacarpal bones or metacarpus, also known as the "palm bones", are the appendicular bones that form the intermediate part of the hand between the phalanges (fingers) and the carpal bones (wrist bones), which articulate with the forearm. The metacarpal bones are homologous to the metatarsal bones in the foot.

The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments (called podomeres) are of Latin origin, and may be confused with terms for bones: coxa (meaning hip, pl.: coxae), trochanter, femur (pl.: femora), tibia (pl.: tibiae), tarsus (pl.: tarsi), ischium (pl.: ischia), metatarsus, carpus, dactylus (meaning finger), patella (pl.: patellae).

Homologies of leg segments between groups are difficult to prove and are the source of much argument. Some authors posit up to eleven segments per leg for the most recent common ancestor of extant arthropods but modern arthropods have eight or fewer. It has been argued that the ancestral leg need not have been so complex, and that other events, such as successive loss of function of a Hox-gene, could result in parallel gains of leg segments.

Pliers are a hand tool used to hold objects firmly, possibly developed from tongs used to handle hot metal in Bronze Age Europe. They are also useful for bending and physically compressing a wide range of materials. Generally, pliers consist of a pair of metal first-class levers joined at a fulcrum positioned closer to one end of the levers, creating short jaws on one side of the fulcrum, and longer handles on the other side. This arrangement creates a mechanical advantage, allowing the force of the grip strength to be amplified and focused on an object with precision. The jaws can also be used to manipulate objects too small or unwieldy to be manipulated with the fingers.

Diagonal pliers, also called side cutters, are a similarly shaped tool used for cutting rather than holding, having a pair of stout blades, similar to scissors except that the cutting surfaces meet parallel to each other rather than overlapping. Ordinary (holding/squeezing) pliers may incorporate a small pair of such cutting blades. Pincers are a similar tool with a different type of head used for cutting and pulling, rather than squeezing. Tools designed for safely handling hot objects are usually called tongs. Special tools for making crimp connections in electrical and electronic applications are often called crimping pliers or crimpers; each type of connection uses its own dedicated tool.

A nail is a protective plate characteristically found at the tip of the digits (fingers and toes) of almost all primates (except for marmosets), corresponding to the claws in other tetrapod animals. Fingernails and toenails are made of a tough rigid protein called alpha-keratin, a polymer also found in the claws, hooves, and horns of vertebrates.