Index finger

The index finger (also referred to as forefinger,^[1] first finger,^[2] second finger,^[3] 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).

Index finger
Left human hand with index finger extended
Details
Artery	Radial artery of index finger, proper palmar digital arteries, dorsal digital arteries
Vein	Palmar digital veins, dorsal digital veins
Nerve	Dorsal digital nerves of radial nerve, proper palmar digital nerves of median nerve
Identifiers
Latin	digitus II manus, digitus secundus manus, index
TA98	A01.1.00.054
TA2	152
FMA	24946
Anatomical terminology [edit on Wikidata]

Anatomy

"Index finger" literally means "pointing finger", from the same Latin source as indicate; its anatomical names are "index finger" and "second digit".

The index finger has three phalanges. It does not contain any muscles, but is controlled by muscles in the hand by attachments of tendons to the bones.

Uses

A man pointing at a woman during an argument

A lone index finger held vertically is often used to represent the number 1 (but finger counting differs across cultures), or when held up or moved side to side (finger-wagging), it can be an admonitory gesture. With the hand held palm out and the thumb and middle fingers touching, it represents the letter d in the American Sign Language alphabet.

Pointing

Pointing with the pointer finger may be used to indicate or identify an item, person, place or object.^[4]

Around age one, babies begin pointing to communicate relatively complex thoughts, including interest, desire, and information. Pointing in human babies can demonstrate the theory of mind, or ability to understand what other people are thinking. This gesture may form one basis for the development of human language.

Non-human primates, lacking the ability to formulate ideas about what others are thinking, use pointing in much less complex ways.^[5] However, corvids, dogs^[6] and elephants^[7] do understand finger pointing.

In some cultures, particularly the Malays and Javanese^[8] in Southeast Asia, pointing using index finger is considered rude, hence the thumb is used instead.

Index finger in Islam

In Islam raising the index finger signifies the Tawhīd (تَوْحِيد), which denotes the indivisible oneness of God. It is used to express the unity of God ("there is no god but God").^{[citation needed]}

In Arabic, the index or fore finger is called musabbiḥa (مُسَبِّحة), mostly used with the definite article: al-musabbiḥa (الْمُسَبِّحة). Sometimes also as-sabbāḥa (السَّبّاحة) is used.^[9][10] The Arabic verb سَبَّحَ - which shares the same root as the Arabic word for index finger - means to praise or glorify God by saying: "Subḥāna Allāh" (سُبْحانَ الله).^{[citation needed]}

Index finger in archaeoastronomy

Before the advent of GPS and compass, early humans used index finger for pointing direction of objects with the help of stellar objects during night time.^[11]

Gestures in art

The index finger pointing up is a sign of teaching authority. This is shown in the depiction of Plato in the School of Athens by Raphael.^[12]

Plato, detail from the School of Athens, Raphael, 1509

A detail from The Creation of Adam, Michelangelo, 1512

As a modern artistic convention, the index finger pointing at the viewer is in the form of a command or summons. Two famous examples of this are recruiting posters used during World War I by the United Kingdom and the United States.

Recruitment poster, Alfred Leete, 1914

Recruitment poster, James Montgomery Flagg, 1917

See also

• Digit ratio, comparative lengths of the index finger and ring finger and androgen levels in utero
• Extensor indicis muscle
• Fingering (disambiguation)
• Finger numbering
• Index (typography)

References

1. "forefinger - definition of forefinger in English | Oxford Dictionaries". Oxford Dictionaries | English. Archived from the original on September 25, 2016. Retrieved 2017-06-08.
2. "first finger - definition of first finger in English | Oxford Dictionaries". Oxford Dictionaries | English. Archived from the original on September 25, 2017. Retrieved 2017-06-08.
3. "second finger". Medical Dictionary. Retrieved 17 August 2022.
4. Gary Imai. "Gestures: Body Language and Nonverbal Communication" (PDF). Archived from the original (PDF) on March 31, 2010. Retrieved 12 November 2009.
5. Day, Nicholas (26 March 2013). "Research on babies and pointing reveals the action's importance". Slate. Retrieved 25 April 2013.
6. Kirchhofer, Katharina C.; Zimmermann, Felizitas; Kaminski, Juliane; Tomasello, Michael (2012). "Dogs (Canis familiaris), but Not Chimpanzees (Pan troglodytes), Understand Imperative Pointing". PLOS ONE. 7 (2): e30913. Bibcode:2012PLoSO...730913K. doi:10.1371/journal.pone.0030913. PMC 3275610. PMID 22347411.

   • "Dogs succeed while chimps fail at following finger pointing: Chimpanzees have difficulty identifying object of interest based on gestures". ScienceDaily (Press release). February 8, 2012.
7. Goodman, M.; Sterner, K. N.; Islam, M.; Uddin, M.; Sherwood, C. C.; Hof, P. R.; Hou, Z. C.; Lipovich, L.; Jia, H.; Grossman, L. I.; Wildman, D. E. (2009). "Phylogenomic analyses reveal convergent patterns of adaptive evolution in elephant and human ancestries". Proceedings of the National Academy of Sciences. 106 (49): 20824–9. Bibcode:2009PNAS..10620824G. doi:10.1073/pnas.0911239106. JSTOR 40536081. PMC 2791620. PMID 19926857.

   • Katie Collins (October 10, 2013). "Elephants found to understand human pointing without training". Wired UK.^{[permanent dead link‍]}
8. Scott, David Clark (12 April 1990). "A Thumb Points the Way in Java". The Christian Science Monitor. ...figures in some reliefs can be seen pointing - with their thumbs. 'Pointing with the index finger is a terrible thing to do. It means death or violence. People used their thumb for polite pointing and it's still the same today,' notes Jan Fontein, curator of the exhibition of ancient Indonesian sculpture sponsored by Mobil Indonesia...
9. Drißner, Gerald (2016). Islam for Nerds - 500 Questions and Answers. Berlin: createspace. p. 521. ISBN 978-1530860180.
10. "What does it mean when a Muslim raises the index-finger?". Arabic for Nerds. 2016-12-31. Archived from the original on 2019-07-18. Retrieved 2019-07-18.
11. "Using The Stars For Direction, Latitude, And Time". Astronomy Trek. 29 November 2012. Retrieved 26 October 2022.
12. Brusati, Celeste; Enenkel, Karl A. E.; Melion, Walter (Nov 11, 2011). The Authority of the Word: Reflecting on Image and Text in Northern Europe, 1400-1700. Brill. p. 168. ISBN 978-9004215153.

External links

Media related to Index fingers at Wikimedia Commons