Editing Finger (section)

====Muscles====
[[File:Temporal-Control-and-Hand-Movement-Efficiency-in-Skilled-Music-Performance-pone.0050901.s001.ogv|thumb|The precision of finger movements in space and time is highlighted in this [[motion capture|motion tracking]] of two [[pianist]]s' fingers playing the same piece (slow motion, no sound).<ref>{{Cite journal | last1 = Goebl | first1 = W. | last2 = Palmer | first2 = C. | editor1-last = Balasubramaniam | editor1-first = Ramesh | doi = 10.1371/journal.pone.0050901 | title = Temporal Control and Hand Movement Efficiency in Skilled Music Performance | journal = PLOS ONE | volume = 8 | issue = 1 | pages = e50901 | year = 2013 | pmid =  23300946| pmc =3536780 | bibcode = 2013PLoSO...850901G | doi-access = free }}</ref>]]
Each finger may [[flexion|flex]] and [[extension (kinesiology)|extend]], [[abduction (kinesiology)|abduct]] and [[adduction|adduct]], and so  also [[circumduction (anatomy)|circumduct]]. Flexion is by far the strongest movement. In humans, there are two large muscles that produce flexion of each finger, and additional muscles that augment the movement. The muscle bulks that move each finger may be partly blended, and the tendons may be attached to each other by a net of fibrous tissue, preventing completely free movement. Although each finger seems to move independently, moving one finger also moves the other fingers slightly which is called finger interdependence or finger enslaving.<ref>{{Cite journal | last1 = Li | first1 = Z.M. | last2 = Latash | first2 = M.L. | last3 = Zatsiorsky | first3 = V.M. | doi = 10.1007/s002210050343 | title = Force sharing among fingers as a model of the redundancy problem | journal = Experimental Brain Research | volume = 119 | issue = 3 | pages = 276–286 | year = 1998| pmid = 9551828 | s2cid = 46568801 }}</ref><ref>{{Cite journal | last1 = Zatsiorsky | first1 = V.M. | last2 = Latash | first2 = M.L. | last3 = Li | first3 = Z.M. | doi = 10.1007/s002219900261 | title = Enslaving effects in multi-finger force production | journal = Experimental Brain Research | volume = 131 | issue = 2 | pages = 187–195 | year = 2000| pmid = 10766271 | s2cid = 23697755 }}</ref><ref>{{Cite journal | last1 = Abolins | first1 = V. | last2 = Latash | first2 = M.L. | doi = 10.1123/mc.2021-0044 | issn=1087-1640  | title = The Nature of Finger Enslaving: New Results and Their Implications | journal = Motor Control | volume = 25 | issue = 4 | pages = 680–703 | year = 2021| pmid = 34530403 | s2cid = 237545122 }}</ref>

Fingers do not contain muscles (other than [[arrector pili]]). The [[muscle]]s that move the finger joints are in the [[Hand#Areas|palm]] and [[forearm]]. The long tendons that deliver motion from the forearm muscles may be observed to move under the skin at the wrist and on the back of the hand.

Muscles of the fingers can be subdivided into extrinsic and intrinsic muscles.
The extrinsic muscles are the long flexors and extensors. They are called extrinsic because the muscle belly is located on the forearm.

The fingers have two long flexors, located on the underside of the forearm. They insert by tendons to the phalanges of the fingers. The deep flexor attaches to the distal phalanx, and the superficial flexor attaches to the middle phalanx. The flexors allow for the actual bending of the fingers. The thumb has one long flexor and a short flexor in the thenar muscle group. The human thumb also has other muscles in the thenar group ([[opponens pollicis|opponens]] and [[abductor pollicis brevis muscle|abductor brevis muscle]]), moving the thumb in opposition, making grasping possible.

The extensors are located on the back of the forearm and are connected in a more complex way than the flexors to the dorsum of the fingers. The tendons unite with the interosseous and lumbrical muscles to form the extensorhood mechanism. The primary function of the extensors is to straighten out the digits. The thumb has two extensors in the forearm; the tendons of these form the [[anatomical snuff box]]. Also, the index finger and the little finger have an extra extensor, used for instance for pointing. The extensors are situated within six separate compartments. The first compartment contains abductor pollicis longus and extensor pollicis brevis. The second compartment contains extensors carpi radialis longus and brevis. The third compartment contains extensor pollicis longus. The extensor digitorum indicis and extensor digitorum communis are within the fourth compartment. Extensor digiti minimi is in the fifth, and extensor carpi ulnaris is in the sixth.

The intrinsic muscle groups are the [[thenar]] and [[hypothenar]] muscles (thenar referring to the thumb, hypothenar to the small finger), the [[dorsal interossei of the hand|dorsal]] and [[palmar interossei muscles]] (between the metacarpal bones) and the [[lumbricals of the hand|lumbrical muscles]]. The lumbricals arise from the [[flexor digitorum profundus muscle|deep flexor]] (and are special because they have no bony origin) and insert on the dorsal extensor hood mechanism.