Editing Upper limb (section)

====Hand====
[[File:Scheme human hand bones-en.svg|thumb|Bones of the hand]]
{{Main|Hand}}
The hand ({{langx|la|manus}}),<ref name="Thieme-Atlas-208" /> the [[Metacarpus|metacarpals]] (in the hand proper) and the [[Phalanx bones|phalanges]] of the fingers, form the [[metacarpophalangeal joint]]s (MCP, including the [[knuckle]]s) and [[interphalangeal articulations of hand|interphalangeal joints]] (IP).

Of the joints between the carpus and metacarpus, the [[carpometacarpal joint]]s, only the saddle-shaped joint of the thumb offers a high degree of mobility while the opposite is true for the metacarpophalangeal joints.  The joints of the fingers are simple hinge joints.
<ref name="Sellers-8" />

The primary role of the hand itself is grasping and manipulation; tasks for which the hand has been adapted to two main grips&nbsp;— power grip and precision grip.  In a power grip an object is held against the palm and in a precision grip an object is held with the fingers, both grips are performed by intrinsic and extrinsic hand muscles together.  Most importantly, the relatively strong thenar muscles of the thumb and the thumb's flexible first joint allow the special opposition movement that brings the distal thumb pad in direct contact with the distal pads of the other four digits.  Opposition is a complex combination of thumb flexion and abduction that also requires the thumb to be rotated 90° about its own axis.  Without this complex movement, humans would not be able to perform a precision grip.
<ref name="Sellers-10">{{harvnb|Sellers|2002| pp=10–11}}</ref>

In addition, the central group of intrinsic hand muscles give important contributions to human dexterity.  The palmar and dorsal interossei adduct and abduct at the MCP joints and are important in pinching.  The lumbricals, attached to the tendons of the [[flexor digitorum profundus]] (FDP) and [[extensor digitorum communis]] (FDC), flex the MCP joints while extending the IP joints and allow a smooth transfer of forces between these two muscles while extending and flexing the fingers.
<ref name="Sellers-10" />

; Muscles: of the hand<ref name="Thieme-Atlas-256" />
:; Metacarpal: [[Lumbricals of the hand|Lumbricals]], [[Palmar interossei muscles|palmar introssei]], [[Dorsal interossei of the hand|dorsal interossei]]
:; [[Thenar]]: [[Abductor pollicis brevis]], [[adductor pollicis]], [[flexor pollicis brevis]], [[opponens pollicis]]
:; [[Hypothenar]]: [[Abductor digiti minimi muscle of hand|Abductor digiti minimi]], [[Flexor digiti minimi brevis (hand)|flexor digiti minimi]], [[opponens digiti minimi]], [[palmaris brevis]]