Editing Foot (section)

====Intrinsic====
On the top of the foot, the tendons of [[extensor digitorum brevis muscle|extensor digitorum brevis]] and [[extensor hallucis brevis muscle|extensor hallucis brevis]] lie deep in the system of long extrinsic extensor tendons. They both arise on the calcaneus and extend into the dorsal [[aponeurosis]] of digits one to four, just beyond the penultimate joints. They act to dorsiflex the digits.<ref name="Platzer-268">Platzer 2004, p. 268</ref> Similar to the intrinsic muscles of the hand, there are three groups of muscles in the ''sole of foot'', those of the first and last digits, and a central group:

{{multiple image
| align = right
| image1 = Gray443.png
| width1 = 83
| alt1 = 
| caption1 = 
| image2 = Gray444.png
| width2 = 91
| alt2 = 
| caption2 = 
| image3 = Gray445.png
| width3 = 100
| alt3 = 
| caption3 = 
| footer = Plantar aspects of foot, varying depths (superficial to deep)
}}

''Muscles of the big toe'': the [[abductor hallucis muscle|abductor hallucis]] stretches medially along the border of the sole, from the calcaneus to the first digit. Below its tendon, the tendons of the long flexors pass through the [[tarsal tunnel|tarsal canal]]. The [[abductor hallucis muscle|abductor hallucis]] is an abductor and a weak flexor, and also helps maintain the arch of the foot. The [[flexor hallucis brevis muscle|flexor hallucis brevis]] arises on the medial cuneiform bone and related ligaments and tendons. An important plantar flexor, it is crucial to ballet dancing. Both these muscles are inserted with two heads proximally and distally to the first [[metatarsophalangeal joints|metatarsophalangeal joint]]. The [[adductor hallucis muscle|adductor hallucis]] is part of this group, though it originally formed a separate system (see [[contrahens]]). It has two heads, the oblique head originating obliquely across the central part of the midfoot, and the transverse head originating near the metatarsophalangeal joints of digits five to three. Both heads are inserted into the lateral [[sesamoid bone]] of the first digit. The adductor hallucis acts as a tensor of the plantar arches and also adducts the big toe and might plantar flex the proximal phalanx.<ref name="Platzer-270">Platzer 2004, pp. 270–72</ref>

''Muscles of the [[fifth toe|little toe]]'': Stretching laterally from the calcaneus to the proximal phalanx of the fifth digit, the [[abductor digiti minimi muscle (foot)|abductor digiti minimi]] form the lateral margin of the foot and are the largest of the muscles of the fifth digit. Arising from the base of the fifth metatarsal, the [[flexor digiti minimi brevis muscle (foot)|flexor digiti minimi]] is inserted together with abductor on the first phalanx. Often absent, the [[opponens digiti minimi muscle|opponens digiti minimi]] originates near the cuboid bone and is inserted on the fifth metatarsal bone. These three muscles act to support the arch of the foot and to plantar flex the fifth digit.<ref name="Platzer-272">Platzer 2004, p. 272</ref>

{{multiple image
| align = right
| image1 = Gray446.png
| width1 = 100
| alt1 = 
| caption1 = 
| image2 = Gray447.png
| width2 = 100
| alt2 = 
| caption2 = 
| footer = Central muscles of foot
}}
''Central muscle group'': The four [[lumbricals of the foot|lumbricals]] arise on the medial side of the tendons of [[flexor digitorum longus muscle|flexor digitorum longus]] and are inserted on the medial margins of the proximal phalanges. The [[quadratus plantae muscle|quadratus plantae]] originates with two slips from the lateral and medial margins of the calcaneus and inserts into the lateral margin of the flexor digitorum tendon. It is also known as the flexor accessorius. The [[flexor digitorum brevis muscle|flexor digitorum brevis]] arises inferiorly on the calcaneus and its three tendons are inserted into the middle phalanges of digits two to four (sometimes also the fifth digit). These tendons divide before their insertions and the tendons of flexor digitorum longus pass through these divisions. Flexor digitorum brevis flexes the middle phalanges. It is occasionally absent. Between the toes, the [[dorsal interossei of the foot|dorsal]] and [[plantar interossei muscles|plantar interossei]] stretch from the metatarsals to the proximal phalanges of digits two to five. The plantar interossei adduct and the dorsal interossei abduct these digits, and are also plantar flexors at the metatarsophalangeal joints.<ref name="Platzer-274">Platzer 2004, p. 274</ref>