| Heel | |
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| A girl's heel | |
| Latin | calx |
In human anatomy, the heel is the prominence at the posterior end of the foot. It is based on the projection of one bone, the calcaneus or heel bone, behind the articulation of the bones of the lower leg.
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The compressive forces applied to the foot are distributed along five rays, three medial (side of big toe) and two lateral (side of little toe). The lateral rays stretch over the cuboid bone to the heel bone and the medial rays over the three cuneiform bones and the navicular bone to the ankle bone. Because the ankle bone is placed over the heel bone, these rays are adjacent near the toes but overriding near the heel, and together they form the arches of the foot that are optimized to distributed compressive forces across an uneven terrain. In this context the heel thus forms the posterior point of support that together with the balls of the large and little toes bear the brunt of the loads. [1]
To distribute the compressive forces exerted on the heel during gait, and especially the stance phase when the heel contacts the ground, the sole of the foot is covered by a layer of subcutaneous connective tissue up to 2 cm thick (under the heel). This tissue has a system of pressure chambers that both acts as a shock absorber and stabilises the sole. Each of these chambers contains fibrofatty tissue covered by a layer of though connective tissue made of collagen fibers. These septa ("walls") are firmly attached both to the plantar aponeurosis above and the sole's skin below. The sole of the foot is one of the most highly vascularized regions of the body surface, and the dense system of blood vessels further stabilize the septa. [2]
The Achilles tendon is the muscle tendon of the triceps surae, a "three-headed" group of muscles -- the soleus and the two heads of the gastrocnemius. The main function of the triceps surae is plantar flexion, i.e. to stretch the foot downward. It is accompanied by a "fourth head", the slight plantaris muscle, the long slender tendon of which is also attached to the heel bone but not visible. [3]
In the long-footed mammals, both the hoofed species (unguligrade) and the clawed forms which walk on the toes (digitigrade), the heel is well above the ground at the apex of the angular joint known as the hock. In plantigrade species it rests on the ground.
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HEEL. (I) (0. Eng. hela, cf. Dutch hiel; a derivative of O. Eng. hoh, hough, hock), that part of the foot in man which is situated below and behind the ankle; by analogy, the calcaneal part of the tarsus in other vertebrates. The heel proper in digitigrades and ungulates is raised off the ground and is commonly known as the "knee" or "hock," while the term "heel" is applied to the hind hoofs. (2) (A variant of the earlier hield; cf. Dutch hellen, for helden), to turn over to one side, especially of a ship. It is this word probably, in the sense of "tip-up," used particularly of the tilting or tipping of a cask or barrel of liquor, that explains the origin of the expression "no heel-taps," a direction to the drinkers of a toast to drain their glasses and leave no dregs remaining. "Tap" is a common word for liquor, and a cask is said to be "heeled" when it is tipped and only dregs or muddy liquor are left. This suits the actual sense of the phrase better than the explanations which connect it with tapping the "heel" or bottom of the glass (see Notes and Queries, 4th series, vols. xi. - xii., and 5th series, vol. i.).
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<< Hedonism |
Categories: HEB-HEN
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Old English hela, from Proto-Germanic *hāhil. Cognate with Dutch hiel, Swedish häl, Icelandic hæll. Compare hock.
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Plural |
heel (plural heels)
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Infinitive |
Third person singular |
Simple past |
Past participle |
Present participle |
to heel (third-person singular simple present heels, present participle heeling, simple past and past participle heeled)
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From Old English hyldan (“‘incline’”), cognate with Old Norse hella (“‘to pour out’”) ( > Danish and Norwegian hælde (“‘lean, pour’”)).
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Infinitive |
Third person singular |
Simple past |
Past participle |
Present participle |
to heel (third-person singular simple present heels, present participle heeling, simple past and past participle heeled)
heel, hele (not comparable)
heel
heel
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