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History Categories
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1.2 HistoryHuman walking is several million years old. A clear an visual evidence of this is the foot prints found in Laetoli in Africa. The foot prints originate presumably from our direct ancestor "Lucy", who is termed "australopithecus aferensis". The skeleton of this female was called Lucy, because she was excavated when the radio played "Lucy in the skies with diamonds" by Lennon and Mcartney. The footprints illustrated below were preserved because the humanoids walked in mud, which was preserved shortly after by dust from the burst of a volcano. It can easily be seen that the foot prints were set by an adult with a child walking along, probably held by hand. However, it has been disclosed that a third person was having some sort of amusement with walking exactly in the foot prints of the other adult. Figure 1.1.1 The foot prints in Laetoli are 3.7 million years old. The human being is the only species, which places the heel on the ground before the forefoot, it is therefore believed that evolution has formed the human foot to a highly specialized structure and not a degenerated hand as often suggested. Human walking seems to be optimized in a way that makes it the most economical pattern of locomotion. Calculated as energy cost per kg body mass per kilometer, no other species move as economical as a walking human being. It has been suggested that the apes developed in a part of Africa with forest, which required climbing and living in the trees. The humanoids, however, lived in the part of Africa with savannah, which led to the development of walking. The human being is not a fast runner, but it is known that he can follow a group of animals for days on the savannah until the animals become totally exhausted. This way of hunting, which relies on walking as a superior kind of locomotion, has been suggested to play an important role for the survival of the human being during several million years. It has often been suggested that biped human walking developed to free the hands for other purposes. One obviously important purpose would be to carry the small children. The human child is born highly immature and it is not able to walk at the pace of an adult until the age of 6-7 years. Accordingly, transportation of children must have been and still is a fundamental human task, which requires the use of the upper extremities. Moreover, running is inconvenient for the purpose of carrying objects mainly because this sort of locomotion, with a flight phase, implies a marked bouncing up and down. Walking displays a double support phase and no flight phases, which together with other mechanisms lead to minimized vertical oscillations of the whole body and thus ideal for carrying children. Based on the thoughts and theories mentioned above, it should be stressed that human walking is a highly sophisticated skill and unique to our species. If a person cannot walk, it is a severe handicap nowadays and in the past it would have been deadly. Evaluating the physical health of a person or the success of medical treatment of a patient may therefore very well be evaluated by gait analysis. |
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