http://www.mathewsopenaccess.com/orthopedics-current-issue.html
Several attributes are especial for primates, some of these are even more unique in humans. These may not be limited to; energy-saving bipedal posture and locomotion, complex manual skills and tool making abilities, social and cultural organisation, augmented cranial capacity, a more developed frontal lobe, and language proficiency. From a Darwinian point of view, erect posture was achieved to free the hands for tool-making. However, more recent theories suggested that bipedal locomotion was related to environmental factors which led to the advent of distinctive and remarkable anatomical features for a form of locomotion that is more energy-economic than quadrupedal locomotion. The purpose of this mini-review is to elaborate on the critical biomechanical and anatomical adaptations in modern human which enabled an energy-efficient form of bipedalism; this form of locomotion is never seen in other species including primates. These anatomic features and adaptations include; adjustments to the general body architectural plan, in addition to cranial and postcranial modifications. The latter is debated to be the most critical for a stable and fuel-efficient upright walking, other anatomic adaptation were parallel and complimentary. The most significant of these anatomical changes took place post-cranially at the level of the pelvis. Some of these changes can be found in Australopithecus afarensis dating back to 3.6 million years ago.
Several features are unique to humans including; an efficient bipedal or upright walking, stable supine posture, an augmented cranial capacity and a complex frontal lobe, ability to speak and interpret speech, complex tool-making abilities, an elaborate social structure. Cultural anthropologists and physical anthropologists consider that all these features contributed eventually to the development of a real culture, rather than a primitive culture (proto-culture) as seen in several primates species including chimpanzees. It is estimated that the earliest of these traits to be established was the upright posture (bipedalism) in Australopithecine; including Lucy’s specie (Australopithecus afarensis).
Several attributes are especial for primates, some of these are even more unique in humans. These may not be limited to; energy-saving bipedal posture and locomotion, complex manual skills and tool making abilities, social and cultural organisation, augmented cranial capacity, a more developed frontal lobe, and language proficiency. From a Darwinian point of view, erect posture was achieved to free the hands for tool-making. However, more recent theories suggested that bipedal locomotion was related to environmental factors which led to the advent of distinctive and remarkable anatomical features for a form of locomotion that is more energy-economic than quadrupedal locomotion. The purpose of this mini-review is to elaborate on the critical biomechanical and anatomical adaptations in modern human which enabled an energy-efficient form of bipedalism; this form of locomotion is never seen in other species including primates. These anatomic features and adaptations include; adjustments to the general body architectural plan, in addition to cranial and postcranial modifications. The latter is debated to be the most critical for a stable and fuel-efficient upright walking, other anatomic adaptation were parallel and complimentary. The most significant of these anatomical changes took place post-cranially at the level of the pelvis. Some of these changes can be found in Australopithecus afarensis dating back to 3.6 million years ago.
Several features are unique to humans including; an efficient bipedal or upright walking, stable supine posture, an augmented cranial capacity and a complex frontal lobe, ability to speak and interpret speech, complex tool-making abilities, an elaborate social structure. Cultural anthropologists and physical anthropologists consider that all these features contributed eventually to the development of a real culture, rather than a primitive culture (proto-culture) as seen in several primates species including chimpanzees. It is estimated that the earliest of these traits to be established was the upright posture (bipedalism) in Australopithecine; including Lucy’s specie (Australopithecus afarensis).
Numerous anatomic adaptations materialised independently
across time; these changes exist cranially and post-cranially,
principally serving the purpose of high energy efficiency. Compared
to apes and quadrupeds, humans spend much less en
ergy in bipedal locomotion. Humans have also acquired
longer lower limbs to serve the propulsive function during
walking. Besides, humans have less body weight (BW) above
the waist (68% of total BW in genus Homo vs. 82% in Apes). Additionally, the line of gravity passes behind the ears
and slightly anterior to the spine, and anterior to the knees. Bipedalism appears to be unique and more advanced
in humans, and particularly in genus Homo, than in all others
primates. Musculoskeletal and anatomical adaptations can be
specifically categorised into; general (1), post-cranial (2), and
cranial (3). The changes started to be perfected in Australopithecus
afarensis at approximately 3.6 million years; it has
been extensively studied via the Laetoli footprints discovered
by Mary Leaky in 1978 near Olduvai gorge in Tanzania.
On the other that hominids adaptations, particularly pelvic redesigning,
were far different for example that of Oreopithecus
bambolii.
No comments:
Post a Comment