| Human legs were once short and designed to better climb the trees
rather than walk on just two legs. The intermediary evolution stage to
walking upright was done in on forest trees by prehistoric humans
who used tree branches for support. So says the research published by
the scientists at Liverpool and Birmingham, which goes against the
previously accepted anthropology theory that early humans trained to
walk on two legs through the intermediary stage of "knuckle walking"
exhibited by gorilla and and chimpanzee these days. The British
research is based on studying the behavior of orangutans which use
tree branches for support when walking on two legs. This breakthrough
scientific paper was published this week and argues that knuckle
walking was only secondary trait developed later, and had little
to do with legs becoming the primary moving limbs. Early human
skeletons show that legs were relatively short and arms were long.
As evolution progressed and humans started to walk upright, their legs
became longer and stronger to compensate for the absence of hands in
walking process. So the next time you see those beautiful long female legs,
remember that thousands of years ago they were shorter and were used
for climbing trees. Neanderthal men still found them attractive,
however, and those legs were considered beautiful in ancient times.
Foot skeleton:
The human foot has 26 bones and form three parts:
• Tarsal (Latin- tarsus) - 7 bones in the proximal part of the foot, connecting with the metatarsal bones.
• Talar (Latin- talus);
• Calcaneal (Latin-. calcaneus);
• Navicular (Latin-. os naviculare);
• Lateral sphenoidal (Latin- os cuneiforme lateralis);
• Intermediate sphenoidal(Latin-. os cuneiforme intermedium);
• Medial sphenoidal(Latin- os cuneiforme medialis);
• Cuboidal (Latin- os cuboideum);
• Metatarsal (Latin- metatarsus) — 5 short tubular bones of the foot located between a tarsal and the phalanges of the fingers.
• Phalanges (Latin - phalanx) — 14 short tubular bones forming segments of the toes of the feet. Two phalanges form the big toe; the other toes consist of three phalanges.
Foot joints:
• Talo-calcanean(Latin - articulatio talocalcanealaris);
• Talo-calcaneo-navicular (Latin- articulatio talocalcaneonavicularis);
• Calcaneocuboid ( Latin - articulatio calcaneocuboidea);
• Transverse tarsal (Latin - articulatio tarsi transversa);
• Metatarsotarsal (Latin - articulationes tarsometatarseae);
• Metatarsophalangeal ( Latin - articulationes metatarsophalangeae);
• Interpharyngeal (Latin - articulationes interphalangeae).
Muscles of the foot:
The muscles of the foot can be divided into dorsal and plantar muscles.
Dorsal muscles include:
• Short extensor of the digits (Latin- extensor digitorum brevis) - extends the metatarsophalangeal joints of the II—IV fingers and abducts them outwards;
• Short extensor of the big toe (Latin- extensor hallucis brevis) - extends the big toe and pulls it outwards.
Three groups of muscles are found on the plantar surface of the foot as well as on the palmar surface of the hand: the medial, forming the big toe eminence; the lateral, forming the little toe eminence and the intermediate group of muscles located between the two. The eminence of the big toe is formed by three short muscles causing flexion, abduction and adduction of the big toe of the foot.
Planter muscles of the foot include:
• Abduction of the little toe (Latin- abductor digiti minimi) — abducts and flexes the little toe;
• Short flexors of the toes (Latin- flexor digitorum brevis) — flexes the toes;
• Abduction of the big toe (Latin-. abductor hallucis) — flexes and abducts the big toe, strengthens the medial part of the foot arch;
• Short flexor of the big toe (Latin- flexor hallucis brevis) — flexes the big toe;
• Lumbriciform (Latin- lumbricales) — flexes the proximal phalanges of the toes and pulls them towards the big toe;
• Short flexors of the little toes (Latin- flexor digiti minimi brevis) — flex the little toe, abduct it and strengthens the longitudinal arch of the foot.
Intermetatarsal muscles:
• Dorsal interosseous (Latin- interossei dorsales) — flex the proximal, slightly extending the middle and distal phalanges of the II—IV toes, abducts the II toe on both sides, III and IV towards the little toe, and strengthen a foot arch.
Plantar muscles in turn are divided into the muscles of the big toe eminence, muscles of the small toe eminence and muscles of the medial eminence. |
Scientific study published this week suggests that humans learned to walk on two legs on trees holding tree branches for support. Skeletons of early humans are consistent with this study and show short legs and long arms. The research rejects the widely accepted theory that humans learned to walk upright on open land by "knuckle-walking" as done by chimpanzees, gorillas, and Rosie O'Donnel.
