delinquent noun [C]. âº a âperson, usually âyoung, who âbehaves in a way that is âillegal or not âacceptable to most âpeople: âjuvenile delinquents.
Sahelanthropus may have walked on two legs. The oldest evidence for walking on two legs comes from one of the earliest humans known, Sahelanthropus. Walking upright may have helped this species survive in the diverse habitats near where it livedâincluding forests and grasslands.
For sitting upright (with the 3 curves of the spine gently at their place), easily and without help, you need a strong AND flexible back, with strong muscles. You also need long hamstrings, which are the second severest limiting factor to a good sitting posture.