Skeletal proof of bipedalism in modern humans was first seen in Australopithecus fossils dating back to around three to four million years ago. A set of fossilized footprints tells scientists and anthropologists that Australopithecus walked upright due to the definite heel shape and human-like arch. In modern humans, the foot shows evolutionary evidence of bipedalism because of the stable ankle attaching the foot to the leg and …show more content…
Walking on two legs largely stresses the hip joints, evolving to keep humans walking without causing major strain on their lower bodies. The femoral neck in humans is much thicker and larger than that in great apes, due to major stress placed on the area while walking upright. The lateral condyle, or the very bottom of the femur where the knee is, tells anthropologists about a skeleton’s locomotion patterns. If the lateral condyle is flat, it suggests the fossil once was bipedal because the flat surface made it easy for them to “lock their knees” and stand straight upright while conserving energy. The femur bone also suggests bipedalism through the valgus knee angle, which evolved to allow humans to maintain their center of balance while standing or walking. The femur is angled towards the middle so that both knees are touching. This keeps the center of gravity in humans within their pelvis and helps them to shift energy from leg to leg as they walk. Hip abductor muscles evolved in humans to keep the pelvis level and stationary while walking upright, instead of wobbling side-to-side. These abductor muscles provide an immense amount of stability to bipedal