Bipedalism

So when it comes to bipedalism for humans one key feature is the limbs of course. Bipedal beings have an orthograde trunk on extended lower limbs. Meaning that their upper body sits upright and their legs are longer than their arms. The reason that humans have achieved erect bipedalism has to do with where their center of gravity is. This allowed human arms to become free of locomotion in order to instead carry things such as tools or babies. The femura also has a lot to do with bipedalism. It has to do with the shape and depth of different parts of the femur such as the femoral head and the gluteal lines.  The femur is more straight and longer than quadrupedal animals. This picture helps give a good look at the femurs between different species and now the femural head has changed.