Final answer:
Bipedalism involves anatomical changes throughout the body, including the angling of the femur, spinal curves for weight balance, and foot arch development. The pelvic girdle attaches the legs to the body and supports abdomen organs, and the femur plays a key role in forming the hip and knee joints. The foot bone structure, particularly the talus, aids in weight distribution during movement.
Step-by-step explanation:
Features relating to bipedalism in hominins can be seen throughout the body. Key adaptations include changes to the spine, pelvis and femur, and the foot structure. The femur angles inward at a valgus angle, positioning the knees and feet directly under the center of the pelvis, crucial for bipedal locomotion.
The spine of bipedal hominins evolved distinct curves that help to balance the weight of the upper body over the hips. The evolution of the arch in the foot and the realignment of the big toe to be parallel with the other toes also play critical roles in weight distribution during walking. The pelvic girdle, including the ilium, pubis, and ischium, is connected to the axial skeleton by ligaments, supporting the organs of the abdomen and attaching legs to the body trunk.
The lower limb consists of the thigh, leg, and foot, with the femur being the longest, heaviest, and strongest bone, forming the hip joint with the pelvis and the knee joint with the tibia and patella. The talus bone of the foot receives and distributes the body's weight toward the ground in both posterior and anterior directions through the arrangement of the tarsal and metatarsal bones.
The developmental aspects can be observed in radiographs, for example, where a radiograph of a child's femur can indicate the approximate age of the child due to the observable growth plates. The clavicle's development differs from other appendicular skeleton bones as it is primarily connected to the axial skeleton via muscles, allowing for increased mobility.