What are the 6 major structural differences between the anatomical plan of the upper and lower limbs?

Answer 1

• The Pelvic Girdle is a complete circle while the Pectoral Girdle is not
• The Pelvic Girdle does not support the weight of the body, rather it is the attachment site for many muscles that move the upper limbs. (the collar bone's main function is to keep the shoulder joint away from the midline of the body allowing greater it greater mobility). In contrast, the pelvic girdle receives the weight of the upper body from the axial skeleton, (the spine) and supports it.
• They both employ hinge joints in the middle, "the ginglymus of the upper extremities and the tibiofemoral joints of the lower extremities"
• They both have an interosseous membrane separating them. (This keeps them at a fixed distance from each other. It only allows slight movements between them.)
• The femur has a landmark called the "fovea" through which a tiny ligament connects it to the acetabulum. The humerous does not have this.
• the most commonly fractured bone of the upper extremities is the upper arm, (humerous), while the most commonly fractured bone(s) of the lower extremities is the lower leg (tibia and fibula,) (the crural region).
• lower extremity has a large sesamoid bone called the patella, upper extremities do not.
• the distal ends of the ulna, radius, tibia, and fibula, are called, the styloid processes and the lateral and medial malleolus. These landmarks help to stabilize the condyloid joints of the wrists and ankles.

there's probably more, but this is all I can think of.