How are long bones of limbs suited/ adapted to their function?

a)Fore limb.
i)Humerus
-At the proximal end, it has a large and broad rounded head; that articulates with the glenoid cavity of the scapula to form a ball and socket joint;
-It has long shaft; to increase the surface area for attachment of muscles;
-The head of the humerus is covered with a cartilage; to reduce friction during movement;
-It has greater and lower/lesser tuberosities; to provide a surface for muscle attachment;
-Between the tuberosities there is a groove called bicipital groove; along which the tendon of the bicep muscle passes;
-At the distal end are two rounded structure called condyles; to articulate with the sigmoid notch of the radius and ulna to form a hinge joint (to allow movement of the arm in one plane);
-Between the two condyles is a groove called trochlea; for articulation with sigmoid notch radius and ulna to form hinge joint;
ii) Ulna-Radius
-They have a sigmoid notch; (at the proximal end) which articulates with (the trochlea and condyles of) the humerus to form hinge joint;
-The ulna has olecranon process; which provides a large surface area for attachment of muscles and tendons and also prevents overstretching of the forearm at the joint when straightened;
-At the distal end there is distal epiphysis; for articulation with the carpals to form gliding joint;
-They have long shaft; to increase surface area for attachment of muscles;
b)Hind limb
i)Femur
-It has a head; (at the proximal end) that articulates with acetabulum of the pelvic girdle to form ball and socket joint;
-The head of the femur is covered with a cartilage; that reduces friction during movement/ locomotion;
-It has rounded condyles; (at the distal end) which articulate with the patella/ knee cap and tibia to form hinge joint;
-It has a long shaft; to provide a large/ increase surface area for muscle attachment and for support;
-The femur has greater and lesser trochanters; to provide a large surface area for muscle attachment;
-Between the condyles there is a groove called patella groove; which articulates with patella/ knee cap;
ii)Tibia and fibula
-They have long shaft; to increase surface area for attachment of muscles and tendons and for support;
-Tibia has articular facets; (at the proximal end) for articulation with condyles of femur to form hinge joint;
-They have distal epiphysis; which articulates with tarsals to form gliding joint;