The appendicular skeleton consists of the bones of the upper and lower
Each member is attached ("appended") to the axial skeleton by a skeletal
element called a girdle.
The girdle of each lower member is called the pelvic girdle.
Each pelvic girdle is attached firmly to the corresponding side of the sacrum. With their
ligaments, the two pelvic girdles and sacrum together form a solid bony circle known as
the bony pelvis.
Page 2 Pectoral Girdles
The girdle of each upper member is called the pectoral girdle.
Unlike the pelvic girdles, each pectoral girdle is very loosely attached to the axial
skeleton. The sole attachment is by the sternoclavicular joint, which in turn is
constructed to increase the degrees of motion.
Page 3 General Structure of the Limbs
Both the upper and lower members have limbs arranged in three segments.
The proximal segment has one bone. The middle segment has two bones. The distal
segment has many bones arranged in a five-rayed (pentadactyl) pattern.
Page 4 Functions of the Lower Member
The skeleton of the lower member is strongly constructed in a columnar fashion for
body support. The foot at the lower end of the lower limb extends at a 90° angle.
Therefore, the foot forms a base for the body during the erect, standing posture.
At the same time, the lower limb has a series of linkages that enable the body to move
from place to place locomotion.
Page 5 Functions of the Upper Member
The grasping hand is the distal segment of the upper member.
The flexible construction of the pectoral girdle and the bones of the upper limb serve
to place the grasping hand into as many positions as possible.
This is particularly helpful in grasping food and placing it into the mouth.
The grasping hand also serves as a tool-holding device.
A significant portion of the brain including special pathways are used to control
the movements of the grasping hand