Explanation:
Similarities of the shapes and arrangement of the upper limbs and the lower limbs bones:
1) The upper limbs and the lower limbs both have three segments which are upper segment, middle segment and the distal segment. In the upper limb we have the arm at the upper segment, forearm at the middle segment and the hand at the distal segment. In the lower limb we have the thigh at the upper segment, the leg at the middle segment, and the foot at the distal segment.
2) The number of bones in the arm and forearm of the upper limbs is the same as that of the thigh and leg in the lower limps. In the arm we have Single bone (i.e humerus) and in the forearm we two bones (i.e Radius and Ulna), also in the thigh we have single bone (i.e femur) and in the leg we have two bones (i.e Tibia and Fibula).
3) Both the upper and the lower limbs are fixed to the trunk by the pectoral and pelvic girdles respectively.
4) The number of compartments in the arm and forearm of the upper limbs is the same as that of the thigh and leg in the lower limps. In the arm we have two compartments and in the forearm we three compartments, also in the thigh we have two compartments and in the leg we have three compartments.
5) The number of phalanges in both the upper and lower limbs are the same (i.e five phalanges in both).
The Differences between the upper limbs and the lower limbs bones:
Upper limbs:
1. Size: The upper limb is smaller and shorter.
2. Mobility: Less firmly attached to trunk and more mobile.
3. Function: Grasping and skilled movement
4. Segment: Arm, Forearm, Hand
5. Bones: arm (humerus), forearm (Radius and Ulna)
,hand (carpals,
metacarpals and phalanges
).
6. Alignment of distal parts
: Aligned along the axis of the limb.
7. Position of pollex/hallux in anatomical position
: Laterally placed
8. Position of flexor surface/muscle: Anteriorly/Posteriorly
9. Carrying angle: Present
Lower limbs:
1) Size: Larger and longer
2) Mobility: More firmly attached to trunk and less mobile
3) Functions: Weight bearing and locomotion
4) Segment: Thigh, Leg, Foot.
5) Bones: thigh (femur)
, leg (Tibia and Fibula)
, foot (Tarsals, Metatarsals and Phalanges
).
6) Alignment of the distal parts: Placed at right angle with the axis of the limb.
7) Position of pollex/hallux in anatomical position: Medially placed.
8) Position of flexor surface/muscle: Posteriorly Anteriorly
.
9) Carrying angle: Absent.
Importance of the upper the limbs and the lower limbs:
The similarities and difference in the upper limbs and the lower limps are of importance so as to be able to perform their various functions effectively.
The main purpose of the upper limb is to move the hand around the body during the daily activities of humans such as grasping and skilled movement of the arm. The shoulder girdle provides a wide range of motion so that the hand can reach in all directions.
The bones of the lower limbs ( i.e thigh, leg and foot) are considerably larger and stronger than the bones of the upper limbs because the lower limbs bones support the entire weight of the body while walking, running, or jumping.
