1. Before measurement, make sure whether there are congenital deformation and old trauma, which should be differentiated from new trauma.

2. Both sick and healthy limbs should be put in a completely symmetric position in measurement for avoiding error.

3. The point for measurement must be right. Marks may be made on both starting and ending parts, and the tape ruler should be well stretched.

4. Commonly used methods for measuring the length of limbs:
1) Length of the upper limb -- from the acromion to styloid process of the radius (or to the tip of the middle finger).
2) Length of the upper arm -- from the acromion to the external epicondyle of humerus.
3) Length of the forearm -- from the external epicondyle of the humerus to the styloid process of radius.
4) Length of the lower limb -- from the anterior superior iliac spine (or the umbilicus) to the inferior border of medial malleolus.
5. Length of the thigh -- from the anterior superior iliac spine to the medial border of knee joint.
6. Length of the leg -- from the medial border of knee joint to the inferior border of medial malleolus.

5. Commonly used methods for measuring the thickness of limbs: The two limbs are measured on the parts at the same level. The most swollen part should be taken for measuring swelling, and the belly of muscle should be taken for measuring muscle atrophy. For example, the place 10 to 15 cm above the patella should be taken for measuring thickness of the thigh, and the thickest part should be taken for measuring thickness of the leg.