Normal Ranges of Upper Extremity Length, Circumference, and Rate of Growth in the Pediatric Population.

Upper extremity length and circumference abnormalities are present in a number of conditions in the pediatric population. In most cases, upper limb hypoplasia and hypertrophy are diagnosed when one limb appears substantially different from the other during physical examination. However, occasionally when this discrepancy exists, it can be difficult to determine which limb is the abnormal one. The purpose of this study was to establish normal values for upper extremity length, circumference, and rate of growth in children aged 0 to 17 years. In all, 377 participants had 4 measurements taken of each upper extremity: upper arm length, upper arm circumference, forearm length, and forearm circumference. Statistical analysis was performed to identify differences and rates of growth. Mean values for arm and forearm length and circumference for each age, 0 to 17 years, were established. The determination of a child's expected arm length is dependent on his or her height, age, and sex, while the calculation of a child's expected forearm length depends on his or her weight, age, and sex. Male and female arms and forearms have similar growth rates of lengths and circumferences. No significant differences were found between right and left extremities for each of the 4 measurements taken. Contralateral limbs can be used for comparison of length and circumference of the arm and forearm in cases of unilateral upper extremity abnormality. The establishment of normal values for upper extremity length, circumference, and growth rate will be a useful diagnostic tool for upper extremity hypoplasia and hypertrophy.