Correlations among height, leg length and arm span in growing Korean children.

A cross-sectional study was performed to find out if any specific correlations exist among height, leg length and arm span in growing Korean children. Height, leg length and arm span were measured in 10,322 healthy children (4740 males and 5582 females). Computed ratios of leg length to height, leg length to arm span and arm span to height for the 3rd, 25th, 50th, 75th and 97th percentiles were made. It was found that the ratios of leg length to height, leg length to arm span, and arm span to height were bigger in taller children in the same age group than the shorter ones in both sexes. All the ratios were bigger in older children in the same percentile than the younger ones in both sexes, showing that the growth rates of leg length and arm span were bigger than that of height in general. However, growth of leg length is faster in shorter children than in taller children until the onset of puberty, after which growth of leg length in taller children is faster than in shorter children. The first and most rapid growth of leg length is seen from birth to 2 years, the second growth spurt is seen during the pubertal period. An exceptional increment in leg length between ages from 10 to 15 is also noted in taller children. After puberty, arm span grows faster than height until 17 years of age in the tallest male child, and taller children have longer arm span than height, while arm span in the shortest children never exceeds height.