Relative long bone proportions and developmental stress in a modern Thai population (919.2)

Abstract

Research on relative limb proportions has revealed interesting patterns of variability with regards to environment. Since there have been few attempts to correlate variability in limb proportion with unrelated stress indicators, this study examined long bone length ratios and linear enamel hypoplasia (LEH) frequency in a modern Thai population. Inter‐limb indices were calculated for 259 adults (105 F/154 M) and compared with LEH frequency. A Spearman’s correlation coefficient analysis indicated significantly shorter relative distal limb lengths in the lower limbs of individuals with high LEH frequencies. This was strongest in females, with significant correlations in the tibia/femur (p=0.038) and the fibula/femur ratios (p=0.009) of both sides, as well as a high correlation between LEH frequency and stature. In males, only the left fibula/femur ratio (p=0.008) demonstrated a significant relationship with LEH frequencies. No correlation between stature and LEH frequency was found in males, or in the upper limbs of either sex. These findings support the claim that distal limb growth is more affected by developmental stress than proximal growth. The disparity of upper and lower limb response, in addition to the relationship between sex and observed correlations, may have significant implications for our understanding of human limb development and catch‐up growth.