Objective: For children from birth to 4 years of age the palm width is more than 2 SD above the mean; for children from 4 to 16 years of age the palm width is above the 95th centile
Subjective: The width of the palm appears disproportionately wide for the length
Hand width is measured across the palm at the level of the MCPJ (radial aspect of the second MCPJ to the ulnar aspect of the fifth MCPJ) [Hall et al., ]. Caution is advised with the subjective assessment as short metacarpals can mimic a broad palm. In persons with polydactyly that includes a supernumerary metacarpal, that should be separately coded and the measurement technique from Hall et al.  would need to be modified to account for the supernumerary digit (i.e., with postaxial polydactyly, measure to the sixth MCPJ).