The scaling of human grip configurations

The many degrees of freedom of the hand and arm afford the wide range and r ich adaptability of human grip configurations in action. Several classifica tion schemes of human grip configurations have been proposed, but none is b ased on scaling laws of physical biology, which are well established for ot her categorizations of fundamental physical activities such as locomotion. This study examined the preferred human grip configurations used to displac e to a new location cubes that varied systematically in length (L), mass (M ), and density (ML-3). The body-scaled equation K = log L + (log M)/h (wher e h refers to anthropometric measures of the hand) predicted the grip confi gurations used to displace objects. The findings suggest that information a bout the dynamic scaling relation is picked up visually and organizes the m any degrees of freedom of the hand-arm complex in the coordination of prehe nsile grip configurations.