A study of the extensor tendons of the hand from point of view of evolution

Present study attempted to explain the presence of these extra muscles on the basis of their actions. Increased supination and pronation movements have been associated with more number of muscles/tendons in the extensor carpi radialis muscle and could explain the formation of extensor carpi radialis tertius muscle observed in the present study. The need to extend wrist and throw an object in a precise direction which was the need of the primate evolving to be the human being, could explain the extra extensors seen over the wrist and digits. A very well developed extensor mechanism is needed for precise functioning of the hand. The present study attempts to link together the functioning of individual extensor muscles to the trajectory of events involved in evolution of primates.