COMEDK 2007 MCQ Answer 171

The correct answer is C

As the hand approaches the objects to be picked up, the extensor tendons posture the hand and fingers in preparation for the grip. The long flexors then clamp the fingers against the palm with the thumb usually in adduction.

The strength of this power grip in proportional to the range of flexion in the smallest joints, so that any cause of interphalangeal joint stiffness leads to serious weakening of the power grip. The final torque of this power grip in grasping objects comes from thenar and hypothenar intrinsics and the loss of this transverse arch movement is noted in ulnar nerve palsy.

The extensor digitorum and forearm flexor digitorum superficialis muscles play an important role in power force matching.