Question

What are two adaptations found in the HUMAN hand which make our hands so useful for grasping tools?

At least 5+ complete sentences.

thank you for your help!

Answer 1

The ability of the small and ring fingers to rotate across the palm to meet the thumb , owing to a unique flexibility of the carpometacarpel joints of these fingers, dowmn in the midddle of the palm makes the human hand unique. and also opposible thumbs is peculiar charecter of human hand.

During evolutio human hand have gained two new grips:the precision grip and the power grip.

These two patterns of movement , which are antomically and physiologically distinct , provides the basis for all prehensile activities.

The precision grip is employed where precision of the movement is required , where as the dominant charecteristic of the power grip is application of force. In each of these grips the carpo-metacarpel joint of the thumb, in full abduction or adduction, is stabilized by congruent articular surfaces and tension of ligaments. In the intermediate position , the joint is most unstable.

Precision grip is a throwing grip and power grip is a clubbing grip.

the first set shows precision grip and second set shows power grip