What might you expect to name a muscle that lies alongside the medial bone of the forearm, crosses the wrist, and acts to open a fist?

Extensor Carpi radialis

Explanation:

Extensor carpi radialis longus is an important muscle out of the five main muscles that control movements at the wrist.

The muscle is long, starting from the lateral side of the humerus, and attached to the base of the second metacarpal bone of the index finger.

it helps the wrist to move the hand towards the thumb and away from the palmar side which increased angle between the palm and the fore arm front . it act to open a fist and close it.