ACE Personal Trainer Practice Exam 2026 - Free Personal Trainer Practice Questions and Study Guide

Supination in the forearm is characterized by the rotating motion that allows the palm of the hand to turn upward or face anteriorly when in the anatomical position. This movement involves the radius rotating around the ulna, resulting in the palm being oriented upwards or forwards. It essentially positions the forearm in a way that the radius and ulna are parallel to each other.

The other choices do not accurately define supination. Internal rotation would result in the palm facing backward, while flexion refers to bending at the elbow joint rather than a rotational movement of the forearm itself. Abrading, or rubbing the forearm inwards, does not relate to the anatomical definition of supination and does not describe any recognized motion of the forearm. Thus, the definition provided in the correct choice effectively captures the essence of supination.