Consider the following when using your computer mouse.
It should be located as close as possible to you and the keyboard, preferably at or near elbow height. Its location should enable the elbow to rest near one’s side. The arm should rest comfortably without outward rotation. The hand should extend from the forearm relatively straight.
Move the mouse using the arm. Shared movement with the shoulder and elbow helps distribute repeated motions across multiple joints, tendons, and muscles. Minimize prolonged or constant arm or wrist support to help free up the arm and stop isolated wrist or finger motions.
Grip the mouse lightly. Partially rest your hand and fingers on the mouse. Avoid pinching it between the thumb and pinky and do not keep the remaining fingers raised off the mouse while navigation, searching, or similar activities.