What Is Horizontal Flexion

Refers to movement where the angle between two bones increases. Extension is otherwise known as straightening. Horizontal flexion: Refers to movement where the angle between two bones decreases and on the horizontal plane.

What is horizontal flexion joint movement?

Horizontal flexion occurs when the arm is pulled across the chest when it is parallel to the floor. Horizontal extension occurs when the arm is returned from the above position out to the side.

What muscle causes horizontal flexion?

The pectoralis major has the largest horizontal flexion moment arm with the humerus elevated 90 degrees, whereas the posterior deltoid and infraspinatus have the largest horizontal extension moment arms in this plane.