Tutorial 105 - Angular Motions of the Joints (Patreon)

This is one of four tutorials on anatomical movements; Angular, rotational, circular and gliding. 

Angular movements change the angle of a joint between two adjoining body structures.

Note: Remember, when discussing these terms we refer to the body in the anatomical position. That is, the body standing upright, arms at the sides, palms facing forwards. 

There are two pairs of angular movements. 

Flexion and Extension

refers to angle changes along the sagittal plane (forward, backward).

Flexion

is a movement that decreases the angle between two body parts. For example, when the knee bends, or when the fist closes. 

Extension

is the opposite movement. When the fist is returning to the natural position of the hand, or when the leg is straight. We can also say something is hyper-extended, to refer to the wrist being bent backwards, for example.

It might help to think of flexion as the movement of a body part that feels most natural. The knee being raised toward the chest is the flexion of the femur and hip joint. Extension is the returning action.

Adduction and Abduction

refers to angle changes along the coronal plane (side-to-side). 

Abduction

is a movement away from the midline of the body, when an arm or leg is raised to the side, for example.

Adduction

is the opposite, when an arm drops to the side.

Why is it important for us to know this stuff!? 

Later, we’ll see that certain muscles are are named with flexor, extensor, abductor and adductor because of the action they enable. For example, abductors are found on the outside of the leg, adductors on the inside. So, when observing a named chart of the muscles we can now begin to understand their actions based on their names.