mediolateral

Mediolateral is an anatomical term used to describe a direction, axis, or projection that runs from the midline of the body toward the side. The term combines the Latin medius meaning middle and lateralis meaning side. It is frequently employed in anatomy, biomechanics, and radiology to orient movements, structures, and imaging views.

In anatomy and movement science, the mediolateral axis is the axis around which flexion and extension generally occur for many joints. This axis runs side-to-side, perpendicular to the sagittal plane. Movements such as bending the knee or extending the elbow are described as occurring about a mediolateral axis. The concept helps distinguish how joints rotate or hinge in relation to the body’s midline.

In medical imaging, a mediolateral view (often abbreviated ML) is a radiographic projection in which the X-ray beam passes from the medial aspect of a body part toward the lateral aspect. Commonly used for the knee, leg, ankle, and foot, the mediolateral view provides information about bone alignment, fractures, and soft-tissue contours that complements anteroposterior and oblique views. Proper positioning is essential to ensure accurate representation of structures.

Other uses of mediolateral describe anatomical relations that lie between the medial and lateral sides, or procedural approaches that access tissues from the medial to the lateral direction. The term is widely used across medicine and allied health fields to convey precise orientation relative to the body's midline.