What is the primary characteristic of the prone position?

The primary characteristic of the prone position is that the person is lying on their abdomen, facing downward. This position is often used in various clinical settings, such as for certain medical examinations, surgical procedures, or therapeutic interventions. When a patient is placed in the prone position, it allows for specific access to the back, chest, and abdomen, which can be essential depending on the clinical scenario.

The prone position can also enhance respiratory function in some patients by improving lung expansion and drainage. It is crucial for nurses and caregivers to understand this position as it can impact patient comfort and care in different contexts.

The other positions mentioned do not align with the definition of prone. Lying on a side refers to the lateral position, sitting at a 90-degree angle describes the upright position, and lying with legs elevated pertains to a position that may be utilized for specific circulatory or comfort needs but does not represent the prone orientation.