What term refers to maintaining the same position for an extended period without movement?

The term that accurately describes maintaining the same position for an extended period without movement is catatonic behavior. This concept is often associated with mental health conditions, particularly psychotic disorders, where a person may exhibit a lack of response to the environment and a refusal to move or speak. Catatonic behavior can manifest as posture maintenance, such as standing or sitting in one position for prolonged durations, demonstrating a specific form of immobility.

While immobility could also refer generally to lack of movement, it is not specific enough to capture the context in which this behavior typically occurs. Likewise, stagnation refers more broadly to a lack of development or movement in a process rather than a physical state, and inactivity denotes a general absence of action, which does not inherently imply the maintenance of a specific pose. Thus, catatonic behavior is the most precise term that encompasses both the lack of movement and the context of a psychological condition that often leads to such a state.