Orthotics Clinical Patient Management (CPM) Practice Exam 2025 - Free CPM Practice Questions and Study Guide

The correct answer regarding the inferior trim line for a lumbar sacral orthosis (LSO) is typically defined as being 1/2" to 1" above the seating surface. This positioning is essential for providing adequate support and stability to the lumbar and sacral regions while ensuring comfort for the patient.

The specified trim line allows the LSO to effectively control motion in the lower back by providing the necessary support without hindering the patient’s ability to sit comfortably. If the trim line were too low, it could interfere with the natural movement of the hips and restrict the patient's range of motion, potentially causing discomfort or compromising functionality during daily activities.

Conversely, a higher trim line may not provide adequate stabilization to the lumbar area, defeating the purpose of the orthotic device in managing conditions related to lower back pain or instability. Therefore, maintaining this specific trim line above the seating surface is crucial for achieving the intended therapeutic effects of the orthosis.