What is a primary purpose of a knee immobilizer in hip precautions?

• A. Limit hip flexion by maintaining knee in extension.
• B. Increase knee flexion ROM.
• C. Stabilize the ankle during gait.
• D. Prevent thigh muscle atrophy.

Answer: (A)

The main idea is that a knee immobilizer helps protect a healing hip by limiting leg movement, specifically keeping the knee in extension to reduce hip flexion. When the knee is locked straight, the leg is less able to move into the flexed position that hip precautions aim to avoid, helping keep the operative hip within a safe range during activities and transfers. This mechanical restraint acts as a reminder and barrier to maintain proper alignment and reduce strain on the healing hip. The other options don’t fit: increasing knee flexion would counter the immobilizer’s purpose, stabilizing the ankle isn’t its function, and preventing thigh muscle atrophy isn’t the primary goal of this device—the focus is on restricting leg motion to protect the hip.