A client with an above-the-knee amputation is being taught methods to prevent hip-flexion deformities. Which instruction should be given to the client? A. "Lie supine with the head elevated on two pillows." B. "Lie prone every 4 hours during the day for \(30 \mathrm{~min}\) utes." C. "Lie on your side with your head elevated." D. "Lie flat during the day."

Let's go through the given options: A. "Lie supine with the head elevated on two pillows." B. "Lie prone every 4 hours during the day for \(30 \mathrm{~min}\) utes." C. "Lie on your side with your head elevated." D. "Lie flat during the day." We need to identify which position can help prevent hip-flexion deformities for an above-the-knee amputee.

We need to understand the impact of various body positions on the hip joint, particularly focusing on hip flexion. A. Supine position with head elevated: In this position, the person lies on their back, but the elevation of the head may not contribute to preventing hip-flexion deformities. B. Prone position: In this position, the person lies facing downward, which can help maintain an extended position of the hip, potentially preventing hip-flexion deformities. C. Lying on side with head elevated: This position may cause uneven pressure on both the hip joints, thus not ideal for preventing hip-flexion deformities. D. Lying flat during the day: This position can potentially maintain hip extension when performed adequately, but it's less efficient than the prone position.

Comparing the different positions, we can conclude that option B, lying prone (face down) every 4 hours during the day for \(30 \mathrm{~min}\) utes, is the most effective method to prevent hip-flexion deformities in a client with an above-the-knee amputation. The correct answer is B. "Lie prone every 4 hours during the day for \(30 \mathrm{~min}\) utes."