Which of the following is NOT listed as a data point for determining the mechanical axis?

• A. Ankle Center
• B. Elbow Center
• C. Knee Center
• D. Hip Center

Answer: (B)

The mechanical axis of the lower limb is defined by a straight line that runs through the centers of the hip, knee, and ankle joints. These three points lie along the leg’s weight-bearing path, so they’re the data points used to assess how the leg aligns under load. The elbow center, by contrast, belongs to the upper limb and has no role in defining the leg’s mechanical axis. Because of that, the elbow center is not listed among the data points used for determining the mechanical axis, while the hip center, knee center, and ankle center are.