Anatomy - 3 joints

Anatomy - 3 joints

• A. Sacroiliac joint
• B. Elbow joint
• C. Knee joint
• D. Ankle joint

Answer: (A)

This item tests recognizing how joints move. The elbow, knee, and ankle are classic hinge joints, meaning they primarily allow movement in one plane (flexion and extension). The sacroiliac joint isn’t a simple hinge; it’s a plane-type joint between the sacrum and ilium with very limited motion, whose main role is to transfer load from the spine to the pelvis with strong ligament support. Because it doesn’t function as a true hinge like the others, it stands out as the correct choice.

This item tests recognizing how joints move. The elbow, knee, and ankle are classic hinge joints, meaning they primarily allow movement in one plane (flexion and extension). The sacroiliac joint isn’t a simple hinge; it’s a plane-type joint between the sacrum and ilium with very limited motion, whose main role is to transfer load from the spine to the pelvis with strong ligament support. Because it doesn’t function as a true hinge like the others, it stands out as the correct choice.