Orbital floor fractures are more likely associated with which forced duction test result?

Orbital floor fractures are more likely associated with which forced duction test result?

• A. Negative Forced Duction
• B. Positive Forced Duction
• C. No Change
• D. Variable

Answer: (B)

The key idea is distinguishing mechanical restriction from nerve or muscle weakness using the forced duction test. A positive forced duction test means there is a physical barrier preventing the eye from moving when the examiner tries to move it passively—you feel resistance. In orbital floor (blow-out) fractures, the inferior rectus muscle or orbital tissue can become trapped in the fracture site, creating a mechanical tether. This entrapment restricts movement, especially upward gaze, so the eye cannot be freely moved in that direction during the test, giving a positive result. If there were no mechanical barrier, the forced duction would be negative, pointing toward a neurogenic or other non-mechanical cause of restriction. Therefore, orbital floor fractures are most likely associated with a positive forced duction test.

The key idea is distinguishing mechanical restriction from nerve or muscle weakness using the forced duction test. A positive forced duction test means there is a physical barrier preventing the eye from moving when the examiner tries to move it passively—you feel resistance. In orbital floor (blow-out) fractures, the inferior rectus muscle or orbital tissue can become trapped in the fracture site, creating a mechanical tether. This entrapment restricts movement, especially upward gaze, so the eye cannot be freely moved in that direction during the test, giving a positive result. If there were no mechanical barrier, the forced duction would be negative, pointing toward a neurogenic or other non-mechanical cause of restriction. Therefore, orbital floor fractures are most likely associated with a positive forced duction test.