The Homan’s sign is a historical physical examination technique. American surgeon Dr. John Homans first described this assessment method in 1941 as a simple, non-invasive way to screen patients presenting with symptoms of a potential deep vein thrombosis. The sign gained widespread use in clinical settings before the advent of modern diagnostic imaging and blood tests. The test involves a specific movement of the foot designed to elicit a reaction suggesting a problem within the calf.
The Homan’s Maneuver
The physical assessment begins with the patient lying flat on their back (supine). The examiner ensures the knee is kept straight, or fully extended. This straight-leg position maximizes tension on the posterior calf muscles and the underlying deep veins.
The core action involves the examiner quickly bending the patient’s foot upward toward the shin, a motion called passive dorsiflexion. This movement stretches the muscles and vessels along the back of the lower leg. In some variations of the technique, the examiner may simultaneously squeeze the calf muscle to increase pressure on the deep venous system. The test is completed by observing the patient’s response to this forced foot movement.
The technique is designed to elicit pain or discomfort within the calf or the area behind the knee. A positive response could also include involuntary flexing of the knee or increased resistance to the dorsiflexion movement. Since the technique is a passive movement, the patient must simply relax their leg.
What a Positive Result Suggests
A finding is considered positive when the characteristic movement causes pain, tenderness, or discomfort deep within the calf muscle or in the popliteal region behind the knee. This reaction historically suggested the possibility of Deep Vein Thrombosis (DVT), a condition where a blood clot forms within a deep vein, most commonly in the leg. This sign was particularly helpful to clinicians when a patient presented with general symptoms like swelling, warmth, and redness in one leg.
The theoretical explanation for the pain involves mechanical traction on the deep veins of the lower leg. When the foot is forcibly dorsiflexed, the calf muscles stretch, pulling on the posterior tibial vein running through the muscle compartments. If a thrombus (clot) is present and causing inflammation within the vein, this sudden stretching movement can irritate the surrounding pain-sensitive structures. This irritation results in the sharp, localized pain that constitutes a positive Homan’s sign.
A positive finding was once used to raise the suspicion of DVT, prompting medical professionals to investigate further. A clot in the deep veins can lead to serious complications, such as the blockage traveling to the lungs. However, a positive sign is not the only indicator, as DVT often presents with other symptoms, including a noticeable difference in the circumference of the affected leg.
Clinical Accuracy and Limitations
Despite its historical use, the Homan’s sign is no longer regarded as a reliable tool for diagnosing deep vein thrombosis in modern clinical settings. Studies have consistently demonstrated that this physical test has both low sensitivity and low specificity. This results in a high rate of false negatives, meaning many patients confirmed to have DVT do not exhibit a positive sign.
Conversely, many patients without DVT may still experience pain during the maneuver, leading to a high rate of false positives. Conditions such as muscle strains, a ruptured Baker’s cyst, or cellulitis can cause calf pain upon dorsiflexion, mimicking a positive sign. Relying on this sign alone is considered insufficient and potentially misleading for diagnosis.
Some clinicians express concern that the forceful manipulation of the leg required to perform the test could, in theory, dislodge a clot if one were present. This risk, combined with the sign’s poor accuracy, has led to its replacement by more objective and non-invasive diagnostic methods. The current standard of care for suspected DVT involves using a validated clinical prediction rule, such as the Wells Score, to estimate the pre-test probability of a clot.
Patients deemed to have a high or intermediate probability are typically evaluated with a D-dimer blood test, which checks for a protein fragment produced when a blood clot dissolves, or immediately with imaging. The most definitive and widely used diagnostic procedure today is compression ultrasonography, often combined with Doppler flow studies, which directly visualizes the veins and confirms the presence or absence of a clot.