Thompson Test

The maneuver links a visible foot movement to the continuity of the calf-Achilles-heel force pathway. A gentle calf squeeze should transmit force through an intact pathway and produce passive plantarflexion. If that movement is absent or markedly reduced, the expected transmission is disrupted, making Achilles tendon rupture a concern.

The heel is the endpoint of the force pathway being examined. The Achilles tendon transmits force from the calf muscles toward the heel, so observing foot plantarflexion provides a functional sign that this calf-tendon-heel connection remains continuous. This makes the response clinically meaningful rather than merely a movement observation.

An absent or markedly reduced response is concerning because it suggests that force from the squeezed calf is not being transmitted normally through the Achilles tendon to the heel. In an acute ankle injury, this finding raises concern for rupture and signals that the patient needs further clinical assessment rather than relying on the bedside observation alone.

Position the patient prone with the feet extending beyond the examination table. The clinician then gently squeezes the calf and watches the foot for passive plantarflexion. Keeping the setup consistent allows the observed movement to be interpreted against the expected response of the calf-Achilles-heel mechanism.

It is particularly useful during the initial assessment of an acute ankle injury, when a clinician needs a rapid bedside indication of Achilles tendon continuity. The result can help determine whether further evaluation is warranted and can contribute to decisions about imaging and treatment planning.

Findings are interpreted as one part of the clinical assessment. A normal plantarflexion response suggests continuity of the calf-Achilles-heel mechanism, whereas absent or markedly reduced movement raises concern for rupture. These observations help clinicians decide how to pursue further evaluation, including imaging, and support treatment planning.