extensor retinaculum
noun
extensor ret·i·nac·u·lum
| \ -ˌret-ᵊn-ˈa-kyə-ləm
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Medical Definition of extensor retinaculum
1
: either of two fibrous bands of fascia crossing the front of the ankle:
a
: a lower band that is attached laterally to the superior aspect of the calcaneus and passes medially to divide in the shape of a Y and that passes over or both over and under the tendons of the extensor muscles at the ankle
— called also inferior extensor retinaculum
b
: an upper band passing over and binding down the tendons of the tibialis anterior, extensor hallucis longus, extensor digitorum longus, and peroneus tertius just above the ankle joint
— called also superior extensor retinaculum, transverse crural ligament
2
: a fibrous band of fascia crossing the back of the wrist and binding down the tendons of the extensor muscles