both gastrocnemii and peroneus longus coactivated, tibialis anterior and peroneus tertius coactivated, and semimembranosus and all three vasti coactivated).
Coactivation of the peroneus tertius improved the range of feasible postures.
The single best electrode combination suggested by this study consists bilaterally of the gastrocnemii coactivated with the peroneus longus (using a branched intramuscular electrode), the tibialis anterior coactivated with the peroneus tertius (via stimulation of the deep peroneal nerve), all of the vasti coactivated with the rectus femoris (via stimulation of the femoral nerve), and intramuscular electrodes in the semimembranosus, gluteus maximus, gluteus medius (with emphasis on the anterior portion), adductor magnus (with emphasis on the superior portion), and erector spinae.
Peroneus tertius is highly variable in its form and muscle bulk but is rarely completely absent.
Peroneus Tertius may play a special proprioceptive role in sensing sudden inversion and then contracting reflexively to protect the anterior tibio-fibular ligament, the most commonly sprained ligament of the body.
The clinical importance of the Peroneus Tertius concerning prevention and treatment of ankle ligament injuries is low.