REIDER PART 2
27

Chapthr 7_Lower I.eg> Foot, and Ankle 287

Figurę 7-58. Functiona! tests. A> Toe walking. B, I leci walking. C, Lateral border walking. D, Medial border walking.

Ankle Dorsiflexors and Toe Extensors The examiner tests the tibialis anterior by placing the patient’s ankle in maximal dorsiflexion while supporting the patients heel with one hand. The patient is then instructed to maintain the ankle position while the exam-iner attempts to passively plantar flex the ankle with the other hand (Fig. 7-59). This test should cause the tibialis anterior tendon to stand out prominently at the anterior ankle. In a normal patient, the examiner is unable to overcome the strength of the tibialis anterior. Although the tibialis anterior is the main ankle dorsiflexor, it is assisted by the extensor hallucis longus, the extensor digitorum longus, and the peroneus tertius. Therefore, if the tibialis anterior is lacerated, weak ankle dorsiflexion is still present. Bccausc all four muscles are innervated by the deep peroneal nerve, a complete palsy of this nerve produces dramatic weakness of dorsiflexion, a condition known as foot drop. An injury to the common peroneal nerve weakens the peroneus longus and brevis as well.

To test the extensor hallucis longus, the examiner supports the paticnt’s forefoot with one hand and instructs the patient to maximally exlend the great toe.