DF-EV Test for Tarsal Tunnel Syndrome

Purpose: Test for the presence of tarsal tunnel syndrome or compression of the posterior tibial nerve.

Test Position: Sitting.

Performing the Test: The examiner maximally dorsiflexes the ankle, everts the foot, and extends all of the toes. Next, the examiner maintains this position for 5-10 seconds while tapping over the tarsal tunnel (just posterior to the medial malleolus). A positive test is complaints of localized nerve tenderness and/or a positive Tinel's Sign.

Diagnostic Accuracy: Unknown.

Importance of the Test: The tibialis posterior, flexor digitorum longus, and tibial neuro-vascular bundle all course through the tarsal tunnel underneath the flexor retinaculum. When the tibial nerve becomes entrapped in this region, it can result in pain and parethesias over the plantar aspect of the foot. The manor in which the tibial nerve becomes entrapped is very similar to how the median nerve becomes trapped during carpal tunnel syndrome. During the DF-EV test, the examiner is placing the tibial nerve on a stretch. If the nerve is irritated, tapping the nerve will reproduce neural symptoms in the region.

Note: these tests should only be performed by a properly trained health care practitioner.

References: 
Neumann, Donald. Kinesiology of the Musculoskeletal System. Second . Mosby Publishing Inc., 2010. 609-613. Print.