REIDER PART 2
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350 Chapter 9 Lumbar Spine

Figurę 9-16, cont'd. D, L4. E, L5. F, SI. G, S2.

L4 Nerve Root. The L4 nerve root is usually evaluated by testing the strength of the tibialis anterior muscle. As previously noted, the examiner may screen for tibialis anterior weakness by asking the patient to heel walk. Specific manuał resistive testing of the tibialis anterior is accomplishcd with the patient seated on the end or the side of the examination table. The patient is asked to maximally dorsiflex the ankle on the side being tested. The patient is then instructed to maintain this position while the examiner presses downward on the foot and attempts to passively plantar flex the ankle (Fig. 9-19). In a normal patient, the examiner should be unable to over-come the strength of the tibialis anterior.

L5 Nerve Root. The L5 nerve root provides the motor supply of the long toe extensors. It is most commonly tested by evaluating the strength of the extensor hallucis longus. To test the extensor hallucis longus, the examiner asks the seated patient to puli up or extend the great toe. The examiner then stabilizes the medial aspect of the patients foot with one hand while pressing downward on the distal phalanx of the great toe with the fingers or the thumb of the other hand. The patient is instructed to resist the examiner s attempt to flex the interphalangeal joint of the toe (Fig. 9-20A).

When normal strength is present, it should be diffl-cult for the examiner to overcome the strength of the