REIDER PART 2
91

L1-L2

Figurę 9-17. Assessing LI and L2 motor function (iliopsoas strength).

extensor hallucis longus. In some patients, the patients ability to demonstrate strength of the extensor hallucis longus may be limited by nonneurologic factors, such as the presence of severe bunions or the anatomie changes due to prior bunion surgery. In these patients, the exam-iner may assess the motor supply of the 1.5 nerve root by testing the other digital extensors or the gluteus medius.

The extensor digitorum longus is assessed in a man-ner analogous to that used for the extensor hallucis longus. In this case, the cxamincr stabilizes the forefoot with one hand and asks the patient to extend the toes as far as possible. The examiner then instructs the patient to

Figurę 9-18. Assessing L3 motor function (quadriceps).

Charter 9_Lumbar Spine 3j> 1

L4

Figurę 9-19. Assessing L4 motor function (tibialis anterior strength).

maintain the extended position of the toes while the examiner attempts to passively flex the toes with his or her fingers (see Fig. 9-20B). In a normal patient, the examiner is able to overcome the strength of the toe extensors with moderate difficulty.

The gluteus medius is evaluated by assessing the strength of hip abduction. For this test, the patient is in the lateral position on the examination table and is asked to abduct the lowcr limb away from the table while main-taining knee cxtension. The examiner then instructs the patient to maintain the position of abduction while the examiner presses downward on the distal thigh, attempt-ing to push the thigh back toward the table (see Fig. 9-20C). In a normal patient, the examiner has con-siderable difficulty overcoming the strength of the gluteus medius. In stronger patients, the examiner may be unable to do so.

57 Nerve Root. The SI nerve root provides motor supply to the plantar flexors, the evertors of the ankle, and the extensors of the hip. As previously described, the examincr may screen for wcakncss of the plantar flexors of the ankle by asking the patient to toe walk. Primary plantar flexion strength is provided by the gastroesoleus complex, with assistance from the toe flexors. Manuał resistance testing of the gastroesoleus is usually carried out in the seated patient. The examincr stabilizes the patients ankle with one hand and instructs the patient to passively plantar flcx the ankle. The patient is told to maintain this position while the examiner attempts to force the ankle back into dorsiflexion by pressing upward on the patient s forefoot with the examiner’s other hand (Fig. 9-2M). In a normal patient, the examiner is unable to overcome the powerful plantar flexor muscles and ini-tiate dorsiflexion.

The peroneus longus and brevis muscles, the prin-cipal evertors of the foot, are tested in the same basie position as the gastroesoleus complex. The examiner