Conjugate Deviation
4. A T1 root lesion and an ulnar nerve lesion:
• A T1 root lesion will cause weakness and wasting of all the small muscles of the hand.
• An ulnar nerve lesion will produce a wasted hand, but the 41/2 mus-cles supplied by the first thoracic root and the median nerve will be preserved. These are the abductor pollicis brevis, opponens pollicis, first and second lumbricales, and half the flexor pollicis brevis (which may be supplied entirely by the ulnar nerve).
The Lower Limb 1 1
The best screening test of lower limb function is watching the patient walk. Gait and its disorders are discussed in detail in Chapter 12. Go to the waiting area yourself to get your patient, and watch him get out of the chair and walk with you to the examining room. Then watch him sit down.
The leg is between the knee and the ankle; the thigh is between the hip and the knee. The detailed examination of the lower limb is subdivided un-der the headings of coordination, size, tone, and power.
COORDINATION
All of the tests of coordination are better lateralizers, but are less helpful when the legs are equally abnormal.
When the patient is not sure whether one or both legs are abnormal and his history is rather vague—for example, “I cannot walk as well as before” or “I seem to stumble and fall down a lot”—the results of the following tests will be abnormal if the problem is weakness, spasticity, sensory loss, or a cere-bellar disorder.
Supine Leg Raising
With the patient supine on the examining table, ask her to lift her leg, with the knee extended, off the table (thigh flexion) as high as she can and then slowly put it down. Have her do this several times with one leg. Then ask her to repeat the movement with the other leg.
If one leg is weak or spastic or has an involuntary movement or a proprio-ceptive sensory defect, this simple leg-raising test will help you identify it. It is a useful lateralizer, if not a localizer, and is similar to, but less sensitive than, arm drift.
Rapid Alternating Movements
1. With the patient supine, ask him to tap the heel of one foot on the mid-dle of the tibia of the opposite leg, as in Figure 11–1A. The tapping foot should rise 30 cm each time. Watch the rhythm, rate, and regularity
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B
Figure 1 1 - 1 . Lower limb coordination. A. Heei tapping. B. Heei siiding.
of this movement and compare the right foot tapping the left tibia and vice versa.
2. Ask the patient to quickly slide the heel of one foot up and down the shin, from knee to ankle, of the opposite leg several times (Figure 11-lB).
Are the rate and rhythm the same, right and left? Or does the right heel, for example, stay on the left tibia throughout the movement while the left heel repeatedly falls off the right tibia?
3. Stand at the foot of the examining table. Put the palm of your hand flat against the sole of the patient’s foot, and ask him to tap your hand (ie, move your hand away about 2–3 cm) with his foot repetitively and as quickly as he can. You can do the same thing with the patient sitting by asking him to tap the floor with his foot.
SIZE
Look at the patient’s bare legs while he is standing and you are squatting about 2 m from him. Look at him front and back while he stands flat-footed, on his toes, on his heels, and with his kneecaps drawn up (ie, standing at at-tention).
When you are looking at the back of his legs and he goes up on his toes, a minor amount of calf muscle wasting in one leg will become obvious.
Then, on the examining table, again in the supine position, measure the circumference of the thigh and calf of each leg and write the measurements in the notes.
Measure the leg at its greatest circumference, which is at about the junc-tion of the upper and middle thirds. Do not measure the circumference at an arbitrary distance below the lower edge of the patella. The greatest circum-ference of the thigh is usually at the top of the thigh. If you always measure the leg and thigh at their greatest circumference, there will be no confusion on follow-up examination 6 months or 1 year later.
TONE
Reread the remarks on tone in Chapter 10 on the upper limb and in Chap-ter 16 on the corticospinal system. When the tone in the legs is increased, watching the patient walk is most revealing.
The bed-bound patient and the patient with slightly increased or decreased tone is more difficult to assess.
At times, older patients have an involuntary, normal inability to let the legs relax. Their legs are stiff. They have normal tendon reflexes, plantar re-sponses are down, there is no clonus, and they do not walk with a spastic gait. You may implore such a patient to “just relax” without any change in this resistance of his lower limbs. This phenomenon, called gegenhalten, precludes assessment of lower limb tone.
Assess the tone of the lower limbs as follows:
1. With the patient supine and his legs straight on the examining