When a normal muscle with an intact nerve supply is relaxed voluntarily, it maintains a slight residual tension known as muscle tone. This is best assessed by feeling the muscle's resistance to passive stretch. Persuade the patient to relax. Hold one hand with yours and, while supporting the elbow, flex and extend the patient's fingers, wrist, and elbow, and put the shoulder through a moderate range of motion. With practice, you can combine these actions into a single smooth movement. On each side, note muscle tone—the resistance offered to your movements. Tense patients may show increased resistance. With repeated practice, you will learn the feel of normal resistance.

If you suspect decreased resistance, hold the forearm and shake the hand loosely back and forth. Normally the hand moves back and forth freely but is not completely floppy.

If resistance is increased, determine if it varies as you move the limb or persists throughout the range of movement and in both directions, for example, during both flexion and extension. Feel for any jerkiness in the resistance.

To assess muscle tone in the legs, support the patient's thigh with one hand, grasp the foot with the other, and flex and extend the patient's knee and ankle on each side. Note the resistance to moving the limb.

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