Spastic hemiparesis is best described as:

• A. The arm is extended and pronated with leg flaccid.
• B. The affected arm is flexed, immobile, and held close to the side, with elbow, wrists, and interphalangeal joints flexed; the affected leg extensors spastic; ankle plantar-flexed and inverted.
• C. Both arms are extended with equal strength.
• D. The legs show normal tone with mild weakness.

Answer: (B)

Spastic hemiparesis reflects an upper motor neuron pattern where the affected side moves with a distinct flexor posture in the upper limb and an extensor posture in the lower limb. The arm tends to be held close to the body in a flexed, adducted position with the elbow, wrist, and fingers flexed (often with pronation), producing a stiff, immobile appearance. Meanwhile, the leg shows spastic extension of the extensors, and the ankle tends to be plantarflexed and inverted. This combination—arm flexed and immobile with flexed joints, and leg with extensor spasticity and a plantarflexed/inverted ankle—fits the classic description of spastic hemiparesis. The other patterns would not match this unilateral UMN syndrome: normal or bilateral symmetric tone, or a flaccid/relaxed limb, would indicate a different type of weakness or no spastic UMN involvement.