Sodium plays a vital role in muscle contraction by helping transmit electrical signals necessary for muscle activity. When a nerve stimulates a muscle, sodium ions move into muscle cells, generating an action potential that leads to contraction. An adequate amount of sodium is essential for maintaining proper fluid balance within cells and ensuring efficient nerve function. However, excessive sodium intake can lead to health issues like hypertension. It's important to balance sodium levels to facilitate muscle function while managing overall cardiovascular health.