Diego, who had not kept in shape, went out to play a game of touch football. As he was running, the calf region of his leg began to hurt. The next day he went to a doctor, who told him he had a...

Diego, who had not kept in shape, went out to play a game of touch football. As he was running, the calf region of his leg began to hurt. The next day he went to a doctor, who told him he had a strain. Diego kept insisting that no joints hurt. Clearly, he was confusing a strain with a sprain. Explain the difference.