He forced himself to concentrate on something other than this pain.

He bit the inside of his cheek to force himself to concentrate.

He forced himself to concentrate, to say what must be said.

Thus was he forced to concentrate on the words to a spell.

He forced himself to concentrate on the matter at hand.

She forced herself to concentrate on the here and now.

He forced himself to concentrate on the tiny computer screen set into the wall.

"You have to force yourself to concentrate the last week or so," he said.

At first, he had to force himself to concentrate, but the words fascinated him.

She forced herself to concentrate on the job at hand.